yading@11: /*
yading@11:  * G.729 bit format muxer and demuxer
yading@11:  * Copyright (c) 2007-2008 Vladimir Voroshilov
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: #include "avformat.h"
yading@11: #include "internal.h"
yading@11: #include "libavcodec/get_bits.h"
yading@11: #include "libavcodec/put_bits.h"
yading@11: 
yading@11: #define MAX_FRAME_SIZE 10
yading@11: 
yading@11: #define SYNC_WORD  0x6b21
yading@11: #define BIT_0      0x7f
yading@11: #define BIT_1      0x81
yading@11: 
yading@11: static int probe(AVProbeData *p)
yading@11: {
yading@11:     int i, j;
yading@11: 
yading@11:     if(p->buf_size < 0x40)
yading@11:         return 0;
yading@11: 
yading@11:     for(i=0; i+3<p->buf_size && i< 10*0x50; ){
yading@11:         if(AV_RL16(&p->buf[0]) != SYNC_WORD)
yading@11:             return 0;
yading@11:         j=AV_RL16(&p->buf[2]);
yading@11:         if(j!=0x40 && j!=0x50)
yading@11:             return 0;
yading@11:         i+=j;
yading@11:     }
yading@11:     return AVPROBE_SCORE_MAX/2;
yading@11: }
yading@11: 
yading@11: static int read_header(AVFormatContext *s)
yading@11: {
yading@11:     AVStream* st;
yading@11: 
yading@11:     st=avformat_new_stream(s, NULL);
yading@11:     if (!st)
yading@11:         return AVERROR(ENOMEM);
yading@11: 
yading@11:     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
yading@11:     st->codec->codec_id=AV_CODEC_ID_G729;
yading@11:     st->codec->sample_rate=8000;
yading@11:     st->codec->block_align = 16;
yading@11:     st->codec->channels=1;
yading@11: 
yading@11:     avpriv_set_pts_info(st, 64, 1, 100);
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int read_packet(AVFormatContext *s,
yading@11:                           AVPacket *pkt)
yading@11: {
yading@11:     AVIOContext *pb = s->pb;
yading@11:     PutBitContext pbo;
yading@11:     uint16_t buf[8 * MAX_FRAME_SIZE + 2];
yading@11:     int packet_size;
yading@11:     uint16_t* src=buf;
yading@11:     int i, j, ret;
yading@11:     int64_t pos= avio_tell(pb);
yading@11: 
yading@11:     if(url_feof(pb))
yading@11:         return AVERROR_EOF;
yading@11: 
yading@11:     avio_rl16(pb); // sync word
yading@11:     packet_size = avio_rl16(pb) / 8;
yading@11:     if(packet_size > MAX_FRAME_SIZE)
yading@11:         return AVERROR_INVALIDDATA;
yading@11: 
yading@11:     ret = avio_read(pb, (uint8_t*)buf, (8 * packet_size) * sizeof(uint16_t));
yading@11:     if(ret<0)
yading@11:         return ret;
yading@11:     if(ret != 8 * packet_size * sizeof(uint16_t))
yading@11:         return AVERROR(EIO);
yading@11: 
yading@11:     if (av_new_packet(pkt, packet_size) < 0)
yading@11:         return AVERROR(ENOMEM);
yading@11: 
yading@11:     init_put_bits(&pbo, pkt->data, packet_size);
yading@11:     for(j=0; j < packet_size; j++)
yading@11:         for(i=0; i<8;i++)
yading@11:             put_bits(&pbo,1, AV_RL16(src++) == BIT_1 ? 1 : 0);
yading@11: 
yading@11:     flush_put_bits(&pbo);
yading@11: 
yading@11:     pkt->duration=1;
yading@11:     pkt->pos = pos;
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: AVInputFormat ff_bit_demuxer = {
yading@11:     .name        = "bit",
yading@11:     .long_name   = NULL_IF_CONFIG_SMALL("G.729 BIT file format"),
yading@11:     .read_probe  = probe,
yading@11:     .read_header = read_header,
yading@11:     .read_packet = read_packet,
yading@11:     .extensions  = "bit",
yading@11: };
yading@11: 
yading@11: #if CONFIG_MUXERS
yading@11: static int write_header(AVFormatContext *s)
yading@11: {
yading@11:     AVCodecContext *enc = s->streams[0]->codec;
yading@11: 
yading@11:     enc->codec_id = AV_CODEC_ID_G729;
yading@11:     enc->channels = 1;
yading@11:     enc->bits_per_coded_sample = 16;
yading@11:     enc->block_align = (enc->bits_per_coded_sample * enc->channels) >> 3;
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int write_packet(AVFormatContext *s, AVPacket *pkt)
yading@11: {
yading@11:     AVIOContext *pb = s->pb;
yading@11:     GetBitContext gb;
yading@11:     int i;
yading@11: 
yading@11:     avio_wl16(pb, SYNC_WORD);
yading@11:     avio_wl16(pb, 8 * 10);
yading@11: 
yading@11:     init_get_bits(&gb, pkt->data, 8*10);
yading@11:     for(i=0; i< 8 * 10; i++)
yading@11:         avio_wl16(pb, get_bits1(&gb) ? BIT_1 : BIT_0);
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: AVOutputFormat ff_bit_muxer = {
yading@11:     .name         = "bit",
yading@11:     .long_name    = NULL_IF_CONFIG_SMALL("G.729 BIT file format"),
yading@11:     .mime_type    = "audio/bit",
yading@11:     .extensions   = "bit",
yading@11:     .audio_codec  = AV_CODEC_ID_G729,
yading@11:     .video_codec  = AV_CODEC_ID_NONE,
yading@11:     .write_header = write_header,
yading@11:     .write_packet = write_packet,
yading@11: };
yading@11: #endif