D-Modem/pjproject-2.11.1/pjmedia/include/pjmedia/splitcomb.h
2021-10-29 14:41:03 -04:00

143 lines
5.2 KiB
C

/* $Id$ */
/*
* Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com)
* Copyright (C) 2003-2008 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_SPLITCOMB_H__
#define __PJMEDIA_SPLITCOMB_H__
/**
* @file splitcomb.h
* @brief Media channel splitter/combiner port.
*/
#include <pjmedia/port.h>
/**
* @addtogroup PJMEDIA_SPLITCOMB Media channel splitter/combiner
* @ingroup PJMEDIA_PORT
* @brief Split and combine multiple mono-channel media ports into
* a single multiple-channels media port
* @{
*
* This section describes media port to split and combine media
* channels in the stream.
*
* A splitter/combiner splits a single stereo/multichannels audio frame into
* multiple audio frames to each channel when put_frame() is called,
* and combines mono frames from each channel into a stereo/multichannel
* frame when get_frame() is called. A common application for the splitter/
* combiner is to split frames from stereo to mono and vise versa.
*/
PJ_BEGIN_DECL
/**
* Create a media splitter/combiner with the specified parameters.
* When the splitter/combiner is created, it creates an instance of
* pjmedia_port. This media port represents the stereo/multichannel side
* of the splitter/combiner. Application needs to supply the splitter/
* combiner with a media port for each audio channels.
*
* @param pool Pool to allocate memory to create the splitter/
* combiner.
* @param clock_rate Audio clock rate/sampling rate.
* @param channel_count Number of channels.
* @param samples_per_frame Number of samples per frame.
* @param bits_per_sample Bits per sample.
* @param options Optional flags.
* @param p_splitcomb Pointer to receive the splitter/combiner.
*
* @return PJ_SUCCESS on success, or the appropriate
* error code.
*/
PJ_DECL(pj_status_t) pjmedia_splitcomb_create(pj_pool_t *pool,
unsigned clock_rate,
unsigned channel_count,
unsigned samples_per_frame,
unsigned bits_per_sample,
unsigned options,
pjmedia_port **p_splitcomb);
/**
* Supply the splitter/combiner with media port for the specified channel
* number. The media port will be called at the
* same phase as the splitter/combiner; which means that when application
* calls get_frame() of the splitter/combiner, it will call get_frame()
* for all ports that have the same phase. And similarly for put_frame().
*
* @param splitcomb The splitter/combiner.
* @param ch_num Audio channel starting number (zero based).
* @param options Must be zero at the moment.
* @param port The media port.
*
* @return PJ_SUCCESS on success, or the appropriate error
* code.
*/
PJ_DECL(pj_status_t) pjmedia_splitcomb_set_channel(pjmedia_port *splitcomb,
unsigned ch_num,
unsigned options,
pjmedia_port *port);
/**
* Create a reverse phase media port for the specified channel number.
* For channels with reversed phase, when application calls put_frame() to
* the splitter/combiner, the splitter/combiner will only put the frame to
* a buffer. Later on, when application calls get_frame() on the channel's
* media port, it will return the frame that are available in the buffer.
* The same process happens when application calls put_frame() to the
* channel's media port, it will only put the frame to another buffer, which
* will be returned when application calls get_frame() to the splitter's
* media port. So this effectively reverse the phase of the media port.
*
* @param pool The pool to allocate memory for the port and
* buffers.
* @param splitcomb The splitter/combiner.
* @param ch_num Audio channel starting number (zero based).
* @param options Normally is zero, but the lower 8-bit of the
* options can be used to specify the number of
* buffers in the circular buffer. If zero, then
* default number will be used (default: 8). The second
* lowest 8 bits can be used to specify the options for
* the underlying delay buffer (see
* #pjmedia_delay_buf_flag for the possible options).
* @param p_chport The media port created with reverse phase for
* the specified audio channel.
*
* @return PJ_SUCCESS on success, or the appropriate error
* code.
*/
PJ_DECL(pj_status_t)
pjmedia_splitcomb_create_rev_channel( pj_pool_t *pool,
pjmedia_port *splitcomb,
unsigned ch_num,
unsigned options,
pjmedia_port **p_chport);
PJ_END_DECL
/**
* @}
*/
#endif /* __PJMEDIA_SPLITCOMB_H__ */