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/* $Id$ */
/*
* Copyright (C) 2003-2007 Benny Prijono <benny@prijono.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef __PJMEDIA_SOUND_PORT_H__
#define __PJMEDIA_SOUND_PORT_H__
/**
* @file sound_port.h
* @brief Media port connection abstraction to sound device.
*/
#include <pjmedia/sound.h>
#include <pjmedia/port.h>
PJ_BEGIN_DECL
/**
* @defgroup PJMED_SND_PORT Sound Device Port
* @ingroup PJMEDIA_PORT_CLOCK
* @brief Media Port Connection Abstraction to the Sound Device
@{
As explained in @ref PJMED_SND, the sound hardware abstraction provides
some callbacks for its user:
- it calls <b><tt>rec_cb</tt></b> callback when it has finished capturing
one media frame, and
- it calls <b><tt>play_cb</tt></b> when it needs media frame to be
played to the sound playback hardware.
The @ref PJMED_SND_PORT (the object being explained here) add a
thin wrapper to the hardware abstraction:
- it will call downstream port's <tt>put_frame()</tt>
when <b><tt>rec_cb()</tt></b> is called (i.e. when the sound hardware
has finished capturing frame), and
- it will call downstream port's <tt>get_frame()</tt> when
<b><tt>play_cb()</tt></b> is called (i.e. every time the
sound hardware needs more frames to be played to the playback hardware).
This simple abstraction enables media to flow automatically (and
in timely manner) from the downstream media port to the sound device.
In other words, the sound device port supplies media clock to
the ports. The media clock concept is explained in @ref PJMEDIA_PORT_CLOCK
section.
Application registers downstream port to the sound device port by
calling #pjmedia_snd_port_connect();
*/
/**
* This opaque type describes sound device port connection.
* Sound device port is not a media port, but it is used to connect media
* port to the sound device.
*/
typedef struct pjmedia_snd_port pjmedia_snd_port;
/**
* Create bidirectional sound port for both capturing and playback of
* audio samples.
*
* @param pool Pool to allocate sound port structure.
* @param rec_id Device index for recorder/capture stream, or
* -1 to use the first capable device.
* @param play_id Device index for playback stream, or -1 to use
* the first capable device.
* @param clock_rate Sound device's clock rate to set.
* @param channel_count Set number of channels, 1 for mono, or 2 for
* stereo. The channel count determines the format
* of the frame.
* @param samples_per_frame Number of samples per frame.
* @param bits_per_sample Set the number of bits per sample. The normal
* value for this parameter is 16 bits per sample.
* @param options Options flag, currently must be zero.
* @param p_port Pointer to receive the sound device port instance.
*
* @return PJ_SUCCESS on success, or the appropriate error
* code.
*/
PJ_DECL(pj_status_t) pjmedia_snd_port_create( pj_pool_t *pool,
int rec_id,
int play_id,
unsigned clock_rate,
unsigned channel_count,
unsigned samples_per_frame,
unsigned bits_per_sample,
unsigned options,
pjmedia_snd_port **p_port);
/**
* Create unidirectional sound device port for capturing audio streams from
* the sound device with the specified parameters.
*
* @param pool Pool to allocate sound port structure.
* @param index Device index, or -1 to let the library choose the
* first available device.
* @param clock_rate Sound device's clock rate to set.
* @param channel_count Set number of channels, 1 for mono, or 2 for
* stereo. The channel count determines the format
* of the frame.
* @param samples_per_frame Number of samples per frame.
* @param bits_per_sample Set the number of bits per sample. The normal
* value for this parameter is 16 bits per sample.
* @param options Options flag, currently must be zero.
* @param p_port Pointer to receive the sound device port instance.
*
* @return PJ_SUCCESS on success, or the appropriate error
* code.
*/
PJ_DECL(pj_status_t) pjmedia_snd_port_create_rec(pj_pool_t *pool,
int index,
unsigned clock_rate,
unsigned channel_count,
unsigned samples_per_frame,
unsigned bits_per_sample,
unsigned options,
pjmedia_snd_port **p_port);
/**
* Create unidirectional sound device port for playing audio streams with the
* specified parameters.
*
* @param pool Pool to allocate sound port structure.
* @param index Device index, or -1 to let the library choose the
* first available device.
* @param clock_rate Sound device's clock rate to set.
* @param channel_count Set number of channels, 1 for mono, or 2 for
* stereo. The channel count determines the format
* of the frame.
* @param samples_per_frame Number of samples per frame.
* @param bits_per_sample Set the number of bits per sample. The normal
* value for this parameter is 16 bits per sample.
* @param options Options flag, currently must be zero.
* @param p_port Pointer to receive the sound device port instance.
*
* @return PJ_SUCCESS on success, or the appropriate error
* code.
*/
PJ_DECL(pj_status_t) pjmedia_snd_port_create_player(pj_pool_t *pool,
int index,
unsigned clock_rate,
unsigned channel_count,
unsigned samples_per_frame,
unsigned bits_per_sample,
unsigned options,
pjmedia_snd_port **p_port);
/**
* Destroy sound device port.
*
* @param snd_port The sound device port.
*
* @return PJ_SUCCESS on success, or the appropriate error
* code.
*/
PJ_DECL(pj_status_t) pjmedia_snd_port_destroy(pjmedia_snd_port *snd_port);
/**
* Retrieve the sound stream associated by this sound device port.
*
* @param snd_port The sound device port.
*
* @return The sound stream instance.
*/
PJ_DECL(pjmedia_snd_stream*) pjmedia_snd_port_get_snd_stream(
pjmedia_snd_port *snd_port);
/**
* Configure the echo cancellation tail length. By default, echo canceller
* is enabled in the sound device with the default tail length. After the
* sound port is created, application can query the current echo canceller
* tail length by calling #pjmedia_snd_port_get_ec_tail.
*
* Note that you should only change the EC settings when the sound port
* is not connected to any downstream ports, otherwise race condition may
* occur.
*
* @param snd_port The sound device port.
* @param pool Pool to re-create the echo canceller if necessary.
* @param tail_ms Maximum echo tail length to be supported, in
* miliseconds. If zero is specified, the EC would
* be disabled.
* @param options The options to be passed to #pjmedia_echo_create().
*
* @return PJ_SUCCESS on success.
*/
PJ_DECL(pj_status_t) pjmedia_snd_port_set_ec( pjmedia_snd_port *snd_port,
pj_pool_t *pool,
unsigned tail_ms,
unsigned options);
/**
* Get current echo canceller tail length, in miliseconds. The tail length
* will be zero if EC is not enabled.
*
* @param snd_port The sound device port.
* @param p_length Pointer to receive the tail length.
*
* @return PJ_SUCCESS on success.
*/
PJ_DECL(pj_status_t) pjmedia_snd_port_get_ec_tail(pjmedia_snd_port *snd_port,
unsigned *p_length);
/**
* Enable or disable echo canceller. By default the EC is enabled after it
* was created, so there is no need to enable the EC after creating it.
* This function is only useful to disable the echo canceller temporarily,
* for example during idle period, to prevent EC from using
*/
/**
* Connect a port to the sound device port. If the sound device port has a
* sound recorder device, then this will start periodic function call to
* the port's put_frame() function. If the sound device has a sound player
* device, then this will start periodic function call to the port's
* get_frame() function.
*
* For this version of PJMEDIA, the media port MUST have the same audio
* settings as the sound device port, or otherwise the connection will
* fail. This means the port MUST have the same clock_rate, channel count,
* samples per frame, and bits per sample as the sound device port.
*
* @param snd_port The sound device port.
* @param port The media port to be connected.
*
* @return PJ_SUCCESS on success, or the appropriate error
* code.
*/
PJ_DECL(pj_status_t) pjmedia_snd_port_connect(pjmedia_snd_port *snd_port,
pjmedia_port *port);
/**
* Retrieve the port instance currently attached to the sound port, if any.
*
* @param snd_port The sound device port.
*
* @return The port instance currently attached to the
* sound device port, or NULL if there is no port
* currently attached to the sound device port.
*/
PJ_DECL(pjmedia_port*) pjmedia_snd_port_get_port(pjmedia_snd_port *snd_port);
/**
* Disconnect currently attached port from the sound device port.
*
* @param snd_port The sound device port.
*
* @return PJ_SUCCESS on success.
*/
PJ_DECL(pj_status_t) pjmedia_snd_port_disconnect(pjmedia_snd_port *snd_port);
/**
* @}
*/
PJ_END_DECL
#endif /* __PJMEDIA_SOUND_PORT_H__ */
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