| @@ -0,0 +1,252 @@ |
| 1 | +/* |
| 2 | + * LC3 muxer and demuxer |
| 3 | + * Copyright (C) 2024 Antoine Soulier <asoulier@google.com> |
| 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 | + * @file |
| 24 | + * Based on the file format specified by : |
| 25 | + * |
| 26 | + * - Bluetooth SIG - Low Complexity Communication Codec Test Suite |
| 27 | + * https://www.bluetooth.org/docman/handlers/downloaddoc.ashx?doc_id=502301 |
| 28 | + * 3.2.8.2 Reference LC3 Codec Bitstream Format |
| 29 | + * |
| 30 | + * - ETSI TI 103 634 V1.4.1 - Low Complexity Communication Codec plus |
| 31 | + * https://www.etsi.org/deliver/etsi_ts/103600_103699/103634/01.04.01_60/ts_103634v010401p.pdf |
| 32 | + * LC3plus conformance script package |
| 33 | + */ |
| 34 | + |
| 35 | +#include "config_components.h" |
| 36 | + |
| 37 | +#include "libavcodec/packet.h" |
| 38 | +#include "libavutil/intreadwrite.h" |
| 39 | + |
| 40 | +#include "avformat.h" |
| 41 | +#include "avio.h" |
| 42 | +#include "demux.h" |
| 43 | +#include "internal.h" |
| 44 | +#include "mux.h" |
| 45 | + |
| 46 | +static int check_frame_length(void *avcl, int srate_hz, int frame_us) |
| 47 | +{ |
| 48 | + if (srate_hz != 8000 && srate_hz != 16000 && srate_hz != 24000 && |
| 49 | + srate_hz != 32000 && srate_hz != 48000 && srate_hz != 96000) { |
| 50 | + if (avcl) |
| 51 | + av_log(avcl, AV_LOG_ERROR, |
| 52 | + "Invalid LC3 sample rate: %d Hz.\n", srate_hz); |
| 53 | + return -1; |
| 54 | + } |
| 55 | + |
| 56 | + if (frame_us != 2500 && frame_us != 5000 && |
| 57 | + frame_us != 7500 && frame_us != 10000) { |
| 58 | + if (avcl) |
| 59 | + av_log(avcl, AV_LOG_ERROR, |
| 60 | + "Invalid LC3 frame duration: %.1f ms.\n", frame_us / 1000.f); |
| 61 | + return -1; |
| 62 | + } |
| 63 | + |
| 64 | + return 0; |
| 65 | +} |
| 66 | + |
| 67 | +#if CONFIG_LC3_DEMUXER |
| 68 | + |
| 69 | +typedef struct LC3DemuxContext { |
| 70 | + int frame_samples; |
| 71 | + int64_t end_dts; |
| 72 | +} LC3DemuxContext; |
| 73 | + |
| 74 | +static int lc3_read_probe(const AVProbeData *p) |
| 75 | +{ |
| 76 | + int frame_us, srate_hz; |
| 77 | + |
| 78 | + if (p->buf_size < 12) |
| 79 | + return 0; |
| 80 | + |
| 81 | + if (AV_RB16(p->buf + 0) != 0x1ccc || |
| 82 | + AV_RL16(p->buf + 2) < 9 * sizeof(uint16_t)) |
| 83 | + return 0; |
| 84 | + |
| 85 | + srate_hz = AV_RL16(p->buf + 4) * 100; |
| 86 | + frame_us = AV_RL16(p->buf + 10) * 10; |
| 87 | + if (check_frame_length(NULL, srate_hz, frame_us) < 0) |
| 88 | + return 0; |
| 89 | + |
| 90 | + return AVPROBE_SCORE_MAX; |
| 91 | +} |
| 92 | + |
| 93 | +static int lc3_read_header(AVFormatContext *s) |
| 94 | +{ |
| 95 | + LC3DemuxContext *lc3 = s->priv_data; |
| 96 | + AVStream *st = NULL; |
| 97 | + uint16_t tag, hdr_size; |
| 98 | + uint32_t length; |
| 99 | + int srate_hz, frame_us, channels, bit_rate; |
| 100 | + int ep_mode, hr_mode; |
| 101 | + int num_extra_params; |
| 102 | + int delay, ret; |
| 103 | + |
| 104 | + tag = avio_rb16(s->pb); |
| 105 | + hdr_size = avio_rl16(s->pb); |
| 106 | + |
| 107 | + if (tag != 0x1ccc || hdr_size < 9 * sizeof(uint16_t)) |
| 108 | + return AVERROR_INVALIDDATA; |
| 109 | + |
| 110 | + num_extra_params = hdr_size / sizeof(uint16_t) - 9; |
| 111 | + |
| 112 | + srate_hz = avio_rl16(s->pb) * 100; |
| 113 | + bit_rate = avio_rl16(s->pb) * 100; |
| 114 | + channels = avio_rl16(s->pb); |
| 115 | + frame_us = avio_rl16(s->pb) * 10; |
| 116 | + ep_mode = avio_rl16(s->pb) != 0; |
| 117 | + length = avio_rl32(s->pb); |
| 118 | + hr_mode = num_extra_params >= 1 && avio_rl16(s->pb); |
| 119 | + |
| 120 | + if (check_frame_length(s, srate_hz, frame_us) < 0) |
| 121 | + return AVERROR_INVALIDDATA; |
| 122 | + |
| 123 | + st = avformat_new_stream(s, NULL); |
| 124 | + if (!st) |
| 125 | + return AVERROR(ENOMEM); |
| 126 | + |
| 127 | + avpriv_set_pts_info(st, 64, 1, srate_hz); |
| 128 | + avpriv_update_cur_dts(s, st, 0); |
| 129 | + st->duration = length; |
| 130 | + |
| 131 | + st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO; |
| 132 | + st->codecpar->codec_id = AV_CODEC_ID_LC3; |
| 133 | + st->codecpar->sample_rate = srate_hz; |
| 134 | + st->codecpar->bit_rate = bit_rate; |
| 135 | + st->codecpar->ch_layout.nb_channels = channels; |
| 136 | + |
| 137 | + if ((ret = ff_alloc_extradata(st->codecpar, 6)) < 0) |
| 138 | + return ret; |
| 139 | + |
| 140 | + AV_WL16(st->codecpar->extradata + 0, frame_us / 10); |
| 141 | + AV_WL16(st->codecpar->extradata + 2, ep_mode); |
| 142 | + AV_WL16(st->codecpar->extradata + 4, hr_mode); |
| 143 | + |
| 144 | + lc3->frame_samples = av_rescale(frame_us, srate_hz, 1000*1000); |
| 145 | + |
| 146 | + delay = av_rescale(frame_us == 7500 ? 4000 : 2500, srate_hz, 1000*1000); |
| 147 | + lc3->end_dts = length ? length + delay : -1; |
| 148 | + |
| 149 | + return 0; |
| 150 | +} |
| 151 | + |
| 152 | +static int lc3_read_packet(AVFormatContext *s, AVPacket *pkt) |
| 153 | +{ |
| 154 | + LC3DemuxContext *lc3 = s->priv_data; |
| 155 | + AVStream *st = s->streams[0]; |
| 156 | + AVIOContext *pb = s->pb; |
| 157 | + int64_t pos = avio_tell(pb); |
| 158 | + int64_t remaining_samples; |
| 159 | + int ret; |
| 160 | + |
| 161 | + ret = av_get_packet(s->pb, pkt, avio_rl16(pb)); |
| 162 | + if (ret < 0) |
| 163 | + return ret; |
| 164 | + |
| 165 | + pkt->pos = pos; |
| 166 | + |
| 167 | + remaining_samples = lc3->end_dts < 0 ? lc3->frame_samples : |
| 168 | + FFMAX(lc3->end_dts - ffstream(st)->cur_dts, 0); |
| 169 | + pkt->duration = FFMIN(lc3->frame_samples, remaining_samples); |
| 170 | + |
| 171 | + return 0; |
| 172 | +} |
| 173 | + |
| 174 | +const FFInputFormat ff_lc3_demuxer = { |
| 175 | + .p.name = "lc3", |
| 176 | + .p.long_name = NULL_IF_CONFIG_SMALL("LC3 (Low Complexity Communication Codec)"), |
| 177 | + .p.extensions = "lc3", |
| 178 | + .p.flags = AVFMT_GENERIC_INDEX, |
| 179 | + .priv_data_size = sizeof(LC3DemuxContext), |
| 180 | + .read_probe = lc3_read_probe, |
| 181 | + .read_header = lc3_read_header, |
| 182 | + .read_packet = lc3_read_packet, |
| 183 | +}; |
| 184 | + |
| 185 | +#endif /* CONFIG_LC3_DEMUXER */ |
| 186 | + |
| 187 | +#if CONFIG_LC3_MUXER |
| 188 | + |
| 189 | +static av_cold int lc3_muxer_init(AVFormatContext *s) |
| 190 | +{ |
| 191 | + if (s->nb_streams != 1) { |
| 192 | + av_log(s, AV_LOG_ERROR, "This muxer only supports a single stream.\n"); |
| 193 | + return AVERROR(EINVAL); |
| 194 | + } |
| 195 | + |
| 196 | + return 0; |
| 197 | +} |
| 198 | + |
| 199 | +static int lc3_write_header(AVFormatContext *s) |
| 200 | +{ |
| 201 | + AVStream *st = s->streams[0]; |
| 202 | + int channels = st->codecpar->ch_layout.nb_channels; |
| 203 | + int srate_hz = st->codecpar->sample_rate; |
| 204 | + int bit_rate = st->codecpar->bit_rate; |
| 205 | + int frame_us, ep_mode, hr_mode; |
| 206 | + uint32_t nb_samples = av_rescale_q( |
| 207 | + st->duration, st->time_base, (AVRational){ 1, srate_hz }); |
| 208 | + |
| 209 | + if (st->codecpar->extradata_size < 6) |
| 210 | + return AVERROR_INVALIDDATA; |
| 211 | + |
| 212 | + frame_us = AV_RL16(st->codecpar->extradata + 0) * 10; |
| 213 | + ep_mode = AV_RL16(st->codecpar->extradata + 2) != 0; |
| 214 | + hr_mode = AV_RL16(st->codecpar->extradata + 4) != 0; |
| 215 | + |
| 216 | + if (check_frame_length(s, srate_hz, frame_us) < 0) |
| 217 | + return AVERROR_INVALIDDATA; |
| 218 | + |
| 219 | + avio_wb16(s->pb, 0x1ccc); |
| 220 | + avio_wl16(s->pb, (9 + hr_mode) * sizeof(uint16_t)); |
| 221 | + avio_wl16(s->pb, srate_hz / 100); |
| 222 | + avio_wl16(s->pb, bit_rate / 100); |
| 223 | + avio_wl16(s->pb, channels); |
| 224 | + avio_wl16(s->pb, frame_us / 10); |
| 225 | + avio_wl16(s->pb, ep_mode); |
| 226 | + avio_wl32(s->pb, nb_samples); |
| 227 | + if (hr_mode) |
| 228 | + avio_wl16(s->pb, hr_mode); |
| 229 | + |
| 230 | + return 0; |
| 231 | +} |
| 232 | + |
| 233 | +static int lc3_write_packet(AVFormatContext *s, AVPacket *pkt) |
| 234 | +{ |
| 235 | + avio_wl16(s->pb, pkt->size); |
| 236 | + avio_write(s->pb, pkt->data, pkt->size); |
| 237 | + return 0; |
| 238 | +} |
| 239 | + |
| 240 | +const FFOutputFormat ff_lc3_muxer = { |
| 241 | + .p.name = "lc3", |
| 242 | + .p.long_name = NULL_IF_CONFIG_SMALL("LC3 (Low Complexity Communication Codec)"), |
| 243 | + .p.extensions = "lc3", |
| 244 | + .p.audio_codec = AV_CODEC_ID_LC3, |
| 245 | + .p.video_codec = AV_CODEC_ID_NONE, |
| 246 | + .p.flags = AVFMT_NOTIMESTAMPS, |
| 247 | + .init = lc3_muxer_init, |
| 248 | + .write_header = lc3_write_header, |
| 249 | + .write_packet = lc3_write_packet, |
| 250 | +}; |
| 251 | + |
| 252 | +#endif /* CONFIG_LC3_MUXER */ |