/* * G.729 bit format muxer and demuxer * Copyright (c) 2007-2008 Vladimir Voroshilov * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */#include "avformat.h"#include "internal.h"#include "libavcodec/get_bits.h"#include "libavcodec/put_bits.h" #define MAX_FRAME_SIZE 10 #define SYNC_WORD  0x6b21#define BIT_0      0x7f#define BIT_1      0x81 static int probe(AVProbeData *p){    int i, j;     if(p->buf_size < 0x40)        return 0;     for(i=0; i+3<p->buf_size && i< 10*0x50; ){        if(AV_RL16(&p->buf[0]) != SYNC_WORD)            return 0;        j=AV_RL16(&p->buf[2]);        if(j!=0x40 && j!=0x50)            return 0;        i+=j;    }    return AVPROBE_SCORE_EXTENSION;} static int read_header(AVFormatContext *s){    AVStream* st;     st=avformat_new_stream(s, NULL);    if (!st)        return AVERROR(ENOMEM);     st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;    st->codecpar->codec_id=AV_CODEC_ID_G729;    st->codecpar->sample_rate=8000;    st->codecpar->block_align = 16;    st->codecpar->channels=1;     avpriv_set_pts_info(st, 64, 1, 100);    return 0;} static int read_packet(AVFormatContext *s,                          AVPacket *pkt){    AVIOContext *pb = s->pb;    PutBitContext pbo;    uint16_t buf[8 * MAX_FRAME_SIZE + 2];    int packet_size;    uint16_t* src=buf;    int i, j, ret;    int64_t pos= avio_tell(pb);     if(avio_feof(pb))        return AVERROR_EOF;     avio_rl16(pb); // sync word    packet_size = avio_rl16(pb) / 8;    if(packet_size > MAX_FRAME_SIZE)        return AVERROR_INVALIDDATA;     ret = avio_read(pb, (uint8_t*)buf, (8 * packet_size) * sizeof(uint16_t));    if(ret<0)        return ret;    if(ret != 8 * packet_size * sizeof(uint16_t))        return AVERROR(EIO);     if (av_new_packet(pkt, packet_size) < 0)        return AVERROR(ENOMEM);     init_put_bits(&pbo, pkt->data, packet_size);    for(j=0; j < packet_size; j++)        for(i=0; i<8;i++)            put_bits(&pbo,1, AV_RL16(src++) == BIT_1 ? 1 : 0);     flush_put_bits(&pbo);     pkt->duration=1;    pkt->pos = pos;    return 0;} AVInputFormat ff_bit_demuxer = {    .name        = "bit",    .long_name   = NULL_IF_CONFIG_SMALL("G.729 BIT file format"),    .read_probe  = probe,    .read_header = read_header,    .read_packet = read_packet,    .extensions  = "bit",}; #if CONFIG_MUXERSstatic int write_header(AVFormatContext *s){    AVCodecParameters *par = s->streams[0]->codecpar;     if ((par->codec_id != AV_CODEC_ID_G729) || par->channels != 1) {        av_log(s, AV_LOG_ERROR,               "only codec g729 with 1 channel is supported by this format\n");        return AVERROR(EINVAL);    }     par->bits_per_coded_sample = 16;    par->block_align = (par->bits_per_coded_sample * par->channels) >> 3;     return 0;} static int write_packet(AVFormatContext *s, AVPacket *pkt){    AVIOContext *pb = s->pb;    GetBitContext gb;    int i;     if (pkt->size != 10)        return AVERROR(EINVAL);     avio_wl16(pb, SYNC_WORD);    avio_wl16(pb, 8 * 10);     init_get_bits(&gb, pkt->data, 8*10);    for(i=0; i< 8 * 10; i++)        avio_wl16(pb, get_bits1(&gb) ? BIT_1 : BIT_0);     return 0;} AVOutputFormat ff_bit_muxer = {    .name         = "bit",    .long_name    = NULL_IF_CONFIG_SMALL("G.729 BIT file format"),    .mime_type    = "audio/bit",    .extensions   = "bit",    .audio_codec  = AV_CODEC_ID_G729,    .video_codec  = AV_CODEC_ID_NONE,    .write_header = write_header,    .write_packet = write_packet,};#endif