2 * G.729 bit format muxer and demuxer
3 * Copyright (c) 2007-2008 Vladimir Voroshilov
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 #include "libavcodec/get_bits.h"
24 #include "libavcodec/put_bits.h"
26 #define MAX_FRAME_SIZE 10
28 #define SYNC_WORD 0x6b21
32 static int probe(AVProbeData *p)
36 if(p->buf_size < 0x40)
39 for(i=0; i+3<p->buf_size && i< 10*0x50; ){
40 if(AV_RL16(&p->buf[0]) != SYNC_WORD)
42 j=AV_RL16(&p->buf[2]);
43 if(j!=0x40 && j!=0x50)
47 return AVPROBE_SCORE_MAX/2;
50 static int read_header(AVFormatContext *s)
54 st=avformat_new_stream(s, NULL);
56 return AVERROR(ENOMEM);
58 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
59 st->codec->codec_id=CODEC_ID_G729;
60 st->codec->sample_rate=8000;
61 st->codec->block_align = 16;
62 st->codec->channels=1;
64 avpriv_set_pts_info(st, 64, 1, 100);
68 static int read_packet(AVFormatContext *s,
71 AVIOContext *pb = s->pb;
73 uint16_t buf[8 * MAX_FRAME_SIZE + 2];
77 int64_t pos= avio_tell(pb);
82 avio_rl16(pb); // sync word
83 packet_size = avio_rl16(pb) / 8;
84 if(packet_size > MAX_FRAME_SIZE)
85 return AVERROR_INVALIDDATA;
87 ret = avio_read(pb, (uint8_t*)buf, (8 * packet_size) * sizeof(uint16_t));
90 if(ret != 8 * packet_size * sizeof(uint16_t))
93 av_new_packet(pkt, packet_size);
95 init_put_bits(&pbo, pkt->data, packet_size);
96 for(j=0; j < packet_size; j++)
98 put_bits(&pbo,1, AV_RL16(src++) == BIT_1 ? 1 : 0);
100 flush_put_bits(&pbo);
107 AVInputFormat ff_bit_demuxer = {
109 .long_name = NULL_IF_CONFIG_SMALL("G.729 BIT file format"),
111 .read_header = read_header,
112 .read_packet = read_packet,
117 static int write_header(AVFormatContext *s)
119 AVCodecContext *enc = s->streams[0]->codec;
121 enc->codec_id = CODEC_ID_G729;
123 enc->bits_per_coded_sample = 16;
124 enc->block_align = (enc->bits_per_coded_sample * enc->channels) >> 3;
129 static int write_packet(AVFormatContext *s, AVPacket *pkt)
131 AVIOContext *pb = s->pb;
135 avio_wl16(pb, SYNC_WORD);
136 avio_wl16(pb, 8 * 10);
138 init_get_bits(&gb, pkt->data, 8*10);
139 for(i=0; i< 8 * 10; i++)
140 avio_wl16(pb, get_bits1(&gb) ? BIT_1 : BIT_0);
146 AVOutputFormat ff_bit_muxer = {
148 .long_name = NULL_IF_CONFIG_SMALL("G.729 BIT file format"),
149 .mime_type = "audio/bit",
151 .audio_codec = CODEC_ID_G729,
152 .video_codec = CODEC_ID_NONE,
153 .write_header = write_header,
154 .write_packet = write_packet,