blob: c3f2fdfbe38421f5f1db462b52a59c964d1c6f4b
| 1 | /* |
| 2 | * G.729 bit format muxer and demuxer |
| 3 | * Copyright (c) 2007-2008 Vladimir Voroshilov |
| 4 | * |
| 5 | * This file is part of FFmpeg. |
| 6 | * |
| 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. |
| 11 | * |
| 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. |
| 16 | * |
| 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 |
| 20 | */ |
| 21 | #include "avformat.h" |
| 22 | #include "internal.h" |
| 23 | #include "libavcodec/get_bits.h" |
| 24 | #include "libavcodec/put_bits.h" |
| 25 | |
| 26 | #define MAX_FRAME_SIZE 10 |
| 27 | |
| 28 | #define SYNC_WORD 0x6b21 |
| 29 | #define BIT_0 0x7f |
| 30 | #define BIT_1 0x81 |
| 31 | |
| 32 | static int probe(AVProbeData *p) |
| 33 | { |
| 34 | int i, j; |
| 35 | |
| 36 | if(p->buf_size < 0x40) |
| 37 | return 0; |
| 38 | |
| 39 | for(i=0; i+3<p->buf_size && i< 10*0x50; ){ |
| 40 | if(AV_RL16(&p->buf[0]) != SYNC_WORD) |
| 41 | return 0; |
| 42 | j=AV_RL16(&p->buf[2]); |
| 43 | if(j!=0x40 && j!=0x50) |
| 44 | return 0; |
| 45 | i+=j; |
| 46 | } |
| 47 | return AVPROBE_SCORE_EXTENSION; |
| 48 | } |
| 49 | |
| 50 | static int read_header(AVFormatContext *s) |
| 51 | { |
| 52 | AVStream* st; |
| 53 | |
| 54 | st=avformat_new_stream(s, NULL); |
| 55 | if (!st) |
| 56 | return AVERROR(ENOMEM); |
| 57 | |
| 58 | st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO; |
| 59 | st->codecpar->codec_id=AV_CODEC_ID_G729; |
| 60 | st->codecpar->sample_rate=8000; |
| 61 | st->codecpar->block_align = 16; |
| 62 | st->codecpar->channels=1; |
| 63 | |
| 64 | avpriv_set_pts_info(st, 64, 1, 100); |
| 65 | return 0; |
| 66 | } |
| 67 | |
| 68 | static int read_packet(AVFormatContext *s, |
| 69 | AVPacket *pkt) |
| 70 | { |
| 71 | AVIOContext *pb = s->pb; |
| 72 | PutBitContext pbo; |
| 73 | uint16_t buf[8 * MAX_FRAME_SIZE + 2]; |
| 74 | int packet_size; |
| 75 | uint16_t* src=buf; |
| 76 | int i, j, ret; |
| 77 | int64_t pos= avio_tell(pb); |
| 78 | |
| 79 | if(avio_feof(pb)) |
| 80 | return AVERROR_EOF; |
| 81 | |
| 82 | avio_rl16(pb); // sync word |
| 83 | packet_size = avio_rl16(pb) / 8; |
| 84 | if(packet_size > MAX_FRAME_SIZE) |
| 85 | return AVERROR_INVALIDDATA; |
| 86 | |
| 87 | ret = avio_read(pb, (uint8_t*)buf, (8 * packet_size) * sizeof(uint16_t)); |
| 88 | if(ret<0) |
| 89 | return ret; |
| 90 | if(ret != 8 * packet_size * sizeof(uint16_t)) |
| 91 | return AVERROR(EIO); |
| 92 | |
| 93 | if (av_new_packet(pkt, packet_size) < 0) |
| 94 | return AVERROR(ENOMEM); |
| 95 | |
| 96 | init_put_bits(&pbo, pkt->data, packet_size); |
| 97 | for(j=0; j < packet_size; j++) |
| 98 | for(i=0; i<8;i++) |
| 99 | put_bits(&pbo,1, AV_RL16(src++) == BIT_1 ? 1 : 0); |
| 100 | |
| 101 | flush_put_bits(&pbo); |
| 102 | |
| 103 | pkt->duration=1; |
| 104 | pkt->pos = pos; |
| 105 | return 0; |
| 106 | } |
| 107 | |
| 108 | AVInputFormat ff_bit_demuxer = { |
| 109 | .name = "bit", |
| 110 | .long_name = NULL_IF_CONFIG_SMALL("G.729 BIT file format"), |
| 111 | .read_probe = probe, |
| 112 | .read_header = read_header, |
| 113 | .read_packet = read_packet, |
| 114 | .extensions = "bit", |
| 115 | }; |
| 116 | |
| 117 | #if CONFIG_MUXERS |
| 118 | static int write_header(AVFormatContext *s) |
| 119 | { |
| 120 | AVCodecParameters *par = s->streams[0]->codecpar; |
| 121 | |
| 122 | if ((par->codec_id != AV_CODEC_ID_G729) || par->channels != 1) { |
| 123 | av_log(s, AV_LOG_ERROR, |
| 124 | "only codec g729 with 1 channel is supported by this format\n"); |
| 125 | return AVERROR(EINVAL); |
| 126 | } |
| 127 | |
| 128 | par->bits_per_coded_sample = 16; |
| 129 | par->block_align = (par->bits_per_coded_sample * par->channels) >> 3; |
| 130 | |
| 131 | return 0; |
| 132 | } |
| 133 | |
| 134 | static int write_packet(AVFormatContext *s, AVPacket *pkt) |
| 135 | { |
| 136 | AVIOContext *pb = s->pb; |
| 137 | GetBitContext gb; |
| 138 | int i; |
| 139 | |
| 140 | if (pkt->size != 10) |
| 141 | return AVERROR(EINVAL); |
| 142 | |
| 143 | avio_wl16(pb, SYNC_WORD); |
| 144 | avio_wl16(pb, 8 * 10); |
| 145 | |
| 146 | init_get_bits(&gb, pkt->data, 8*10); |
| 147 | for(i=0; i< 8 * 10; i++) |
| 148 | avio_wl16(pb, get_bits1(&gb) ? BIT_1 : BIT_0); |
| 149 | |
| 150 | return 0; |
| 151 | } |
| 152 | |
| 153 | AVOutputFormat ff_bit_muxer = { |
| 154 | .name = "bit", |
| 155 | .long_name = NULL_IF_CONFIG_SMALL("G.729 BIT file format"), |
| 156 | .mime_type = "audio/bit", |
| 157 | .extensions = "bit", |
| 158 | .audio_codec = AV_CODEC_ID_G729, |
| 159 | .video_codec = AV_CODEC_ID_NONE, |
| 160 | .write_header = write_header, |
| 161 | .write_packet = write_packet, |
| 162 | }; |
| 163 | #endif |
| 164 |