g711.c

基于sip协议的网络电话源码

/* $Id: g711.c 974 2007-02-19 01:13:53Z bennylp $ */
/* 
 * Copyright (C) 2003-2007 Benny Prijono <[e-mail]>
 *
 * 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 
 */
/* This file contains file from Sun Microsystems, Inc, with the complete 
 * notice in the second half of this file.
 */
#include <pjmedia/codec.h>
#include <pjmedia/alaw_ulaw.h>
#include <pjmedia/endpoint.h>
#include <pjmedia/errno.h>
#include <pjmedia/port.h>
#include <pjmedia/plc.h>
#include <pjmedia/silencedet.h>
#include <pj/pool.h>
#include <pj/string.h>
#include <pj/assert.h>

#if defined(PJMEDIA_HAS_G711_CODEC) && PJMEDIA_HAS_G711_CODEC!=0


#define G711_BPS	    64000
#define G711_CODEC_CNT	    0	/* number of codec to preallocate in memory */
#define PTIME		    10	/* basic frame size is 10 msec	    */
#define FRAME_SIZE	    (8000 * PTIME / 1000)   /* 80 bytes	    */
#define SAMPLES_PER_FRAME   (8000 * PTIME / 1000)   /* 80 samples   */

/* These are the only public functions exported to applications */
PJ_DECL(pj_status_t) g711_init_factory (pjmedia_codec_factory *factory, 
					pj_pool_t *pool);

/* Prototypes for G711 factory */
static pj_status_t g711_test_alloc( pjmedia_codec_factory *factory, 
				    const pjmedia_codec_info *id );
static pj_status_t g711_default_attr( pjmedia_codec_factory *factory, 
				      const pjmedia_codec_info *id, 
				      pjmedia_codec_param *attr );
static pj_status_t g711_enum_codecs (pjmedia_codec_factory *factory, 
				     unsigned *count, 
				     pjmedia_codec_info codecs[]);
static pj_status_t g711_alloc_codec( pjmedia_codec_factory *factory, 
				     const pjmedia_codec_info *id, 
				     pjmedia_codec **p_codec);
static pj_status_t g711_dealloc_codec( pjmedia_codec_factory *factory, 
				       pjmedia_codec *codec );

/* Prototypes for G711 implementation. */
static pj_status_t  g711_init( pjmedia_codec *codec, 
			       pj_pool_t *pool );
static pj_status_t  g711_open( pjmedia_codec *codec, 
			       pjmedia_codec_param *attr );
static pj_status_t  g711_close( pjmedia_codec *codec );
static pj_status_t  g711_modify(pjmedia_codec *codec, 
			        const pjmedia_codec_param *attr );
static pj_status_t  g711_parse(pjmedia_codec *codec,
			       void *pkt,
			       pj_size_t pkt_size,
			       const pj_timestamp *timestamp,
			       unsigned *frame_cnt,
			       pjmedia_frame frames[]);
static pj_status_t  g711_encode( pjmedia_codec *codec, 
				 const struct pjmedia_frame *input,
				 unsigned output_buf_len, 
				 struct pjmedia_frame *output);
static pj_status_t  g711_decode( pjmedia_codec *codec, 
				 const struct pjmedia_frame *input,
				 unsigned output_buf_len, 
				 struct pjmedia_frame *output);
static pj_status_t  g711_recover( pjmedia_codec *codec,
				  unsigned output_buf_len,
				  struct pjmedia_frame *output);

/* Definition for G711 codec operations. */
static pjmedia_codec_op g711_op = 
{
    &g711_init,
    &g711_open,
    &g711_close,
    &g711_modify,
    &g711_parse,
    &g711_encode,
    &g711_decode,
    &g711_recover
};

/* Definition for G711 codec factory operations. */
static pjmedia_codec_factory_op g711_factory_op =
{
    &g711_test_alloc,
    &g711_default_attr,
    &g711_enum_codecs,
    &g711_alloc_codec,
    &g711_dealloc_codec
};

/* G711 factory private data */
static struct g711_factory
{
    pjmedia_codec_factory	base;
    pjmedia_endpt	       *endpt;
    pj_pool_t		       *pool;
    pj_mutex_t		       *mutex;
    pjmedia_codec		codec_list;
} g711_factory;

/* G711 codec private data. */
struct g711_private
{
    unsigned		 pt;
    pj_bool_t		 plc_enabled;
    pjmedia_plc		*plc;
    pj_bool_t		 vad_enabled;
    pjmedia_silence_det *vad;
    pj_timestamp	 last_tx;
};


PJ_DEF(pj_status_t) pjmedia_codec_g711_init(pjmedia_endpt *endpt)
{
    pjmedia_codec_mgr *codec_mgr;
    pj_status_t status;

    if (g711_factory.endpt != NULL) {
	/* Already initialized. */
	return PJ_SUCCESS;
    }

    /* Init factory */
    g711_factory.base.op = &g711_factory_op;
    g711_factory.base.factory_data = NULL;
    g711_factory.endpt = endpt;

    pj_list_init(&g711_factory.codec_list);

    /* Create pool */
    g711_factory.pool = pjmedia_endpt_create_pool(endpt, "g711", 4000, 4000);
    if (!g711_factory.pool)
	return PJ_ENOMEM;

    /* Create mutex. */
    status = pj_mutex_create_simple(g711_factory.pool, "g611", 
				    &g711_factory.mutex);
    if (status != PJ_SUCCESS)
	goto on_error;

    /* Get the codec manager. */
    codec_mgr = pjmedia_endpt_get_codec_mgr(endpt);
    if (!codec_mgr) {
	return PJ_EINVALIDOP;
    }

    /* Register codec factory to endpoint. */
    status = pjmedia_codec_mgr_register_factory(codec_mgr, 
						&g711_factory.base);
    if (status != PJ_SUCCESS)
	return status;


    return PJ_SUCCESS;

on_error:
    if (g711_factory.mutex) {
	pj_mutex_destroy(g711_factory.mutex);
	g711_factory.mutex = NULL;
    }
    if (g711_factory.pool) {
	pj_pool_release(g711_factory.pool);
	g711_factory.pool = NULL;
    }
    return status;
}

PJ_DEF(pj_status_t) pjmedia_codec_g711_deinit(void)
{
    pjmedia_codec_mgr *codec_mgr;
    pj_status_t status;

    if (g711_factory.endpt == NULL) {
	/* Not registered. */
	return PJ_SUCCESS;
    }

    /* Lock mutex. */
    pj_mutex_lock(g711_factory.mutex);

    /* Get the codec manager. */
    codec_mgr = pjmedia_endpt_get_codec_mgr(g711_factory.endpt);
    if (!codec_mgr) {
	g711_factory.endpt = NULL;
	pj_mutex_unlock(g711_factory.mutex);
	return PJ_EINVALIDOP;
    }

    /* Unregister G711 codec factory. */
    status = pjmedia_codec_mgr_unregister_factory(codec_mgr,
						  &g711_factory.base);
    g711_factory.endpt = NULL;

    /* Destroy mutex. */
    pj_mutex_destroy(g711_factory.mutex);
    g711_factory.mutex = NULL;


    /* Release pool. */
    pj_pool_release(g711_factory.pool);
    g711_factory.pool = NULL;


    return status;
}

static pj_status_t g711_test_alloc(pjmedia_codec_factory *factory, 
				   const pjmedia_codec_info *id )
{
    PJ_UNUSED_ARG(factory);

    /* It's sufficient to check payload type only. */
    return (id->pt==PJMEDIA_RTP_PT_PCMU || id->pt==PJMEDIA_RTP_PT_PCMA)? 0:-1;
}

static pj_status_t g711_default_attr (pjmedia_codec_factory *factory, 
				      const pjmedia_codec_info *id, 
				      pjmedia_codec_param *attr )
{
    PJ_UNUSED_ARG(factory);

    pj_bzero(attr, sizeof(pjmedia_codec_param));
    attr->info.clock_rate = 8000;
    attr->info.channel_cnt = 1;
    attr->info.avg_bps = G711_BPS;
    attr->info.pcm_bits_per_sample = 16;
    attr->info.frm_ptime = PTIME;
    attr->info.pt = (pj_uint8_t)id->pt;

    /* Set default frames per packet to 2 (or 20ms) */
    attr->setting.frm_per_pkt = 2;

    /* Enable plc by default. */
    attr->setting.plc = 1;

    /* Enable VAD by default. */
    attr->setting.vad = 1;

    /* Default all other flag bits disabled. */

    return PJ_SUCCESS;
}

static pj_status_t g711_enum_codecs(pjmedia_codec_factory *factory, 
				    unsigned *max_count, 
				    pjmedia_codec_info codecs[])
{
    unsigned count = 0;

    PJ_UNUSED_ARG(factory);

    if (count < *max_count) {
	codecs[count].type = PJMEDIA_TYPE_AUDIO;
	codecs[count].pt = PJMEDIA_RTP_PT_PCMU;
	codecs[count].encoding_name = pj_str("PCMU");
	codecs[count].clock_rate = 8000;
	codecs[count].channel_cnt = 1;
	++count;
    }
    if (count < *max_count) {
	codecs[count].type = PJMEDIA_TYPE_AUDIO;
	codecs[count].pt = PJMEDIA_RTP_PT_PCMA;
	codecs[count].encoding_name = pj_str("PCMA");
	codecs[count].clock_rate = 8000;
	codecs[count].channel_cnt = 1;
	++count;
    }

    *max_count = count;

    return PJ_SUCCESS;
}

static pj_status_t g711_alloc_codec( pjmedia_codec_factory *factory, 
				     const pjmedia_codec_info *id,
				     pjmedia_codec **p_codec)
{