diff options
Diffstat (limited to 'pjmedia/src/pjmedia/portaudio/pa_linux_alsa.c')
| -rw-r--r-- | pjmedia/src/pjmedia/portaudio/pa_linux_alsa.c | 3272 |
1 files changed, 3272 insertions, 0 deletions
diff --git a/pjmedia/src/pjmedia/portaudio/pa_linux_alsa.c b/pjmedia/src/pjmedia/portaudio/pa_linux_alsa.c new file mode 100644 index 00000000..8f115d0e --- /dev/null +++ b/pjmedia/src/pjmedia/portaudio/pa_linux_alsa.c @@ -0,0 +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;
+}
|