| 1 | /* |
| 2 | * amr file format |
| 3 | * Copyright (c) 2001 ffmpeg project |
| 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 | |
| 22 | /* |
| 23 | Write and read amr data according to RFC3267, http://www.ietf.org/rfc/rfc3267.txt?number=3267 |
| 24 | |
| 25 | Only mono files are supported. |
| 26 | |
| 27 | */ |
| 28 | |
| 29 | #include "libavutil/channel_layout.h" |
| 30 | #include "avformat.h" |
| 31 | #include "internal.h" |
| 32 | |
| 33 | typedef struct { |
| 34 | uint64_t cumulated_size; |
| 35 | uint64_t block_count; |
| 36 | } AMRContext; |
| 37 | |
| 38 | static const char AMR_header[] = "#!AMR\n"; |
| 39 | static const char AMRWB_header[] = "#!AMR-WB\n"; |
| 40 | |
| 41 | #if CONFIG_AMR_MUXER |
| 42 | static int amr_write_header(AVFormatContext *s) |
| 43 | { |
| 44 | AVIOContext *pb = s->pb; |
| 45 | AVCodecContext *enc = s->streams[0]->codec; |
| 46 | |
| 47 | s->priv_data = NULL; |
| 48 | |
| 49 | if (enc->codec_id == AV_CODEC_ID_AMR_NB) { |
| 50 | avio_write(pb, AMR_header, sizeof(AMR_header) - 1); /* magic number */ |
| 51 | } else if (enc->codec_id == AV_CODEC_ID_AMR_WB) { |
| 52 | avio_write(pb, AMRWB_header, sizeof(AMRWB_header) - 1); /* magic number */ |
| 53 | } else { |
| 54 | return -1; |
| 55 | } |
| 56 | avio_flush(pb); |
| 57 | return 0; |
| 58 | } |
| 59 | |
| 60 | static int amr_write_packet(AVFormatContext *s, AVPacket *pkt) |
| 61 | { |
| 62 | avio_write(s->pb, pkt->data, pkt->size); |
| 63 | return 0; |
| 64 | } |
| 65 | #endif /* CONFIG_AMR_MUXER */ |
| 66 | |
| 67 | static int amr_probe(AVProbeData *p) |
| 68 | { |
| 69 | // Only check for "#!AMR" which could be amr-wb, amr-nb. |
| 70 | // This will also trigger multichannel files: "#!AMR_MC1.0\n" and |
| 71 | // "#!AMR-WB_MC1.0\n" (not supported) |
| 72 | |
| 73 | if (!memcmp(p->buf, AMR_header, 5)) |
| 74 | return AVPROBE_SCORE_MAX; |
| 75 | else |
| 76 | return 0; |
| 77 | } |
| 78 | |
| 79 | /* amr input */ |
| 80 | static int amr_read_header(AVFormatContext *s) |
| 81 | { |
| 82 | AVIOContext *pb = s->pb; |
| 83 | AVStream *st; |
| 84 | uint8_t header[9]; |
| 85 | |
| 86 | avio_read(pb, header, 6); |
| 87 | |
| 88 | st = avformat_new_stream(s, NULL); |
| 89 | if (!st) |
| 90 | return AVERROR(ENOMEM); |
| 91 | if (memcmp(header, AMR_header, 6)) { |
| 92 | avio_read(pb, header + 6, 3); |
| 93 | if (memcmp(header, AMRWB_header, 9)) { |
| 94 | return -1; |
| 95 | } |
| 96 | |
| 97 | st->codec->codec_tag = MKTAG('s', 'a', 'w', 'b'); |
| 98 | st->codec->codec_id = AV_CODEC_ID_AMR_WB; |
| 99 | st->codec->sample_rate = 16000; |
| 100 | } else { |
| 101 | st->codec->codec_tag = MKTAG('s', 'a', 'm', 'r'); |
| 102 | st->codec->codec_id = AV_CODEC_ID_AMR_NB; |
| 103 | st->codec->sample_rate = 8000; |
| 104 | } |
| 105 | st->codec->channels = 1; |
| 106 | st->codec->channel_layout = AV_CH_LAYOUT_MONO; |
| 107 | st->codec->codec_type = AVMEDIA_TYPE_AUDIO; |
| 108 | avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate); |
| 109 | |
| 110 | return 0; |
| 111 | } |
| 112 | |
| 113 | static int amr_read_packet(AVFormatContext *s, AVPacket *pkt) |
| 114 | { |
| 115 | AVCodecContext *enc = s->streams[0]->codec; |
| 116 | int read, size = 0, toc, mode; |
| 117 | int64_t pos = avio_tell(s->pb); |
| 118 | AMRContext *amr = s->priv_data; |
| 119 | |
| 120 | if (avio_feof(s->pb)) { |
| 121 | return AVERROR(EIO); |
| 122 | } |
| 123 | |
| 124 | // FIXME this is wrong, this should rather be in a AVParser |
| 125 | toc = avio_r8(s->pb); |
| 126 | mode = (toc >> 3) & 0x0F; |
| 127 | |
| 128 | if (enc->codec_id == AV_CODEC_ID_AMR_NB) { |
| 129 | static const uint8_t packed_size[16] = { |
| 130 | 12, 13, 15, 17, 19, 20, 26, 31, 5, 0, 0, 0, 0, 0, 0, 0 |
| 131 | }; |
| 132 | |
| 133 | size = packed_size[mode] + 1; |
| 134 | } else if (enc->codec_id == AV_CODEC_ID_AMR_WB) { |
| 135 | static const uint8_t packed_size[16] = { |
| 136 | 18, 24, 33, 37, 41, 47, 51, 59, 61, 6, 6, 0, 0, 0, 1, 1 |
| 137 | }; |
| 138 | |
| 139 | size = packed_size[mode]; |
| 140 | } |
| 141 | |
| 142 | if (!size || av_new_packet(pkt, size)) |
| 143 | return AVERROR(EIO); |
| 144 | |
| 145 | if (amr->cumulated_size < UINT64_MAX - size) { |
| 146 | amr->cumulated_size += size; |
| 147 | /* Both AMR formats have 50 frames per second */ |
| 148 | s->streams[0]->codec->bit_rate = amr->cumulated_size / ++amr->block_count * 8 * 50; |
| 149 | } |
| 150 | |
| 151 | pkt->stream_index = 0; |
| 152 | pkt->pos = pos; |
| 153 | pkt->data[0] = toc; |
| 154 | pkt->duration = enc->codec_id == AV_CODEC_ID_AMR_NB ? 160 : 320; |
| 155 | read = avio_read(s->pb, pkt->data + 1, size - 1); |
| 156 | |
| 157 | if (read != size - 1) { |
| 158 | av_free_packet(pkt); |
| 159 | return AVERROR(EIO); |
| 160 | } |
| 161 | |
| 162 | return 0; |
| 163 | } |
| 164 | |
| 165 | #if CONFIG_AMR_DEMUXER |
| 166 | AVInputFormat ff_amr_demuxer = { |
| 167 | .name = "amr", |
| 168 | .long_name = NULL_IF_CONFIG_SMALL("3GPP AMR"), |
| 169 | .priv_data_size = sizeof(AMRContext), |
| 170 | .read_probe = amr_probe, |
| 171 | .read_header = amr_read_header, |
| 172 | .read_packet = amr_read_packet, |
| 173 | .flags = AVFMT_GENERIC_INDEX, |
| 174 | }; |
| 175 | #endif |
| 176 | |
| 177 | #if CONFIG_AMR_MUXER |
| 178 | AVOutputFormat ff_amr_muxer = { |
| 179 | .name = "amr", |
| 180 | .long_name = NULL_IF_CONFIG_SMALL("3GPP AMR"), |
| 181 | .mime_type = "audio/amr", |
| 182 | .extensions = "amr", |
| 183 | .audio_codec = AV_CODEC_ID_AMR_NB, |
| 184 | .video_codec = AV_CODEC_ID_NONE, |
| 185 | .write_header = amr_write_header, |
| 186 | .write_packet = amr_write_packet, |
| 187 | .flags = AVFMT_NOTIMESTAMPS, |
| 188 | }; |
| 189 | #endif |