diff options
Diffstat (limited to 'pjmedia/src/pjmedia/portaudio/pa_linux_alsa.c')
-rw-r--r-- | pjmedia/src/pjmedia/portaudio/pa_linux_alsa.c | 6544 |
1 files changed, 3272 insertions, 3272 deletions
diff --git a/pjmedia/src/pjmedia/portaudio/pa_linux_alsa.c b/pjmedia/src/pjmedia/portaudio/pa_linux_alsa.c index 8f115d0e..3b047163 100644 --- a/pjmedia/src/pjmedia/portaudio/pa_linux_alsa.c +++ b/pjmedia/src/pjmedia/portaudio/pa_linux_alsa.c @@ -1,3272 +1,3272 @@ -/*
- * $Id: pa_linux_alsa.c,v 1.1.2.71 2005/04/15 18:20:18 aknudsen Exp $
- * PortAudio Portable Real-Time Audio Library
- * Latest Version at: http://www.portaudio.com
- * ALSA implementation by Joshua Haberman and Arve Knudsen
- *
- * Copyright (c) 2002 Joshua Haberman <joshua@haberman.com>
- * Copyright (c) 2005 Arve Knudsen <aknuds-1@broadpark.no>
- *
- * Based on the Open Source API proposed by Ross Bencina
- * Copyright (c) 1999-2002 Ross Bencina, Phil Burk
- *
- * Permission is hereby granted, free of charge, to any person obtaining
- * a copy of this software and associated documentation files
- * (the "Software"), to deal in the Software without restriction,
- * including without limitation the rights to use, copy, modify, merge,
- * publish, distribute, sublicense, and/or sell copies of the Software,
- * and to permit persons to whom the Software is furnished to do so,
- * subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be
- * included in all copies or substantial portions of the Software.
- *
- * Any person wishing to distribute modifications to the Software is
- * requested to send the modifications to the original developer so that
- * they can be incorporated into the canonical version.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
- * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
- * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
- * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
- * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
- * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
- * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
- */
-
-#define ALSA_PCM_NEW_HW_PARAMS_API
-#define ALSA_PCM_NEW_SW_PARAMS_API
-#include <alsa/asoundlib.h>
-#undef ALSA_PCM_NEW_HW_PARAMS_API
-#undef ALSA_PCM_NEW_SW_PARAMS_API
-
-#include <sys/poll.h>
-#include <string.h> /* strlen() */
-#include <limits.h>
-#include <math.h>
-#include <pthread.h>
-#include <signal.h>
-#include <time.h>
-#include <sys/mman.h>
-#include <signal.h> /* For sig_atomic_t */
-
-#include "portaudio.h"
-#include "pa_util.h"
-#include "pa_unix_util.h"
-#include "pa_allocation.h"
-#include "pa_hostapi.h"
-#include "pa_stream.h"
-#include "pa_cpuload.h"
-#include "pa_process.h"
-
-#include "pa_linux_alsa.h"
-
-/* Check return value of ALSA function, and map it to PaError */
-#define ENSURE_(expr, code) \
- do { \
- if( UNLIKELY( (aErr_ = (expr)) < 0 ) ) \
- { \
- /* PaUtil_SetLastHostErrorInfo should only be used in the main thread */ \
- if( (code) == paUnanticipatedHostError && pthread_self() != callbackThread_ ) \
- { \
- PaUtil_SetLastHostErrorInfo( paALSA, aErr_, snd_strerror( aErr_ ) ); \
- } \
- PaUtil_DebugPrint(( "Expression '" #expr "' failed in '" __FILE__ "', line: " STRINGIZE( __LINE__ ) "\n" )); \
- result = (code); \
- goto error; \
- } \
- } while( 0 );
-
-#define ASSERT_CALL_(expr, success) \
- aErr_ = (expr); \
- assert( aErr_ == success );
-
-static int aErr_; /* Used with ENSURE_ */
-static pthread_t callbackThread_;
-
-typedef enum
-{
- StreamDirection_In,
- StreamDirection_Out
-} StreamDirection;
-
-/* Threading utility struct */
-typedef struct PaAlsaThreading
-{
- pthread_t watchdogThread;
- pthread_t callbackThread;
- int watchdogRunning;
- int rtSched;
- int rtPrio;
- int useWatchdog;
- unsigned long throttledSleepTime;
- volatile PaTime callbackTime;
- volatile PaTime callbackCpuTime;
- PaUtilCpuLoadMeasurer *cpuLoadMeasurer;
-} PaAlsaThreading;
-
-typedef struct
-{
- PaSampleFormat hostSampleFormat;
- unsigned long framesPerBuffer;
- int numUserChannels, numHostChannels;
- int userInterleaved, hostInterleaved;
-
- snd_pcm_t *pcm;
- snd_pcm_uframes_t bufferSize;
- snd_pcm_format_t nativeFormat;
- unsigned int nfds;
- int ready; /* Marked ready from poll */
- void **userBuffers;
- snd_pcm_uframes_t offset;
- StreamDirection streamDir;
-
- snd_pcm_channel_area_t *channelAreas; /* Needed for channel adaption */
-} PaAlsaStreamComponent;
-
-/* Implementation specific stream structure */
-typedef struct PaAlsaStream
-{
- PaUtilStreamRepresentation streamRepresentation;
- PaUtilCpuLoadMeasurer cpuLoadMeasurer;
- PaUtilBufferProcessor bufferProcessor;
- PaAlsaThreading threading;
-
- unsigned long framesPerUserBuffer;
-
- int primeBuffers;
- int callbackMode; /* bool: are we running in callback mode? */
- int pcmsSynced; /* Have we successfully synced pcms */
-
- /* the callback thread uses these to poll the sound device(s), waiting
- * for data to be ready/available */
- struct pollfd *pfds;
- int pollTimeout;
-
- /* Used in communication between threads */
- volatile sig_atomic_t callback_finished; /* bool: are we in the "callback finished" state? */
- volatile sig_atomic_t callbackAbort; /* Drop frames? */
- volatile sig_atomic_t callbackStop; /* Signal a stop */
- volatile sig_atomic_t isActive; /* Is stream in active state? (Between StartStream and StopStream || !paContinue) */
- pthread_mutex_t stateMtx; /* Used to synchronize access to stream state */
- pthread_mutex_t startMtx; /* Used to synchronize stream start in callback mode */
- pthread_cond_t startCond; /* Wait untill audio is started in callback thread */
-
- int neverDropInput;
-
- PaTime underrun;
- PaTime overrun;
-
- PaAlsaStreamComponent capture, playback;
-}
-PaAlsaStream;
-
-/* PaAlsaHostApiRepresentation - host api datastructure specific to this implementation */
-
-typedef struct PaAlsaHostApiRepresentation
-{
- PaUtilHostApiRepresentation commonHostApiRep;
- PaUtilStreamInterface callbackStreamInterface;
- PaUtilStreamInterface blockingStreamInterface;
-
- PaUtilAllocationGroup *allocations;
-
- PaHostApiIndex hostApiIndex;
-}
-PaAlsaHostApiRepresentation;
-
-typedef struct PaAlsaDeviceInfo
-{
- PaDeviceInfo commonDeviceInfo;
- char *alsaName;
- int isPlug;
- int minInputChannels;
- int minOutputChannels;
-}
-PaAlsaDeviceInfo;
-
-/* Threading utilities */
-
-static void InitializeThreading( PaAlsaThreading *th, PaUtilCpuLoadMeasurer *clm )
-{
- th->watchdogRunning = 0;
- th->rtSched = 0;
- th->callbackTime = 0;
- th->callbackCpuTime = 0;
- th->useWatchdog = 1;
- th->throttledSleepTime = 0;
- th->cpuLoadMeasurer = clm;
-
- th->rtPrio = (sched_get_priority_max( SCHED_FIFO ) - sched_get_priority_min( SCHED_FIFO )) / 2
- + sched_get_priority_min( SCHED_FIFO );
-}
-
-static PaError KillCallbackThread( PaAlsaThreading *th, int wait, PaError *exitResult, PaError *watchdogExitResult )
-{
- PaError result = paNoError;
- void *pret;
-
- if( exitResult )
- *exitResult = paNoError;
- if( watchdogExitResult )
- *watchdogExitResult = paNoError;
-
- if( th->watchdogRunning )
- {
- pthread_cancel( th->watchdogThread );
- ASSERT_CALL_( pthread_join( th->watchdogThread, &pret ), 0 );
-
- if( pret && pret != PTHREAD_CANCELED )
- {
- if( watchdogExitResult )
- *watchdogExitResult = *(PaError *) pret;
- free( pret );
- }
- }
-
- /* Only kill the thread if it isn't in the process of stopping (flushing adaptation buffers) */
- /* TODO: Make join time out */
- if( !wait )
- pthread_cancel( th->callbackThread ); /* XXX: Safe to call this if the thread has exited on its own? */
- ASSERT_CALL_( pthread_join( th->callbackThread, &pret ), 0 );
-
- if( pret && pret != PTHREAD_CANCELED )
- {
- if( exitResult )
- *exitResult = *(PaError *) pret;
- free( pret );
- }
-
- return result;
-}
-
-static void OnWatchdogExit( void *userData )
-{
- PaAlsaThreading *th = (PaAlsaThreading *) userData;
- struct sched_param spm = { 0 };
- assert( th );
-
- ASSERT_CALL_( pthread_setschedparam( th->callbackThread, SCHED_OTHER, &spm ), 0 ); /* Lower before exiting */
- PA_DEBUG(( "Watchdog exiting\n" ));
-}
-
-static PaError BoostPriority( PaAlsaThreading *th )
-{
- PaError result = paNoError;
- struct sched_param spm = { 0 };
- spm.sched_priority = th->rtPrio;
-
- assert( th );
-
- if( pthread_setschedparam( th->callbackThread, SCHED_FIFO, &spm ) != 0 )
- {
- PA_UNLESS( errno == EPERM, paInternalError ); /* Lack permission to raise priority */
- PA_DEBUG(( "Failed bumping priority\n" ));
- result = 0;
- }
- else
- result = 1; /* Success */
-error:
- return result;
-}
-
-static void *WatchdogFunc( void *userData )
-{
- PaError result = paNoError, *pres = NULL;
- int err;
- PaAlsaThreading *th = (PaAlsaThreading *) userData;
- unsigned intervalMsec = 500;
- const PaTime maxSeconds = 3.; /* Max seconds between callbacks */
- PaTime timeThen = PaUtil_GetTime(), timeNow, timeElapsed, cpuTimeThen, cpuTimeNow, cpuTimeElapsed;
- double cpuLoad, avgCpuLoad = 0.;
- int throttled = 0;
-
- assert( th );
-
- pthread_cleanup_push( &OnWatchdogExit, th ); /* Execute OnWatchdogExit when exiting */
-
- /* Boost priority of callback thread */
- PA_ENSURE( result = BoostPriority( th ) );
- if( !result )
- {
- pthread_exit( NULL ); /* Boost failed, might as well exit */
- }
-
- cpuTimeThen = th->callbackCpuTime;
- {
- int policy;
- struct sched_param spm = { 0 };
- pthread_getschedparam( pthread_self(), &policy, &spm );
- PA_DEBUG(( "%s: Watchdog priority is %d\n", __FUNCTION__, spm.sched_priority ));
- }
-
- while( 1 )
- {
- double lowpassCoeff = 0.9, lowpassCoeff1 = 0.99999 - lowpassCoeff;
-
- /* Test before and after in case whatever underlying sleep call isn't interrupted by pthread_cancel */
- pthread_testcancel();
- Pa_Sleep( intervalMsec );
- pthread_testcancel();
-
- if( PaUtil_GetTime() - th->callbackTime > maxSeconds )
- {
- PA_DEBUG(( "Watchdog: Terminating callback thread\n" ));
- /* Tell thread to terminate */
- err = pthread_kill( th->callbackThread, SIGKILL );
- pthread_exit( NULL );
- }
-
- PA_DEBUG(( "%s: PortAudio reports CPU load: %g\n", __FUNCTION__, PaUtil_GetCpuLoad( th->cpuLoadMeasurer ) ));
-
- /* Check if we should throttle, or unthrottle :P */
- cpuTimeNow = th->callbackCpuTime;
- cpuTimeElapsed = cpuTimeNow - cpuTimeThen;
- cpuTimeThen = cpuTimeNow;
-
- timeNow = PaUtil_GetTime();
- timeElapsed = timeNow - timeThen;
- timeThen = timeNow;
- cpuLoad = cpuTimeElapsed / timeElapsed;
- avgCpuLoad = avgCpuLoad * lowpassCoeff + cpuLoad * lowpassCoeff1;
- /*
- if( throttled )
- PA_DEBUG(( "Watchdog: CPU load: %g, %g\n", avgCpuLoad, cpuTimeElapsed ));
- */
- if( PaUtil_GetCpuLoad( th->cpuLoadMeasurer ) > .925 )
- {
- static int policy;
- static struct sched_param spm = { 0 };
- static const struct sched_param defaultSpm = { 0 };
- PA_DEBUG(( "%s: Throttling audio thread, priority %d\n", __FUNCTION__, spm.sched_priority ));
-
- pthread_getschedparam( th->callbackThread, &policy, &spm );
- if( !pthread_setschedparam( th->callbackThread, SCHED_OTHER, &defaultSpm ) )
- {
- throttled = 1;
- }
- else
- PA_DEBUG(( "Watchdog: Couldn't lower priority of audio thread: %s\n", strerror( errno ) ));
-
- /* Give other processes a go, before raising priority again */
- PA_DEBUG(( "%s: Watchdog sleeping for %lu msecs before unthrottling\n", __FUNCTION__, th->throttledSleepTime ));
- Pa_Sleep( th->throttledSleepTime );
-
- /* Reset callback priority */
- if( pthread_setschedparam( th->callbackThread, SCHED_FIFO, &spm ) != 0 )
- {
- PA_DEBUG(( "%s: Couldn't raise priority of audio thread: %s\n", __FUNCTION__, strerror( errno ) ));
- }
-
- if( PaUtil_GetCpuLoad( th->cpuLoadMeasurer ) >= .99 )
- intervalMsec = 50;
- else
- intervalMsec = 100;
-
- /*
- lowpassCoeff = .97;
- lowpassCoeff1 = .99999 - lowpassCoeff;
- */
- }
- else if( throttled && avgCpuLoad < .8 )
- {
- intervalMsec = 500;
- throttled = 0;
-
- /*
- lowpassCoeff = .9;
- lowpassCoeff1 = .99999 - lowpassCoeff;
- */
- }
- }
-
- pthread_cleanup_pop( 1 ); /* Execute cleanup on exit */
-
-error:
- /* Shouldn't get here in the normal case */
-
- /* Pass on error code */
- pres = malloc( sizeof (PaError) );
- *pres = result;
-
- pthread_exit( pres );
-}
-
-static PaError CreateCallbackThread( PaAlsaThreading *th, void *(*callbackThreadFunc)( void * ), PaStream *s )
-{
- PaError result = paNoError;
- pthread_attr_t attr;
- int started = 0;
-
-#if defined _POSIX_MEMLOCK && (_POSIX_MEMLOCK != -1)
- if( th->rtSched )
- {
- if( mlockall( MCL_CURRENT | MCL_FUTURE ) < 0 )
- {
- int savedErrno = errno; /* In case errno gets overwritten */
- assert( savedErrno != EINVAL ); /* Most likely a programmer error */
- PA_UNLESS( (savedErrno == EPERM), paInternalError );
- PA_DEBUG(( "%s: Failed locking memory\n", __FUNCTION__ ));
- }
- else
- PA_DEBUG(( "%s: Successfully locked memory\n", __FUNCTION__ ));
- }
-#endif
-
- PA_UNLESS( !pthread_attr_init( &attr ), paInternalError );
- /* Priority relative to other processes */
- PA_UNLESS( !pthread_attr_setscope( &attr, PTHREAD_SCOPE_SYSTEM ), paInternalError );
-
- PA_UNLESS( !pthread_create( &th->callbackThread, &attr, callbackThreadFunc, s ), paInternalError );
- started = 1;
-
- if( th->rtSched )
- {
- if( th->useWatchdog )
- {
- int err;
- struct sched_param wdSpm = { 0 };
- /* Launch watchdog, watchdog sets callback thread priority */
- int prio = PA_MIN( th->rtPrio + 4, sched_get_priority_max( SCHED_FIFO ) );
- wdSpm.sched_priority = prio;
-
- PA_UNLESS( !pthread_attr_init( &attr ), paInternalError );
- PA_UNLESS( !pthread_attr_setinheritsched( &attr, PTHREAD_EXPLICIT_SCHED ), paInternalError );
- PA_UNLESS( !pthread_attr_setscope( &attr, PTHREAD_SCOPE_SYSTEM ), paInternalError );
- PA_UNLESS( !pthread_attr_setschedpolicy( &attr, SCHED_FIFO ), paInternalError );
- PA_UNLESS( !pthread_attr_setschedparam( &attr, &wdSpm ), paInternalError );
- if( (err = pthread_create( &th->watchdogThread, &attr, &WatchdogFunc, th )) )
- {
- PA_UNLESS( err == EPERM, paInternalError );
- /* Permission error, go on without realtime privileges */
- PA_DEBUG(( "Failed bumping priority\n" ));
- }
- else
- {
- int policy;
- th->watchdogRunning = 1;
- ASSERT_CALL_( pthread_getschedparam( th->watchdogThread, &policy, &wdSpm ), 0 );
- /* Check if priority is right, policy could potentially differ from SCHED_FIFO (but that's alright) */
- if( wdSpm.sched_priority != prio )
- {
- PA_DEBUG(( "Watchdog priority not set correctly (%d)\n", wdSpm.sched_priority ));
- PA_ENSURE( paInternalError );
- }
- }
- }
- else
- PA_ENSURE( BoostPriority( th ) );
- }
-
-end:
- return result;
-error:
- if( started )
- KillCallbackThread( th, 0, NULL, NULL );
-
- goto end;
-}
-
-static void CallbackUpdate( PaAlsaThreading *th )
-{
- th->callbackTime = PaUtil_GetTime();
- th->callbackCpuTime = PaUtil_GetCpuLoad( th->cpuLoadMeasurer );
-}
-
-/* prototypes for functions declared in this file */
-
-static void Terminate( struct PaUtilHostApiRepresentation *hostApi );
-static PaError IsFormatSupported( struct PaUtilHostApiRepresentation *hostApi,
- const PaStreamParameters *inputParameters,
- const PaStreamParameters *outputParameters,
- double sampleRate );
-static PaError OpenStream( struct PaUtilHostApiRepresentation *hostApi,
- PaStream** s,
- const PaStreamParameters *inputParameters,
- const PaStreamParameters *outputParameters,
- double sampleRate,
- unsigned long framesPerBuffer,
- PaStreamFlags streamFlags,
- PaStreamCallback *callback,
- void *userData );
-static PaError CloseStream( PaStream* stream );
-static PaError StartStream( PaStream *stream );
-static PaError StopStream( PaStream *stream );
-static PaError AbortStream( PaStream *stream );
-static PaError IsStreamStopped( PaStream *s );
-static PaError IsStreamActive( PaStream *stream );
-static PaTime GetStreamTime( PaStream *stream );
-static double GetStreamCpuLoad( PaStream* stream );
-static PaError BuildDeviceList( PaAlsaHostApiRepresentation *hostApi );
-static int SetApproximateSampleRate( snd_pcm_t *pcm, snd_pcm_hw_params_t *hwParams, double sampleRate );
-static int GetExactSampleRate( snd_pcm_hw_params_t *hwParams, double *sampleRate );
-
-/* Callback prototypes */
-static void *CallbackThreadFunc( void *userData );
-
-/* Blocking prototypes */
-static signed long GetStreamReadAvailable( PaStream* s );
-static signed long GetStreamWriteAvailable( PaStream* s );
-static PaError ReadStream( PaStream* stream, void *buffer, unsigned long frames );
-static PaError WriteStream( PaStream* stream, const void *buffer, unsigned long frames );
-
-
-static const PaAlsaDeviceInfo *GetDeviceInfo( const PaUtilHostApiRepresentation *hostApi, int device )
-{
- return (const PaAlsaDeviceInfo *)hostApi->deviceInfos[device];
-}
-
-PaError PaAlsa_Initialize( PaUtilHostApiRepresentation **hostApi, PaHostApiIndex hostApiIndex )
-{
- PaError result = paNoError;
- PaAlsaHostApiRepresentation *alsaHostApi = NULL;
-
- PA_UNLESS( alsaHostApi = (PaAlsaHostApiRepresentation*) PaUtil_AllocateMemory(
- sizeof(PaAlsaHostApiRepresentation) ), paInsufficientMemory );
- PA_UNLESS( alsaHostApi->allocations = PaUtil_CreateAllocationGroup(), paInsufficientMemory );
- alsaHostApi->hostApiIndex = hostApiIndex;
-
- *hostApi = (PaUtilHostApiRepresentation*)alsaHostApi;
- (*hostApi)->info.structVersion = 1;
- (*hostApi)->info.type = paALSA;
- (*hostApi)->info.name = "ALSA";
-
- (*hostApi)->Terminate = Terminate;
- (*hostApi)->OpenStream = OpenStream;
- (*hostApi)->IsFormatSupported = IsFormatSupported;
-
- PA_ENSURE( BuildDeviceList( alsaHostApi ) );
-
- PaUtil_InitializeStreamInterface( &alsaHostApi->callbackStreamInterface,
- CloseStream, StartStream,
- StopStream, AbortStream,
- IsStreamStopped, IsStreamActive,
- GetStreamTime, GetStreamCpuLoad,
- PaUtil_DummyRead, PaUtil_DummyWrite,
- PaUtil_DummyGetReadAvailable,
- PaUtil_DummyGetWriteAvailable );
-
- PaUtil_InitializeStreamInterface( &alsaHostApi->blockingStreamInterface,
- CloseStream, StartStream,
- StopStream, AbortStream,
- IsStreamStopped, IsStreamActive,
- GetStreamTime, PaUtil_DummyGetCpuLoad,
- ReadStream, WriteStream,
- GetStreamReadAvailable,
- GetStreamWriteAvailable );
-
- return result;
-
-error:
- if( alsaHostApi )
- {
- if( alsaHostApi->allocations )
- {
- PaUtil_FreeAllAllocations( alsaHostApi->allocations );
- PaUtil_DestroyAllocationGroup( alsaHostApi->allocations );
- }
-
- PaUtil_FreeMemory( alsaHostApi );
- }
-
- return result;
-}
-
-static void Terminate( struct PaUtilHostApiRepresentation *hostApi )
-{
- PaAlsaHostApiRepresentation *alsaHostApi = (PaAlsaHostApiRepresentation*)hostApi;
-
- assert( hostApi );
-
- if( alsaHostApi->allocations )
- {
- PaUtil_FreeAllAllocations( alsaHostApi->allocations );
- PaUtil_DestroyAllocationGroup( alsaHostApi->allocations );
- }
-
- PaUtil_FreeMemory( alsaHostApi );
- snd_config_update_free_global();
-}
-
-/*! Determine max channels and default latencies.
- *
- * This function provides functionality to grope an opened (might be opened for capture or playback) pcm device for
- * traits like max channels, suitable default latencies and default sample rate. Upon error, max channels is set to zero,
- * and a suitable result returned. The device is closed before returning.
- */
-static PaError GropeDevice( snd_pcm_t *pcm, int *minChannels, int *maxChannels, double *defaultLowLatency,
- double *defaultHighLatency, double *defaultSampleRate, int isPlug )
-{
- PaError result = paNoError;
- snd_pcm_hw_params_t *hwParams;
- snd_pcm_uframes_t lowLatency = 512, highLatency = 2048;
- unsigned int minChans, maxChans;
- double defaultSr = *defaultSampleRate;
-
- assert( pcm );
-
- ENSURE_( snd_pcm_nonblock( pcm, 0 ), paUnanticipatedHostError );
-
- snd_pcm_hw_params_alloca( &hwParams );
- snd_pcm_hw_params_any( pcm, hwParams );
-
- if( defaultSr >= 0 )
- {
- /* Could be that the device opened in one mode supports samplerates that the other mode wont have,
- * so try again .. */
- if( SetApproximateSampleRate( pcm, hwParams, defaultSr ) < 0 )
- {
- defaultSr = -1.;
- PA_DEBUG(( "%s: Original default samplerate failed, trying again ..\n", __FUNCTION__ ));
- }
- }
-
- if( defaultSr < 0. ) /* Default sample rate not set */
- {
- unsigned int sampleRate = 44100; /* Will contain approximate rate returned by alsa-lib */
- ENSURE_( snd_pcm_hw_params_set_rate_near( pcm, hwParams, &sampleRate, NULL ), paUnanticipatedHostError );
- ENSURE_( GetExactSampleRate( hwParams, &defaultSr ), paUnanticipatedHostError );
- }
-
- ENSURE_( snd_pcm_hw_params_get_channels_min( hwParams, &minChans ), paUnanticipatedHostError );
- ENSURE_( snd_pcm_hw_params_get_channels_max( hwParams, &maxChans ), paUnanticipatedHostError );
- assert( maxChans <= INT_MAX );
- assert( maxChans > 0 ); /* Weird linking issue could cause wrong version of ALSA symbols to be called,
- resulting in zeroed values */
-
- /* XXX: Limit to sensible number (ALSA plugins accept a crazy amount of channels)? */
- if( isPlug && maxChans > 128 )
- {
- maxChans = 128;
- PA_DEBUG(( "%s: Limiting number of plugin channels to %u\n", __FUNCTION__, maxChans ));
- }
-
- /* TWEAKME:
- *
- * Giving values for default min and max latency is not
- * straightforward. Here are our objectives:
- *
- * * for low latency, we want to give the lowest value
- * that will work reliably. This varies based on the
- * sound card, kernel, CPU, etc. I think it is better
- * to give sub-optimal latency than to give a number
- * too low and cause dropouts. My conservative
- * estimate at this point is to base it on 4096-sample
- * latency at 44.1 kHz, which gives a latency of 23ms.
- * * for high latency we want to give a large enough
- * value that dropouts are basically impossible. This
- * doesn't really require as much tweaking, since
- * providing too large a number will just cause us to
- * select the nearest setting that will work at stream
- * config time.
- */
- ENSURE_( snd_pcm_hw_params_set_buffer_size_near( pcm, hwParams, &lowLatency ), paUnanticipatedHostError );
-
- /* Have to reset hwParams, to set new buffer size */
- ENSURE_( snd_pcm_hw_params_any( pcm, hwParams ), paUnanticipatedHostError );
- ENSURE_( snd_pcm_hw_params_set_buffer_size_near( pcm, hwParams, &highLatency ), paUnanticipatedHostError );
-
- *minChannels = (int)minChans;
- *maxChannels = (int)maxChans;
- *defaultSampleRate = defaultSr;
- *defaultLowLatency = (double) lowLatency / *defaultSampleRate;
- *defaultHighLatency = (double) highLatency / *defaultSampleRate;
-
-end:
- snd_pcm_close( pcm );
- return result;
-
-error:
- goto end;
-}
-
-/* Initialize device info with invalid values (maxInputChannels and maxOutputChannels are set to zero since these indicate
- * wether input/output is available) */
-static void InitializeDeviceInfo( PaDeviceInfo *deviceInfo )
-{
- deviceInfo->structVersion = -1;
- deviceInfo->name = NULL;
- deviceInfo->hostApi = -1;
- deviceInfo->maxInputChannels = 0;
- deviceInfo->maxOutputChannels = 0;
- deviceInfo->defaultLowInputLatency = -1.;
- deviceInfo->defaultLowOutputLatency = -1.;
- deviceInfo->defaultHighInputLatency = -1.;
- deviceInfo->defaultHighOutputLatency = -1.;
- deviceInfo->defaultSampleRate = -1.;
-}
-
-/* Helper struct */
-typedef struct
-{
- char *alsaName;
- char *name;
- int isPlug;
- int hasPlayback;
- int hasCapture;
-} DeviceNames;
-
-static PaError PaAlsa_StrDup( PaAlsaHostApiRepresentation *alsaApi,
- char **dst,
- const char *src)
-{
- PaError result = paNoError;
- int len = strlen( src ) + 1;
-
- /* PA_DEBUG(("PaStrDup %s %d\n", src, len)); */
-
- PA_UNLESS( *dst = (char *)PaUtil_GroupAllocateMemory( alsaApi->allocations, len ),
- paInsufficientMemory );
- strncpy( *dst, src, len );
-
-error:
- return result;
-}
-
-/* Disregard standard plugins
- * XXX: Might want to make the "default" plugin available, if we can make it work
- */
-static int IgnorePlugin( const char *pluginId )
-{
-#define numIgnored 10
- static const char *ignoredPlugins[numIgnored] = {"hw", "plughw", "plug", "default", "dsnoop", "dmix", "tee",
- "file", "null", "shm"};
- int i;
-
- for( i = 0; i < numIgnored; ++i )
- {
- if( !strcmp( pluginId, ignoredPlugins[i] ) )
- {
- return 1;
- }
- }
-
- return 0;
-}
-
-/* Build PaDeviceInfo list, ignore devices for which we cannot determine capabilities (possibly busy, sigh) */
-static PaError BuildDeviceList( PaAlsaHostApiRepresentation *alsaApi )
-{
- PaUtilHostApiRepresentation *commonApi = &alsaApi->commonHostApiRep;
- PaAlsaDeviceInfo *deviceInfoArray;
- int cardIdx = -1, devIdx = 0;
- snd_ctl_card_info_t *cardInfo;
- PaError result = paNoError;
- size_t numDeviceNames = 0, maxDeviceNames = 1, i;
- DeviceNames *deviceNames = NULL;
- snd_config_t *topNode = NULL;
- snd_pcm_info_t *pcmInfo;
- int res;
- int blocking = SND_PCM_NONBLOCK;
- char alsaCardName[50];
- if( getenv( "PA_ALSA_INITIALIZE_BLOCK" ) && atoi( getenv( "PA_ALSA_INITIALIZE_BLOCK" ) ) )
- blocking = 0;
-
- /* These two will be set to the first working input and output device, respectively */
- commonApi->info.defaultInputDevice = paNoDevice;
- commonApi->info.defaultOutputDevice = paNoDevice;
-
- /* count the devices by enumerating all the card numbers */
-
- /* snd_card_next() modifies the integer passed to it to be:
- * the index of the first card if the parameter is -1
- * the index of the next card if the parameter is the index of a card
- * -1 if there are no more cards
- *
- * The function itself returns 0 if it succeeded. */
- cardIdx = -1;
- snd_ctl_card_info_alloca( &cardInfo );
- snd_pcm_info_alloca( &pcmInfo );
- while( snd_card_next( &cardIdx ) == 0 && cardIdx >= 0 )
- {
- char *cardName;
- int devIdx = -1;
- snd_ctl_t *ctl;
- char buf[50];
-
- snprintf( alsaCardName, sizeof (alsaCardName), "hw:%d", cardIdx );
-
- /* Acquire name of card */
- if( snd_ctl_open( &ctl, alsaCardName, 0 ) < 0 )
- continue; /* Unable to open card :( */
- snd_ctl_card_info( ctl, cardInfo );
-
- PA_ENSURE( PaAlsa_StrDup( alsaApi, &cardName, snd_ctl_card_info_get_name( cardInfo )) );
-
- while( snd_ctl_pcm_next_device( ctl, &devIdx ) == 0 && devIdx >= 0 )
- {
- char *alsaDeviceName, *deviceName;
- size_t len;
- int hasPlayback = 0, hasCapture = 0;
- snprintf( buf, sizeof (buf), "%s:%d,%d", "hw", cardIdx, devIdx );
-
- /* Obtain info about this particular device */
- snd_pcm_info_set_device( pcmInfo, devIdx );
- snd_pcm_info_set_subdevice( pcmInfo, 0 );
- snd_pcm_info_set_stream( pcmInfo, SND_PCM_STREAM_CAPTURE );
- if( snd_ctl_pcm_info( ctl, pcmInfo ) >= 0 )
- hasCapture = 1;
-
- snd_pcm_info_set_stream( pcmInfo, SND_PCM_STREAM_PLAYBACK );
- if( snd_ctl_pcm_info( ctl, pcmInfo ) >= 0 )
- hasPlayback = 1;
-
- if( !hasPlayback && !hasCapture )
- {
- continue; /* Error */
- }
-
- /* The length of the string written by snprintf plus terminating 0 */
- len = snprintf( NULL, 0, "%s: %s (%s)", cardName, snd_pcm_info_get_name( pcmInfo ), buf ) + 1;
- PA_UNLESS( deviceName = (char *)PaUtil_GroupAllocateMemory( alsaApi->allocations, len ),
- paInsufficientMemory );
- snprintf( deviceName, len, "%s: %s (%s)", cardName,
- snd_pcm_info_get_name( pcmInfo ), buf );
-
- ++numDeviceNames;
- if( !deviceNames || numDeviceNames > maxDeviceNames )
- {
- maxDeviceNames *= 2;
- PA_UNLESS( deviceNames = (DeviceNames *) realloc( deviceNames, maxDeviceNames * sizeof (DeviceNames) ),
- paInsufficientMemory );
- }
-
- PA_ENSURE( PaAlsa_StrDup( alsaApi, &alsaDeviceName, buf ) );
-
- deviceNames[ numDeviceNames - 1 ].alsaName = alsaDeviceName;
- deviceNames[ numDeviceNames - 1 ].name = deviceName;
- deviceNames[ numDeviceNames - 1 ].isPlug = 0;
- deviceNames[ numDeviceNames - 1 ].hasPlayback = hasPlayback;
- deviceNames[ numDeviceNames - 1 ].hasCapture = hasCapture;
- }
- snd_ctl_close( ctl );
- }
-
- /* Iterate over plugin devices */
- snd_config_update();
- if( (res = snd_config_search( snd_config, "pcm", &topNode )) >= 0 )
- {
- snd_config_iterator_t i, next;
-
- snd_config_for_each( i, next, topNode )
- {
- const char *tpStr = NULL, *idStr = NULL;
- char *alsaDeviceName, *deviceName;
- snd_config_t *n = snd_config_iterator_entry( i ), *tp = NULL;
- if( snd_config_get_type( n ) != SND_CONFIG_TYPE_COMPOUND )
- continue;
-
- ENSURE_( snd_config_search( n, "type", &tp ), paUnanticipatedHostError );
- ENSURE_( snd_config_get_string( tp, &tpStr ), paUnanticipatedHostError );
-
- ENSURE_( snd_config_get_id( n, &idStr ), paUnanticipatedHostError );
- if( IgnorePlugin( idStr ) )
- {
- PA_DEBUG(( "%s: Ignoring ALSA plugin device %s of type %s\n", __FUNCTION__, idStr, tpStr ));
- continue;
- }
-
- PA_DEBUG(( "%s: Found plugin %s of type %s\n", __FUNCTION__, idStr, tpStr ));
-
- PA_UNLESS( alsaDeviceName = (char*)PaUtil_GroupAllocateMemory( alsaApi->allocations,
- strlen(idStr) + 6 ), paInsufficientMemory );
- strcpy( alsaDeviceName, idStr );
- PA_UNLESS( deviceName = (char*)PaUtil_GroupAllocateMemory( alsaApi->allocations,
- strlen(idStr) + 1 ), paInsufficientMemory );
- strcpy( deviceName, idStr );
-
- ++numDeviceNames;
- if( !deviceNames || numDeviceNames > maxDeviceNames )
- {
- maxDeviceNames *= 2;
- PA_UNLESS( deviceNames = (DeviceNames *) realloc( deviceNames, maxDeviceNames * sizeof (DeviceNames) ),
- paInsufficientMemory );
- }
-
- deviceNames[numDeviceNames - 1].alsaName = alsaDeviceName;
- deviceNames[numDeviceNames - 1].name = deviceName;
- deviceNames[numDeviceNames - 1].isPlug = 1;
- deviceNames[numDeviceNames - 1].hasPlayback = 1;
- deviceNames[numDeviceNames - 1].hasCapture = 1;
- }
- }
- else
- PA_DEBUG(( "%s: Iterating over ALSA plugins failed: %s\n", __FUNCTION__, snd_strerror( res ) ));
-
- /* allocate deviceInfo memory based on the number of devices */
- PA_UNLESS( commonApi->deviceInfos = (PaDeviceInfo**)PaUtil_GroupAllocateMemory(
- alsaApi->allocations, sizeof(PaDeviceInfo*) * (numDeviceNames) ), paInsufficientMemory );
-
- /* allocate all device info structs in a contiguous block */
- PA_UNLESS( deviceInfoArray = (PaAlsaDeviceInfo*)PaUtil_GroupAllocateMemory(
- alsaApi->allocations, sizeof(PaAlsaDeviceInfo) * numDeviceNames ), paInsufficientMemory );
-
- /* Loop over list of cards, filling in info, if a device is deemed unavailable (can't get name),
- * it's ignored.
- */
- /* while( snd_card_next( &cardIdx ) == 0 && cardIdx >= 0 ) */
- for( i = 0, devIdx = 0; i < numDeviceNames; ++i )
- {
- snd_pcm_t *pcm;
- PaAlsaDeviceInfo *deviceInfo = &deviceInfoArray[devIdx];
- PaDeviceInfo *commonDeviceInfo = &deviceInfo->commonDeviceInfo;
-
- /* Zero fields */
- InitializeDeviceInfo( commonDeviceInfo );
-
- /* to determine device capabilities, we must open the device and query the
- * hardware parameter configuration space */
-
- /* Query capture */
- if( deviceNames[i].hasCapture &&
- snd_pcm_open( &pcm, deviceNames[i].alsaName, SND_PCM_STREAM_CAPTURE, blocking ) >= 0 )
- {
- if( GropeDevice( pcm, &deviceInfo->minInputChannels, &commonDeviceInfo->maxInputChannels,
- &commonDeviceInfo->defaultLowInputLatency, &commonDeviceInfo->defaultHighInputLatency,
- &commonDeviceInfo->defaultSampleRate, deviceNames[i].isPlug ) != paNoError )
- continue; /* Error */
- }
-
- /* Query playback */
- if( deviceNames[i].hasPlayback &&
- snd_pcm_open( &pcm, deviceNames[i].alsaName, SND_PCM_STREAM_PLAYBACK, blocking ) >= 0 )
- {
- if( GropeDevice( pcm, &deviceInfo->minOutputChannels, &commonDeviceInfo->maxOutputChannels,
- &commonDeviceInfo->defaultLowOutputLatency, &commonDeviceInfo->defaultHighOutputLatency,
- &commonDeviceInfo->defaultSampleRate, deviceNames[i].isPlug ) != paNoError )
- continue; /* Error */
- }
-
- commonDeviceInfo->structVersion = 2;
- commonDeviceInfo->hostApi = alsaApi->hostApiIndex;
- commonDeviceInfo->name = deviceNames[i].name;
- deviceInfo->alsaName = deviceNames[i].alsaName;
- deviceInfo->isPlug = deviceNames[i].isPlug;
-
- /* A: Storing pointer to PaAlsaDeviceInfo object as pointer to PaDeviceInfo object.
- * Should now be safe to add device info, unless the device supports neither capture nor playback
- */
- if( commonDeviceInfo->maxInputChannels > 0 || commonDeviceInfo->maxOutputChannels > 0 )
- {
- if( commonApi->info.defaultInputDevice == paNoDevice && commonDeviceInfo->maxInputChannels > 0 )
- commonApi->info.defaultInputDevice = devIdx;
- if( commonApi->info.defaultOutputDevice == paNoDevice && commonDeviceInfo->maxOutputChannels > 0 )
- commonApi->info.defaultOutputDevice = devIdx;
-
- commonApi->deviceInfos[devIdx++] = (PaDeviceInfo *) deviceInfo;
- }
- }
- free( deviceNames );
-
- commonApi->info.deviceCount = devIdx; /* Number of successfully queried devices */
-
-end:
- return result;
-
-error:
- goto end; /* No particular action */
-}
-
-/* Check against known device capabilities */
-static PaError ValidateParameters( const PaStreamParameters *parameters, PaUtilHostApiRepresentation *hostApi, StreamDirection mode )
-{
- PaError result = paNoError;
- int maxChans;
- const PaAlsaDeviceInfo *deviceInfo = NULL;
- assert( parameters );
-
- if( parameters->device != paUseHostApiSpecificDeviceSpecification )
- {
- assert( parameters->device < hostApi->info.deviceCount );
- PA_UNLESS( parameters->hostApiSpecificStreamInfo == NULL, paBadIODeviceCombination );
- deviceInfo = GetDeviceInfo( hostApi, parameters->device );
- }
- else
- {
- const PaAlsaStreamInfo *streamInfo = parameters->hostApiSpecificStreamInfo;
-
- PA_UNLESS( parameters->device == paUseHostApiSpecificDeviceSpecification, paInvalidDevice );
- PA_UNLESS( streamInfo->size == sizeof (PaAlsaStreamInfo) && streamInfo->version == 1,
- paIncompatibleHostApiSpecificStreamInfo );
-
- return paNoError; /* Skip further checking */
- }
-
- assert( deviceInfo );
- assert( parameters->hostApiSpecificStreamInfo == NULL );
- maxChans = (StreamDirection_In == mode ? deviceInfo->commonDeviceInfo.maxInputChannels :
- deviceInfo->commonDeviceInfo.maxOutputChannels);
- PA_UNLESS( parameters->channelCount <= maxChans, paInvalidChannelCount );
-
-error:
- return result;
-}
-
-/* Given an open stream, what sample formats are available? */
-
-static PaSampleFormat GetAvailableFormats( snd_pcm_t *pcm )
-{
- PaSampleFormat available = 0;
- snd_pcm_hw_params_t *hwParams;
- snd_pcm_hw_params_alloca( &hwParams );
-
- snd_pcm_hw_params_any( pcm, hwParams );
-
- if( snd_pcm_hw_params_test_format( pcm, hwParams, SND_PCM_FORMAT_FLOAT ) >= 0)
- available |= paFloat32;
-
- if( snd_pcm_hw_params_test_format( pcm, hwParams, SND_PCM_FORMAT_S32 ) >= 0)
- available |= paInt32;
-
- if( snd_pcm_hw_params_test_format( pcm, hwParams, SND_PCM_FORMAT_S24 ) >= 0)
- available |= paInt24;
-
- if( snd_pcm_hw_params_test_format( pcm, hwParams, SND_PCM_FORMAT_S16 ) >= 0)
- available |= paInt16;
-
- if( snd_pcm_hw_params_test_format( pcm, hwParams, SND_PCM_FORMAT_U8 ) >= 0)
- available |= paUInt8;
-
- if( snd_pcm_hw_params_test_format( pcm, hwParams, SND_PCM_FORMAT_S8 ) >= 0)
- available |= paInt8;
-
- return available;
-}
-
-static snd_pcm_format_t Pa2AlsaFormat( PaSampleFormat paFormat )
-{
- switch( paFormat )
- {
- case paFloat32:
- return SND_PCM_FORMAT_FLOAT;
-
- case paInt16:
- return SND_PCM_FORMAT_S16;
-
- case paInt24:
- return SND_PCM_FORMAT_S24;
-
- case paInt32:
- return SND_PCM_FORMAT_S32;
-
- case paInt8:
- return SND_PCM_FORMAT_S8;
-
- case paUInt8:
- return SND_PCM_FORMAT_U8;
-
- default:
- return SND_PCM_FORMAT_UNKNOWN;
- }
-}
-
-/** Open an ALSA pcm handle.
- *
- * The device to be open can be specified in a custom PaAlsaStreamInfo struct, or it will be a device number. In case of a
- * device number, it maybe specified through an env variable (PA_ALSA_PLUGHW) that we should open the corresponding plugin
- * device.
- */
-static PaError AlsaOpen( const PaUtilHostApiRepresentation *hostApi, const PaStreamParameters *params, StreamDirection
- streamDir, snd_pcm_t **pcm )
-{
- PaError result = paNoError;
- int ret;
- const char *deviceName = alloca( 50 );
- const PaAlsaDeviceInfo *deviceInfo = NULL;
- PaAlsaStreamInfo *streamInfo = (PaAlsaStreamInfo *)params->hostApiSpecificStreamInfo;
-
- if( !streamInfo )
- {
- int usePlug = 0;
- deviceInfo = GetDeviceInfo( hostApi, params->device );
-
- /* If device name starts with hw: and PA_ALSA_PLUGHW is 1, we open the plughw device instead */
- if( !strncmp( "hw:", deviceInfo->alsaName, 3 ) && getenv( "PA_ALSA_PLUGHW" ) )
- usePlug = atoi( getenv( "PA_ALSA_PLUGHW" ) );
- if( usePlug )
- snprintf( (char *) deviceName, 50, "plug%s", deviceInfo->alsaName );
- else
- deviceName = deviceInfo->alsaName;
- }
- else
- deviceName = streamInfo->deviceString;
-
- if( (ret = snd_pcm_open( pcm, deviceName, streamDir == StreamDirection_In ? SND_PCM_STREAM_CAPTURE : SND_PCM_STREAM_PLAYBACK,
- SND_PCM_NONBLOCK )) < 0 )
- {
- *pcm = NULL; /* Not to be closed */
- ENSURE_( ret, ret == -EBUSY ? paDeviceUnavailable : paBadIODeviceCombination );
- }
- ENSURE_( snd_pcm_nonblock( *pcm, 0 ), paUnanticipatedHostError );
-
-end:
- return result;
-
-error:
- goto end;
-}
-
-static PaError TestParameters( const PaUtilHostApiRepresentation *hostApi, const PaStreamParameters *parameters,
- double sampleRate, StreamDirection streamDir )
-{
- PaError result = paNoError;
- snd_pcm_t *pcm = NULL;
- PaSampleFormat availableFormats;
- /* We are able to adapt to a number of channels less than what the device supports */
- unsigned int numHostChannels;
- PaSampleFormat hostFormat;
- snd_pcm_hw_params_t *hwParams;
- snd_pcm_hw_params_alloca( &hwParams );
-
- if( !parameters->hostApiSpecificStreamInfo )
- {
- const PaAlsaDeviceInfo *devInfo = GetDeviceInfo( hostApi, parameters->device );
- numHostChannels = PA_MAX( parameters->channelCount, StreamDirection_In == streamDir ?
- devInfo->minInputChannels : devInfo->minOutputChannels );
- }
- else
- numHostChannels = parameters->channelCount;
-
- PA_ENSURE( AlsaOpen( hostApi, parameters, streamDir, &pcm ) );
-
- snd_pcm_hw_params_any( pcm, hwParams );
-
- if( SetApproximateSampleRate( pcm, hwParams, sampleRate ) < 0 )
- {
- result = paInvalidSampleRate;
- goto error;
- }
-
- if( snd_pcm_hw_params_set_channels( pcm, hwParams, numHostChannels ) < 0 )
- {
- result = paInvalidChannelCount;
- goto error;
- }
-
- /* See if we can find a best possible match */
- availableFormats = GetAvailableFormats( pcm );
- PA_ENSURE( hostFormat = PaUtil_SelectClosestAvailableFormat( availableFormats, parameters->sampleFormat ) );
- ENSURE_( snd_pcm_hw_params_set_format( pcm, hwParams, Pa2AlsaFormat( hostFormat ) ), paUnanticipatedHostError );
-
- ENSURE_( snd_pcm_hw_params( pcm, hwParams ), paUnanticipatedHostError );
-
-end:
- if( pcm )
- snd_pcm_close( pcm );
- return result;
-
-error:
- goto end;
-}
-
-static PaError IsFormatSupported( struct PaUtilHostApiRepresentation *hostApi,
- const PaStreamParameters *inputParameters,
- const PaStreamParameters *outputParameters,
- double sampleRate )
-{
- int inputChannelCount = 0, outputChannelCount = 0;
- PaSampleFormat inputSampleFormat, outputSampleFormat;
- PaError result = paFormatIsSupported;
-
- if( inputParameters )
- {
- PA_ENSURE( ValidateParameters( inputParameters, hostApi, StreamDirection_In ) );
-
- inputChannelCount = inputParameters->channelCount;
- inputSampleFormat = inputParameters->sampleFormat;
- }
-
- if( outputParameters )
- {
- PA_ENSURE( ValidateParameters( outputParameters, hostApi, StreamDirection_Out ) );
-
- outputChannelCount = outputParameters->channelCount;
- outputSampleFormat = outputParameters->sampleFormat;
- }
-
- if( inputChannelCount )
- {
- if( (result = TestParameters( hostApi, inputParameters, sampleRate, StreamDirection_In ))
- != paNoError )
- goto error;
- }
- if ( outputChannelCount )
- {
- if( (result = TestParameters( hostApi, outputParameters, sampleRate, StreamDirection_Out ))
- != paNoError )
- goto error;
- }
-
- return paFormatIsSupported;
-
-error:
- return result;
-}
-
-static PaError PaAlsaStreamComponent_Initialize( PaAlsaStreamComponent *self, PaAlsaHostApiRepresentation *alsaApi,
- const PaStreamParameters *params, StreamDirection streamDir, int callbackMode )
-{
- PaError result = paNoError;
- PaSampleFormat userSampleFormat = params->sampleFormat, hostSampleFormat;
- assert( params->channelCount > 0 );
-
- /* Make sure things have an initial value */
- memset( self, 0, sizeof (PaAlsaStreamComponent) );
-
- if( NULL == params->hostApiSpecificStreamInfo )
- {
- const PaAlsaDeviceInfo *devInfo = GetDeviceInfo( &alsaApi->commonHostApiRep, params->device );
- self->numHostChannels = PA_MAX( params->channelCount, StreamDirection_In == streamDir ? devInfo->minInputChannels
- : devInfo->minOutputChannels );
- }
- else
- {
- /* We're blissfully unaware of the minimum channelCount */
- self->numHostChannels = params->channelCount;
- }
-
- PA_ENSURE( AlsaOpen( &alsaApi->commonHostApiRep, params, streamDir, &self->pcm ) );
- self->nfds = snd_pcm_poll_descriptors_count( self->pcm );
- hostSampleFormat = PaUtil_SelectClosestAvailableFormat( GetAvailableFormats( self->pcm ), userSampleFormat );
-
- self->hostSampleFormat = hostSampleFormat;
- self->nativeFormat = Pa2AlsaFormat( hostSampleFormat );
- self->hostInterleaved = self->userInterleaved = !(userSampleFormat & paNonInterleaved);
- self->numUserChannels = params->channelCount;
- self->streamDir = streamDir;
-
- if( !callbackMode && !self->userInterleaved )
- {
- /* Pre-allocate non-interleaved user provided buffers */
- PA_UNLESS( self->userBuffers = PaUtil_AllocateMemory( sizeof (void *) * self->numUserChannels ),
- paInsufficientMemory );
- }
-
-error:
- return result;
-}
-
-static void PaAlsaStreamComponent_Terminate( PaAlsaStreamComponent *self )
-{
- snd_pcm_close( self->pcm );
- if( self->userBuffers )
- PaUtil_FreeMemory( self->userBuffers );
-}
-
-/** Configure the associated ALSA pcm.
- *
- */
-static PaError PaAlsaStreamComponent_Configure( PaAlsaStreamComponent *self, const PaStreamParameters *params, unsigned long
- framesPerHostBuffer, int primeBuffers, int callbackMode, double *sampleRate, PaTime *returnedLatency )
-{
- /*
- int numPeriods;
-
- if( getenv("PA_NUMPERIODS") != NULL )
- numPeriods = atoi( getenv("PA_NUMPERIODS") );
- else
- numPeriods = ( (latency * sampleRate) / *framesPerBuffer ) + 1;
-
- PA_DEBUG(( "latency: %f, rate: %f, framesPerBuffer: %d\n", latency, sampleRate, *framesPerBuffer ));
- if( numPeriods <= 1 )
- numPeriods = 2;
- */
-
- /* Configuration consists of setting all of ALSA's parameters.
- * These parameters come in two flavors: hardware parameters
- * and software paramters. Hardware parameters will affect
- * the way the device is initialized, software parameters
- * affect the way ALSA interacts with me, the user-level client.
- */
-
- snd_pcm_hw_params_t *hwParams;
- snd_pcm_sw_params_t *swParams;
- PaError result = paNoError;
- snd_pcm_access_t accessMode, alternateAccessMode;
- unsigned int numPeriods, minPeriods = 2;
- int dir = 0;
- snd_pcm_t *pcm = self->pcm;
- PaTime latency = params->suggestedLatency;
- double sr = *sampleRate;
- *returnedLatency = -1.;
-
- snd_pcm_hw_params_alloca( &hwParams );
- snd_pcm_sw_params_alloca( &swParams );
-
- self->framesPerBuffer = framesPerHostBuffer;
-
- /* ... fill up the configuration space with all possibile
- * combinations of parameters this device will accept */
- ENSURE_( snd_pcm_hw_params_any( pcm, hwParams ), paUnanticipatedHostError );
-
- ENSURE_( snd_pcm_hw_params_set_periods_integer( pcm, hwParams ), paUnanticipatedHostError );
- ENSURE_( snd_pcm_hw_params_set_period_size_integer( pcm, hwParams ), paUnanticipatedHostError );
-
- if( self->userInterleaved )
- {
- accessMode = SND_PCM_ACCESS_MMAP_INTERLEAVED;
- alternateAccessMode = SND_PCM_ACCESS_MMAP_NONINTERLEAVED;
- }
- else
- {
- accessMode = SND_PCM_ACCESS_MMAP_NONINTERLEAVED;
- alternateAccessMode = SND_PCM_ACCESS_MMAP_INTERLEAVED;
- }
-
- /* If requested access mode fails, try alternate mode */
- if( snd_pcm_hw_params_set_access( pcm, hwParams, accessMode ) < 0 )
- {
- ENSURE_( snd_pcm_hw_params_set_access( pcm, hwParams, alternateAccessMode ), paUnanticipatedHostError );
- /* Flip mode */
- self->hostInterleaved = !self->userInterleaved;
- }
-
- ENSURE_( snd_pcm_hw_params_set_format( pcm, hwParams, self->nativeFormat ), paUnanticipatedHostError );
-
- ENSURE_( SetApproximateSampleRate( pcm, hwParams, sr ), paInvalidSampleRate );
- ENSURE_( GetExactSampleRate( hwParams, &sr ), paUnanticipatedHostError );
- /* reject if there's no sample rate within 1% of the one requested */
- if( (fabs( *sampleRate - sr ) / *sampleRate) > 0.01 )
- {
- PA_DEBUG(("%s: Wanted %f, closest sample rate was %d\n", __FUNCTION__, sampleRate, sr ));
- PA_ENSURE( paInvalidSampleRate );
- }
-
- ENSURE_( snd_pcm_hw_params_set_channels( pcm, hwParams, self->numHostChannels ), paInvalidChannelCount );
-
- /* I think there should be at least 2 periods (even though ALSA doesn't appear to enforce this) */
- dir = 0;
- ENSURE_( snd_pcm_hw_params_set_periods_min( pcm, hwParams, &minPeriods, &dir ), paUnanticipatedHostError );
- dir = 0;
- ENSURE_( snd_pcm_hw_params_set_period_size_near( pcm, hwParams, &self->framesPerBuffer, &dir ), paUnanticipatedHostError );
-
- /* Find an acceptable number of periods */
- numPeriods = (latency * sr) / self->framesPerBuffer + 1;
- dir = 0;
- ENSURE_( snd_pcm_hw_params_set_periods_near( pcm, hwParams, &numPeriods, &dir ), paUnanticipatedHostError );
- /* Minimum of periods should already be 2 */
- PA_UNLESS( numPeriods >= 2, paInternalError );
-
- /* Set the parameters! */
- ENSURE_( snd_pcm_hw_params( pcm, hwParams ), paUnanticipatedHostError );
- ENSURE_( snd_pcm_hw_params_get_buffer_size( hwParams, &self->bufferSize ), paUnanticipatedHostError );
-
- /* Latency in seconds, one period is not counted as latency */
- latency = (numPeriods - 1) * self->framesPerBuffer / sr;
-
- /* Now software parameters... */
- ENSURE_( snd_pcm_sw_params_current( pcm, swParams ), paUnanticipatedHostError );
-
- ENSURE_( snd_pcm_sw_params_set_start_threshold( pcm, swParams, self->framesPerBuffer ), paUnanticipatedHostError );
- ENSURE_( snd_pcm_sw_params_set_stop_threshold( pcm, swParams, self->bufferSize ), paUnanticipatedHostError );
-
- /* Silence buffer in the case of underrun */
- if( !primeBuffers ) /* XXX: Make sense? */
- {
- snd_pcm_uframes_t boundary;
- ENSURE_( snd_pcm_sw_params_get_boundary( swParams, &boundary ), paUnanticipatedHostError );
- ENSURE_( snd_pcm_sw_params_set_silence_threshold( pcm, swParams, 0 ), paUnanticipatedHostError );
- ENSURE_( snd_pcm_sw_params_set_silence_size( pcm, swParams, boundary ), paUnanticipatedHostError );
- }
-
- ENSURE_( snd_pcm_sw_params_set_avail_min( pcm, swParams, self->framesPerBuffer ), paUnanticipatedHostError );
- ENSURE_( snd_pcm_sw_params_set_xfer_align( pcm, swParams, 1 ), paUnanticipatedHostError );
- ENSURE_( snd_pcm_sw_params_set_tstamp_mode( pcm, swParams, SND_PCM_TSTAMP_MMAP ), paUnanticipatedHostError );
-
- /* Set the parameters! */
- ENSURE_( snd_pcm_sw_params( pcm, swParams ), paUnanticipatedHostError );
-
- *sampleRate = sr;
- *returnedLatency = latency;
-
-end:
- return result;
-
-error:
- goto end; /* No particular action */
-}
-
-static PaError PaAlsaStream_Initialize( PaAlsaStream *self, PaAlsaHostApiRepresentation *alsaApi, const PaStreamParameters *inParams,
- const PaStreamParameters *outParams, double sampleRate, unsigned long framesPerUserBuffer, PaStreamCallback callback,
- PaStreamFlags streamFlags, void *userData )
-{
- PaError result = paNoError;
- assert( self );
-
- memset( self, 0, sizeof (PaAlsaStream) );
-
- if( NULL != callback )
- {
- PaUtil_InitializeStreamRepresentation( &self->streamRepresentation,
- &alsaApi->callbackStreamInterface,
- callback, userData );
- self->callbackMode = 1;
- }
- else
- {
- PaUtil_InitializeStreamRepresentation( &self->streamRepresentation,
- &alsaApi->blockingStreamInterface,
- NULL, userData );
- }
-
- self->framesPerUserBuffer = framesPerUserBuffer;
- self->neverDropInput = streamFlags & paNeverDropInput;
- /* XXX: Ignore paPrimeOutputBuffersUsingStreamCallback untill buffer priming is fully supported in pa_process.c */
- /*
- if( outParams & streamFlags & paPrimeOutputBuffersUsingStreamCallback )
- self->primeBuffers = 1;
- */
- memset( &self->capture, 0, sizeof (PaAlsaStreamComponent) );
- memset( &self->playback, 0, sizeof (PaAlsaStreamComponent) );
- if( inParams )
- PA_ENSURE( PaAlsaStreamComponent_Initialize( &self->capture, alsaApi, inParams, StreamDirection_In, NULL != callback ) );
- if( outParams )
- PA_ENSURE( PaAlsaStreamComponent_Initialize( &self->playback, alsaApi, outParams, StreamDirection_Out, NULL != callback ) );
-
- assert( self->capture.nfds || self->playback.nfds );
-
- PA_UNLESS( self->pfds = (struct pollfd*)PaUtil_AllocateMemory( (self->capture.nfds +
- self->playback.nfds) * sizeof (struct pollfd) ), paInsufficientMemory );
-
- PaUtil_InitializeCpuLoadMeasurer( &self->cpuLoadMeasurer, sampleRate );
- InitializeThreading( &self->threading, &self->cpuLoadMeasurer );
- ASSERT_CALL_( pthread_mutex_init( &self->stateMtx, NULL ), 0 );
- ASSERT_CALL_( pthread_mutex_init( &self->startMtx, NULL ), 0 );
- ASSERT_CALL_( pthread_cond_init( &self->startCond, NULL ), 0 );
-
-error:
- return result;
-}
-
-/** Free resources associated with stream, and eventually stream itself.
- *
- * Frees allocated memory, and terminates individual StreamComponents.
- */
-static void PaAlsaStream_Terminate( PaAlsaStream *self )
-{
- assert( self );
-
- if( self->capture.pcm )
- {
- PaAlsaStreamComponent_Terminate( &self->capture );
- }
- if( self->playback.pcm )
- {
- PaAlsaStreamComponent_Terminate( &self->playback );
- }
-
- PaUtil_FreeMemory( self->pfds );
- ASSERT_CALL_( pthread_mutex_destroy( &self->stateMtx ), 0 );
- ASSERT_CALL_( pthread_mutex_destroy( &self->startMtx ), 0 );
- ASSERT_CALL_( pthread_cond_destroy( &self->startCond ), 0 );
-
- PaUtil_FreeMemory( self );
-}
-
-/** Calculate polling timeout
- *
- * @param frames Time to wait
- * @return Polling timeout in milliseconds
- */
-static int CalculatePollTimeout( const PaAlsaStream *stream, unsigned long frames )
-{
- assert( stream->streamRepresentation.streamInfo.sampleRate > 0.0 );
- /* Period in msecs, rounded up */
- return (int)ceil( 1000 * frames / stream->streamRepresentation.streamInfo.sampleRate );
-}
-
-/** Set up ALSA stream parameters.
- *
- */
-static PaError PaAlsaStream_Configure( PaAlsaStream *self, const PaStreamParameters *inParams, const PaStreamParameters
- *outParams, double sampleRate, unsigned long framesPerHostBuffer, double *inputLatency, double *outputLatency,
- unsigned long *maxHostBufferSize )
-{
- PaError result = paNoError;
- double realSr = sampleRate;
-
- if( self->capture.pcm )
- PA_ENSURE( PaAlsaStreamComponent_Configure( &self->capture, inParams, framesPerHostBuffer, self->primeBuffers,
- self->callbackMode, &realSr, inputLatency ) );
- if( self->playback.pcm )
- PA_ENSURE( PaAlsaStreamComponent_Configure( &self->playback, outParams, framesPerHostBuffer, self->primeBuffers,
- self->callbackMode, &realSr, outputLatency ) );
-
- /* Should be exact now */
- self->streamRepresentation.streamInfo.sampleRate = realSr;
-
- /* this will cause the two streams to automatically start/stop/prepare in sync.
- * We only need to execute these operations on one of the pair.
- * A: We don't want to do this on a blocking stream.
- */
- if( self->callbackMode && self->capture.pcm && self->playback.pcm )
- {
- int err = snd_pcm_link( self->capture.pcm, self->playback.pcm );
- if( err >= 0 )
- self->pcmsSynced = 1;
- else
- PA_DEBUG(( "%s: Unable to sync pcms: %s\n", __FUNCTION__, snd_strerror( err ) ));
- }
-
- /* Frames per host buffer for the stream is set as a compromise between the two directions */
- framesPerHostBuffer = PA_MIN( self->capture.pcm ? self->capture.framesPerBuffer : ULONG_MAX,
- self->playback.pcm ? self->playback.framesPerBuffer : ULONG_MAX );
- self->pollTimeout = CalculatePollTimeout( self, framesPerHostBuffer ); /* Period in msecs, rounded up */
-
- *maxHostBufferSize = PA_MAX( self->capture.pcm ? self->capture.bufferSize : 0,
- self->playback.pcm ? self->playback.bufferSize : 0 );
-
- /* Time before watchdog unthrottles realtime thread == 1/4 of period time in msecs */
- self->threading.throttledSleepTime = (unsigned long) (framesPerHostBuffer / sampleRate / 4 * 1000);
-
- if( self->callbackMode )
- {
- /* If the user expects a certain number of frames per callback we will either have to rely on block adaption
- * (framesPerHostBuffer is not an integer multiple of framesPerBuffer) or we can simply align the number
- * of host buffer frames with what the user specified */
- if( self->framesPerUserBuffer != paFramesPerBufferUnspecified )
- {
- /* self->alignFrames = 1; */
-
- /* Unless the ratio between number of host and user buffer frames is an integer we will have to rely
- * on block adaption */
- /*
- if( framesPerHostBuffer % framesPerBuffer != 0 || (self->capture.pcm && self->playback.pcm &&
- self->capture.framesPerBuffer != self->playback.framesPerBuffer) )
- self->useBlockAdaption = 1;
- else
- self->alignFrames = 1;
- */
- }
- }
-
-error:
- return result;
-}
-
-/* We need to determine how many frames per host buffer to use. Our
- * goals are to provide the best possible performance, but also to
- * most closely honor the requested latency settings. Therefore this
- * decision is based on:
- *
- * - the period sizes that playback and/or capture support. The
- * host buffer size has to be one of these.
- * - the number of periods that playback and/or capture support.
- *
- * We want to make period_size*(num_periods-1) to be as close as possible
- * to latency*rate for both playback and capture.
- *
- * This is one of those blocks of code that will just take a lot of
- * refinement to be any good.
- *
- * In the full-duplex case it is possible that the routine was unable
- * to find a number of frames per buffer acceptable to both devices
- * TODO: Implement an algorithm to find the value closest to acceptance
- * by both devices, to minimize difference between period sizes?
- */
-static PaError DetermineFramesPerBuffer( const PaAlsaStream *stream, double sampleRate, const PaStreamParameters *inputParameters,
- const PaStreamParameters *outputParameters, unsigned long *determinedFrames, const PaUtilHostApiRepresentation *hostApi )
-{
- PaError result = paNoError;
- unsigned long framesPerBuffer = 0;
- int numHostInputChannels = 0, numHostOutputChannels = 0;
-
- /* XXX: Clean this up */
- if( stream->capture.pcm )
- {
- const PaAlsaDeviceInfo *devInfo = GetDeviceInfo( hostApi, inputParameters->device );
- numHostInputChannels = PA_MAX( inputParameters->channelCount, devInfo->minInputChannels );
- }
- if( stream->playback.pcm )
- {
- const PaAlsaDeviceInfo *devInfo = GetDeviceInfo( hostApi, outputParameters->device );
- numHostOutputChannels = PA_MAX( outputParameters->channelCount, devInfo->minOutputChannels );
- }
-
- if( stream->capture.pcm && stream->playback.pcm )
- {
- snd_pcm_uframes_t desiredLatency, e;
- snd_pcm_uframes_t minPeriodSize, minPlayback, minCapture, maxPeriodSize, maxPlayback, maxCapture,
- optimalPeriodSize, periodSize;
- int dir = 0;
- unsigned int minPeriods = 2;
-
- snd_pcm_t *pcm;
- snd_pcm_hw_params_t *hwParamsPlayback, *hwParamsCapture;
-
- snd_pcm_hw_params_alloca( &hwParamsPlayback );
- snd_pcm_hw_params_alloca( &hwParamsCapture );
-
- /* Come up with a common desired latency */
- pcm = stream->playback.pcm;
- snd_pcm_hw_params_any( pcm, hwParamsPlayback );
- ENSURE_( SetApproximateSampleRate( pcm, hwParamsPlayback, sampleRate ), paInvalidSampleRate );
- ENSURE_( snd_pcm_hw_params_set_channels( pcm, hwParamsPlayback, numHostOutputChannels ),
- paBadIODeviceCombination );
-
- ENSURE_( snd_pcm_hw_params_set_period_size_integer( pcm, hwParamsPlayback ), paUnanticipatedHostError );
- ENSURE_( snd_pcm_hw_params_set_periods_integer( pcm, hwParamsPlayback ), paUnanticipatedHostError );
- ENSURE_( snd_pcm_hw_params_set_periods_min( pcm, hwParamsPlayback, &minPeriods, &dir ), paUnanticipatedHostError );
- ENSURE_( snd_pcm_hw_params_get_period_size_min( hwParamsPlayback, &minPlayback, &dir ), paUnanticipatedHostError );
- ENSURE_( snd_pcm_hw_params_get_period_size_max( hwParamsPlayback, &maxPlayback, &dir ), paUnanticipatedHostError );
-
- pcm = stream->capture.pcm;
- ENSURE_( snd_pcm_hw_params_any( pcm, hwParamsCapture ), paUnanticipatedHostError );
- ENSURE_( SetApproximateSampleRate( pcm, hwParamsCapture, sampleRate ), paBadIODeviceCombination );
- ENSURE_( snd_pcm_hw_params_set_channels( pcm, hwParamsCapture, numHostInputChannels ),
- paBadIODeviceCombination );
-
- ENSURE_( snd_pcm_hw_params_set_period_size_integer( pcm, hwParamsCapture ), paUnanticipatedHostError );
- ENSURE_( snd_pcm_hw_params_set_periods_integer( pcm, hwParamsCapture ), paUnanticipatedHostError );
- ENSURE_( snd_pcm_hw_params_set_periods_min( pcm, hwParamsCapture, &minPeriods, &dir ), paUnanticipatedHostError );
- ENSURE_( snd_pcm_hw_params_get_period_size_min( hwParamsCapture, &minCapture, &dir ), paUnanticipatedHostError );
- ENSURE_( snd_pcm_hw_params_get_period_size_max( hwParamsCapture, &maxCapture, &dir ), paUnanticipatedHostError );
-
- minPeriodSize = PA_MAX( minPlayback, minCapture );
- maxPeriodSize = PA_MIN( maxPlayback, maxCapture );
-
- desiredLatency = (snd_pcm_uframes_t) (PA_MIN( outputParameters->suggestedLatency, inputParameters->suggestedLatency )
- * sampleRate);
- /* Clamp desiredLatency */
- {
- snd_pcm_uframes_t tmp, maxBufferSize = ULONG_MAX;
- ENSURE_( snd_pcm_hw_params_get_buffer_size_max( hwParamsPlayback, &maxBufferSize ), paUnanticipatedHostError );
- ENSURE_( snd_pcm_hw_params_get_buffer_size_max( hwParamsCapture, &tmp ), paUnanticipatedHostError );
- maxBufferSize = PA_MIN( maxBufferSize, tmp );
-
- desiredLatency = PA_MIN( desiredLatency, maxBufferSize );
- }
-
- /* Find the closest power of 2 */
- e = ilogb( minPeriodSize );
- if( minPeriodSize & (minPeriodSize - 1) )
- e += 1;
- periodSize = (snd_pcm_uframes_t) pow( 2, e );
-
- while( periodSize <= maxPeriodSize )
- {
- if( snd_pcm_hw_params_test_period_size( stream->playback.pcm, hwParamsPlayback, periodSize, 0 ) >= 0 &&
- snd_pcm_hw_params_test_period_size( stream->capture.pcm, hwParamsCapture, periodSize, 0 ) >= 0 )
- break; /* Ok! */
-
- periodSize *= 2;
- }
-
- /* 4 periods considered optimal */
- optimalPeriodSize = PA_MAX( desiredLatency / 4, minPeriodSize );
- optimalPeriodSize = PA_MIN( optimalPeriodSize, maxPeriodSize );
-
- /* Find the closest power of 2 */
- e = ilogb( optimalPeriodSize );
- if( optimalPeriodSize & (optimalPeriodSize - 1) )
- e += 1;
- optimalPeriodSize = (snd_pcm_uframes_t) pow( 2, e );
-
- while( optimalPeriodSize >= periodSize )
- {
- pcm = stream->playback.pcm;
- if( snd_pcm_hw_params_test_period_size( pcm, hwParamsPlayback, optimalPeriodSize, 0 ) < 0 )
- continue;
-
- pcm = stream->capture.pcm;
- if( snd_pcm_hw_params_test_period_size( pcm, hwParamsCapture, optimalPeriodSize, 0 ) >= 0 )
- break;
-
- optimalPeriodSize /= 2;
- }
-
- if( optimalPeriodSize > periodSize )
- periodSize = optimalPeriodSize;
-
- if( periodSize <= maxPeriodSize )
- {
- /* Looks good */
- framesPerBuffer = periodSize;
- }
- else
- {
- /* Unable to find a common period size, oh well */
- optimalPeriodSize = PA_MAX( desiredLatency / 4, minPeriodSize );
- optimalPeriodSize = PA_MIN( optimalPeriodSize, maxPeriodSize );
-
- /* ConfigureStream should find individual period sizes acceptable for each device */
- framesPerBuffer = optimalPeriodSize;
- /* PA_ENSURE( paBadIODeviceCombination ); */
- }
- }
- else /* half-duplex is a slightly simpler case */
- {
- unsigned long bufferSize, channels;
- snd_pcm_t *pcm;
- snd_pcm_hw_params_t *hwParams;
-
- snd_pcm_hw_params_alloca( &hwParams );
-
- if( stream->capture.pcm )
- {
- pcm = stream->capture.pcm;
- bufferSize = inputParameters->suggestedLatency * sampleRate;
- channels = numHostInputChannels;
- }
- else
- {
- pcm = stream->playback.pcm;
- bufferSize = outputParameters->suggestedLatency * sampleRate;
- channels = numHostOutputChannels;
- }
-
- ENSURE_( snd_pcm_hw_params_any( pcm, hwParams ), paUnanticipatedHostError );
- ENSURE_( SetApproximateSampleRate( pcm, hwParams, sampleRate ), paInvalidSampleRate );
- ENSURE_( snd_pcm_hw_params_set_channels( pcm, hwParams, channels ), paBadIODeviceCombination );
-
- ENSURE_( snd_pcm_hw_params_set_period_size_integer( pcm, hwParams ), paUnanticipatedHostError );
- ENSURE_( snd_pcm_hw_params_set_periods_integer( pcm, hwParams ), paUnanticipatedHostError );
-
- /* Using 5 as a base number of periods, we try to approximate the suggested latency (+1 period),
- finding a combination of period/buffer size which best fits these constraints */
- framesPerBuffer = bufferSize / 4;
- bufferSize += framesPerBuffer; /* One period doesn't count as latency */
- ENSURE_( snd_pcm_hw_params_set_buffer_size_near( pcm, hwParams, &bufferSize ), paUnanticipatedHostError );
- ENSURE_( snd_pcm_hw_params_set_period_size_near( pcm, hwParams, &framesPerBuffer, NULL ), paUnanticipatedHostError );
- }
-
- PA_UNLESS( framesPerBuffer != 0, paInternalError );
- *determinedFrames = framesPerBuffer;
-
-error:
- return result;
-}
-
-static PaError OpenStream( struct PaUtilHostApiRepresentation *hostApi,
- PaStream** s,
- const PaStreamParameters *inputParameters,
- const PaStreamParameters *outputParameters,
- double sampleRate,
- unsigned long framesPerBuffer,
- PaStreamFlags streamFlags,
- PaStreamCallback *callback,
- void *userData )
-{
- PaError result = paNoError;
- PaAlsaHostApiRepresentation *alsaHostApi = (PaAlsaHostApiRepresentation*)hostApi;
- PaAlsaStream *stream = NULL;
- PaSampleFormat hostInputSampleFormat = 0, hostOutputSampleFormat = 0;
- PaSampleFormat inputSampleFormat = 0, outputSampleFormat = 0;
- int numInputChannels = 0, numOutputChannels = 0;
- PaTime inputLatency, outputLatency;
- unsigned long framesPerHostBuffer;
- PaUtilHostBufferSizeMode hostBufferSizeMode = paUtilBoundedHostBufferSize;
- unsigned long maxHostBufferSize; /* Upper bound of host buffer size */
-
- if( (streamFlags & paPlatformSpecificFlags) != 0 )
- return paInvalidFlag;
-
- if( inputParameters )
- {
- PA_ENSURE( ValidateParameters( inputParameters, hostApi, StreamDirection_In ) );
-
- numInputChannels = inputParameters->channelCount;
- inputSampleFormat = inputParameters->sampleFormat;
- }
- if( outputParameters )
- {
- PA_ENSURE( ValidateParameters( outputParameters, hostApi, StreamDirection_Out ) );
-
- numOutputChannels = outputParameters->channelCount;
- outputSampleFormat = outputParameters->sampleFormat;
- }
-
- /* XXX: Why do we support this anyway? */
- if( framesPerBuffer == paFramesPerBufferUnspecified && getenv( "PA_ALSA_PERIODSIZE" ) != NULL )
- {
- PA_DEBUG(( "%s: Getting framesPerBuffer from environment\n", __FUNCTION__ ));
- framesPerBuffer = atoi( getenv("PA_ALSA_PERIODSIZE") );
- }
- framesPerHostBuffer = framesPerBuffer;
-
- PA_UNLESS( stream = (PaAlsaStream*)PaUtil_AllocateMemory( sizeof(PaAlsaStream) ), paInsufficientMemory );
- PA_ENSURE( PaAlsaStream_Initialize( stream, alsaHostApi, inputParameters, outputParameters, sampleRate,
- framesPerBuffer, callback, streamFlags, userData ) );
-
- /* If the number of frames per buffer is unspecified, we have to come up with
- * one. This is both a blessing and a curse: a blessing because we can optimize
- * the number to best meet the requirements, but a curse because that's really
- * hard to do well. For this reason we also support an interface where the user
- * specifies these by setting environment variables. */
- if( framesPerBuffer == paFramesPerBufferUnspecified )
- {
- PA_ENSURE( DetermineFramesPerBuffer( stream, sampleRate, inputParameters, outputParameters, &framesPerHostBuffer,
- hostApi ) );
- }
-
- PA_ENSURE( PaAlsaStream_Configure( stream, inputParameters, outputParameters, sampleRate, framesPerHostBuffer,
- &inputLatency, &outputLatency, &maxHostBufferSize ) );
- hostInputSampleFormat = stream->capture.hostSampleFormat;
- hostOutputSampleFormat = stream->playback.hostSampleFormat;
-
- if( framesPerHostBuffer != framesPerBuffer )
- {
- PA_DEBUG(( "%s: Number of frames per user and host buffer differs\n", __FUNCTION__ ));
- }
-
- PA_ENSURE( PaUtil_InitializeBufferProcessor( &stream->bufferProcessor,
- numInputChannels, inputSampleFormat, hostInputSampleFormat,
- numOutputChannels, outputSampleFormat, hostOutputSampleFormat,
- sampleRate, streamFlags, framesPerBuffer, maxHostBufferSize,
- hostBufferSizeMode, callback, userData ) );
-
- /* Ok, buffer processor is initialized, now we can deduce it's latency */
- if( numInputChannels > 0 )
- stream->streamRepresentation.streamInfo.inputLatency = inputLatency + PaUtil_GetBufferProcessorInputLatency(
- &stream->bufferProcessor );
- if( numOutputChannels > 0 )
- stream->streamRepresentation.streamInfo.outputLatency = outputLatency + PaUtil_GetBufferProcessorOutputLatency(
- &stream->bufferProcessor );
-
- *s = (PaStream*)stream;
-
- return result;
-
-error:
- if( stream )
- PaAlsaStream_Terminate( stream );
-
- return result;
-}
-
-static PaError CloseStream( PaStream* s )
-{
- PaError result = paNoError;
- PaAlsaStream *stream = (PaAlsaStream*)s;
-
- PaUtil_TerminateBufferProcessor( &stream->bufferProcessor );
- PaUtil_TerminateStreamRepresentation( &stream->streamRepresentation );
-
- PaAlsaStream_Terminate( stream );
-
- return result;
-}
-
-static void SilenceBuffer( PaAlsaStream *stream )
-{
- const snd_pcm_channel_area_t *areas;
- snd_pcm_uframes_t frames = (snd_pcm_uframes_t)snd_pcm_avail_update( stream->playback.pcm ), offset;
-
- snd_pcm_mmap_begin( stream->playback.pcm, &areas, &offset, &frames );
- snd_pcm_areas_silence( areas, offset, stream->playback.numHostChannels, frames, stream->playback.nativeFormat );
- snd_pcm_mmap_commit( stream->playback.pcm, offset, frames );
-}
-
-/** Start/prepare pcm(s) for streaming.
- *
- * Depending on wether the stream is in callback or blocking mode, we will respectively start or simply
- * prepare the playback pcm. If the buffer has _not_ been primed, we will in callback mode prepare and
- * silence the buffer before starting playback. In blocking mode we simply prepare, as the playback will
- * be started automatically as the user writes to output.
- *
- * The capture pcm, however, will simply be prepared and started.
- *
- * PaAlsaStream::startMtx makes sure access is synchronized (useful in callback mode)
- */
-static PaError AlsaStart( PaAlsaStream *stream, int priming )
-{
- PaError result = paNoError;
-
- if( stream->playback.pcm )
- {
- if( stream->callbackMode )
- {
- if( !priming )
- {
- /* Buffer isn't primed, so prepare and silence */
- ENSURE_( snd_pcm_prepare( stream->playback.pcm ), paUnanticipatedHostError );
- SilenceBuffer( stream );
- }
- ENSURE_( snd_pcm_start( stream->playback.pcm ), paUnanticipatedHostError );
- }
- else
- ENSURE_( snd_pcm_prepare( stream->playback.pcm ), paUnanticipatedHostError );
- }
- if( stream->capture.pcm && !stream->pcmsSynced )
- {
- ENSURE_( snd_pcm_prepare( stream->capture.pcm ), paUnanticipatedHostError );
- /* For a blocking stream we want to start capture as well, since nothing will happen otherwise */
- ENSURE_( snd_pcm_start( stream->capture.pcm ), paUnanticipatedHostError );
- }
-
-end:
- return result;
-error:
- goto end;
-}
-
-/** Utility function for determining if pcms are in running state.
- *
- */
-static int IsRunning( PaAlsaStream *stream )
-{
- int result = 0;
-
- ASSERT_CALL_( pthread_mutex_lock( &stream->stateMtx ), 0 ); /* Synchronize access to pcm state */
- if( stream->capture.pcm )
- {
- snd_pcm_state_t capture_state = snd_pcm_state( stream->capture.pcm );
-
- if( capture_state == SND_PCM_STATE_RUNNING || capture_state == SND_PCM_STATE_XRUN
- || capture_state == SND_PCM_STATE_DRAINING )
- {
- result = 1;
- goto end;
- }
- }
-
- if( stream->playback.pcm )
- {
- snd_pcm_state_t playback_state = snd_pcm_state( stream->playback.pcm );
-
- if( playback_state == SND_PCM_STATE_RUNNING || playback_state == SND_PCM_STATE_XRUN
- || playback_state == SND_PCM_STATE_DRAINING )
- {
- result = 1;
- goto end;
- }
- }
-
-end:
- ASSERT_CALL_( pthread_mutex_unlock( &stream->stateMtx ), 0 );
-
- return result;
-}
-
-static PaError StartStream( PaStream *s )
-{
- PaError result = paNoError;
- PaAlsaStream *stream = (PaAlsaStream*)s;
- int streamStarted = 0; /* So we can know wether we need to take the stream down */
-
- /* Ready the processor */
- PaUtil_ResetBufferProcessor( &stream->bufferProcessor );
-
- /* Set now, so we can test for activity further down */
- stream->isActive = 1;
-
- if( stream->callbackMode )
- {
- int res = 0;
- PaTime pt = PaUtil_GetTime();
- struct timespec ts;
-
- PA_ENSURE( CreateCallbackThread( &stream->threading, &CallbackThreadFunc, stream ) );
- streamStarted = 1;
-
- /* Wait for stream to be started */
- ts.tv_sec = (time_t) floor( pt + 1 );
- ts.tv_nsec = (long) ((pt - floor( pt )) * 1000000000);
-
- /* Since we'll be holding a lock on the startMtx (when not waiting on the condition), IsRunning won't be checking
- * stream state at the same time as the callback thread affects it. We also check IsStreamActive, in the unlikely
- * case the callback thread exits in the meantime (the stream will be considered inactive after the thread exits) */
- ASSERT_CALL_( pthread_mutex_lock( &stream->startMtx ), 0 );
-
- /* Due to possible spurious wakeups, we enclose in a loop */
- while( !IsRunning( stream ) && IsStreamActive( s ) && !res )
- {
- res = pthread_cond_timedwait( &stream->startCond, &stream->startMtx, &ts );
- }
- ASSERT_CALL_( pthread_mutex_unlock( &stream->startMtx ), 0 );
-
- PA_UNLESS( !res || res == ETIMEDOUT, paInternalError );
- PA_DEBUG(( "%s: Waited for %g seconds for stream to start\n", __FUNCTION__, PaUtil_GetTime() - pt ));
-
- if( res == ETIMEDOUT )
- {
- PA_ENSURE( paTimedOut );
- }
- }
- else
- {
- PA_ENSURE( AlsaStart( stream, 0 ) );
- streamStarted = 1;
- }
-
-end:
- return result;
-error:
- if( streamStarted )
- AbortStream( stream );
- stream->isActive = 0;
-
- goto end;
-}
-
-static PaError AlsaStop( PaAlsaStream *stream, int abort )
-{
- PaError result = paNoError;
-
- if( abort )
- {
- if( stream->playback.pcm )
- ENSURE_( snd_pcm_drop( stream->playback.pcm ), paUnanticipatedHostError );
- if( stream->capture.pcm && !stream->pcmsSynced )
- ENSURE_( snd_pcm_drop( stream->capture.pcm ), paUnanticipatedHostError );
-
- PA_DEBUG(( "Dropped frames\n" ));
- }
- else
- {
- if( stream->playback.pcm )
- ENSURE_( snd_pcm_drain( stream->playback.pcm ), paUnanticipatedHostError );
- if( stream->capture.pcm && !stream->pcmsSynced )
- ENSURE_( snd_pcm_drain( stream->capture.pcm ), paUnanticipatedHostError );
- }
-
-end:
- return result;
-error:
- goto end;
-}
-
-/** Stop or abort stream.
- *
- * If a stream is in callback mode we will have to inspect wether the background thread has
- * finished, or we will have to take it out. In either case we join the thread before
- * returning. In blocking mode, we simply tell ALSA to stop abruptly (abort) or finish
- * buffers (drain)
- *
- * Stream will be considered inactive (!PaAlsaStream::isActive) after a call to this function
- */
-static PaError RealStop( PaAlsaStream *stream, int abort )
-{
- PaError result = paNoError;
-
- /* First deal with the callback thread, cancelling and/or joining
- * it if necessary
- */
- if( stream->callbackMode )
- {
- PaError threadRes, watchdogRes;
- stream->callbackAbort = abort;
-
- if( !abort )
- {
- PA_DEBUG(( "Stopping callback\n" ));
- stream->callbackStop = 1;
- }
- PA_ENSURE( KillCallbackThread( &stream->threading, !abort, &threadRes, &watchdogRes ) );
- if( threadRes != paNoError )
- PA_DEBUG(( "Callback thread returned: %d\n", threadRes ));
- if( watchdogRes != paNoError )
- PA_DEBUG(( "Watchdog thread returned: %d\n", watchdogRes ));
-
- stream->callbackStop = 0; /* The deed is done */
- stream->callback_finished = 0;
- }
- else
- {
- PA_ENSURE( AlsaStop( stream, abort ) );
- }
-
- stream->isActive = 0;
-
-end:
- return result;
-
-error:
- goto end;
-}
-
-static PaError StopStream( PaStream *s )
-{
- return RealStop( (PaAlsaStream *) s, 0 );
-}
-
-static PaError AbortStream( PaStream *s )
-{
- return RealStop( (PaAlsaStream * ) s, 1 );
-}
-
-/** The stream is considered stopped before StartStream, or AFTER a call to Abort/StopStream (callback
- * returning !paContinue is not considered)
- *
- */
-static PaError IsStreamStopped( PaStream *s )
-{
- PaAlsaStream *stream = (PaAlsaStream *)s;
-
- /* callback_finished indicates we need to join callback thread (ie. in Abort/StopStream) */
- return !IsStreamActive( s ) && !stream->callback_finished;
-}
-
-static PaError IsStreamActive( PaStream *s )
-{
- PaAlsaStream *stream = (PaAlsaStream*)s;
- return stream->isActive;
-}
-
-static PaTime GetStreamTime( PaStream *s )
-{
- PaAlsaStream *stream = (PaAlsaStream*)s;
-
- snd_timestamp_t timestamp;
- snd_pcm_status_t *status;
- snd_pcm_status_alloca( &status );
-
- /* TODO: what if we have both? does it really matter? */
-
- /* TODO: if running in callback mode, this will mean
- * libasound routines are being called from multiple threads.
- * need to verify that libasound is thread-safe. */
-
- if( stream->capture.pcm )
- {
- snd_pcm_status( stream->capture.pcm, status );
- }
- else if( stream->playback.pcm )
- {
- snd_pcm_status( stream->playback.pcm, status );
- }
-
- snd_pcm_status_get_tstamp( status, ×tamp );
- return timestamp.tv_sec + (PaTime)timestamp.tv_usec / 1000000.0;
-}
-
-static double GetStreamCpuLoad( PaStream* s )
-{
- PaAlsaStream *stream = (PaAlsaStream*)s;
-
- return PaUtil_GetCpuLoad( &stream->cpuLoadMeasurer );
-}
-
-static int SetApproximateSampleRate( snd_pcm_t *pcm, snd_pcm_hw_params_t *hwParams, double sampleRate )
-{
- unsigned long approx = (unsigned long) sampleRate;
- int dir = 0;
- double fraction = sampleRate - approx;
-
- assert( pcm && hwParams );
-
- if( fraction > 0.0 )
- {
- if( fraction > 0.5 )
- {
- ++approx;
- dir = -1;
- }
- else
- dir = 1;
- }
-
- return snd_pcm_hw_params_set_rate( pcm, hwParams, approx, dir );
-}
-
-/* Return exact sample rate in param sampleRate */
-static int GetExactSampleRate( snd_pcm_hw_params_t *hwParams, double *sampleRate )
-{
- unsigned int num, den;
- int err;
-
- assert( hwParams );
-
- err = snd_pcm_hw_params_get_rate_numden( hwParams, &num, &den );
- *sampleRate = (double) num / den;
-
- return err;
-}
-
-/* Utility functions for blocking/callback interfaces */
-
-/* Atomic restart of stream (we don't want the intermediate state visible) */
-static PaError AlsaRestart( PaAlsaStream *stream )
-{
- PaError result = paNoError;
-
- ASSERT_CALL_( pthread_mutex_lock( &stream->stateMtx ), 0 );
- PA_ENSURE( AlsaStop( stream, 0 ) );
- PA_ENSURE( AlsaStart( stream, 0 ) );
-
- PA_DEBUG(( "%s: Restarted audio\n", __FUNCTION__ ));
-
-error:
- ASSERT_CALL_( pthread_mutex_unlock( &stream->stateMtx ), 0 );
- return result;
-}
-
-/** Recover from xrun state.
- *
- */
-static PaError PaAlsaStream_HandleXrun( PaAlsaStream *self )
-{
- PaError result = paNoError;
- snd_pcm_status_t *st;
- PaTime now = PaUtil_GetTime();
- snd_timestamp_t t;
-
- snd_pcm_status_alloca( &st );
-
- if( self->playback.pcm )
- {
- snd_pcm_status( self->playback.pcm, st );
- if( snd_pcm_status_get_state( st ) == SND_PCM_STATE_XRUN )
- {
- snd_pcm_status_get_trigger_tstamp( st, &t );
- self->underrun = now * 1000 - ((PaTime) t.tv_sec * 1000 + (PaTime) t.tv_usec / 1000);
- }
- }
- if( self->capture.pcm )
- {
- snd_pcm_status( self->capture.pcm, st );
- if( snd_pcm_status_get_state( st ) == SND_PCM_STATE_XRUN )
- {
- snd_pcm_status_get_trigger_tstamp( st, &t );
- self->overrun = now * 1000 - ((PaTime) t.tv_sec * 1000 + (PaTime) t.tv_usec / 1000);
- }
- }
-
- PA_ENSURE( AlsaRestart( self ) );
-
-end:
- return result;
-error:
- goto end;
-}
-
-/** Decide if we should continue polling for specified direction, eventually adjust the poll timeout.
- *
- */
-static PaError ContinuePoll( const PaAlsaStream *stream, StreamDirection streamDir, int *pollTimeout, int *continuePoll )
-{
- PaError result = paNoError;
- snd_pcm_sframes_t delay, margin;
- int err;
- const PaAlsaStreamComponent *component = NULL, *otherComponent = NULL;
-
- *continuePoll = 1;
-
- if( StreamDirection_In == streamDir )
- {
- component = &stream->capture;
- otherComponent = &stream->playback;
- }
- else
- {
- component = &stream->playback;
- otherComponent = &stream->capture;
- }
-
- /* ALSA docs say that negative delay should indicate xrun, but in my experience snd_pcm_delay returns -EPIPE */
- if( (err = snd_pcm_delay( otherComponent->pcm, &delay )) < 0 )
- {
- if( err == -EPIPE )
- {
- /* Xrun */
- *continuePoll = 0;
- goto error;
- }
-
- ENSURE_( err, paUnanticipatedHostError );
- }
-
- if( StreamDirection_Out == streamDir )
- {
- /* Number of eligible frames before capture overrun */
- delay = otherComponent->bufferSize - delay;
- }
- margin = delay - otherComponent->framesPerBuffer / 2;
-
- if( margin < 0 )
- {
- PA_DEBUG(( "%s: Stopping poll for %s\n", __FUNCTION__, StreamDirection_In == streamDir ? "capture" : "playback" ));
- *continuePoll = 0;
- }
- else if( margin < otherComponent->framesPerBuffer )
- {
- *pollTimeout = CalculatePollTimeout( stream, margin );
- PA_DEBUG(( "%s: Trying to poll again for %s frames, pollTimeout: %d\n",
- __FUNCTION__, StreamDirection_In == streamDir ? "capture" : "playback", *pollTimeout ));
- }
-
-error:
- return result;
-}
-
-/* Callback interface */
-
-static void OnExit( void *data )
-{
- PaAlsaStream *stream = (PaAlsaStream *) data;
-
- assert( data );
-
- PaUtil_ResetCpuLoadMeasurer( &stream->cpuLoadMeasurer );
-
- stream->callback_finished = 1; /* Let the outside world know stream was stopped in callback */
- AlsaStop( stream, stream->callbackAbort );
- stream->callbackAbort = 0; /* Clear state */
-
- PA_DEBUG(( "OnExit: Stoppage\n" ));
-
- /* Eventually notify user all buffers have played */
- if( stream->streamRepresentation.streamFinishedCallback )
- stream->streamRepresentation.streamFinishedCallback( stream->streamRepresentation.userData );
- stream->isActive = 0;
-}
-
-static void CalculateTimeInfo( PaAlsaStream *stream, PaStreamCallbackTimeInfo *timeInfo )
-{
- snd_pcm_status_t *capture_status, *playback_status;
- snd_timestamp_t capture_timestamp, playback_timestamp;
- PaTime capture_time = 0., playback_time = 0.;
-
- snd_pcm_status_alloca( &capture_status );
- snd_pcm_status_alloca( &playback_status );
-
- if( stream->capture.pcm )
- {
- snd_pcm_sframes_t capture_delay;
-
- snd_pcm_status( stream->capture.pcm, capture_status );
- snd_pcm_status_get_tstamp( capture_status, &capture_timestamp );
-
- capture_time = capture_timestamp.tv_sec +
- ((PaTime)capture_timestamp.tv_usec / 1000000.0);
- timeInfo->currentTime = capture_time;
-
- capture_delay = snd_pcm_status_get_delay( capture_status );
- timeInfo->inputBufferAdcTime = timeInfo->currentTime -
- (PaTime)capture_delay / stream->streamRepresentation.streamInfo.sampleRate;
- }
- if( stream->playback.pcm )
- {
- snd_pcm_sframes_t playback_delay;
-
- snd_pcm_status( stream->playback.pcm, playback_status );
- snd_pcm_status_get_tstamp( playback_status, &playback_timestamp );
-
- playback_time = playback_timestamp.tv_sec +
- ((PaTime)playback_timestamp.tv_usec / 1000000.0);
-
- if( stream->capture.pcm ) /* Full duplex */
- {
- /* Hmm, we have both a playback and a capture timestamp.
- * Hopefully they are the same... */
- if( fabs( capture_time - playback_time ) > 0.01 )
- PA_DEBUG(("Capture time and playback time differ by %f\n", fabs(capture_time-playback_time)));
- }
- else
- timeInfo->currentTime = playback_time;
-
- playback_delay = snd_pcm_status_get_delay( playback_status );
- timeInfo->outputBufferDacTime = timeInfo->currentTime +
- (PaTime)playback_delay / stream->streamRepresentation.streamInfo.sampleRate;
- }
-}
-
-/** Called after buffer processing is finished.
- *
- * A number of mmapped frames is committed, it is possible that an xrun has occurred in the meantime.
- *
- * @param numFrames The number of frames that has been processed
- * @param xrun Return whether an xrun has occurred
- */
-static PaError PaAlsaStreamComponent_EndProcessing( PaAlsaStreamComponent *self, unsigned long numFrames, int *xrun )
-{
- PaError result = paNoError;
- int res;
-
- /* @concern FullDuplex It is possible that only one direction is marked ready after polling, and processed
- * afterwards
- */
- if( !self->ready )
- goto end;
-
- res = snd_pcm_mmap_commit( self->pcm, self->offset, numFrames );
- if( res == -EPIPE || res == -ESTRPIPE )
- {
- *xrun = 1;
- }
- else
- {
- ENSURE_( res, paUnanticipatedHostError );
- }
-
-end:
-error:
- return result;
-}
-
-/* Extract buffer from channel area */
-static unsigned char *ExtractAddress( const snd_pcm_channel_area_t *area, snd_pcm_uframes_t offset )
-{
- return (unsigned char *) area->addr + (area->first + offset * area->step) / 8;
-}
-
-/** Do necessary adaption between user and host channels.
- *
- @concern ChannelAdaption Adapting between user and host channels can involve silencing unused channels and
- duplicating mono information if host outputs come in pairs.
- */
-static PaError PaAlsaStreamComponent_DoChannelAdaption( PaAlsaStreamComponent *self, PaUtilBufferProcessor *bp, int numFrames )
-{
- PaError result = paNoError;
- unsigned char *p;
- int i;
- int unusedChans = self->numHostChannels - self->numUserChannels;
- unsigned char *src, *dst;
- int convertMono = (self->numHostChannels % 2) == 0 && (self->numUserChannels % 2) != 0;
-
- assert( StreamDirection_Out == self->streamDir );
-
- if( self->hostInterleaved )
- {
- int swidth = snd_pcm_format_size( self->nativeFormat, 1 );
- unsigned char *buffer = ExtractAddress( self->channelAreas, self->offset );
-
- /* Start after the last user channel */
- p = buffer + self->numUserChannels * swidth;
-
- if( convertMono )
- {
- /* Convert the last user channel into stereo pair */
- src = buffer + (self->numUserChannels - 1) * swidth;
- for( i = 0; i < numFrames; ++i )
- {
- dst = src + swidth;
- memcpy( dst, src, swidth );
- src += self->numHostChannels * swidth;
- }
-
- /* Don't touch the channel we just wrote to */
- p += swidth;
- --unusedChans;
- }
-
- if( unusedChans > 0 )
- {
- /* Silence unused output channels */
- for( i = 0; i < numFrames; ++i )
- {
- memset( p, 0, swidth * unusedChans );
- p += self->numHostChannels * swidth;
- }
- }
- }
- else
- {
- /* We extract the last user channel */
- if( convertMono )
- {
- ENSURE_( snd_pcm_area_copy( self->channelAreas + self->numUserChannels, self->offset, self->channelAreas +
- (self->numUserChannels - 1), self->offset, numFrames, self->nativeFormat ), paUnanticipatedHostError );
- --unusedChans;
- }
- if( unusedChans > 0 )
- {
- snd_pcm_areas_silence( self->channelAreas + (self->numHostChannels - unusedChans), self->offset, unusedChans, numFrames,
- self->nativeFormat );
- }
- }
-
-error:
- return result;
-}
-
-static PaError PaAlsaStream_EndProcessing( PaAlsaStream *self, unsigned long numFrames, int *xrunOccurred )
-{
- PaError result = paNoError;
- int xrun = 0;
-
- if( self->capture.pcm )
- {
- PA_ENSURE( PaAlsaStreamComponent_EndProcessing( &self->capture, numFrames, &xrun ) );
- }
- if( self->playback.pcm )
- {
- if( self->playback.numHostChannels > self->playback.numUserChannels )
- PA_ENSURE( PaAlsaStreamComponent_DoChannelAdaption( &self->playback, &self->bufferProcessor, numFrames ) );
- PA_ENSURE( PaAlsaStreamComponent_EndProcessing( &self->playback, numFrames, &xrun ) );
- }
-
-error:
- *xrunOccurred = xrun;
- return result;
-}
-
-/** Update the number of available frames.
- *
- */
-static PaError PaAlsaStreamComponent_GetAvailableFrames( PaAlsaStreamComponent *self, unsigned long *numFrames, int *xrunOccurred )
-{
- PaError result = paNoError;
- snd_pcm_sframes_t framesAvail = snd_pcm_avail_update( self->pcm );
- *xrunOccurred = 0;
-
- if( -EPIPE == framesAvail )
- {
- *xrunOccurred = 1;
- framesAvail = 0;
- }
- else
- ENSURE_( framesAvail, paUnanticipatedHostError );
-
- *numFrames = framesAvail;
-
-error:
- return result;
-}
-
-/** Fill in pollfd objects.
- */
-static PaError PaAlsaStreamComponent_BeginPolling( PaAlsaStreamComponent *self, struct pollfd *pfds )
-{
- PaError result = paNoError;
- int ret = snd_pcm_poll_descriptors( self->pcm, pfds, self->nfds );
- assert( ret == self->nfds );
-
- self->ready = 0;
-
- return result;
-}
-
-/** Examine results from poll().
- *
- * @param pfds pollfds to inspect
- * @param shouldPoll Should we continue to poll
- * @param xrun Has an xrun occurred
- */
-static PaError PaAlsaStreamComponent_EndPolling( PaAlsaStreamComponent *self, struct pollfd *pfds, int *shouldPoll, int *xrun )
-{
- PaError result = paNoError;
- unsigned short revents;
-
- ENSURE_( snd_pcm_poll_descriptors_revents( self->pcm, pfds, self->nfds, &revents ), paUnanticipatedHostError );
- if( revents != 0 )
- {
- if( revents & POLLERR )
- {
- *xrun = 1;
- }
- else
- self->ready = 1;
-
- *shouldPoll = 0;
- }
-
-error:
- return result;
-}
-
-/** Return the number of available frames for this stream.
- *
- * @concern FullDuplex The minimum available for the two directions is calculated, it might be desirable to ignore
- * one direction however (not marked ready from poll), so this is controlled by queryCapture and queryPlayback.
- *
- * @param queryCapture Check available for capture
- * @param queryPlayback Check available for playback
- * @param available The returned number of frames
- * @param xrunOccurred Return whether an xrun has occurred
- */
-static PaError PaAlsaStream_GetAvailableFrames( PaAlsaStream *self, int queryCapture, int queryPlayback, unsigned long
- *available, int *xrunOccurred )
-{
- PaError result = paNoError;
- unsigned long captureFrames, playbackFrames;
- *xrunOccurred = 0;
-
- assert( queryCapture || queryPlayback );
-
- if( queryCapture )
- {
- assert( self->capture.pcm );
- PA_ENSURE( PaAlsaStreamComponent_GetAvailableFrames( &self->capture, &captureFrames, xrunOccurred ) );
- if( *xrunOccurred )
- goto end;
- }
- if( queryPlayback )
- {
- assert( self->playback.pcm );
- PA_ENSURE( PaAlsaStreamComponent_GetAvailableFrames( &self->playback, &playbackFrames, xrunOccurred ) );
- if( *xrunOccurred )
- goto end;
- }
-
- if( queryCapture && queryPlayback )
- {
- *available = PA_MIN( captureFrames, playbackFrames );
- }
- else if( queryCapture )
- {
- *available = captureFrames;
- }
- else
- {
- *available = playbackFrames;
- }
-
-end:
-error:
- return result;
-}
-
-/** Wait for and report available buffer space from ALSA.
- *
- * Unless ALSA reports a minimum of frames available for I/O, we poll the ALSA filedescriptors for more.
- * Both of these operations can uncover xrun conditions.
- *
- * @concern Xruns Both polling and querying available frames can report an xrun condition.
- *
- * @param framesAvail Return the number of available frames
- * @param xrunOccurred Return whether an xrun has occurred
- */
-static PaError PaAlsaStream_WaitForFrames( PaAlsaStream *self, unsigned long *framesAvail, int *xrunOccurred )
-{
- PaError result = paNoError;
- int pollPlayback = self->playback.pcm != NULL, pollCapture = self->capture.pcm != NULL;
- int pollTimeout = self->pollTimeout;
- int xrun = 0;
-
- assert( self );
- assert( framesAvail );
-
- if( !self->callbackMode )
- {
- /* In blocking mode we will only wait if necessary */
- PA_ENSURE( PaAlsaStream_GetAvailableFrames( self, self->capture.pcm != NULL, self->playback.pcm != NULL,
- framesAvail, &xrun ) );
- if( xrun )
- {
- goto end;
- }
-
- if( *framesAvail > 0 )
- {
- /* Mark pcms ready from poll */
- if( self->capture.pcm )
- self->capture.ready = 1;
- if( self->playback.pcm )
- self->playback.ready = 1;
-
- goto end;
- }
- }
-
- while( pollPlayback || pollCapture )
- {
- int totalFds = 0;
- struct pollfd *capturePfds = NULL, *playbackPfds = NULL;
-
- pthread_testcancel();
-
- if( pollCapture )
- {
- capturePfds = self->pfds;
- PA_ENSURE( PaAlsaStreamComponent_BeginPolling( &self->capture, capturePfds ) );
- totalFds += self->capture.nfds;
- }
- if( pollPlayback )
- {
- playbackPfds = self->pfds + (self->capture.pcm ? self->capture.nfds : 0);
- PA_ENSURE( PaAlsaStreamComponent_BeginPolling( &self->playback, playbackPfds ) );
- totalFds += self->playback.nfds;
- }
-
- if( poll( self->pfds, totalFds, pollTimeout ) < 0 )
- {
- /* XXX: Depend on preprocessor condition? */
- if( errno == EINTR ) { /* gdb */
- continue;
- }
-
- /* TODO: Add macro for checking system calls */
- PA_ENSURE( paInternalError );
- }
-
- /* check the return status of our pfds */
- if( pollCapture )
- {
- PA_ENSURE( PaAlsaStreamComponent_EndPolling( &self->capture, capturePfds, &pollCapture, &xrun ) );
- }
- if( pollPlayback )
- {
- PA_ENSURE( PaAlsaStreamComponent_EndPolling( &self->playback, playbackPfds, &pollPlayback, &xrun ) );
- }
- if( xrun )
- {
- break;
- }
-
- /* @concern FullDuplex If only one of two pcms is ready we may want to compromise between the two.
- * If there is less than half a period's worth of samples left of frames in the other pcm's buffer we will
- * stop polling.
- */
- if( self->capture.pcm && self->playback.pcm )
- {
- if( pollCapture && !pollPlayback )
- {
- PA_ENSURE( ContinuePoll( self, StreamDirection_In, &pollTimeout, &pollCapture ) );
- }
- else if( pollPlayback && !pollCapture )
- {
- PA_ENSURE( ContinuePoll( self, StreamDirection_Out, &pollTimeout, &pollPlayback ) );
- }
- }
- }
-
- if( !xrun )
- {
- /* Get the number of available frames for the pcms that are marked ready.
- * @concern FullDuplex If only one direction is marked ready (from poll), the number of frames available for
- * the other direction is returned. This under the assumption that input is dropped earlier if paNeverDropInput
- * is not specified.
- */
- int captureReady = self->capture.pcm ? self->capture.ready : 0,
- playbackReady = self->playback.pcm ? self->playback.ready : 0;
- PA_ENSURE( PaAlsaStream_GetAvailableFrames( self, captureReady, playbackReady, framesAvail, &xrun ) );
-
- if( self->capture.pcm && self->playback.pcm )
- {
- if( !self->playback.ready && !self->neverDropInput )
- {
- /* TODO: Drop input */
- }
- }
- }
-
-end:
-error:
- if( xrun )
- {
- /* Recover from the xrun state */
- PA_ENSURE( PaAlsaStream_HandleXrun( self ) );
- *framesAvail = 0;
- }
- *xrunOccurred = xrun;
-
- return result;
-}
-
-/** Register per-channel ALSA buffer information with buffer processor.
- *
- * Mmapped buffer space is acquired from ALSA, and registered with the buffer processor. Differences between the
- * number of host and user channels is taken into account.
- *
- * @param numFrames On entrance the number of requested frames, on exit the number of contiguously accessible frames.
- */
-static PaError PaAlsaStreamComponent_RegisterChannels( PaAlsaStreamComponent *self, PaUtilBufferProcessor *bp,
- unsigned long *numFrames, int *xrun )
-{
- PaError result = paNoError;
- const snd_pcm_channel_area_t *areas, *area;
- void (*setChannel)(PaUtilBufferProcessor *, unsigned int, void *, unsigned int) =
- StreamDirection_In == self->streamDir ? PaUtil_SetInputChannel : PaUtil_SetOutputChannel;
- unsigned char *buffer, *p;
- int i;
- unsigned long framesAvail;
-
- /* This _must_ be called before mmap_begin */
- PA_ENSURE( PaAlsaStreamComponent_GetAvailableFrames( self, &framesAvail, xrun ) );
- if( *xrun )
- {
- *numFrames = 0;
- goto end;
- }
-
- ENSURE_( snd_pcm_mmap_begin( self->pcm, &areas, &self->offset, numFrames ), paUnanticipatedHostError );
-
- if( self->hostInterleaved )
- {
- int swidth = snd_pcm_format_size( self->nativeFormat, 1 );
-
- p = buffer = ExtractAddress( areas, self->offset );
- for( i = 0; i < self->numUserChannels; ++i )
- {
- /* We're setting the channels up to userChannels, but the stride will be hostChannels samples */
- setChannel( bp, i, p, self->numHostChannels );
- p += swidth;
- }
- }
- else
- {
- for( i = 0; i < self->numUserChannels; ++i )
- {
- area = areas + i;
- buffer = ExtractAddress( area, self->offset );
- setChannel( bp, i, buffer, 1 );
- }
- }
-
- /* @concern ChannelAdaption Buffer address is recorded so we can do some channel adaption later */
- self->channelAreas = (snd_pcm_channel_area_t *)areas;
-
-end:
-error:
- return result;
-}
-
-/** Initiate buffer processing.
- *
- * ALSA buffers are registered with the PA buffer processor and the buffer size (in frames) set.
- *
- * @concern FullDuplex If both directions are being processed, the minimum amount of frames for the two directions is
- * calculated.
- *
- * @param numFrames On entrance the number of available frames, on exit the number of received frames
- * @param xrunOccurred Return whether an xrun has occurred
- */
-static PaError PaAlsaStream_SetUpBuffers( PaAlsaStream *self, unsigned long *numFrames, int *xrunOccurred )
-{
- PaError result = paNoError;
- unsigned long captureFrames = ULONG_MAX, playbackFrames = ULONG_MAX, commonFrames = 0;
- int xrun = 0;
-
- /* Extract per-channel ALSA buffer pointers and register them with the buffer processor.
- * It is possible that a direction is not marked ready however, because it is out of sync with the other.
- */
- if( self->capture.pcm && self->capture.ready )
- {
- captureFrames = *numFrames;
- PA_ENSURE( PaAlsaStreamComponent_RegisterChannels( &self->capture, &self->bufferProcessor, &captureFrames,
- &xrun ) );
- }
- if( self->playback.pcm && self->playback.ready )
- {
- playbackFrames = *numFrames;
- PA_ENSURE( PaAlsaStreamComponent_RegisterChannels( &self->playback, &self->bufferProcessor, &playbackFrames,
- &xrun ) );
- }
- if( xrun )
- {
- /* Nothing more to do */
- assert( 0 == commonFrames );
- goto end;
- }
-
- commonFrames = PA_MIN( captureFrames, playbackFrames );
- assert( commonFrames <= *numFrames );
-
- /* Inform PortAudio of the number of frames we got.
- * @concern FullDuplex We might be experiencing underflow in either end; if its an input underflow, we go on
- * with output. If its output underflow however, depending on the paNeverDropInput flag, we may want to simply
- * discard the excess input or call the callback with paOutputOverflow flagged.
- */
- if( self->capture.pcm )
- {
- if( self->capture.ready )
- {
- PaUtil_SetInputFrameCount( &self->bufferProcessor, commonFrames );
- }
- else
- {
- /* We have input underflow */
- PaUtil_SetNoInput( &self->bufferProcessor );
- }
- }
- if( self->playback.pcm )
- {
- if( self->playback.ready )
- {
- PaUtil_SetOutputFrameCount( &self->bufferProcessor, commonFrames );
- }
- else
- {
- /* We have output underflow, but keeping input data (paNeverDropInput) */
- /* assert( self->neverDropInput ); */
- PaUtil_SetNoOutput( &self->bufferProcessor );
- }
- }
-
-end:
- *numFrames = commonFrames;
-error:
- if( xrun )
- {
- PA_ENSURE( PaAlsaStream_HandleXrun( self ) );
- *numFrames = 0;
- }
- *xrunOccurred = xrun;
-
- return result;
-}
-
-/** Callback thread's function.
- *
- * Roughly, the workflow can be described in the following way: The number of available frames that can be processed
- * directly is obtained from ALSA, we then request as much directly accessible memory as possible within this amount
- * from ALSA. The buffer memory is registered with the PA buffer processor and processing is carried out with
- * PaUtil_EndBufferProcessing. Finally, the number of processed frames is reported to ALSA. The processing can
- * happen in several iterations untill we have consumed the known number of available frames (or an xrun is detected).
- */
-static void *CallbackThreadFunc( void *userData )
-{
- PaError result = paNoError, *pres = NULL;
- PaAlsaStream *stream = (PaAlsaStream*) userData;
- PaStreamCallbackTimeInfo timeInfo = {0, 0, 0};
- snd_pcm_sframes_t startThreshold = 0;
- int callbackResult = paContinue;
- PaStreamCallbackFlags cbFlags = 0; /* We might want to keep state across iterations */
- int streamStarted = 0;
-
- assert( stream );
-
- callbackThread_ = pthread_self();
- /* Execute OnExit when exiting */
- pthread_cleanup_push( &OnExit, stream );
-
- /* Not implemented */
- assert( !stream->primeBuffers );
-
- /* @concern StreamStart If the output is being primed the output pcm needs to be prepared, otherwise the
- * stream is started immediately. The latter involves signaling the waiting main thread.
- */
- if( stream->primeBuffers )
- {
- snd_pcm_sframes_t avail;
-
- if( stream->playback.pcm )
- ENSURE_( snd_pcm_prepare( stream->playback.pcm ), paUnanticipatedHostError );
- if( stream->capture.pcm && !stream->pcmsSynced )
- ENSURE_( snd_pcm_prepare( stream->capture.pcm ), paUnanticipatedHostError );
-
- /* We can't be certain that the whole ring buffer is available for priming, but there should be
- * at least one period */
- avail = snd_pcm_avail_update( stream->playback.pcm );
- startThreshold = avail - (avail % stream->playback.framesPerBuffer);
- assert( startThreshold >= stream->playback.framesPerBuffer );
- }
- else
- {
- ASSERT_CALL_( pthread_mutex_lock( &stream->startMtx ), 0 );
- PA_ENSURE( AlsaStart( stream, 0 ) ); /* Buffer will be zeroed */
- ASSERT_CALL_( pthread_cond_signal( &stream->startCond ), 0 );
- ASSERT_CALL_( pthread_mutex_unlock( &stream->startMtx ), 0 );
-
- streamStarted = 1;
- }
-
- while( 1 )
- {
- unsigned long framesAvail, framesGot;
- int xrun = 0;
-
- pthread_testcancel();
-
- /* @concern StreamStop if the main thread has requested a stop and the stream has not been effectively
- * stopped we signal this condition by modifying callbackResult (we'll want to flush buffered output).
- */
- if( stream->callbackStop && paContinue == callbackResult )
- {
- PA_DEBUG(( "Setting callbackResult to paComplete\n" ));
- callbackResult = paComplete;
- }
-
- if( paContinue != callbackResult )
- {
- stream->callbackAbort = (paAbort == callbackResult);
- if( stream->callbackAbort ||
- /** @concern BlockAdaption Go on if adaption buffers are empty */
- PaUtil_IsBufferProcessorOutputEmpty( &stream->bufferProcessor ) )
- goto end;
-
- PA_DEBUG(( "%s: Flushing buffer processor\n", __FUNCTION__ ));
- /* There is still buffered output that needs to be processed */
- }
-
- /* Wait for data to become available, this comes down to polling the ALSA file descriptors untill we have
- * a number of available frames.
- */
- PA_ENSURE( PaAlsaStream_WaitForFrames( stream, &framesAvail, &xrun ) );
- if( xrun )
- {
- assert( 0 == framesAvail );
- continue;
-
- /* XXX: Report xruns to the user? A situation is conceivable where the callback is never invoked due
- * to constant xruns, it might be desirable to notify the user of this.
- */
- }
-
- /* Consume buffer space. Once we have a number of frames available for consumption we must retrieve the
- * mmapped buffers from ALSA, this is contiguously accessible memory however, so we may receive smaller
- * portions at a time than is available as a whole. Therefore we should be prepared to process several
- * chunks successively. The buffers are passed to the PA buffer processor.
- */
- while( framesAvail > 0 )
- {
- xrun = 0;
-
- pthread_testcancel();
-
- /** @concern Xruns Under/overflows are to be reported to the callback */
- if( stream->underrun > 0.0 )
- {
- cbFlags |= paOutputUnderflow;
- stream->underrun = 0.0;
- }
- if( stream->overrun > 0.0 )
- {
- cbFlags |= paInputOverflow;
- stream->overrun = 0.0;
- }
- if( stream->capture.pcm && stream->playback.pcm )
- {
- /** @concern FullDuplex It's possible that only one direction is being processed to avoid an
- * under- or overflow, this should be reported correspondingly */
- if( !stream->capture.ready )
- {
- cbFlags |= paInputUnderflow;
- PA_DEBUG(( "%s: Input underflow\n", __FUNCTION__ ));
- }
- else if( !stream->playback.ready )
- {
- cbFlags |= paOutputOverflow;
- PA_DEBUG(( "%s: Output overflow\n", __FUNCTION__ ));
- }
- }
-
- CallbackUpdate( &stream->threading );
- CalculateTimeInfo( stream, &timeInfo );
- PaUtil_BeginBufferProcessing( &stream->bufferProcessor, &timeInfo, cbFlags );
- cbFlags = 0;
-
- /* CPU load measurement should include processing activivity external to the stream callback */
- PaUtil_BeginCpuLoadMeasurement( &stream->cpuLoadMeasurer );
-
- framesGot = framesAvail;
- PA_ENSURE( PaAlsaStream_SetUpBuffers( stream, &framesGot, &xrun ) );
- framesAvail -= framesGot;
-
- if( framesGot > 0 )
- {
- assert( !xrun );
-
- PaUtil_EndBufferProcessing( &stream->bufferProcessor, &callbackResult );
- PA_ENSURE( PaAlsaStream_EndProcessing( stream, framesGot, &xrun ) );
- }
- PaUtil_EndCpuLoadMeasurement( &stream->cpuLoadMeasurer, framesGot );
-
- if( framesGot == 0 )
- {
- if( !xrun )
- PA_DEBUG(( "%s: Received less frames than reported from ALSA!\n", __FUNCTION__ ));
-
- /* Go back to polling for more frames */
- break;
-
- }
-
- if( paContinue != callbackResult )
- break;
- }
- }
-
- /* Match pthread_cleanup_push */
- pthread_cleanup_pop( 1 );
-
-end:
- pthread_exit( pres );
-
-error:
- /* Pass on error code */
- pres = malloc( sizeof (PaError) );
- *pres = result;
-
- goto end;
-}
-
-/* Blocking interface */
-
-static PaError ReadStream( PaStream* s, void *buffer, unsigned long frames )
-{
- PaError result = paNoError;
- PaAlsaStream *stream = (PaAlsaStream*)s;
- unsigned long framesGot, framesAvail;
- void *userBuffer;
- snd_pcm_t *save = stream->playback.pcm;
-
- assert( stream );
-
- PA_UNLESS( stream->capture.pcm, paCanNotReadFromAnOutputOnlyStream );
-
- /* Disregard playback */
- stream->playback.pcm = NULL;
-
- if( stream->overrun > 0. )
- {
- result = paInputOverflowed;
- stream->overrun = 0.0;
- }
-
- if( stream->capture.userInterleaved )
- userBuffer = buffer;
- else
- {
- /* Copy channels into local array */
- userBuffer = stream->capture.userBuffers;
- memcpy( userBuffer, buffer, sizeof (void *) * stream->capture.numUserChannels );
- }
-
- /* Start stream if in prepared state */
- if( snd_pcm_state( stream->capture.pcm ) == SND_PCM_STATE_PREPARED )
- {
- ENSURE_( snd_pcm_start( stream->capture.pcm ), paUnanticipatedHostError );
- }
-
- while( frames > 0 )
- {
- int xrun = 0;
- PA_ENSURE( PaAlsaStream_WaitForFrames( stream, &framesAvail, &xrun ) );
- framesGot = PA_MIN( framesAvail, frames );
-
- PA_ENSURE( PaAlsaStream_SetUpBuffers( stream, &framesGot, &xrun ) );
- if( framesGot > 0 )
- {
- framesGot = PaUtil_CopyInput( &stream->bufferProcessor, &userBuffer, framesGot );
- PA_ENSURE( PaAlsaStream_EndProcessing( stream, framesGot, &xrun ) );
- frames -= framesGot;
- }
- }
-
-end:
- stream->playback.pcm = save;
- return result;
-error:
- goto end;
-}
-
-static PaError WriteStream( PaStream* s, const void *buffer, unsigned long frames )
-{
- PaError result = paNoError;
- signed long err;
- PaAlsaStream *stream = (PaAlsaStream*)s;
- snd_pcm_uframes_t framesGot, framesAvail;
- const void *userBuffer;
- snd_pcm_t *save = stream->capture.pcm;
-
- assert( stream );
-
- PA_UNLESS( stream->playback.pcm, paCanNotWriteToAnInputOnlyStream );
-
- /* Disregard capture */
- stream->capture.pcm = NULL;
-
- if( stream->underrun > 0. )
- {
- result = paOutputUnderflowed;
- stream->underrun = 0.0;
- }
-
- if( stream->playback.userInterleaved )
- userBuffer = buffer;
- else /* Copy channels into local array */
- {
- userBuffer = stream->playback.userBuffers;
- memcpy( (void *)userBuffer, buffer, sizeof (void *) * stream->playback.numUserChannels );
- }
-
- while( frames > 0 )
- {
- int xrun = 0;
- snd_pcm_uframes_t hwAvail;
-
- PA_ENSURE( PaAlsaStream_WaitForFrames( stream, &framesAvail, &xrun ) );
- framesGot = PA_MIN( framesAvail, frames );
-
- PA_ENSURE( PaAlsaStream_SetUpBuffers( stream, &framesGot, &xrun ) );
- if( framesGot > 0 )
- {
- framesGot = PaUtil_CopyOutput( &stream->bufferProcessor, &userBuffer, framesGot );
- PA_ENSURE( PaAlsaStream_EndProcessing( stream, framesGot, &xrun ) );
- frames -= framesGot;
- }
-
- /* Frames residing in buffer */
- PA_ENSURE( err = GetStreamWriteAvailable( stream ) );
- framesAvail = err;
- hwAvail = stream->playback.bufferSize - framesAvail;
-
- /* Start stream after one period of samples worth */
- if( snd_pcm_state( stream->playback.pcm ) == SND_PCM_STATE_PREPARED &&
- hwAvail >= stream->playback.framesPerBuffer )
- {
- ENSURE_( snd_pcm_start( stream->playback.pcm ), paUnanticipatedHostError );
- }
- }
-
-end:
- stream->capture.pcm = save;
- return result;
-error:
- goto end;
-}
-
-/* Return frames available for reading. In the event of an overflow, the capture pcm will be restarted */
-static signed long GetStreamReadAvailable( PaStream* s )
-{
- PaError result = paNoError;
- PaAlsaStream *stream = (PaAlsaStream*)s;
- unsigned long avail;
- int xrun;
-
- PA_ENSURE( PaAlsaStreamComponent_GetAvailableFrames( &stream->capture, &avail, &xrun ) );
- if( xrun )
- {
- PA_ENSURE( PaAlsaStream_HandleXrun( stream ) );
- PA_ENSURE( PaAlsaStreamComponent_GetAvailableFrames( &stream->capture, &avail, &xrun ) );
- if( xrun )
- PA_ENSURE( paInputOverflowed );
- }
-
- return (signed long)avail;
-
-error:
- return result;
-}
-
-static signed long GetStreamWriteAvailable( PaStream* s )
-{
- PaError result = paNoError;
- PaAlsaStream *stream = (PaAlsaStream*)s;
- unsigned long avail;
- int xrun;
-
- PA_ENSURE( PaAlsaStreamComponent_GetAvailableFrames( &stream->playback, &avail, &xrun ) );
- if( xrun )
- {
- snd_pcm_sframes_t savail;
-
- PA_ENSURE( PaAlsaStream_HandleXrun( stream ) );
- savail = snd_pcm_avail_update( stream->playback.pcm );
-
- /* savail should not contain -EPIPE now, since PaAlsaStream_HandleXrun will only prepare the pcm */
- ENSURE_( savail, paUnanticipatedHostError );
-
- avail = (unsigned long) savail;
- }
-
- return (signed long)avail;
-
-error:
- return result;
-}
-
-/* Extensions */
-
-/* Initialize host api specific structure */
-void PaAlsa_InitializeStreamInfo( PaAlsaStreamInfo *info )
-{
- info->size = sizeof (PaAlsaStreamInfo);
- info->hostApiType = paALSA;
- info->version = 1;
- info->deviceString = NULL;
-}
-
-void PaAlsa_EnableRealtimeScheduling( PaStream *s, int enable )
-{
- PaAlsaStream *stream = (PaAlsaStream *) s;
- stream->threading.rtSched = enable;
-}
-
-void PaAlsa_EnableWatchdog( PaStream *s, int enable )
-{
- PaAlsaStream *stream = (PaAlsaStream *) s;
- stream->threading.useWatchdog = enable;
-}
+/* + * $Id: pa_linux_alsa.c,v 1.1.2.71 2005/04/15 18:20:18 aknudsen Exp $ + * PortAudio Portable Real-Time Audio Library + * Latest Version at: http://www.portaudio.com + * ALSA implementation by Joshua Haberman and Arve Knudsen + * + * Copyright (c) 2002 Joshua Haberman <joshua@haberman.com> + * Copyright (c) 2005 Arve Knudsen <aknuds-1@broadpark.no> + * + * Based on the Open Source API proposed by Ross Bencina + * Copyright (c) 1999-2002 Ross Bencina, Phil Burk + * + * Permission is hereby granted, free of charge, to any person obtaining + * a copy of this software and associated documentation files + * (the "Software"), to deal in the Software without restriction, + * including without limitation the rights to use, copy, modify, merge, + * publish, distribute, sublicense, and/or sell copies of the Software, + * and to permit persons to whom the Software is furnished to do so, + * subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * Any person wishing to distribute modifications to the Software is + * requested to send the modifications to the original developer so that + * they can be incorporated into the canonical version. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. + * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR + * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF + * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION + * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. + */ + +#define ALSA_PCM_NEW_HW_PARAMS_API +#define ALSA_PCM_NEW_SW_PARAMS_API +#include <alsa/asoundlib.h> +#undef ALSA_PCM_NEW_HW_PARAMS_API +#undef ALSA_PCM_NEW_SW_PARAMS_API + +#include <sys/poll.h> +#include <string.h> /* strlen() */ +#include <limits.h> +#include <math.h> +#include <pthread.h> +#include <signal.h> +#include <time.h> +#include <sys/mman.h> +#include <signal.h> /* For sig_atomic_t */ + +#include "portaudio.h" +#include "pa_util.h" +#include "pa_unix_util.h" +#include "pa_allocation.h" +#include "pa_hostapi.h" +#include "pa_stream.h" +#include "pa_cpuload.h" +#include "pa_process.h" + +#include "pa_linux_alsa.h" + +/* Check return value of ALSA function, and map it to PaError */ +#define ENSURE_(expr, code) \ + do { \ + if( UNLIKELY( (aErr_ = (expr)) < 0 ) ) \ + { \ + /* PaUtil_SetLastHostErrorInfo should only be used in the main thread */ \ + if( (code) == paUnanticipatedHostError && pthread_self() != callbackThread_ ) \ + { \ + PaUtil_SetLastHostErrorInfo( paALSA, aErr_, snd_strerror( aErr_ ) ); \ + } \ + PaUtil_DebugPrint(( "Expression '" #expr "' failed in '" __FILE__ "', line: " STRINGIZE( __LINE__ ) "\n" )); \ + result = (code); \ + goto error; \ + } \ + } while( 0 ); + +#define ASSERT_CALL_(expr, success) \ + aErr_ = (expr); \ + assert( aErr_ == success ); + +static int aErr_; /* Used with ENSURE_ */ +static pthread_t callbackThread_; + +typedef enum +{ + StreamDirection_In, + StreamDirection_Out +} StreamDirection; + +/* Threading utility struct */ +typedef struct PaAlsaThreading +{ + pthread_t watchdogThread; + pthread_t callbackThread; + int watchdogRunning; + int rtSched; + int rtPrio; + int useWatchdog; + unsigned long throttledSleepTime; + volatile PaTime callbackTime; + volatile PaTime callbackCpuTime; + PaUtilCpuLoadMeasurer *cpuLoadMeasurer; +} PaAlsaThreading; + +typedef struct +{ + PaSampleFormat hostSampleFormat; + unsigned long framesPerBuffer; + int numUserChannels, numHostChannels; + int userInterleaved, hostInterleaved; + + snd_pcm_t *pcm; + snd_pcm_uframes_t bufferSize; + snd_pcm_format_t nativeFormat; + unsigned int nfds; + int ready; /* Marked ready from poll */ + void **userBuffers; + snd_pcm_uframes_t offset; + StreamDirection streamDir; + + snd_pcm_channel_area_t *channelAreas; /* Needed for channel adaption */ +} PaAlsaStreamComponent; + +/* Implementation specific stream structure */ +typedef struct PaAlsaStream +{ + PaUtilStreamRepresentation streamRepresentation; + PaUtilCpuLoadMeasurer cpuLoadMeasurer; + PaUtilBufferProcessor bufferProcessor; + PaAlsaThreading threading; + + unsigned long framesPerUserBuffer; + + int primeBuffers; + int callbackMode; /* bool: are we running in callback mode? */ + int pcmsSynced; /* Have we successfully synced pcms */ + + /* the callback thread uses these to poll the sound device(s), waiting + * for data to be ready/available */ + struct pollfd *pfds; + int pollTimeout; + + /* Used in communication between threads */ + volatile sig_atomic_t callback_finished; /* bool: are we in the "callback finished" state? */ + volatile sig_atomic_t callbackAbort; /* Drop frames? */ + volatile sig_atomic_t callbackStop; /* Signal a stop */ + volatile sig_atomic_t isActive; /* Is stream in active state? (Between StartStream and StopStream || !paContinue) */ + pthread_mutex_t stateMtx; /* Used to synchronize access to stream state */ + pthread_mutex_t startMtx; /* Used to synchronize stream start in callback mode */ + pthread_cond_t startCond; /* Wait untill audio is started in callback thread */ + + int neverDropInput; + + PaTime underrun; + PaTime overrun; + + PaAlsaStreamComponent capture, playback; +} +PaAlsaStream; + +/* PaAlsaHostApiRepresentation - host api datastructure specific to this implementation */ + +typedef struct PaAlsaHostApiRepresentation +{ + PaUtilHostApiRepresentation commonHostApiRep; + PaUtilStreamInterface callbackStreamInterface; + PaUtilStreamInterface blockingStreamInterface; + + PaUtilAllocationGroup *allocations; + + PaHostApiIndex hostApiIndex; +} +PaAlsaHostApiRepresentation; + +typedef struct PaAlsaDeviceInfo +{ + PaDeviceInfo commonDeviceInfo; + char *alsaName; + int isPlug; + int minInputChannels; + int minOutputChannels; +} +PaAlsaDeviceInfo; + +/* Threading utilities */ + +static void InitializeThreading( PaAlsaThreading *th, PaUtilCpuLoadMeasurer *clm ) +{ + th->watchdogRunning = 0; + th->rtSched = 0; + th->callbackTime = 0; + th->callbackCpuTime = 0; + th->useWatchdog = 1; + th->throttledSleepTime = 0; + th->cpuLoadMeasurer = clm; + + th->rtPrio = (sched_get_priority_max( SCHED_FIFO ) - sched_get_priority_min( SCHED_FIFO )) / 2 + + sched_get_priority_min( SCHED_FIFO ); +} + +static PaError KillCallbackThread( PaAlsaThreading *th, int wait, PaError *exitResult, PaError *watchdogExitResult ) +{ + PaError result = paNoError; + void *pret; + + if( exitResult ) + *exitResult = paNoError; + if( watchdogExitResult ) + *watchdogExitResult = paNoError; + + if( th->watchdogRunning ) + { + pthread_cancel( th->watchdogThread ); + ASSERT_CALL_( pthread_join( th->watchdogThread, &pret ), 0 ); + + if( pret && pret != PTHREAD_CANCELED ) + { + if( watchdogExitResult ) + *watchdogExitResult = *(PaError *) pret; + free( pret ); + } + } + + /* Only kill the thread if it isn't in the process of stopping (flushing adaptation buffers) */ + /* TODO: Make join time out */ + if( !wait ) + pthread_cancel( th->callbackThread ); /* XXX: Safe to call this if the thread has exited on its own? */ + ASSERT_CALL_( pthread_join( th->callbackThread, &pret ), 0 ); + + if( pret && pret != PTHREAD_CANCELED ) + { + if( exitResult ) + *exitResult = *(PaError *) pret; + free( pret ); + } + + return result; +} + +static void OnWatchdogExit( void *userData ) +{ + PaAlsaThreading *th = (PaAlsaThreading *) userData; + struct sched_param spm = { 0 }; + assert( th ); + + ASSERT_CALL_( pthread_setschedparam( th->callbackThread, SCHED_OTHER, &spm ), 0 ); /* Lower before exiting */ + PA_DEBUG(( "Watchdog exiting\n" )); +} + +static PaError BoostPriority( PaAlsaThreading *th ) +{ + PaError result = paNoError; + struct sched_param spm = { 0 }; + spm.sched_priority = th->rtPrio; + + assert( th ); + + if( pthread_setschedparam( th->callbackThread, SCHED_FIFO, &spm ) != 0 ) + { + PA_UNLESS( errno == EPERM, paInternalError ); /* Lack permission to raise priority */ + PA_DEBUG(( "Failed bumping priority\n" )); + result = 0; + } + else + result = 1; /* Success */ +error: + return result; +} + +static void *WatchdogFunc( void *userData ) +{ + PaError result = paNoError, *pres = NULL; + int err; + PaAlsaThreading *th = (PaAlsaThreading *) userData; + unsigned intervalMsec = 500; + const PaTime maxSeconds = 3.; /* Max seconds between callbacks */ + PaTime timeThen = PaUtil_GetTime(), timeNow, timeElapsed, cpuTimeThen, cpuTimeNow, cpuTimeElapsed; + double cpuLoad, avgCpuLoad = 0.; + int throttled = 0; + + assert( th ); + + pthread_cleanup_push( &OnWatchdogExit, th ); /* Execute OnWatchdogExit when exiting */ + + /* Boost priority of callback thread */ + PA_ENSURE( result = BoostPriority( th ) ); + if( !result ) + { + pthread_exit( NULL ); /* Boost failed, might as well exit */ + } + + cpuTimeThen = th->callbackCpuTime; + { + int policy; + struct sched_param spm = { 0 }; + pthread_getschedparam( pthread_self(), &policy, &spm ); + PA_DEBUG(( "%s: Watchdog priority is %d\n", __FUNCTION__, spm.sched_priority )); + } + + while( 1 ) + { + double lowpassCoeff = 0.9, lowpassCoeff1 = 0.99999 - lowpassCoeff; + + /* Test before and after in case whatever underlying sleep call isn't interrupted by pthread_cancel */ + pthread_testcancel(); + Pa_Sleep( intervalMsec ); + pthread_testcancel(); + + if( PaUtil_GetTime() - th->callbackTime > maxSeconds ) + { + PA_DEBUG(( "Watchdog: Terminating callback thread\n" )); + /* Tell thread to terminate */ + err = pthread_kill( th->callbackThread, SIGKILL ); + pthread_exit( NULL ); + } + + PA_DEBUG(( "%s: PortAudio reports CPU load: %g\n", __FUNCTION__, PaUtil_GetCpuLoad( th->cpuLoadMeasurer ) )); + + /* Check if we should throttle, or unthrottle :P */ + cpuTimeNow = th->callbackCpuTime; + cpuTimeElapsed = cpuTimeNow - cpuTimeThen; + cpuTimeThen = cpuTimeNow; + + timeNow = PaUtil_GetTime(); + timeElapsed = timeNow - timeThen; + timeThen = timeNow; + cpuLoad = cpuTimeElapsed / timeElapsed; + avgCpuLoad = avgCpuLoad * lowpassCoeff + cpuLoad * lowpassCoeff1; + /* + if( throttled ) + PA_DEBUG(( "Watchdog: CPU load: %g, %g\n", avgCpuLoad, cpuTimeElapsed )); + */ + if( PaUtil_GetCpuLoad( th->cpuLoadMeasurer ) > .925 ) + { + static int policy; + static struct sched_param spm = { 0 }; + static const struct sched_param defaultSpm = { 0 }; + PA_DEBUG(( "%s: Throttling audio thread, priority %d\n", __FUNCTION__, spm.sched_priority )); + + pthread_getschedparam( th->callbackThread, &policy, &spm ); + if( !pthread_setschedparam( th->callbackThread, SCHED_OTHER, &defaultSpm ) ) + { + throttled = 1; + } + else + PA_DEBUG(( "Watchdog: Couldn't lower priority of audio thread: %s\n", strerror( errno ) )); + + /* Give other processes a go, before raising priority again */ + PA_DEBUG(( "%s: Watchdog sleeping for %lu msecs before unthrottling\n", __FUNCTION__, th->throttledSleepTime )); + Pa_Sleep( th->throttledSleepTime ); + + /* Reset callback priority */ + if( pthread_setschedparam( th->callbackThread, SCHED_FIFO, &spm ) != 0 ) + { + PA_DEBUG(( "%s: Couldn't raise priority of audio thread: %s\n", __FUNCTION__, strerror( errno ) )); + } + + if( PaUtil_GetCpuLoad( th->cpuLoadMeasurer ) >= .99 ) + intervalMsec = 50; + else + intervalMsec = 100; + + /* + lowpassCoeff = .97; + lowpassCoeff1 = .99999 - lowpassCoeff; + */ + } + else if( throttled && avgCpuLoad < .8 ) + { + intervalMsec = 500; + throttled = 0; + + /* + lowpassCoeff = .9; + lowpassCoeff1 = .99999 - lowpassCoeff; + */ + } + } + + pthread_cleanup_pop( 1 ); /* Execute cleanup on exit */ + +error: + /* Shouldn't get here in the normal case */ + + /* Pass on error code */ + pres = malloc( sizeof (PaError) ); + *pres = result; + + pthread_exit( pres ); +} + +static PaError CreateCallbackThread( PaAlsaThreading *th, void *(*callbackThreadFunc)( void * ), PaStream *s ) +{ + PaError result = paNoError; + pthread_attr_t attr; + int started = 0; + +#if defined _POSIX_MEMLOCK && (_POSIX_MEMLOCK != -1) + if( th->rtSched ) + { + if( mlockall( MCL_CURRENT | MCL_FUTURE ) < 0 ) + { + int savedErrno = errno; /* In case errno gets overwritten */ + assert( savedErrno != EINVAL ); /* Most likely a programmer error */ + PA_UNLESS( (savedErrno == EPERM), paInternalError ); + PA_DEBUG(( "%s: Failed locking memory\n", __FUNCTION__ )); + } + else + PA_DEBUG(( "%s: Successfully locked memory\n", __FUNCTION__ )); + } +#endif + + PA_UNLESS( !pthread_attr_init( &attr ), paInternalError ); + /* Priority relative to other processes */ + PA_UNLESS( !pthread_attr_setscope( &attr, PTHREAD_SCOPE_SYSTEM ), paInternalError ); + + PA_UNLESS( !pthread_create( &th->callbackThread, &attr, callbackThreadFunc, s ), paInternalError ); + started = 1; + + if( th->rtSched ) + { + if( th->useWatchdog ) + { + int err; + struct sched_param wdSpm = { 0 }; + /* Launch watchdog, watchdog sets callback thread priority */ + int prio = PA_MIN( th->rtPrio + 4, sched_get_priority_max( SCHED_FIFO ) ); + wdSpm.sched_priority = prio; + + PA_UNLESS( !pthread_attr_init( &attr ), paInternalError ); + PA_UNLESS( !pthread_attr_setinheritsched( &attr, PTHREAD_EXPLICIT_SCHED ), paInternalError ); + PA_UNLESS( !pthread_attr_setscope( &attr, PTHREAD_SCOPE_SYSTEM ), paInternalError ); + PA_UNLESS( !pthread_attr_setschedpolicy( &attr, SCHED_FIFO ), paInternalError ); + PA_UNLESS( !pthread_attr_setschedparam( &attr, &wdSpm ), paInternalError ); + if( (err = pthread_create( &th->watchdogThread, &attr, &WatchdogFunc, th )) ) + { + PA_UNLESS( err == EPERM, paInternalError ); + /* Permission error, go on without realtime privileges */ + PA_DEBUG(( "Failed bumping priority\n" )); + } + else + { + int policy; + th->watchdogRunning = 1; + ASSERT_CALL_( pthread_getschedparam( th->watchdogThread, &policy, &wdSpm ), 0 ); + /* Check if priority is right, policy could potentially differ from SCHED_FIFO (but that's alright) */ + if( wdSpm.sched_priority != prio ) + { + PA_DEBUG(( "Watchdog priority not set correctly (%d)\n", wdSpm.sched_priority )); + PA_ENSURE( paInternalError ); + } + } + } + else + PA_ENSURE( BoostPriority( th ) ); + } + +end: + return result; +error: + if( started ) + KillCallbackThread( th, 0, NULL, NULL ); + + goto end; +} + +static void CallbackUpdate( PaAlsaThreading *th ) +{ + th->callbackTime = PaUtil_GetTime(); + th->callbackCpuTime = PaUtil_GetCpuLoad( th->cpuLoadMeasurer ); +} + +/* prototypes for functions declared in this file */ + +static void Terminate( struct PaUtilHostApiRepresentation *hostApi ); +static PaError IsFormatSupported( struct PaUtilHostApiRepresentation *hostApi, + const PaStreamParameters *inputParameters, + const PaStreamParameters *outputParameters, + double sampleRate ); +static PaError OpenStream( struct PaUtilHostApiRepresentation *hostApi, + PaStream** s, + const PaStreamParameters *inputParameters, + const PaStreamParameters *outputParameters, + double sampleRate, + unsigned long framesPerBuffer, + PaStreamFlags streamFlags, + PaStreamCallback *callback, + void *userData ); +static PaError CloseStream( PaStream* stream ); +static PaError StartStream( PaStream *stream ); +static PaError StopStream( PaStream *stream ); +static PaError AbortStream( PaStream *stream ); +static PaError IsStreamStopped( PaStream *s ); +static PaError IsStreamActive( PaStream *stream ); +static PaTime GetStreamTime( PaStream *stream ); +static double GetStreamCpuLoad( PaStream* stream ); +static PaError BuildDeviceList( PaAlsaHostApiRepresentation *hostApi ); +static int SetApproximateSampleRate( snd_pcm_t *pcm, snd_pcm_hw_params_t *hwParams, double sampleRate ); +static int GetExactSampleRate( snd_pcm_hw_params_t *hwParams, double *sampleRate ); + +/* Callback prototypes */ +static void *CallbackThreadFunc( void *userData ); + +/* Blocking prototypes */ +static signed long GetStreamReadAvailable( PaStream* s ); +static signed long GetStreamWriteAvailable( PaStream* s ); +static PaError ReadStream( PaStream* stream, void *buffer, unsigned long frames ); +static PaError WriteStream( PaStream* stream, const void *buffer, unsigned long frames ); + + +static const PaAlsaDeviceInfo *GetDeviceInfo( const PaUtilHostApiRepresentation *hostApi, int device ) +{ + return (const PaAlsaDeviceInfo *)hostApi->deviceInfos[device]; +} + +PaError PaAlsa_Initialize( PaUtilHostApiRepresentation **hostApi, PaHostApiIndex hostApiIndex ) +{ + PaError result = paNoError; + PaAlsaHostApiRepresentation *alsaHostApi = NULL; + + PA_UNLESS( alsaHostApi = (PaAlsaHostApiRepresentation*) PaUtil_AllocateMemory( + sizeof(PaAlsaHostApiRepresentation) ), paInsufficientMemory ); + PA_UNLESS( alsaHostApi->allocations = PaUtil_CreateAllocationGroup(), paInsufficientMemory ); + alsaHostApi->hostApiIndex = hostApiIndex; + + *hostApi = (PaUtilHostApiRepresentation*)alsaHostApi; + (*hostApi)->info.structVersion = 1; + (*hostApi)->info.type = paALSA; + (*hostApi)->info.name = "ALSA"; + + (*hostApi)->Terminate = Terminate; + (*hostApi)->OpenStream = OpenStream; + (*hostApi)->IsFormatSupported = IsFormatSupported; + + PA_ENSURE( BuildDeviceList( alsaHostApi ) ); + + PaUtil_InitializeStreamInterface( &alsaHostApi->callbackStreamInterface, + CloseStream, StartStream, + StopStream, AbortStream, + IsStreamStopped, IsStreamActive, + GetStreamTime, GetStreamCpuLoad, + PaUtil_DummyRead, PaUtil_DummyWrite, + PaUtil_DummyGetReadAvailable, + PaUtil_DummyGetWriteAvailable ); + + PaUtil_InitializeStreamInterface( &alsaHostApi->blockingStreamInterface, + CloseStream, StartStream, + StopStream, AbortStream, + IsStreamStopped, IsStreamActive, + GetStreamTime, PaUtil_DummyGetCpuLoad, + ReadStream, WriteStream, + GetStreamReadAvailable, + GetStreamWriteAvailable ); + + return result; + +error: + if( alsaHostApi ) + { + if( alsaHostApi->allocations ) + { + PaUtil_FreeAllAllocations( alsaHostApi->allocations ); + PaUtil_DestroyAllocationGroup( alsaHostApi->allocations ); + } + + PaUtil_FreeMemory( alsaHostApi ); + } + + return result; +} + +static void Terminate( struct PaUtilHostApiRepresentation *hostApi ) +{ + PaAlsaHostApiRepresentation *alsaHostApi = (PaAlsaHostApiRepresentation*)hostApi; + + assert( hostApi ); + + if( alsaHostApi->allocations ) + { + PaUtil_FreeAllAllocations( alsaHostApi->allocations ); + PaUtil_DestroyAllocationGroup( alsaHostApi->allocations ); + } + + PaUtil_FreeMemory( alsaHostApi ); + snd_config_update_free_global(); +} + +/*! Determine max channels and default latencies. + * + * This function provides functionality to grope an opened (might be opened for capture or playback) pcm device for + * traits like max channels, suitable default latencies and default sample rate. Upon error, max channels is set to zero, + * and a suitable result returned. The device is closed before returning. + */ +static PaError GropeDevice( snd_pcm_t *pcm, int *minChannels, int *maxChannels, double *defaultLowLatency, + double *defaultHighLatency, double *defaultSampleRate, int isPlug ) +{ + PaError result = paNoError; + snd_pcm_hw_params_t *hwParams; + snd_pcm_uframes_t lowLatency = 512, highLatency = 2048; + unsigned int minChans, maxChans; + double defaultSr = *defaultSampleRate; + + assert( pcm ); + + ENSURE_( snd_pcm_nonblock( pcm, 0 ), paUnanticipatedHostError ); + + snd_pcm_hw_params_alloca( &hwParams ); + snd_pcm_hw_params_any( pcm, hwParams ); + + if( defaultSr >= 0 ) + { + /* Could be that the device opened in one mode supports samplerates that the other mode wont have, + * so try again .. */ + if( SetApproximateSampleRate( pcm, hwParams, defaultSr ) < 0 ) + { + defaultSr = -1.; + PA_DEBUG(( "%s: Original default samplerate failed, trying again ..\n", __FUNCTION__ )); + } + } + + if( defaultSr < 0. ) /* Default sample rate not set */ + { + unsigned int sampleRate = 44100; /* Will contain approximate rate returned by alsa-lib */ + ENSURE_( snd_pcm_hw_params_set_rate_near( pcm, hwParams, &sampleRate, NULL ), paUnanticipatedHostError ); + ENSURE_( GetExactSampleRate( hwParams, &defaultSr ), paUnanticipatedHostError ); + } + + ENSURE_( snd_pcm_hw_params_get_channels_min( hwParams, &minChans ), paUnanticipatedHostError ); + ENSURE_( snd_pcm_hw_params_get_channels_max( hwParams, &maxChans ), paUnanticipatedHostError ); + assert( maxChans <= INT_MAX ); + assert( maxChans > 0 ); /* Weird linking issue could cause wrong version of ALSA symbols to be called, + resulting in zeroed values */ + + /* XXX: Limit to sensible number (ALSA plugins accept a crazy amount of channels)? */ + if( isPlug && maxChans > 128 ) + { + maxChans = 128; + PA_DEBUG(( "%s: Limiting number of plugin channels to %u\n", __FUNCTION__, maxChans )); + } + + /* TWEAKME: + * + * Giving values for default min and max latency is not + * straightforward. Here are our objectives: + * + * * for low latency, we want to give the lowest value + * that will work reliably. This varies based on the + * sound card, kernel, CPU, etc. I think it is better + * to give sub-optimal latency than to give a number + * too low and cause dropouts. My conservative + * estimate at this point is to base it on 4096-sample + * latency at 44.1 kHz, which gives a latency of 23ms. + * * for high latency we want to give a large enough + * value that dropouts are basically impossible. This + * doesn't really require as much tweaking, since + * providing too large a number will just cause us to + * select the nearest setting that will work at stream + * config time. + */ + ENSURE_( snd_pcm_hw_params_set_buffer_size_near( pcm, hwParams, &lowLatency ), paUnanticipatedHostError ); + + /* Have to reset hwParams, to set new buffer size */ + ENSURE_( snd_pcm_hw_params_any( pcm, hwParams ), paUnanticipatedHostError ); + ENSURE_( snd_pcm_hw_params_set_buffer_size_near( pcm, hwParams, &highLatency ), paUnanticipatedHostError ); + + *minChannels = (int)minChans; + *maxChannels = (int)maxChans; + *defaultSampleRate = defaultSr; + *defaultLowLatency = (double) lowLatency / *defaultSampleRate; + *defaultHighLatency = (double) highLatency / *defaultSampleRate; + +end: + snd_pcm_close( pcm ); + return result; + +error: + goto end; +} + +/* Initialize device info with invalid values (maxInputChannels and maxOutputChannels are set to zero since these indicate + * wether input/output is available) */ +static void InitializeDeviceInfo( PaDeviceInfo *deviceInfo ) +{ + deviceInfo->structVersion = -1; + deviceInfo->name = NULL; + deviceInfo->hostApi = -1; + deviceInfo->maxInputChannels = 0; + deviceInfo->maxOutputChannels = 0; + deviceInfo->defaultLowInputLatency = -1.; + deviceInfo->defaultLowOutputLatency = -1.; + deviceInfo->defaultHighInputLatency = -1.; + deviceInfo->defaultHighOutputLatency = -1.; + deviceInfo->defaultSampleRate = -1.; +} + +/* Helper struct */ +typedef struct +{ + char *alsaName; + char *name; + int isPlug; + int hasPlayback; + int hasCapture; +} DeviceNames; + +static PaError PaAlsa_StrDup( PaAlsaHostApiRepresentation *alsaApi, + char **dst, + const char *src) +{ + PaError result = paNoError; + int len = strlen( src ) + 1; + + /* PA_DEBUG(("PaStrDup %s %d\n", src, len)); */ + + PA_UNLESS( *dst = (char *)PaUtil_GroupAllocateMemory( alsaApi->allocations, len ), + paInsufficientMemory ); + strncpy( *dst, src, len ); + +error: + return result; +} + +/* Disregard standard plugins + * XXX: Might want to make the "default" plugin available, if we can make it work + */ +static int IgnorePlugin( const char *pluginId ) +{ +#define numIgnored 10 + static const char *ignoredPlugins[numIgnored] = {"hw", "plughw", "plug", "default", "dsnoop", "dmix", "tee", + "file", "null", "shm"}; + int i; + + for( i = 0; i < numIgnored; ++i ) + { + if( !strcmp( pluginId, ignoredPlugins[i] ) ) + { + return 1; + } + } + + return 0; +} + +/* Build PaDeviceInfo list, ignore devices for which we cannot determine capabilities (possibly busy, sigh) */ +static PaError BuildDeviceList( PaAlsaHostApiRepresentation *alsaApi ) +{ + PaUtilHostApiRepresentation *commonApi = &alsaApi->commonHostApiRep; + PaAlsaDeviceInfo *deviceInfoArray; + int cardIdx = -1, devIdx = 0; + snd_ctl_card_info_t *cardInfo; + PaError result = paNoError; + size_t numDeviceNames = 0, maxDeviceNames = 1, i; + DeviceNames *deviceNames = NULL; + snd_config_t *topNode = NULL; + snd_pcm_info_t *pcmInfo; + int res; + int blocking = SND_PCM_NONBLOCK; + char alsaCardName[50]; + if( getenv( "PA_ALSA_INITIALIZE_BLOCK" ) && atoi( getenv( "PA_ALSA_INITIALIZE_BLOCK" ) ) ) + blocking = 0; + + /* These two will be set to the first working input and output device, respectively */ + commonApi->info.defaultInputDevice = paNoDevice; + commonApi->info.defaultOutputDevice = paNoDevice; + + /* count the devices by enumerating all the card numbers */ + + /* snd_card_next() modifies the integer passed to it to be: + * the index of the first card if the parameter is -1 + * the index of the next card if the parameter is the index of a card + * -1 if there are no more cards + * + * The function itself returns 0 if it succeeded. */ + cardIdx = -1; + snd_ctl_card_info_alloca( &cardInfo ); + snd_pcm_info_alloca( &pcmInfo ); + while( snd_card_next( &cardIdx ) == 0 && cardIdx >= 0 ) + { + char *cardName; + int devIdx = -1; + snd_ctl_t *ctl; + char buf[50]; + + snprintf( alsaCardName, sizeof (alsaCardName), "hw:%d", cardIdx ); + + /* Acquire name of card */ + if( snd_ctl_open( &ctl, alsaCardName, 0 ) < 0 ) + continue; /* Unable to open card :( */ + snd_ctl_card_info( ctl, cardInfo ); + + PA_ENSURE( PaAlsa_StrDup( alsaApi, &cardName, snd_ctl_card_info_get_name( cardInfo )) ); + + while( snd_ctl_pcm_next_device( ctl, &devIdx ) == 0 && devIdx >= 0 ) + { + char *alsaDeviceName, *deviceName; + size_t len; + int hasPlayback = 0, hasCapture = 0; + snprintf( buf, sizeof (buf), "%s:%d,%d", "hw", cardIdx, devIdx ); + + /* Obtain info about this particular device */ + snd_pcm_info_set_device( pcmInfo, devIdx ); + snd_pcm_info_set_subdevice( pcmInfo, 0 ); + snd_pcm_info_set_stream( pcmInfo, SND_PCM_STREAM_CAPTURE ); + if( snd_ctl_pcm_info( ctl, pcmInfo ) >= 0 ) + hasCapture = 1; + + snd_pcm_info_set_stream( pcmInfo, SND_PCM_STREAM_PLAYBACK ); + if( snd_ctl_pcm_info( ctl, pcmInfo ) >= 0 ) + hasPlayback = 1; + + if( !hasPlayback && !hasCapture ) + { + continue; /* Error */ + } + + /* The length of the string written by snprintf plus terminating 0 */ + len = snprintf( NULL, 0, "%s: %s (%s)", cardName, snd_pcm_info_get_name( pcmInfo ), buf ) + 1; + PA_UNLESS( deviceName = (char *)PaUtil_GroupAllocateMemory( alsaApi->allocations, len ), + paInsufficientMemory ); + snprintf( deviceName, len, "%s: %s (%s)", cardName, + snd_pcm_info_get_name( pcmInfo ), buf ); + + ++numDeviceNames; + if( !deviceNames || numDeviceNames > maxDeviceNames ) + { + maxDeviceNames *= 2; + PA_UNLESS( deviceNames = (DeviceNames *) realloc( deviceNames, maxDeviceNames * sizeof (DeviceNames) ), + paInsufficientMemory ); + } + + PA_ENSURE( PaAlsa_StrDup( alsaApi, &alsaDeviceName, buf ) ); + + deviceNames[ numDeviceNames - 1 ].alsaName = alsaDeviceName; + deviceNames[ numDeviceNames - 1 ].name = deviceName; + deviceNames[ numDeviceNames - 1 ].isPlug = 0; + deviceNames[ numDeviceNames - 1 ].hasPlayback = hasPlayback; + deviceNames[ numDeviceNames - 1 ].hasCapture = hasCapture; + } + snd_ctl_close( ctl ); + } + + /* Iterate over plugin devices */ + snd_config_update(); + if( (res = snd_config_search( snd_config, "pcm", &topNode )) >= 0 ) + { + snd_config_iterator_t i, next; + + snd_config_for_each( i, next, topNode ) + { + const char *tpStr = NULL, *idStr = NULL; + char *alsaDeviceName, *deviceName; + snd_config_t *n = snd_config_iterator_entry( i ), *tp = NULL; + if( snd_config_get_type( n ) != SND_CONFIG_TYPE_COMPOUND ) + continue; + + ENSURE_( snd_config_search( n, "type", &tp ), paUnanticipatedHostError ); + ENSURE_( snd_config_get_string( tp, &tpStr ), paUnanticipatedHostError ); + + ENSURE_( snd_config_get_id( n, &idStr ), paUnanticipatedHostError ); + if( IgnorePlugin( idStr ) ) + { + PA_DEBUG(( "%s: Ignoring ALSA plugin device %s of type %s\n", __FUNCTION__, idStr, tpStr )); + continue; + } + + PA_DEBUG(( "%s: Found plugin %s of type %s\n", __FUNCTION__, idStr, tpStr )); + + PA_UNLESS( alsaDeviceName = (char*)PaUtil_GroupAllocateMemory( alsaApi->allocations, + strlen(idStr) + 6 ), paInsufficientMemory ); + strcpy( alsaDeviceName, idStr ); + PA_UNLESS( deviceName = (char*)PaUtil_GroupAllocateMemory( alsaApi->allocations, + strlen(idStr) + 1 ), paInsufficientMemory ); + strcpy( deviceName, idStr ); + + ++numDeviceNames; + if( !deviceNames || numDeviceNames > maxDeviceNames ) + { + maxDeviceNames *= 2; + PA_UNLESS( deviceNames = (DeviceNames *) realloc( deviceNames, maxDeviceNames * sizeof (DeviceNames) ), + paInsufficientMemory ); + } + + deviceNames[numDeviceNames - 1].alsaName = alsaDeviceName; + deviceNames[numDeviceNames - 1].name = deviceName; + deviceNames[numDeviceNames - 1].isPlug = 1; + deviceNames[numDeviceNames - 1].hasPlayback = 1; + deviceNames[numDeviceNames - 1].hasCapture = 1; + } + } + else + PA_DEBUG(( "%s: Iterating over ALSA plugins failed: %s\n", __FUNCTION__, snd_strerror( res ) )); + + /* allocate deviceInfo memory based on the number of devices */ + PA_UNLESS( commonApi->deviceInfos = (PaDeviceInfo**)PaUtil_GroupAllocateMemory( + alsaApi->allocations, sizeof(PaDeviceInfo*) * (numDeviceNames) ), paInsufficientMemory ); + + /* allocate all device info structs in a contiguous block */ + PA_UNLESS( deviceInfoArray = (PaAlsaDeviceInfo*)PaUtil_GroupAllocateMemory( + alsaApi->allocations, sizeof(PaAlsaDeviceInfo) * numDeviceNames ), paInsufficientMemory ); + + /* Loop over list of cards, filling in info, if a device is deemed unavailable (can't get name), + * it's ignored. + */ + /* while( snd_card_next( &cardIdx ) == 0 && cardIdx >= 0 ) */ + for( i = 0, devIdx = 0; i < numDeviceNames; ++i ) + { + snd_pcm_t *pcm; + PaAlsaDeviceInfo *deviceInfo = &deviceInfoArray[devIdx]; + PaDeviceInfo *commonDeviceInfo = &deviceInfo->commonDeviceInfo; + + /* Zero fields */ + InitializeDeviceInfo( commonDeviceInfo ); + + /* to determine device capabilities, we must open the device and query the + * hardware parameter configuration space */ + + /* Query capture */ + if( deviceNames[i].hasCapture && + snd_pcm_open( &pcm, deviceNames[i].alsaName, SND_PCM_STREAM_CAPTURE, blocking ) >= 0 ) + { + if( GropeDevice( pcm, &deviceInfo->minInputChannels, &commonDeviceInfo->maxInputChannels, + &commonDeviceInfo->defaultLowInputLatency, &commonDeviceInfo->defaultHighInputLatency, + &commonDeviceInfo->defaultSampleRate, deviceNames[i].isPlug ) != paNoError ) + continue; /* Error */ + } + + /* Query playback */ + if( deviceNames[i].hasPlayback && + snd_pcm_open( &pcm, deviceNames[i].alsaName, SND_PCM_STREAM_PLAYBACK, blocking ) >= 0 ) + { + if( GropeDevice( pcm, &deviceInfo->minOutputChannels, &commonDeviceInfo->maxOutputChannels, + &commonDeviceInfo->defaultLowOutputLatency, &commonDeviceInfo->defaultHighOutputLatency, + &commonDeviceInfo->defaultSampleRate, deviceNames[i].isPlug ) != paNoError ) + continue; /* Error */ + } + + commonDeviceInfo->structVersion = 2; + commonDeviceInfo->hostApi = alsaApi->hostApiIndex; + commonDeviceInfo->name = deviceNames[i].name; + deviceInfo->alsaName = deviceNames[i].alsaName; + deviceInfo->isPlug = deviceNames[i].isPlug; + + /* A: Storing pointer to PaAlsaDeviceInfo object as pointer to PaDeviceInfo object. + * Should now be safe to add device info, unless the device supports neither capture nor playback + */ + if( commonDeviceInfo->maxInputChannels > 0 || commonDeviceInfo->maxOutputChannels > 0 ) + { + if( commonApi->info.defaultInputDevice == paNoDevice && commonDeviceInfo->maxInputChannels > 0 ) + commonApi->info.defaultInputDevice = devIdx; + if( commonApi->info.defaultOutputDevice == paNoDevice && commonDeviceInfo->maxOutputChannels > 0 ) + commonApi->info.defaultOutputDevice = devIdx; + + commonApi->deviceInfos[devIdx++] = (PaDeviceInfo *) deviceInfo; + } + } + free( deviceNames ); + + commonApi->info.deviceCount = devIdx; /* Number of successfully queried devices */ + +end: + return result; + +error: + goto end; /* No particular action */ +} + +/* Check against known device capabilities */ +static PaError ValidateParameters( const PaStreamParameters *parameters, PaUtilHostApiRepresentation *hostApi, StreamDirection mode ) +{ + PaError result = paNoError; + int maxChans; + const PaAlsaDeviceInfo *deviceInfo = NULL; + assert( parameters ); + + if( parameters->device != paUseHostApiSpecificDeviceSpecification ) + { + assert( parameters->device < hostApi->info.deviceCount ); + PA_UNLESS( parameters->hostApiSpecificStreamInfo == NULL, paBadIODeviceCombination ); + deviceInfo = GetDeviceInfo( hostApi, parameters->device ); + } + else + { + const PaAlsaStreamInfo *streamInfo = parameters->hostApiSpecificStreamInfo; + + PA_UNLESS( parameters->device == paUseHostApiSpecificDeviceSpecification, paInvalidDevice ); + PA_UNLESS( streamInfo->size == sizeof (PaAlsaStreamInfo) && streamInfo->version == 1, + paIncompatibleHostApiSpecificStreamInfo ); + + return paNoError; /* Skip further checking */ + } + + assert( deviceInfo ); + assert( parameters->hostApiSpecificStreamInfo == NULL ); + maxChans = (StreamDirection_In == mode ? deviceInfo->commonDeviceInfo.maxInputChannels : + deviceInfo->commonDeviceInfo.maxOutputChannels); + PA_UNLESS( parameters->channelCount <= maxChans, paInvalidChannelCount ); + +error: + return result; +} + +/* Given an open stream, what sample formats are available? */ + +static PaSampleFormat GetAvailableFormats( snd_pcm_t *pcm ) +{ + PaSampleFormat available = 0; + snd_pcm_hw_params_t *hwParams; + snd_pcm_hw_params_alloca( &hwParams ); + + snd_pcm_hw_params_any( pcm, hwParams ); + + if( snd_pcm_hw_params_test_format( pcm, hwParams, SND_PCM_FORMAT_FLOAT ) >= 0) + available |= paFloat32; + + if( snd_pcm_hw_params_test_format( pcm, hwParams, SND_PCM_FORMAT_S32 ) >= 0) + available |= paInt32; + + if( snd_pcm_hw_params_test_format( pcm, hwParams, SND_PCM_FORMAT_S24 ) >= 0) + available |= paInt24; + + if( snd_pcm_hw_params_test_format( pcm, hwParams, SND_PCM_FORMAT_S16 ) >= 0) + available |= paInt16; + + if( snd_pcm_hw_params_test_format( pcm, hwParams, SND_PCM_FORMAT_U8 ) >= 0) + available |= paUInt8; + + if( snd_pcm_hw_params_test_format( pcm, hwParams, SND_PCM_FORMAT_S8 ) >= 0) + available |= paInt8; + + return available; +} + +static snd_pcm_format_t Pa2AlsaFormat( PaSampleFormat paFormat ) +{ + switch( paFormat ) + { + case paFloat32: + return SND_PCM_FORMAT_FLOAT; + + case paInt16: + return SND_PCM_FORMAT_S16; + + case paInt24: + return SND_PCM_FORMAT_S24; + + case paInt32: + return SND_PCM_FORMAT_S32; + + case paInt8: + return SND_PCM_FORMAT_S8; + + case paUInt8: + return SND_PCM_FORMAT_U8; + + default: + return SND_PCM_FORMAT_UNKNOWN; + } +} + +/** Open an ALSA pcm handle. + * + * The device to be open can be specified in a custom PaAlsaStreamInfo struct, or it will be a device number. In case of a + * device number, it maybe specified through an env variable (PA_ALSA_PLUGHW) that we should open the corresponding plugin + * device. + */ +static PaError AlsaOpen( const PaUtilHostApiRepresentation *hostApi, const PaStreamParameters *params, StreamDirection + streamDir, snd_pcm_t **pcm ) +{ + PaError result = paNoError; + int ret; + const char *deviceName = alloca( 50 ); + const PaAlsaDeviceInfo *deviceInfo = NULL; + PaAlsaStreamInfo *streamInfo = (PaAlsaStreamInfo *)params->hostApiSpecificStreamInfo; + + if( !streamInfo ) + { + int usePlug = 0; + deviceInfo = GetDeviceInfo( hostApi, params->device ); + + /* If device name starts with hw: and PA_ALSA_PLUGHW is 1, we open the plughw device instead */ + if( !strncmp( "hw:", deviceInfo->alsaName, 3 ) && getenv( "PA_ALSA_PLUGHW" ) ) + usePlug = atoi( getenv( "PA_ALSA_PLUGHW" ) ); + if( usePlug ) + snprintf( (char *) deviceName, 50, "plug%s", deviceInfo->alsaName ); + else + deviceName = deviceInfo->alsaName; + } + else + deviceName = streamInfo->deviceString; + + if( (ret = snd_pcm_open( pcm, deviceName, streamDir == StreamDirection_In ? SND_PCM_STREAM_CAPTURE : SND_PCM_STREAM_PLAYBACK, + SND_PCM_NONBLOCK )) < 0 ) + { + *pcm = NULL; /* Not to be closed */ + ENSURE_( ret, ret == -EBUSY ? paDeviceUnavailable : paBadIODeviceCombination ); + } + ENSURE_( snd_pcm_nonblock( *pcm, 0 ), paUnanticipatedHostError ); + +end: + return result; + +error: + goto end; +} + +static PaError TestParameters( const PaUtilHostApiRepresentation *hostApi, const PaStreamParameters *parameters, + double sampleRate, StreamDirection streamDir ) +{ + PaError result = paNoError; + snd_pcm_t *pcm = NULL; + PaSampleFormat availableFormats; + /* We are able to adapt to a number of channels less than what the device supports */ + unsigned int numHostChannels; + PaSampleFormat hostFormat; + snd_pcm_hw_params_t *hwParams; + snd_pcm_hw_params_alloca( &hwParams ); + + if( !parameters->hostApiSpecificStreamInfo ) + { + const PaAlsaDeviceInfo *devInfo = GetDeviceInfo( hostApi, parameters->device ); + numHostChannels = PA_MAX( parameters->channelCount, StreamDirection_In == streamDir ? + devInfo->minInputChannels : devInfo->minOutputChannels ); + } + else + numHostChannels = parameters->channelCount; + + PA_ENSURE( AlsaOpen( hostApi, parameters, streamDir, &pcm ) ); + + snd_pcm_hw_params_any( pcm, hwParams ); + + if( SetApproximateSampleRate( pcm, hwParams, sampleRate ) < 0 ) + { + result = paInvalidSampleRate; + goto error; + } + + if( snd_pcm_hw_params_set_channels( pcm, hwParams, numHostChannels ) < 0 ) + { + result = paInvalidChannelCount; + goto error; + } + + /* See if we can find a best possible match */ + availableFormats = GetAvailableFormats( pcm ); + PA_ENSURE( hostFormat = PaUtil_SelectClosestAvailableFormat( availableFormats, parameters->sampleFormat ) ); + ENSURE_( snd_pcm_hw_params_set_format( pcm, hwParams, Pa2AlsaFormat( hostFormat ) ), paUnanticipatedHostError ); + + ENSURE_( snd_pcm_hw_params( pcm, hwParams ), paUnanticipatedHostError ); + +end: + if( pcm ) + snd_pcm_close( pcm ); + return result; + +error: + goto end; +} + +static PaError IsFormatSupported( struct PaUtilHostApiRepresentation *hostApi, + const PaStreamParameters *inputParameters, + const PaStreamParameters *outputParameters, + double sampleRate ) +{ + int inputChannelCount = 0, outputChannelCount = 0; + PaSampleFormat inputSampleFormat, outputSampleFormat; + PaError result = paFormatIsSupported; + + if( inputParameters ) + { + PA_ENSURE( ValidateParameters( inputParameters, hostApi, StreamDirection_In ) ); + + inputChannelCount = inputParameters->channelCount; + inputSampleFormat = inputParameters->sampleFormat; + } + + if( outputParameters ) + { + PA_ENSURE( ValidateParameters( outputParameters, hostApi, StreamDirection_Out ) ); + + outputChannelCount = outputParameters->channelCount; + outputSampleFormat = outputParameters->sampleFormat; + } + + if( inputChannelCount ) + { + if( (result = TestParameters( hostApi, inputParameters, sampleRate, StreamDirection_In )) + != paNoError ) + goto error; + } + if ( outputChannelCount ) + { + if( (result = TestParameters( hostApi, outputParameters, sampleRate, StreamDirection_Out )) + != paNoError ) + goto error; + } + + return paFormatIsSupported; + +error: + return result; +} + +static PaError PaAlsaStreamComponent_Initialize( PaAlsaStreamComponent *self, PaAlsaHostApiRepresentation *alsaApi, + const PaStreamParameters *params, StreamDirection streamDir, int callbackMode ) +{ + PaError result = paNoError; + PaSampleFormat userSampleFormat = params->sampleFormat, hostSampleFormat; + assert( params->channelCount > 0 ); + + /* Make sure things have an initial value */ + memset( self, 0, sizeof (PaAlsaStreamComponent) ); + + if( NULL == params->hostApiSpecificStreamInfo ) + { + const PaAlsaDeviceInfo *devInfo = GetDeviceInfo( &alsaApi->commonHostApiRep, params->device ); + self->numHostChannels = PA_MAX( params->channelCount, StreamDirection_In == streamDir ? devInfo->minInputChannels + : devInfo->minOutputChannels ); + } + else + { + /* We're blissfully unaware of the minimum channelCount */ + self->numHostChannels = params->channelCount; + } + + PA_ENSURE( AlsaOpen( &alsaApi->commonHostApiRep, params, streamDir, &self->pcm ) ); + self->nfds = snd_pcm_poll_descriptors_count( self->pcm ); + hostSampleFormat = PaUtil_SelectClosestAvailableFormat( GetAvailableFormats( self->pcm ), userSampleFormat ); + + self->hostSampleFormat = hostSampleFormat; + self->nativeFormat = Pa2AlsaFormat( hostSampleFormat ); + self->hostInterleaved = self->userInterleaved = !(userSampleFormat & paNonInterleaved); + self->numUserChannels = params->channelCount; + self->streamDir = streamDir; + + if( !callbackMode && !self->userInterleaved ) + { + /* Pre-allocate non-interleaved user provided buffers */ + PA_UNLESS( self->userBuffers = PaUtil_AllocateMemory( sizeof (void *) * self->numUserChannels ), + paInsufficientMemory ); + } + +error: + return result; +} + +static void PaAlsaStreamComponent_Terminate( PaAlsaStreamComponent *self ) +{ + snd_pcm_close( self->pcm ); + if( self->userBuffers ) + PaUtil_FreeMemory( self->userBuffers ); +} + +/** Configure the associated ALSA pcm. + * + */ +static PaError PaAlsaStreamComponent_Configure( PaAlsaStreamComponent *self, const PaStreamParameters *params, unsigned long + framesPerHostBuffer, int primeBuffers, int callbackMode, double *sampleRate, PaTime *returnedLatency ) +{ + /* + int numPeriods; + + if( getenv("PA_NUMPERIODS") != NULL ) + numPeriods = atoi( getenv("PA_NUMPERIODS") ); + else + numPeriods = ( (latency * sampleRate) / *framesPerBuffer ) + 1; + + PA_DEBUG(( "latency: %f, rate: %f, framesPerBuffer: %d\n", latency, sampleRate, *framesPerBuffer )); + if( numPeriods <= 1 ) + numPeriods = 2; + */ + + /* Configuration consists of setting all of ALSA's parameters. + * These parameters come in two flavors: hardware parameters + * and software paramters. Hardware parameters will affect + * the way the device is initialized, software parameters + * affect the way ALSA interacts with me, the user-level client. + */ + + snd_pcm_hw_params_t *hwParams; + snd_pcm_sw_params_t *swParams; + PaError result = paNoError; + snd_pcm_access_t accessMode, alternateAccessMode; + unsigned int numPeriods, minPeriods = 2; + int dir = 0; + snd_pcm_t *pcm = self->pcm; + PaTime latency = params->suggestedLatency; + double sr = *sampleRate; + *returnedLatency = -1.; + + snd_pcm_hw_params_alloca( &hwParams ); + snd_pcm_sw_params_alloca( &swParams ); + + self->framesPerBuffer = framesPerHostBuffer; + + /* ... fill up the configuration space with all possibile + * combinations of parameters this device will accept */ + ENSURE_( snd_pcm_hw_params_any( pcm, hwParams ), paUnanticipatedHostError ); + + ENSURE_( snd_pcm_hw_params_set_periods_integer( pcm, hwParams ), paUnanticipatedHostError ); + ENSURE_( snd_pcm_hw_params_set_period_size_integer( pcm, hwParams ), paUnanticipatedHostError ); + + if( self->userInterleaved ) + { + accessMode = SND_PCM_ACCESS_MMAP_INTERLEAVED; + alternateAccessMode = SND_PCM_ACCESS_MMAP_NONINTERLEAVED; + } + else + { + accessMode = SND_PCM_ACCESS_MMAP_NONINTERLEAVED; + alternateAccessMode = SND_PCM_ACCESS_MMAP_INTERLEAVED; + } + + /* If requested access mode fails, try alternate mode */ + if( snd_pcm_hw_params_set_access( pcm, hwParams, accessMode ) < 0 ) + { + ENSURE_( snd_pcm_hw_params_set_access( pcm, hwParams, alternateAccessMode ), paUnanticipatedHostError ); + /* Flip mode */ + self->hostInterleaved = !self->userInterleaved; + } + + ENSURE_( snd_pcm_hw_params_set_format( pcm, hwParams, self->nativeFormat ), paUnanticipatedHostError ); + + ENSURE_( SetApproximateSampleRate( pcm, hwParams, sr ), paInvalidSampleRate ); + ENSURE_( GetExactSampleRate( hwParams, &sr ), paUnanticipatedHostError ); + /* reject if there's no sample rate within 1% of the one requested */ + if( (fabs( *sampleRate - sr ) / *sampleRate) > 0.01 ) + { + PA_DEBUG(("%s: Wanted %f, closest sample rate was %d\n", __FUNCTION__, sampleRate, sr )); + PA_ENSURE( paInvalidSampleRate ); + } + + ENSURE_( snd_pcm_hw_params_set_channels( pcm, hwParams, self->numHostChannels ), paInvalidChannelCount ); + + /* I think there should be at least 2 periods (even though ALSA doesn't appear to enforce this) */ + dir = 0; + ENSURE_( snd_pcm_hw_params_set_periods_min( pcm, hwParams, &minPeriods, &dir ), paUnanticipatedHostError ); + dir = 0; + ENSURE_( snd_pcm_hw_params_set_period_size_near( pcm, hwParams, &self->framesPerBuffer, &dir ), paUnanticipatedHostError ); + + /* Find an acceptable number of periods */ + numPeriods = (latency * sr) / self->framesPerBuffer + 1; + dir = 0; + ENSURE_( snd_pcm_hw_params_set_periods_near( pcm, hwParams, &numPeriods, &dir ), paUnanticipatedHostError ); + /* Minimum of periods should already be 2 */ + PA_UNLESS( numPeriods >= 2, paInternalError ); + + /* Set the parameters! */ + ENSURE_( snd_pcm_hw_params( pcm, hwParams ), paUnanticipatedHostError ); + ENSURE_( snd_pcm_hw_params_get_buffer_size( hwParams, &self->bufferSize ), paUnanticipatedHostError ); + + /* Latency in seconds, one period is not counted as latency */ + latency = (numPeriods - 1) * self->framesPerBuffer / sr; + + /* Now software parameters... */ + ENSURE_( snd_pcm_sw_params_current( pcm, swParams ), paUnanticipatedHostError ); + + ENSURE_( snd_pcm_sw_params_set_start_threshold( pcm, swParams, self->framesPerBuffer ), paUnanticipatedHostError ); + ENSURE_( snd_pcm_sw_params_set_stop_threshold( pcm, swParams, self->bufferSize ), paUnanticipatedHostError ); + + /* Silence buffer in the case of underrun */ + if( !primeBuffers ) /* XXX: Make sense? */ + { + snd_pcm_uframes_t boundary; + ENSURE_( snd_pcm_sw_params_get_boundary( swParams, &boundary ), paUnanticipatedHostError ); + ENSURE_( snd_pcm_sw_params_set_silence_threshold( pcm, swParams, 0 ), paUnanticipatedHostError ); + ENSURE_( snd_pcm_sw_params_set_silence_size( pcm, swParams, boundary ), paUnanticipatedHostError ); + } + + ENSURE_( snd_pcm_sw_params_set_avail_min( pcm, swParams, self->framesPerBuffer ), paUnanticipatedHostError ); + ENSURE_( snd_pcm_sw_params_set_xfer_align( pcm, swParams, 1 ), paUnanticipatedHostError ); + ENSURE_( snd_pcm_sw_params_set_tstamp_mode( pcm, swParams, SND_PCM_TSTAMP_MMAP ), paUnanticipatedHostError ); + + /* Set the parameters! */ + ENSURE_( snd_pcm_sw_params( pcm, swParams ), paUnanticipatedHostError ); + + *sampleRate = sr; + *returnedLatency = latency; + +end: + return result; + +error: + goto end; /* No particular action */ +} + +static PaError PaAlsaStream_Initialize( PaAlsaStream *self, PaAlsaHostApiRepresentation *alsaApi, const PaStreamParameters *inParams, + const PaStreamParameters *outParams, double sampleRate, unsigned long framesPerUserBuffer, PaStreamCallback callback, + PaStreamFlags streamFlags, void *userData ) +{ + PaError result = paNoError; + assert( self ); + + memset( self, 0, sizeof (PaAlsaStream) ); + + if( NULL != callback ) + { + PaUtil_InitializeStreamRepresentation( &self->streamRepresentation, + &alsaApi->callbackStreamInterface, + callback, userData ); + self->callbackMode = 1; + } + else + { + PaUtil_InitializeStreamRepresentation( &self->streamRepresentation, + &alsaApi->blockingStreamInterface, + NULL, userData ); + } + + self->framesPerUserBuffer = framesPerUserBuffer; + self->neverDropInput = streamFlags & paNeverDropInput; + /* XXX: Ignore paPrimeOutputBuffersUsingStreamCallback untill buffer priming is fully supported in pa_process.c */ + /* + if( outParams & streamFlags & paPrimeOutputBuffersUsingStreamCallback ) + self->primeBuffers = 1; + */ + memset( &self->capture, 0, sizeof (PaAlsaStreamComponent) ); + memset( &self->playback, 0, sizeof (PaAlsaStreamComponent) ); + if( inParams ) + PA_ENSURE( PaAlsaStreamComponent_Initialize( &self->capture, alsaApi, inParams, StreamDirection_In, NULL != callback ) ); + if( outParams ) + PA_ENSURE( PaAlsaStreamComponent_Initialize( &self->playback, alsaApi, outParams, StreamDirection_Out, NULL != callback ) ); + + assert( self->capture.nfds || self->playback.nfds ); + + PA_UNLESS( self->pfds = (struct pollfd*)PaUtil_AllocateMemory( (self->capture.nfds + + self->playback.nfds) * sizeof (struct pollfd) ), paInsufficientMemory ); + + PaUtil_InitializeCpuLoadMeasurer( &self->cpuLoadMeasurer, sampleRate ); + InitializeThreading( &self->threading, &self->cpuLoadMeasurer ); + ASSERT_CALL_( pthread_mutex_init( &self->stateMtx, NULL ), 0 ); + ASSERT_CALL_( pthread_mutex_init( &self->startMtx, NULL ), 0 ); + ASSERT_CALL_( pthread_cond_init( &self->startCond, NULL ), 0 ); + +error: + return result; +} + +/** Free resources associated with stream, and eventually stream itself. + * + * Frees allocated memory, and terminates individual StreamComponents. + */ +static void PaAlsaStream_Terminate( PaAlsaStream *self ) +{ + assert( self ); + + if( self->capture.pcm ) + { + PaAlsaStreamComponent_Terminate( &self->capture ); + } + if( self->playback.pcm ) + { + PaAlsaStreamComponent_Terminate( &self->playback ); + } + + PaUtil_FreeMemory( self->pfds ); + ASSERT_CALL_( pthread_mutex_destroy( &self->stateMtx ), 0 ); + ASSERT_CALL_( pthread_mutex_destroy( &self->startMtx ), 0 ); + ASSERT_CALL_( pthread_cond_destroy( &self->startCond ), 0 ); + + PaUtil_FreeMemory( self ); +} + +/** Calculate polling timeout + * + * @param frames Time to wait + * @return Polling timeout in milliseconds + */ +static int CalculatePollTimeout( const PaAlsaStream *stream, unsigned long frames ) +{ + assert( stream->streamRepresentation.streamInfo.sampleRate > 0.0 ); + /* Period in msecs, rounded up */ + return (int)ceil( 1000 * frames / stream->streamRepresentation.streamInfo.sampleRate ); +} + +/** Set up ALSA stream parameters. + * + */ +static PaError PaAlsaStream_Configure( PaAlsaStream *self, const PaStreamParameters *inParams, const PaStreamParameters + *outParams, double sampleRate, unsigned long framesPerHostBuffer, double *inputLatency, double *outputLatency, + unsigned long *maxHostBufferSize ) +{ + PaError result = paNoError; + double realSr = sampleRate; + + if( self->capture.pcm ) + PA_ENSURE( PaAlsaStreamComponent_Configure( &self->capture, inParams, framesPerHostBuffer, self->primeBuffers, + self->callbackMode, &realSr, inputLatency ) ); + if( self->playback.pcm ) + PA_ENSURE( PaAlsaStreamComponent_Configure( &self->playback, outParams, framesPerHostBuffer, self->primeBuffers, + self->callbackMode, &realSr, outputLatency ) ); + + /* Should be exact now */ + self->streamRepresentation.streamInfo.sampleRate = realSr; + + /* this will cause the two streams to automatically start/stop/prepare in sync. + * We only need to execute these operations on one of the pair. + * A: We don't want to do this on a blocking stream. + */ + if( self->callbackMode && self->capture.pcm && self->playback.pcm ) + { + int err = snd_pcm_link( self->capture.pcm, self->playback.pcm ); + if( err >= 0 ) + self->pcmsSynced = 1; + else + PA_DEBUG(( "%s: Unable to sync pcms: %s\n", __FUNCTION__, snd_strerror( err ) )); + } + + /* Frames per host buffer for the stream is set as a compromise between the two directions */ + framesPerHostBuffer = PA_MIN( self->capture.pcm ? self->capture.framesPerBuffer : ULONG_MAX, + self->playback.pcm ? self->playback.framesPerBuffer : ULONG_MAX ); + self->pollTimeout = CalculatePollTimeout( self, framesPerHostBuffer ); /* Period in msecs, rounded up */ + + *maxHostBufferSize = PA_MAX( self->capture.pcm ? self->capture.bufferSize : 0, + self->playback.pcm ? self->playback.bufferSize : 0 ); + + /* Time before watchdog unthrottles realtime thread == 1/4 of period time in msecs */ + self->threading.throttledSleepTime = (unsigned long) (framesPerHostBuffer / sampleRate / 4 * 1000); + + if( self->callbackMode ) + { + /* If the user expects a certain number of frames per callback we will either have to rely on block adaption + * (framesPerHostBuffer is not an integer multiple of framesPerBuffer) or we can simply align the number + * of host buffer frames with what the user specified */ + if( self->framesPerUserBuffer != paFramesPerBufferUnspecified ) + { + /* self->alignFrames = 1; */ + + /* Unless the ratio between number of host and user buffer frames is an integer we will have to rely + * on block adaption */ + /* + if( framesPerHostBuffer % framesPerBuffer != 0 || (self->capture.pcm && self->playback.pcm && + self->capture.framesPerBuffer != self->playback.framesPerBuffer) ) + self->useBlockAdaption = 1; + else + self->alignFrames = 1; + */ + } + } + +error: + return result; +} + +/* We need to determine how many frames per host buffer to use. Our + * goals are to provide the best possible performance, but also to + * most closely honor the requested latency settings. Therefore this + * decision is based on: + * + * - the period sizes that playback and/or capture support. The + * host buffer size has to be one of these. + * - the number of periods that playback and/or capture support. + * + * We want to make period_size*(num_periods-1) to be as close as possible + * to latency*rate for both playback and capture. + * + * This is one of those blocks of code that will just take a lot of + * refinement to be any good. + * + * In the full-duplex case it is possible that the routine was unable + * to find a number of frames per buffer acceptable to both devices + * TODO: Implement an algorithm to find the value closest to acceptance + * by both devices, to minimize difference between period sizes? + */ +static PaError DetermineFramesPerBuffer( const PaAlsaStream *stream, double sampleRate, const PaStreamParameters *inputParameters, + const PaStreamParameters *outputParameters, unsigned long *determinedFrames, const PaUtilHostApiRepresentation *hostApi ) +{ + PaError result = paNoError; + unsigned long framesPerBuffer = 0; + int numHostInputChannels = 0, numHostOutputChannels = 0; + + /* XXX: Clean this up */ + if( stream->capture.pcm ) + { + const PaAlsaDeviceInfo *devInfo = GetDeviceInfo( hostApi, inputParameters->device ); + numHostInputChannels = PA_MAX( inputParameters->channelCount, devInfo->minInputChannels ); + } + if( stream->playback.pcm ) + { + const PaAlsaDeviceInfo *devInfo = GetDeviceInfo( hostApi, outputParameters->device ); + numHostOutputChannels = PA_MAX( outputParameters->channelCount, devInfo->minOutputChannels ); + } + + if( stream->capture.pcm && stream->playback.pcm ) + { + snd_pcm_uframes_t desiredLatency, e; + snd_pcm_uframes_t minPeriodSize, minPlayback, minCapture, maxPeriodSize, maxPlayback, maxCapture, + optimalPeriodSize, periodSize; + int dir = 0; + unsigned int minPeriods = 2; + + snd_pcm_t *pcm; + snd_pcm_hw_params_t *hwParamsPlayback, *hwParamsCapture; + + snd_pcm_hw_params_alloca( &hwParamsPlayback ); + snd_pcm_hw_params_alloca( &hwParamsCapture ); + + /* Come up with a common desired latency */ + pcm = stream->playback.pcm; + snd_pcm_hw_params_any( pcm, hwParamsPlayback ); + ENSURE_( SetApproximateSampleRate( pcm, hwParamsPlayback, sampleRate ), paInvalidSampleRate ); + ENSURE_( snd_pcm_hw_params_set_channels( pcm, hwParamsPlayback, numHostOutputChannels ), + paBadIODeviceCombination ); + + ENSURE_( snd_pcm_hw_params_set_period_size_integer( pcm, hwParamsPlayback ), paUnanticipatedHostError ); + ENSURE_( snd_pcm_hw_params_set_periods_integer( pcm, hwParamsPlayback ), paUnanticipatedHostError ); + ENSURE_( snd_pcm_hw_params_set_periods_min( pcm, hwParamsPlayback, &minPeriods, &dir ), paUnanticipatedHostError ); + ENSURE_( snd_pcm_hw_params_get_period_size_min( hwParamsPlayback, &minPlayback, &dir ), paUnanticipatedHostError ); + ENSURE_( snd_pcm_hw_params_get_period_size_max( hwParamsPlayback, &maxPlayback, &dir ), paUnanticipatedHostError ); + + pcm = stream->capture.pcm; + ENSURE_( snd_pcm_hw_params_any( pcm, hwParamsCapture ), paUnanticipatedHostError ); + ENSURE_( SetApproximateSampleRate( pcm, hwParamsCapture, sampleRate ), paBadIODeviceCombination ); + ENSURE_( snd_pcm_hw_params_set_channels( pcm, hwParamsCapture, numHostInputChannels ), + paBadIODeviceCombination ); + + ENSURE_( snd_pcm_hw_params_set_period_size_integer( pcm, hwParamsCapture ), paUnanticipatedHostError ); + ENSURE_( snd_pcm_hw_params_set_periods_integer( pcm, hwParamsCapture ), paUnanticipatedHostError ); + ENSURE_( snd_pcm_hw_params_set_periods_min( pcm, hwParamsCapture, &minPeriods, &dir ), paUnanticipatedHostError ); + ENSURE_( snd_pcm_hw_params_get_period_size_min( hwParamsCapture, &minCapture, &dir ), paUnanticipatedHostError ); + ENSURE_( snd_pcm_hw_params_get_period_size_max( hwParamsCapture, &maxCapture, &dir ), paUnanticipatedHostError ); + + minPeriodSize = PA_MAX( minPlayback, minCapture ); + maxPeriodSize = PA_MIN( maxPlayback, maxCapture ); + + desiredLatency = (snd_pcm_uframes_t) (PA_MIN( outputParameters->suggestedLatency, inputParameters->suggestedLatency ) + * sampleRate); + /* Clamp desiredLatency */ + { + snd_pcm_uframes_t tmp, maxBufferSize = ULONG_MAX; + ENSURE_( snd_pcm_hw_params_get_buffer_size_max( hwParamsPlayback, &maxBufferSize ), paUnanticipatedHostError ); + ENSURE_( snd_pcm_hw_params_get_buffer_size_max( hwParamsCapture, &tmp ), paUnanticipatedHostError ); + maxBufferSize = PA_MIN( maxBufferSize, tmp ); + + desiredLatency = PA_MIN( desiredLatency, maxBufferSize ); + } + + /* Find the closest power of 2 */ + e = ilogb( minPeriodSize ); + if( minPeriodSize & (minPeriodSize - 1) ) + e += 1; + periodSize = (snd_pcm_uframes_t) pow( 2, e ); + + while( periodSize <= maxPeriodSize ) + { + if( snd_pcm_hw_params_test_period_size( stream->playback.pcm, hwParamsPlayback, periodSize, 0 ) >= 0 && + snd_pcm_hw_params_test_period_size( stream->capture.pcm, hwParamsCapture, periodSize, 0 ) >= 0 ) + break; /* Ok! */ + + periodSize *= 2; + } + + /* 4 periods considered optimal */ + optimalPeriodSize = PA_MAX( desiredLatency / 4, minPeriodSize ); + optimalPeriodSize = PA_MIN( optimalPeriodSize, maxPeriodSize ); + + /* Find the closest power of 2 */ + e = ilogb( optimalPeriodSize ); + if( optimalPeriodSize & (optimalPeriodSize - 1) ) + e += 1; + optimalPeriodSize = (snd_pcm_uframes_t) pow( 2, e ); + + while( optimalPeriodSize >= periodSize ) + { + pcm = stream->playback.pcm; + if( snd_pcm_hw_params_test_period_size( pcm, hwParamsPlayback, optimalPeriodSize, 0 ) < 0 ) + continue; + + pcm = stream->capture.pcm; + if( snd_pcm_hw_params_test_period_size( pcm, hwParamsCapture, optimalPeriodSize, 0 ) >= 0 ) + break; + + optimalPeriodSize /= 2; + } + + if( optimalPeriodSize > periodSize ) + periodSize = optimalPeriodSize; + + if( periodSize <= maxPeriodSize ) + { + /* Looks good */ + framesPerBuffer = periodSize; + } + else + { + /* Unable to find a common period size, oh well */ + optimalPeriodSize = PA_MAX( desiredLatency / 4, minPeriodSize ); + optimalPeriodSize = PA_MIN( optimalPeriodSize, maxPeriodSize ); + + /* ConfigureStream should find individual period sizes acceptable for each device */ + framesPerBuffer = optimalPeriodSize; + /* PA_ENSURE( paBadIODeviceCombination ); */ + } + } + else /* half-duplex is a slightly simpler case */ + { + unsigned long bufferSize, channels; + snd_pcm_t *pcm; + snd_pcm_hw_params_t *hwParams; + + snd_pcm_hw_params_alloca( &hwParams ); + + if( stream->capture.pcm ) + { + pcm = stream->capture.pcm; + bufferSize = inputParameters->suggestedLatency * sampleRate; + channels = numHostInputChannels; + } + else + { + pcm = stream->playback.pcm; + bufferSize = outputParameters->suggestedLatency * sampleRate; + channels = numHostOutputChannels; + } + + ENSURE_( snd_pcm_hw_params_any( pcm, hwParams ), paUnanticipatedHostError ); + ENSURE_( SetApproximateSampleRate( pcm, hwParams, sampleRate ), paInvalidSampleRate ); + ENSURE_( snd_pcm_hw_params_set_channels( pcm, hwParams, channels ), paBadIODeviceCombination ); + + ENSURE_( snd_pcm_hw_params_set_period_size_integer( pcm, hwParams ), paUnanticipatedHostError ); + ENSURE_( snd_pcm_hw_params_set_periods_integer( pcm, hwParams ), paUnanticipatedHostError ); + + /* Using 5 as a base number of periods, we try to approximate the suggested latency (+1 period), + finding a combination of period/buffer size which best fits these constraints */ + framesPerBuffer = bufferSize / 4; + bufferSize += framesPerBuffer; /* One period doesn't count as latency */ + ENSURE_( snd_pcm_hw_params_set_buffer_size_near( pcm, hwParams, &bufferSize ), paUnanticipatedHostError ); + ENSURE_( snd_pcm_hw_params_set_period_size_near( pcm, hwParams, &framesPerBuffer, NULL ), paUnanticipatedHostError ); + } + + PA_UNLESS( framesPerBuffer != 0, paInternalError ); + *determinedFrames = framesPerBuffer; + +error: + return result; +} + +static PaError OpenStream( struct PaUtilHostApiRepresentation *hostApi, + PaStream** s, + const PaStreamParameters *inputParameters, + const PaStreamParameters *outputParameters, + double sampleRate, + unsigned long framesPerBuffer, + PaStreamFlags streamFlags, + PaStreamCallback *callback, + void *userData ) +{ + PaError result = paNoError; + PaAlsaHostApiRepresentation *alsaHostApi = (PaAlsaHostApiRepresentation*)hostApi; + PaAlsaStream *stream = NULL; + PaSampleFormat hostInputSampleFormat = 0, hostOutputSampleFormat = 0; + PaSampleFormat inputSampleFormat = 0, outputSampleFormat = 0; + int numInputChannels = 0, numOutputChannels = 0; + PaTime inputLatency, outputLatency; + unsigned long framesPerHostBuffer; + PaUtilHostBufferSizeMode hostBufferSizeMode = paUtilBoundedHostBufferSize; + unsigned long maxHostBufferSize; /* Upper bound of host buffer size */ + + if( (streamFlags & paPlatformSpecificFlags) != 0 ) + return paInvalidFlag; + + if( inputParameters ) + { + PA_ENSURE( ValidateParameters( inputParameters, hostApi, StreamDirection_In ) ); + + numInputChannels = inputParameters->channelCount; + inputSampleFormat = inputParameters->sampleFormat; + } + if( outputParameters ) + { + PA_ENSURE( ValidateParameters( outputParameters, hostApi, StreamDirection_Out ) ); + + numOutputChannels = outputParameters->channelCount; + outputSampleFormat = outputParameters->sampleFormat; + } + + /* XXX: Why do we support this anyway? */ + if( framesPerBuffer == paFramesPerBufferUnspecified && getenv( "PA_ALSA_PERIODSIZE" ) != NULL ) + { + PA_DEBUG(( "%s: Getting framesPerBuffer from environment\n", __FUNCTION__ )); + framesPerBuffer = atoi( getenv("PA_ALSA_PERIODSIZE") ); + } + framesPerHostBuffer = framesPerBuffer; + + PA_UNLESS( stream = (PaAlsaStream*)PaUtil_AllocateMemory( sizeof(PaAlsaStream) ), paInsufficientMemory ); + PA_ENSURE( PaAlsaStream_Initialize( stream, alsaHostApi, inputParameters, outputParameters, sampleRate, + framesPerBuffer, callback, streamFlags, userData ) ); + + /* If the number of frames per buffer is unspecified, we have to come up with + * one. This is both a blessing and a curse: a blessing because we can optimize + * the number to best meet the requirements, but a curse because that's really + * hard to do well. For this reason we also support an interface where the user + * specifies these by setting environment variables. */ + if( framesPerBuffer == paFramesPerBufferUnspecified ) + { + PA_ENSURE( DetermineFramesPerBuffer( stream, sampleRate, inputParameters, outputParameters, &framesPerHostBuffer, + hostApi ) ); + } + + PA_ENSURE( PaAlsaStream_Configure( stream, inputParameters, outputParameters, sampleRate, framesPerHostBuffer, + &inputLatency, &outputLatency, &maxHostBufferSize ) ); + hostInputSampleFormat = stream->capture.hostSampleFormat; + hostOutputSampleFormat = stream->playback.hostSampleFormat; + + if( framesPerHostBuffer != framesPerBuffer ) + { + PA_DEBUG(( "%s: Number of frames per user and host buffer differs\n", __FUNCTION__ )); + } + + PA_ENSURE( PaUtil_InitializeBufferProcessor( &stream->bufferProcessor, + numInputChannels, inputSampleFormat, hostInputSampleFormat, + numOutputChannels, outputSampleFormat, hostOutputSampleFormat, + sampleRate, streamFlags, framesPerBuffer, maxHostBufferSize, + hostBufferSizeMode, callback, userData ) ); + + /* Ok, buffer processor is initialized, now we can deduce it's latency */ + if( numInputChannels > 0 ) + stream->streamRepresentation.streamInfo.inputLatency = inputLatency + PaUtil_GetBufferProcessorInputLatency( + &stream->bufferProcessor ); + if( numOutputChannels > 0 ) + stream->streamRepresentation.streamInfo.outputLatency = outputLatency + PaUtil_GetBufferProcessorOutputLatency( + &stream->bufferProcessor ); + + *s = (PaStream*)stream; + + return result; + +error: + if( stream ) + PaAlsaStream_Terminate( stream ); + + return result; +} + +static PaError CloseStream( PaStream* s ) +{ + PaError result = paNoError; + PaAlsaStream *stream = (PaAlsaStream*)s; + + PaUtil_TerminateBufferProcessor( &stream->bufferProcessor ); + PaUtil_TerminateStreamRepresentation( &stream->streamRepresentation ); + + PaAlsaStream_Terminate( stream ); + + return result; +} + +static void SilenceBuffer( PaAlsaStream *stream ) +{ + const snd_pcm_channel_area_t *areas; + snd_pcm_uframes_t frames = (snd_pcm_uframes_t)snd_pcm_avail_update( stream->playback.pcm ), offset; + + snd_pcm_mmap_begin( stream->playback.pcm, &areas, &offset, &frames ); + snd_pcm_areas_silence( areas, offset, stream->playback.numHostChannels, frames, stream->playback.nativeFormat ); + snd_pcm_mmap_commit( stream->playback.pcm, offset, frames ); +} + +/** Start/prepare pcm(s) for streaming. + * + * Depending on wether the stream is in callback or blocking mode, we will respectively start or simply + * prepare the playback pcm. If the buffer has _not_ been primed, we will in callback mode prepare and + * silence the buffer before starting playback. In blocking mode we simply prepare, as the playback will + * be started automatically as the user writes to output. + * + * The capture pcm, however, will simply be prepared and started. + * + * PaAlsaStream::startMtx makes sure access is synchronized (useful in callback mode) + */ +static PaError AlsaStart( PaAlsaStream *stream, int priming ) +{ + PaError result = paNoError; + + if( stream->playback.pcm ) + { + if( stream->callbackMode ) + { + if( !priming ) + { + /* Buffer isn't primed, so prepare and silence */ + ENSURE_( snd_pcm_prepare( stream->playback.pcm ), paUnanticipatedHostError ); + SilenceBuffer( stream ); + } + ENSURE_( snd_pcm_start( stream->playback.pcm ), paUnanticipatedHostError ); + } + else + ENSURE_( snd_pcm_prepare( stream->playback.pcm ), paUnanticipatedHostError ); + } + if( stream->capture.pcm && !stream->pcmsSynced ) + { + ENSURE_( snd_pcm_prepare( stream->capture.pcm ), paUnanticipatedHostError ); + /* For a blocking stream we want to start capture as well, since nothing will happen otherwise */ + ENSURE_( snd_pcm_start( stream->capture.pcm ), paUnanticipatedHostError ); + } + +end: + return result; +error: + goto end; +} + +/** Utility function for determining if pcms are in running state. + * + */ +static int IsRunning( PaAlsaStream *stream ) +{ + int result = 0; + + ASSERT_CALL_( pthread_mutex_lock( &stream->stateMtx ), 0 ); /* Synchronize access to pcm state */ + if( stream->capture.pcm ) + { + snd_pcm_state_t capture_state = snd_pcm_state( stream->capture.pcm ); + + if( capture_state == SND_PCM_STATE_RUNNING || capture_state == SND_PCM_STATE_XRUN + || capture_state == SND_PCM_STATE_DRAINING ) + { + result = 1; + goto end; + } + } + + if( stream->playback.pcm ) + { + snd_pcm_state_t playback_state = snd_pcm_state( stream->playback.pcm ); + + if( playback_state == SND_PCM_STATE_RUNNING || playback_state == SND_PCM_STATE_XRUN + || playback_state == SND_PCM_STATE_DRAINING ) + { + result = 1; + goto end; + } + } + +end: + ASSERT_CALL_( pthread_mutex_unlock( &stream->stateMtx ), 0 ); + + return result; +} + +static PaError StartStream( PaStream *s ) +{ + PaError result = paNoError; + PaAlsaStream *stream = (PaAlsaStream*)s; + int streamStarted = 0; /* So we can know wether we need to take the stream down */ + + /* Ready the processor */ + PaUtil_ResetBufferProcessor( &stream->bufferProcessor ); + + /* Set now, so we can test for activity further down */ + stream->isActive = 1; + + if( stream->callbackMode ) + { + int res = 0; + PaTime pt = PaUtil_GetTime(); + struct timespec ts; + + PA_ENSURE( CreateCallbackThread( &stream->threading, &CallbackThreadFunc, stream ) ); + streamStarted = 1; + + /* Wait for stream to be started */ + ts.tv_sec = (time_t) floor( pt + 1 ); + ts.tv_nsec = (long) ((pt - floor( pt )) * 1000000000); + + /* Since we'll be holding a lock on the startMtx (when not waiting on the condition), IsRunning won't be checking + * stream state at the same time as the callback thread affects it. We also check IsStreamActive, in the unlikely + * case the callback thread exits in the meantime (the stream will be considered inactive after the thread exits) */ + ASSERT_CALL_( pthread_mutex_lock( &stream->startMtx ), 0 ); + + /* Due to possible spurious wakeups, we enclose in a loop */ + while( !IsRunning( stream ) && IsStreamActive( s ) && !res ) + { + res = pthread_cond_timedwait( &stream->startCond, &stream->startMtx, &ts ); + } + ASSERT_CALL_( pthread_mutex_unlock( &stream->startMtx ), 0 ); + + PA_UNLESS( !res || res == ETIMEDOUT, paInternalError ); + PA_DEBUG(( "%s: Waited for %g seconds for stream to start\n", __FUNCTION__, PaUtil_GetTime() - pt )); + + if( res == ETIMEDOUT ) + { + PA_ENSURE( paTimedOut ); + } + } + else + { + PA_ENSURE( AlsaStart( stream, 0 ) ); + streamStarted = 1; + } + +end: + return result; +error: + if( streamStarted ) + AbortStream( stream ); + stream->isActive = 0; + + goto end; +} + +static PaError AlsaStop( PaAlsaStream *stream, int abort ) +{ + PaError result = paNoError; + + if( abort ) + { + if( stream->playback.pcm ) + ENSURE_( snd_pcm_drop( stream->playback.pcm ), paUnanticipatedHostError ); + if( stream->capture.pcm && !stream->pcmsSynced ) + ENSURE_( snd_pcm_drop( stream->capture.pcm ), paUnanticipatedHostError ); + + PA_DEBUG(( "Dropped frames\n" )); + } + else + { + if( stream->playback.pcm ) + ENSURE_( snd_pcm_drain( stream->playback.pcm ), paUnanticipatedHostError ); + if( stream->capture.pcm && !stream->pcmsSynced ) + ENSURE_( snd_pcm_drain( stream->capture.pcm ), paUnanticipatedHostError ); + } + +end: + return result; +error: + goto end; +} + +/** Stop or abort stream. + * + * If a stream is in callback mode we will have to inspect wether the background thread has + * finished, or we will have to take it out. In either case we join the thread before + * returning. In blocking mode, we simply tell ALSA to stop abruptly (abort) or finish + * buffers (drain) + * + * Stream will be considered inactive (!PaAlsaStream::isActive) after a call to this function + */ +static PaError RealStop( PaAlsaStream *stream, int abort ) +{ + PaError result = paNoError; + + /* First deal with the callback thread, cancelling and/or joining + * it if necessary + */ + if( stream->callbackMode ) + { + PaError threadRes, watchdogRes; + stream->callbackAbort = abort; + + if( !abort ) + { + PA_DEBUG(( "Stopping callback\n" )); + stream->callbackStop = 1; + } + PA_ENSURE( KillCallbackThread( &stream->threading, !abort, &threadRes, &watchdogRes ) ); + if( threadRes != paNoError ) + PA_DEBUG(( "Callback thread returned: %d\n", threadRes )); + if( watchdogRes != paNoError ) + PA_DEBUG(( "Watchdog thread returned: %d\n", watchdogRes )); + + stream->callbackStop = 0; /* The deed is done */ + stream->callback_finished = 0; + } + else + { + PA_ENSURE( AlsaStop( stream, abort ) ); + } + + stream->isActive = 0; + +end: + return result; + +error: + goto end; +} + +static PaError StopStream( PaStream *s ) +{ + return RealStop( (PaAlsaStream *) s, 0 ); +} + +static PaError AbortStream( PaStream *s ) +{ + return RealStop( (PaAlsaStream * ) s, 1 ); +} + +/** The stream is considered stopped before StartStream, or AFTER a call to Abort/StopStream (callback + * returning !paContinue is not considered) + * + */ +static PaError IsStreamStopped( PaStream *s ) +{ + PaAlsaStream *stream = (PaAlsaStream *)s; + + /* callback_finished indicates we need to join callback thread (ie. in Abort/StopStream) */ + return !IsStreamActive( s ) && !stream->callback_finished; +} + +static PaError IsStreamActive( PaStream *s ) +{ + PaAlsaStream *stream = (PaAlsaStream*)s; + return stream->isActive; +} + +static PaTime GetStreamTime( PaStream *s ) +{ + PaAlsaStream *stream = (PaAlsaStream*)s; + + snd_timestamp_t timestamp; + snd_pcm_status_t *status; + snd_pcm_status_alloca( &status ); + + /* TODO: what if we have both? does it really matter? */ + + /* TODO: if running in callback mode, this will mean + * libasound routines are being called from multiple threads. + * need to verify that libasound is thread-safe. */ + + if( stream->capture.pcm ) + { + snd_pcm_status( stream->capture.pcm, status ); + } + else if( stream->playback.pcm ) + { + snd_pcm_status( stream->playback.pcm, status ); + } + + snd_pcm_status_get_tstamp( status, ×tamp ); + return timestamp.tv_sec + (PaTime)timestamp.tv_usec / 1000000.0; +} + +static double GetStreamCpuLoad( PaStream* s ) +{ + PaAlsaStream *stream = (PaAlsaStream*)s; + + return PaUtil_GetCpuLoad( &stream->cpuLoadMeasurer ); +} + +static int SetApproximateSampleRate( snd_pcm_t *pcm, snd_pcm_hw_params_t *hwParams, double sampleRate ) +{ + unsigned long approx = (unsigned long) sampleRate; + int dir = 0; + double fraction = sampleRate - approx; + + assert( pcm && hwParams ); + + if( fraction > 0.0 ) + { + if( fraction > 0.5 ) + { + ++approx; + dir = -1; + } + else + dir = 1; + } + + return snd_pcm_hw_params_set_rate( pcm, hwParams, approx, dir ); +} + +/* Return exact sample rate in param sampleRate */ +static int GetExactSampleRate( snd_pcm_hw_params_t *hwParams, double *sampleRate ) +{ + unsigned int num, den; + int err; + + assert( hwParams ); + + err = snd_pcm_hw_params_get_rate_numden( hwParams, &num, &den ); + *sampleRate = (double) num / den; + + return err; +} + +/* Utility functions for blocking/callback interfaces */ + +/* Atomic restart of stream (we don't want the intermediate state visible) */ +static PaError AlsaRestart( PaAlsaStream *stream ) +{ + PaError result = paNoError; + + ASSERT_CALL_( pthread_mutex_lock( &stream->stateMtx ), 0 ); + PA_ENSURE( AlsaStop( stream, 0 ) ); + PA_ENSURE( AlsaStart( stream, 0 ) ); + + PA_DEBUG(( "%s: Restarted audio\n", __FUNCTION__ )); + +error: + ASSERT_CALL_( pthread_mutex_unlock( &stream->stateMtx ), 0 ); + return result; +} + +/** Recover from xrun state. + * + */ +static PaError PaAlsaStream_HandleXrun( PaAlsaStream *self ) +{ + PaError result = paNoError; + snd_pcm_status_t *st; + PaTime now = PaUtil_GetTime(); + snd_timestamp_t t; + + snd_pcm_status_alloca( &st ); + + if( self->playback.pcm ) + { + snd_pcm_status( self->playback.pcm, st ); + if( snd_pcm_status_get_state( st ) == SND_PCM_STATE_XRUN ) + { + snd_pcm_status_get_trigger_tstamp( st, &t ); + self->underrun = now * 1000 - ((PaTime) t.tv_sec * 1000 + (PaTime) t.tv_usec / 1000); + } + } + if( self->capture.pcm ) + { + snd_pcm_status( self->capture.pcm, st ); + if( snd_pcm_status_get_state( st ) == SND_PCM_STATE_XRUN ) + { + snd_pcm_status_get_trigger_tstamp( st, &t ); + self->overrun = now * 1000 - ((PaTime) t.tv_sec * 1000 + (PaTime) t.tv_usec / 1000); + } + } + + PA_ENSURE( AlsaRestart( self ) ); + +end: + return result; +error: + goto end; +} + +/** Decide if we should continue polling for specified direction, eventually adjust the poll timeout. + * + */ +static PaError ContinuePoll( const PaAlsaStream *stream, StreamDirection streamDir, int *pollTimeout, int *continuePoll ) +{ + PaError result = paNoError; + snd_pcm_sframes_t delay, margin; + int err; + const PaAlsaStreamComponent *component = NULL, *otherComponent = NULL; + + *continuePoll = 1; + + if( StreamDirection_In == streamDir ) + { + component = &stream->capture; + otherComponent = &stream->playback; + } + else + { + component = &stream->playback; + otherComponent = &stream->capture; + } + + /* ALSA docs say that negative delay should indicate xrun, but in my experience snd_pcm_delay returns -EPIPE */ + if( (err = snd_pcm_delay( otherComponent->pcm, &delay )) < 0 ) + { + if( err == -EPIPE ) + { + /* Xrun */ + *continuePoll = 0; + goto error; + } + + ENSURE_( err, paUnanticipatedHostError ); + } + + if( StreamDirection_Out == streamDir ) + { + /* Number of eligible frames before capture overrun */ + delay = otherComponent->bufferSize - delay; + } + margin = delay - otherComponent->framesPerBuffer / 2; + + if( margin < 0 ) + { + PA_DEBUG(( "%s: Stopping poll for %s\n", __FUNCTION__, StreamDirection_In == streamDir ? "capture" : "playback" )); + *continuePoll = 0; + } + else if( margin < otherComponent->framesPerBuffer ) + { + *pollTimeout = CalculatePollTimeout( stream, margin ); + PA_DEBUG(( "%s: Trying to poll again for %s frames, pollTimeout: %d\n", + __FUNCTION__, StreamDirection_In == streamDir ? "capture" : "playback", *pollTimeout )); + } + +error: + return result; +} + +/* Callback interface */ + +static void OnExit( void *data ) +{ + PaAlsaStream *stream = (PaAlsaStream *) data; + + assert( data ); + + PaUtil_ResetCpuLoadMeasurer( &stream->cpuLoadMeasurer ); + + stream->callback_finished = 1; /* Let the outside world know stream was stopped in callback */ + AlsaStop( stream, stream->callbackAbort ); + stream->callbackAbort = 0; /* Clear state */ + + PA_DEBUG(( "OnExit: Stoppage\n" )); + + /* Eventually notify user all buffers have played */ + if( stream->streamRepresentation.streamFinishedCallback ) + stream->streamRepresentation.streamFinishedCallback( stream->streamRepresentation.userData ); + stream->isActive = 0; +} + +static void CalculateTimeInfo( PaAlsaStream *stream, PaStreamCallbackTimeInfo *timeInfo ) +{ + snd_pcm_status_t *capture_status, *playback_status; + snd_timestamp_t capture_timestamp, playback_timestamp; + PaTime capture_time = 0., playback_time = 0.; + + snd_pcm_status_alloca( &capture_status ); + snd_pcm_status_alloca( &playback_status ); + + if( stream->capture.pcm ) + { + snd_pcm_sframes_t capture_delay; + + snd_pcm_status( stream->capture.pcm, capture_status ); + snd_pcm_status_get_tstamp( capture_status, &capture_timestamp ); + + capture_time = capture_timestamp.tv_sec + + ((PaTime)capture_timestamp.tv_usec / 1000000.0); + timeInfo->currentTime = capture_time; + + capture_delay = snd_pcm_status_get_delay( capture_status ); + timeInfo->inputBufferAdcTime = timeInfo->currentTime - + (PaTime)capture_delay / stream->streamRepresentation.streamInfo.sampleRate; + } + if( stream->playback.pcm ) + { + snd_pcm_sframes_t playback_delay; + + snd_pcm_status( stream->playback.pcm, playback_status ); + snd_pcm_status_get_tstamp( playback_status, &playback_timestamp ); + + playback_time = playback_timestamp.tv_sec + + ((PaTime)playback_timestamp.tv_usec / 1000000.0); + + if( stream->capture.pcm ) /* Full duplex */ + { + /* Hmm, we have both a playback and a capture timestamp. + * Hopefully they are the same... */ + if( fabs( capture_time - playback_time ) > 0.01 ) + PA_DEBUG(("Capture time and playback time differ by %f\n", fabs(capture_time-playback_time))); + } + else + timeInfo->currentTime = playback_time; + + playback_delay = snd_pcm_status_get_delay( playback_status ); + timeInfo->outputBufferDacTime = timeInfo->currentTime + + (PaTime)playback_delay / stream->streamRepresentation.streamInfo.sampleRate; + } +} + +/** Called after buffer processing is finished. + * + * A number of mmapped frames is committed, it is possible that an xrun has occurred in the meantime. + * + * @param numFrames The number of frames that has been processed + * @param xrun Return whether an xrun has occurred + */ +static PaError PaAlsaStreamComponent_EndProcessing( PaAlsaStreamComponent *self, unsigned long numFrames, int *xrun ) +{ + PaError result = paNoError; + int res; + + /* @concern FullDuplex It is possible that only one direction is marked ready after polling, and processed + * afterwards + */ + if( !self->ready ) + goto end; + + res = snd_pcm_mmap_commit( self->pcm, self->offset, numFrames ); + if( res == -EPIPE || res == -ESTRPIPE ) + { + *xrun = 1; + } + else + { + ENSURE_( res, paUnanticipatedHostError ); + } + +end: +error: + return result; +} + +/* Extract buffer from channel area */ +static unsigned char *ExtractAddress( const snd_pcm_channel_area_t *area, snd_pcm_uframes_t offset ) +{ + return (unsigned char *) area->addr + (area->first + offset * area->step) / 8; +} + +/** Do necessary adaption between user and host channels. + * + @concern ChannelAdaption Adapting between user and host channels can involve silencing unused channels and + duplicating mono information if host outputs come in pairs. + */ +static PaError PaAlsaStreamComponent_DoChannelAdaption( PaAlsaStreamComponent *self, PaUtilBufferProcessor *bp, int numFrames ) +{ + PaError result = paNoError; + unsigned char *p; + int i; + int unusedChans = self->numHostChannels - self->numUserChannels; + unsigned char *src, *dst; + int convertMono = (self->numHostChannels % 2) == 0 && (self->numUserChannels % 2) != 0; + + assert( StreamDirection_Out == self->streamDir ); + + if( self->hostInterleaved ) + { + int swidth = snd_pcm_format_size( self->nativeFormat, 1 ); + unsigned char *buffer = ExtractAddress( self->channelAreas, self->offset ); + + /* Start after the last user channel */ + p = buffer + self->numUserChannels * swidth; + + if( convertMono ) + { + /* Convert the last user channel into stereo pair */ + src = buffer + (self->numUserChannels - 1) * swidth; + for( i = 0; i < numFrames; ++i ) + { + dst = src + swidth; + memcpy( dst, src, swidth ); + src += self->numHostChannels * swidth; + } + + /* Don't touch the channel we just wrote to */ + p += swidth; + --unusedChans; + } + + if( unusedChans > 0 ) + { + /* Silence unused output channels */ + for( i = 0; i < numFrames; ++i ) + { + memset( p, 0, swidth * unusedChans ); + p += self->numHostChannels * swidth; + } + } + } + else + { + /* We extract the last user channel */ + if( convertMono ) + { + ENSURE_( snd_pcm_area_copy( self->channelAreas + self->numUserChannels, self->offset, self->channelAreas + + (self->numUserChannels - 1), self->offset, numFrames, self->nativeFormat ), paUnanticipatedHostError ); + --unusedChans; + } + if( unusedChans > 0 ) + { + snd_pcm_areas_silence( self->channelAreas + (self->numHostChannels - unusedChans), self->offset, unusedChans, numFrames, + self->nativeFormat ); + } + } + +error: + return result; +} + +static PaError PaAlsaStream_EndProcessing( PaAlsaStream *self, unsigned long numFrames, int *xrunOccurred ) +{ + PaError result = paNoError; + int xrun = 0; + + if( self->capture.pcm ) + { + PA_ENSURE( PaAlsaStreamComponent_EndProcessing( &self->capture, numFrames, &xrun ) ); + } + if( self->playback.pcm ) + { + if( self->playback.numHostChannels > self->playback.numUserChannels ) + PA_ENSURE( PaAlsaStreamComponent_DoChannelAdaption( &self->playback, &self->bufferProcessor, numFrames ) ); + PA_ENSURE( PaAlsaStreamComponent_EndProcessing( &self->playback, numFrames, &xrun ) ); + } + +error: + *xrunOccurred = xrun; + return result; +} + +/** Update the number of available frames. + * + */ +static PaError PaAlsaStreamComponent_GetAvailableFrames( PaAlsaStreamComponent *self, unsigned long *numFrames, int *xrunOccurred ) +{ + PaError result = paNoError; + snd_pcm_sframes_t framesAvail = snd_pcm_avail_update( self->pcm ); + *xrunOccurred = 0; + + if( -EPIPE == framesAvail ) + { + *xrunOccurred = 1; + framesAvail = 0; + } + else + ENSURE_( framesAvail, paUnanticipatedHostError ); + + *numFrames = framesAvail; + +error: + return result; +} + +/** Fill in pollfd objects. + */ +static PaError PaAlsaStreamComponent_BeginPolling( PaAlsaStreamComponent *self, struct pollfd *pfds ) +{ + PaError result = paNoError; + int ret = snd_pcm_poll_descriptors( self->pcm, pfds, self->nfds ); + assert( ret == self->nfds ); + + self->ready = 0; + + return result; +} + +/** Examine results from poll(). + * + * @param pfds pollfds to inspect + * @param shouldPoll Should we continue to poll + * @param xrun Has an xrun occurred + */ +static PaError PaAlsaStreamComponent_EndPolling( PaAlsaStreamComponent *self, struct pollfd *pfds, int *shouldPoll, int *xrun ) +{ + PaError result = paNoError; + unsigned short revents; + + ENSURE_( snd_pcm_poll_descriptors_revents( self->pcm, pfds, self->nfds, &revents ), paUnanticipatedHostError ); + if( revents != 0 ) + { + if( revents & POLLERR ) + { + *xrun = 1; + } + else + self->ready = 1; + + *shouldPoll = 0; + } + +error: + return result; +} + +/** Return the number of available frames for this stream. + * + * @concern FullDuplex The minimum available for the two directions is calculated, it might be desirable to ignore + * one direction however (not marked ready from poll), so this is controlled by queryCapture and queryPlayback. + * + * @param queryCapture Check available for capture + * @param queryPlayback Check available for playback + * @param available The returned number of frames + * @param xrunOccurred Return whether an xrun has occurred + */ +static PaError PaAlsaStream_GetAvailableFrames( PaAlsaStream *self, int queryCapture, int queryPlayback, unsigned long + *available, int *xrunOccurred ) +{ + PaError result = paNoError; + unsigned long captureFrames, playbackFrames; + *xrunOccurred = 0; + + assert( queryCapture || queryPlayback ); + + if( queryCapture ) + { + assert( self->capture.pcm ); + PA_ENSURE( PaAlsaStreamComponent_GetAvailableFrames( &self->capture, &captureFrames, xrunOccurred ) ); + if( *xrunOccurred ) + goto end; + } + if( queryPlayback ) + { + assert( self->playback.pcm ); + PA_ENSURE( PaAlsaStreamComponent_GetAvailableFrames( &self->playback, &playbackFrames, xrunOccurred ) ); + if( *xrunOccurred ) + goto end; + } + + if( queryCapture && queryPlayback ) + { + *available = PA_MIN( captureFrames, playbackFrames ); + } + else if( queryCapture ) + { + *available = captureFrames; + } + else + { + *available = playbackFrames; + } + +end: +error: + return result; +} + +/** Wait for and report available buffer space from ALSA. + * + * Unless ALSA reports a minimum of frames available for I/O, we poll the ALSA filedescriptors for more. + * Both of these operations can uncover xrun conditions. + * + * @concern Xruns Both polling and querying available frames can report an xrun condition. + * + * @param framesAvail Return the number of available frames + * @param xrunOccurred Return whether an xrun has occurred + */ +static PaError PaAlsaStream_WaitForFrames( PaAlsaStream *self, unsigned long *framesAvail, int *xrunOccurred ) +{ + PaError result = paNoError; + int pollPlayback = self->playback.pcm != NULL, pollCapture = self->capture.pcm != NULL; + int pollTimeout = self->pollTimeout; + int xrun = 0; + + assert( self ); + assert( framesAvail ); + + if( !self->callbackMode ) + { + /* In blocking mode we will only wait if necessary */ + PA_ENSURE( PaAlsaStream_GetAvailableFrames( self, self->capture.pcm != NULL, self->playback.pcm != NULL, + framesAvail, &xrun ) ); + if( xrun ) + { + goto end; + } + + if( *framesAvail > 0 ) + { + /* Mark pcms ready from poll */ + if( self->capture.pcm ) + self->capture.ready = 1; + if( self->playback.pcm ) + self->playback.ready = 1; + + goto end; + } + } + + while( pollPlayback || pollCapture ) + { + int totalFds = 0; + struct pollfd *capturePfds = NULL, *playbackPfds = NULL; + + pthread_testcancel(); + + if( pollCapture ) + { + capturePfds = self->pfds; + PA_ENSURE( PaAlsaStreamComponent_BeginPolling( &self->capture, capturePfds ) ); + totalFds += self->capture.nfds; + } + if( pollPlayback ) + { + playbackPfds = self->pfds + (self->capture.pcm ? self->capture.nfds : 0); + PA_ENSURE( PaAlsaStreamComponent_BeginPolling( &self->playback, playbackPfds ) ); + totalFds += self->playback.nfds; + } + + if( poll( self->pfds, totalFds, pollTimeout ) < 0 ) + { + /* XXX: Depend on preprocessor condition? */ + if( errno == EINTR ) { /* gdb */ + continue; + } + + /* TODO: Add macro for checking system calls */ + PA_ENSURE( paInternalError ); + } + + /* check the return status of our pfds */ + if( pollCapture ) + { + PA_ENSURE( PaAlsaStreamComponent_EndPolling( &self->capture, capturePfds, &pollCapture, &xrun ) ); + } + if( pollPlayback ) + { + PA_ENSURE( PaAlsaStreamComponent_EndPolling( &self->playback, playbackPfds, &pollPlayback, &xrun ) ); + } + if( xrun ) + { + break; + } + + /* @concern FullDuplex If only one of two pcms is ready we may want to compromise between the two. + * If there is less than half a period's worth of samples left of frames in the other pcm's buffer we will + * stop polling. + */ + if( self->capture.pcm && self->playback.pcm ) + { + if( pollCapture && !pollPlayback ) + { + PA_ENSURE( ContinuePoll( self, StreamDirection_In, &pollTimeout, &pollCapture ) ); + } + else if( pollPlayback && !pollCapture ) + { + PA_ENSURE( ContinuePoll( self, StreamDirection_Out, &pollTimeout, &pollPlayback ) ); + } + } + } + + if( !xrun ) + { + /* Get the number of available frames for the pcms that are marked ready. + * @concern FullDuplex If only one direction is marked ready (from poll), the number of frames available for + * the other direction is returned. This under the assumption that input is dropped earlier if paNeverDropInput + * is not specified. + */ + int captureReady = self->capture.pcm ? self->capture.ready : 0, + playbackReady = self->playback.pcm ? self->playback.ready : 0; + PA_ENSURE( PaAlsaStream_GetAvailableFrames( self, captureReady, playbackReady, framesAvail, &xrun ) ); + + if( self->capture.pcm && self->playback.pcm ) + { + if( !self->playback.ready && !self->neverDropInput ) + { + /* TODO: Drop input */ + } + } + } + +end: +error: + if( xrun ) + { + /* Recover from the xrun state */ + PA_ENSURE( PaAlsaStream_HandleXrun( self ) ); + *framesAvail = 0; + } + *xrunOccurred = xrun; + + return result; +} + +/** Register per-channel ALSA buffer information with buffer processor. + * + * Mmapped buffer space is acquired from ALSA, and registered with the buffer processor. Differences between the + * number of host and user channels is taken into account. + * + * @param numFrames On entrance the number of requested frames, on exit the number of contiguously accessible frames. + */ +static PaError PaAlsaStreamComponent_RegisterChannels( PaAlsaStreamComponent *self, PaUtilBufferProcessor *bp, + unsigned long *numFrames, int *xrun ) +{ + PaError result = paNoError; + const snd_pcm_channel_area_t *areas, *area; + void (*setChannel)(PaUtilBufferProcessor *, unsigned int, void *, unsigned int) = + StreamDirection_In == self->streamDir ? PaUtil_SetInputChannel : PaUtil_SetOutputChannel; + unsigned char *buffer, *p; + int i; + unsigned long framesAvail; + + /* This _must_ be called before mmap_begin */ + PA_ENSURE( PaAlsaStreamComponent_GetAvailableFrames( self, &framesAvail, xrun ) ); + if( *xrun ) + { + *numFrames = 0; + goto end; + } + + ENSURE_( snd_pcm_mmap_begin( self->pcm, &areas, &self->offset, numFrames ), paUnanticipatedHostError ); + + if( self->hostInterleaved ) + { + int swidth = snd_pcm_format_size( self->nativeFormat, 1 ); + + p = buffer = ExtractAddress( areas, self->offset ); + for( i = 0; i < self->numUserChannels; ++i ) + { + /* We're setting the channels up to userChannels, but the stride will be hostChannels samples */ + setChannel( bp, i, p, self->numHostChannels ); + p += swidth; + } + } + else + { + for( i = 0; i < self->numUserChannels; ++i ) + { + area = areas + i; + buffer = ExtractAddress( area, self->offset ); + setChannel( bp, i, buffer, 1 ); + } + } + + /* @concern ChannelAdaption Buffer address is recorded so we can do some channel adaption later */ + self->channelAreas = (snd_pcm_channel_area_t *)areas; + +end: +error: + return result; +} + +/** Initiate buffer processing. + * + * ALSA buffers are registered with the PA buffer processor and the buffer size (in frames) set. + * + * @concern FullDuplex If both directions are being processed, the minimum amount of frames for the two directions is + * calculated. + * + * @param numFrames On entrance the number of available frames, on exit the number of received frames + * @param xrunOccurred Return whether an xrun has occurred + */ +static PaError PaAlsaStream_SetUpBuffers( PaAlsaStream *self, unsigned long *numFrames, int *xrunOccurred ) +{ + PaError result = paNoError; + unsigned long captureFrames = ULONG_MAX, playbackFrames = ULONG_MAX, commonFrames = 0; + int xrun = 0; + + /* Extract per-channel ALSA buffer pointers and register them with the buffer processor. + * It is possible that a direction is not marked ready however, because it is out of sync with the other. + */ + if( self->capture.pcm && self->capture.ready ) + { + captureFrames = *numFrames; + PA_ENSURE( PaAlsaStreamComponent_RegisterChannels( &self->capture, &self->bufferProcessor, &captureFrames, + &xrun ) ); + } + if( self->playback.pcm && self->playback.ready ) + { + playbackFrames = *numFrames; + PA_ENSURE( PaAlsaStreamComponent_RegisterChannels( &self->playback, &self->bufferProcessor, &playbackFrames, + &xrun ) ); + } + if( xrun ) + { + /* Nothing more to do */ + assert( 0 == commonFrames ); + goto end; + } + + commonFrames = PA_MIN( captureFrames, playbackFrames ); + assert( commonFrames <= *numFrames ); + + /* Inform PortAudio of the number of frames we got. + * @concern FullDuplex We might be experiencing underflow in either end; if its an input underflow, we go on + * with output. If its output underflow however, depending on the paNeverDropInput flag, we may want to simply + * discard the excess input or call the callback with paOutputOverflow flagged. + */ + if( self->capture.pcm ) + { + if( self->capture.ready ) + { + PaUtil_SetInputFrameCount( &self->bufferProcessor, commonFrames ); + } + else + { + /* We have input underflow */ + PaUtil_SetNoInput( &self->bufferProcessor ); + } + } + if( self->playback.pcm ) + { + if( self->playback.ready ) + { + PaUtil_SetOutputFrameCount( &self->bufferProcessor, commonFrames ); + } + else + { + /* We have output underflow, but keeping input data (paNeverDropInput) */ + /* assert( self->neverDropInput ); */ + PaUtil_SetNoOutput( &self->bufferProcessor ); + } + } + +end: + *numFrames = commonFrames; +error: + if( xrun ) + { + PA_ENSURE( PaAlsaStream_HandleXrun( self ) ); + *numFrames = 0; + } + *xrunOccurred = xrun; + + return result; +} + +/** Callback thread's function. + * + * Roughly, the workflow can be described in the following way: The number of available frames that can be processed + * directly is obtained from ALSA, we then request as much directly accessible memory as possible within this amount + * from ALSA. The buffer memory is registered with the PA buffer processor and processing is carried out with + * PaUtil_EndBufferProcessing. Finally, the number of processed frames is reported to ALSA. The processing can + * happen in several iterations untill we have consumed the known number of available frames (or an xrun is detected). + */ +static void *CallbackThreadFunc( void *userData ) +{ + PaError result = paNoError, *pres = NULL; + PaAlsaStream *stream = (PaAlsaStream*) userData; + PaStreamCallbackTimeInfo timeInfo = {0, 0, 0}; + snd_pcm_sframes_t startThreshold = 0; + int callbackResult = paContinue; + PaStreamCallbackFlags cbFlags = 0; /* We might want to keep state across iterations */ + int streamStarted = 0; + + assert( stream ); + + callbackThread_ = pthread_self(); + /* Execute OnExit when exiting */ + pthread_cleanup_push( &OnExit, stream ); + + /* Not implemented */ + assert( !stream->primeBuffers ); + + /* @concern StreamStart If the output is being primed the output pcm needs to be prepared, otherwise the + * stream is started immediately. The latter involves signaling the waiting main thread. + */ + if( stream->primeBuffers ) + { + snd_pcm_sframes_t avail; + + if( stream->playback.pcm ) + ENSURE_( snd_pcm_prepare( stream->playback.pcm ), paUnanticipatedHostError ); + if( stream->capture.pcm && !stream->pcmsSynced ) + ENSURE_( snd_pcm_prepare( stream->capture.pcm ), paUnanticipatedHostError ); + + /* We can't be certain that the whole ring buffer is available for priming, but there should be + * at least one period */ + avail = snd_pcm_avail_update( stream->playback.pcm ); + startThreshold = avail - (avail % stream->playback.framesPerBuffer); + assert( startThreshold >= stream->playback.framesPerBuffer ); + } + else + { + ASSERT_CALL_( pthread_mutex_lock( &stream->startMtx ), 0 ); + PA_ENSURE( AlsaStart( stream, 0 ) ); /* Buffer will be zeroed */ + ASSERT_CALL_( pthread_cond_signal( &stream->startCond ), 0 ); + ASSERT_CALL_( pthread_mutex_unlock( &stream->startMtx ), 0 ); + + streamStarted = 1; + } + + while( 1 ) + { + unsigned long framesAvail, framesGot; + int xrun = 0; + + pthread_testcancel(); + + /* @concern StreamStop if the main thread has requested a stop and the stream has not been effectively + * stopped we signal this condition by modifying callbackResult (we'll want to flush buffered output). + */ + if( stream->callbackStop && paContinue == callbackResult ) + { + PA_DEBUG(( "Setting callbackResult to paComplete\n" )); + callbackResult = paComplete; + } + + if( paContinue != callbackResult ) + { + stream->callbackAbort = (paAbort == callbackResult); + if( stream->callbackAbort || + /** @concern BlockAdaption Go on if adaption buffers are empty */ + PaUtil_IsBufferProcessorOutputEmpty( &stream->bufferProcessor ) ) + goto end; + + PA_DEBUG(( "%s: Flushing buffer processor\n", __FUNCTION__ )); + /* There is still buffered output that needs to be processed */ + } + + /* Wait for data to become available, this comes down to polling the ALSA file descriptors untill we have + * a number of available frames. + */ + PA_ENSURE( PaAlsaStream_WaitForFrames( stream, &framesAvail, &xrun ) ); + if( xrun ) + { + assert( 0 == framesAvail ); + continue; + + /* XXX: Report xruns to the user? A situation is conceivable where the callback is never invoked due + * to constant xruns, it might be desirable to notify the user of this. + */ + } + + /* Consume buffer space. Once we have a number of frames available for consumption we must retrieve the + * mmapped buffers from ALSA, this is contiguously accessible memory however, so we may receive smaller + * portions at a time than is available as a whole. Therefore we should be prepared to process several + * chunks successively. The buffers are passed to the PA buffer processor. + */ + while( framesAvail > 0 ) + { + xrun = 0; + + pthread_testcancel(); + + /** @concern Xruns Under/overflows are to be reported to the callback */ + if( stream->underrun > 0.0 ) + { + cbFlags |= paOutputUnderflow; + stream->underrun = 0.0; + } + if( stream->overrun > 0.0 ) + { + cbFlags |= paInputOverflow; + stream->overrun = 0.0; + } + if( stream->capture.pcm && stream->playback.pcm ) + { + /** @concern FullDuplex It's possible that only one direction is being processed to avoid an + * under- or overflow, this should be reported correspondingly */ + if( !stream->capture.ready ) + { + cbFlags |= paInputUnderflow; + PA_DEBUG(( "%s: Input underflow\n", __FUNCTION__ )); + } + else if( !stream->playback.ready ) + { + cbFlags |= paOutputOverflow; + PA_DEBUG(( "%s: Output overflow\n", __FUNCTION__ )); + } + } + + CallbackUpdate( &stream->threading ); + CalculateTimeInfo( stream, &timeInfo ); + PaUtil_BeginBufferProcessing( &stream->bufferProcessor, &timeInfo, cbFlags ); + cbFlags = 0; + + /* CPU load measurement should include processing activivity external to the stream callback */ + PaUtil_BeginCpuLoadMeasurement( &stream->cpuLoadMeasurer ); + + framesGot = framesAvail; + PA_ENSURE( PaAlsaStream_SetUpBuffers( stream, &framesGot, &xrun ) ); + framesAvail -= framesGot; + + if( framesGot > 0 ) + { + assert( !xrun ); + + PaUtil_EndBufferProcessing( &stream->bufferProcessor, &callbackResult ); + PA_ENSURE( PaAlsaStream_EndProcessing( stream, framesGot, &xrun ) ); + } + PaUtil_EndCpuLoadMeasurement( &stream->cpuLoadMeasurer, framesGot ); + + if( framesGot == 0 ) + { + if( !xrun ) + PA_DEBUG(( "%s: Received less frames than reported from ALSA!\n", __FUNCTION__ )); + + /* Go back to polling for more frames */ + break; + + } + + if( paContinue != callbackResult ) + break; + } + } + + /* Match pthread_cleanup_push */ + pthread_cleanup_pop( 1 ); + +end: + pthread_exit( pres ); + +error: + /* Pass on error code */ + pres = malloc( sizeof (PaError) ); + *pres = result; + + goto end; +} + +/* Blocking interface */ + +static PaError ReadStream( PaStream* s, void *buffer, unsigned long frames ) +{ + PaError result = paNoError; + PaAlsaStream *stream = (PaAlsaStream*)s; + unsigned long framesGot, framesAvail; + void *userBuffer; + snd_pcm_t *save = stream->playback.pcm; + + assert( stream ); + + PA_UNLESS( stream->capture.pcm, paCanNotReadFromAnOutputOnlyStream ); + + /* Disregard playback */ + stream->playback.pcm = NULL; + + if( stream->overrun > 0. ) + { + result = paInputOverflowed; + stream->overrun = 0.0; + } + + if( stream->capture.userInterleaved ) + userBuffer = buffer; + else + { + /* Copy channels into local array */ + userBuffer = stream->capture.userBuffers; + memcpy( userBuffer, buffer, sizeof (void *) * stream->capture.numUserChannels ); + } + + /* Start stream if in prepared state */ + if( snd_pcm_state( stream->capture.pcm ) == SND_PCM_STATE_PREPARED ) + { + ENSURE_( snd_pcm_start( stream->capture.pcm ), paUnanticipatedHostError ); + } + + while( frames > 0 ) + { + int xrun = 0; + PA_ENSURE( PaAlsaStream_WaitForFrames( stream, &framesAvail, &xrun ) ); + framesGot = PA_MIN( framesAvail, frames ); + + PA_ENSURE( PaAlsaStream_SetUpBuffers( stream, &framesGot, &xrun ) ); + if( framesGot > 0 ) + { + framesGot = PaUtil_CopyInput( &stream->bufferProcessor, &userBuffer, framesGot ); + PA_ENSURE( PaAlsaStream_EndProcessing( stream, framesGot, &xrun ) ); + frames -= framesGot; + } + } + +end: + stream->playback.pcm = save; + return result; +error: + goto end; +} + +static PaError WriteStream( PaStream* s, const void *buffer, unsigned long frames ) +{ + PaError result = paNoError; + signed long err; + PaAlsaStream *stream = (PaAlsaStream*)s; + snd_pcm_uframes_t framesGot, framesAvail; + const void *userBuffer; + snd_pcm_t *save = stream->capture.pcm; + + assert( stream ); + + PA_UNLESS( stream->playback.pcm, paCanNotWriteToAnInputOnlyStream ); + + /* Disregard capture */ + stream->capture.pcm = NULL; + + if( stream->underrun > 0. ) + { + result = paOutputUnderflowed; + stream->underrun = 0.0; + } + + if( stream->playback.userInterleaved ) + userBuffer = buffer; + else /* Copy channels into local array */ + { + userBuffer = stream->playback.userBuffers; + memcpy( (void *)userBuffer, buffer, sizeof (void *) * stream->playback.numUserChannels ); + } + + while( frames > 0 ) + { + int xrun = 0; + snd_pcm_uframes_t hwAvail; + + PA_ENSURE( PaAlsaStream_WaitForFrames( stream, &framesAvail, &xrun ) ); + framesGot = PA_MIN( framesAvail, frames ); + + PA_ENSURE( PaAlsaStream_SetUpBuffers( stream, &framesGot, &xrun ) ); + if( framesGot > 0 ) + { + framesGot = PaUtil_CopyOutput( &stream->bufferProcessor, &userBuffer, framesGot ); + PA_ENSURE( PaAlsaStream_EndProcessing( stream, framesGot, &xrun ) ); + frames -= framesGot; + } + + /* Frames residing in buffer */ + PA_ENSURE( err = GetStreamWriteAvailable( stream ) ); + framesAvail = err; + hwAvail = stream->playback.bufferSize - framesAvail; + + /* Start stream after one period of samples worth */ + if( snd_pcm_state( stream->playback.pcm ) == SND_PCM_STATE_PREPARED && + hwAvail >= stream->playback.framesPerBuffer ) + { + ENSURE_( snd_pcm_start( stream->playback.pcm ), paUnanticipatedHostError ); + } + } + +end: + stream->capture.pcm = save; + return result; +error: + goto end; +} + +/* Return frames available for reading. In the event of an overflow, the capture pcm will be restarted */ +static signed long GetStreamReadAvailable( PaStream* s ) +{ + PaError result = paNoError; + PaAlsaStream *stream = (PaAlsaStream*)s; + unsigned long avail; + int xrun; + + PA_ENSURE( PaAlsaStreamComponent_GetAvailableFrames( &stream->capture, &avail, &xrun ) ); + if( xrun ) + { + PA_ENSURE( PaAlsaStream_HandleXrun( stream ) ); + PA_ENSURE( PaAlsaStreamComponent_GetAvailableFrames( &stream->capture, &avail, &xrun ) ); + if( xrun ) + PA_ENSURE( paInputOverflowed ); + } + + return (signed long)avail; + +error: + return result; +} + +static signed long GetStreamWriteAvailable( PaStream* s ) +{ + PaError result = paNoError; + PaAlsaStream *stream = (PaAlsaStream*)s; + unsigned long avail; + int xrun; + + PA_ENSURE( PaAlsaStreamComponent_GetAvailableFrames( &stream->playback, &avail, &xrun ) ); + if( xrun ) + { + snd_pcm_sframes_t savail; + + PA_ENSURE( PaAlsaStream_HandleXrun( stream ) ); + savail = snd_pcm_avail_update( stream->playback.pcm ); + + /* savail should not contain -EPIPE now, since PaAlsaStream_HandleXrun will only prepare the pcm */ + ENSURE_( savail, paUnanticipatedHostError ); + + avail = (unsigned long) savail; + } + + return (signed long)avail; + +error: + return result; +} + +/* Extensions */ + +/* Initialize host api specific structure */ +void PaAlsa_InitializeStreamInfo( PaAlsaStreamInfo *info ) +{ + info->size = sizeof (PaAlsaStreamInfo); + info->hostApiType = paALSA; + info->version = 1; + info->deviceString = NULL; +} + +void PaAlsa_EnableRealtimeScheduling( PaStream *s, int enable ) +{ + PaAlsaStream *stream = (PaAlsaStream *) s; + stream->threading.rtSched = enable; +} + +void PaAlsa_EnableWatchdog( PaStream *s, int enable ) +{ + PaAlsaStream *stream = (PaAlsaStream *) s; + stream->threading.useWatchdog = enable; +} |