| 1 | /* |
| 2 | * Opus parser for Ogg |
| 3 | * Copyright (c) 2012 Nicolas George |
| 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 | #include <string.h> |
| 23 | |
| 24 | #include "libavutil/intreadwrite.h" |
| 25 | #include "avformat.h" |
| 26 | #include "internal.h" |
| 27 | #include "oggdec.h" |
| 28 | |
| 29 | struct oggopus_private { |
| 30 | int need_comments; |
| 31 | unsigned pre_skip; |
| 32 | int64_t cur_dts; |
| 33 | }; |
| 34 | |
| 35 | #define OPUS_SEEK_PREROLL_MS 80 |
| 36 | #define OPUS_HEAD_SIZE 19 |
| 37 | |
| 38 | static int opus_header(AVFormatContext *avf, int idx) |
| 39 | { |
| 40 | struct ogg *ogg = avf->priv_data; |
| 41 | struct ogg_stream *os = &ogg->streams[idx]; |
| 42 | AVStream *st = avf->streams[idx]; |
| 43 | struct oggopus_private *priv = os->private; |
| 44 | uint8_t *packet = os->buf + os->pstart; |
| 45 | |
| 46 | if (!priv) { |
| 47 | priv = os->private = av_mallocz(sizeof(*priv)); |
| 48 | if (!priv) |
| 49 | return AVERROR(ENOMEM); |
| 50 | } |
| 51 | |
| 52 | if (os->flags & OGG_FLAG_BOS) { |
| 53 | if (os->psize < OPUS_HEAD_SIZE || (AV_RL8(packet + 8) & 0xF0) != 0) |
| 54 | return AVERROR_INVALIDDATA; |
| 55 | st->codec->codec_type = AVMEDIA_TYPE_AUDIO; |
| 56 | st->codec->codec_id = AV_CODEC_ID_OPUS; |
| 57 | st->codec->channels = AV_RL8 (packet + 9); |
| 58 | priv->pre_skip = AV_RL16(packet + 10); |
| 59 | st->codec->delay = priv->pre_skip; |
| 60 | /*orig_sample_rate = AV_RL32(packet + 12);*/ |
| 61 | /*gain = AV_RL16(packet + 16);*/ |
| 62 | /*channel_map = AV_RL8 (packet + 18);*/ |
| 63 | |
| 64 | if (ff_alloc_extradata(st->codec, os->psize)) |
| 65 | return AVERROR(ENOMEM); |
| 66 | |
| 67 | memcpy(st->codec->extradata, packet, os->psize); |
| 68 | |
| 69 | st->codec->sample_rate = 48000; |
| 70 | av_codec_set_seek_preroll(st->codec, |
| 71 | av_rescale(OPUS_SEEK_PREROLL_MS, |
| 72 | st->codec->sample_rate, 1000)); |
| 73 | avpriv_set_pts_info(st, 64, 1, 48000); |
| 74 | priv->need_comments = 1; |
| 75 | return 1; |
| 76 | } |
| 77 | |
| 78 | if (priv->need_comments) { |
| 79 | if (os->psize < 8 || memcmp(packet, "OpusTags", 8)) |
| 80 | return AVERROR_INVALIDDATA; |
| 81 | ff_vorbis_stream_comment(avf, st, packet + 8, os->psize - 8); |
| 82 | priv->need_comments--; |
| 83 | return 1; |
| 84 | } |
| 85 | |
| 86 | return 0; |
| 87 | } |
| 88 | |
| 89 | static int opus_duration(uint8_t *src, int size) |
| 90 | { |
| 91 | unsigned nb_frames = 1; |
| 92 | unsigned toc = src[0]; |
| 93 | unsigned toc_config = toc >> 3; |
| 94 | unsigned toc_count = toc & 3; |
| 95 | unsigned frame_size = toc_config < 12 ? FFMAX(480, 960 * (toc_config & 3)) : |
| 96 | toc_config < 16 ? 480 << (toc_config & 1) : |
| 97 | 120 << (toc_config & 3); |
| 98 | if (toc_count == 3) { |
| 99 | if (size<2) |
| 100 | return AVERROR_INVALIDDATA; |
| 101 | nb_frames = src[1] & 0x3F; |
| 102 | } else if (toc_count) { |
| 103 | nb_frames = 2; |
| 104 | } |
| 105 | |
| 106 | return frame_size * nb_frames; |
| 107 | } |
| 108 | |
| 109 | static int opus_packet(AVFormatContext *avf, int idx) |
| 110 | { |
| 111 | struct ogg *ogg = avf->priv_data; |
| 112 | struct ogg_stream *os = &ogg->streams[idx]; |
| 113 | AVStream *st = avf->streams[idx]; |
| 114 | struct oggopus_private *priv = os->private; |
| 115 | uint8_t *packet = os->buf + os->pstart; |
| 116 | int ret; |
| 117 | |
| 118 | if (!os->psize) |
| 119 | return AVERROR_INVALIDDATA; |
| 120 | |
| 121 | if ((!os->lastpts || os->lastpts == AV_NOPTS_VALUE) && !(os->flags & OGG_FLAG_EOS)) { |
| 122 | int seg, d; |
| 123 | int duration; |
| 124 | uint8_t *last_pkt = os->buf + os->pstart; |
| 125 | uint8_t *next_pkt = last_pkt; |
| 126 | |
| 127 | duration = 0; |
| 128 | seg = os->segp; |
| 129 | d = opus_duration(last_pkt, os->psize); |
| 130 | if (d < 0) { |
| 131 | os->pflags |= AV_PKT_FLAG_CORRUPT; |
| 132 | return 0; |
| 133 | } |
| 134 | duration += d; |
| 135 | last_pkt = next_pkt = next_pkt + os->psize; |
| 136 | for (; seg < os->nsegs; seg++) { |
| 137 | next_pkt += os->segments[seg]; |
| 138 | if (os->segments[seg] < 255 && next_pkt != last_pkt) { |
| 139 | int d = opus_duration(last_pkt, next_pkt - last_pkt); |
| 140 | if (d > 0) |
| 141 | duration += d; |
| 142 | last_pkt = next_pkt; |
| 143 | } |
| 144 | } |
| 145 | os->lastpts = |
| 146 | os->lastdts = os->granule - duration; |
| 147 | } |
| 148 | |
| 149 | if ((ret = opus_duration(packet, os->psize)) < 0) |
| 150 | return ret; |
| 151 | |
| 152 | os->pduration = ret; |
| 153 | if (os->lastpts != AV_NOPTS_VALUE) { |
| 154 | if (st->start_time == AV_NOPTS_VALUE) |
| 155 | st->start_time = os->lastpts; |
| 156 | priv->cur_dts = os->lastdts = os->lastpts -= priv->pre_skip; |
| 157 | } |
| 158 | |
| 159 | priv->cur_dts += os->pduration; |
| 160 | if ((os->flags & OGG_FLAG_EOS)) { |
| 161 | int64_t skip = priv->cur_dts - os->granule + priv->pre_skip; |
| 162 | skip = FFMIN(skip, os->pduration); |
| 163 | if (skip > 0) { |
| 164 | os->pduration = skip < os->pduration ? os->pduration - skip : 1; |
| 165 | os->end_trimming = skip; |
| 166 | av_log(avf, AV_LOG_DEBUG, |
| 167 | "Last packet was truncated to %d due to end trimming.\n", |
| 168 | os->pduration); |
| 169 | } |
| 170 | } |
| 171 | |
| 172 | return 0; |
| 173 | } |
| 174 | |
| 175 | const struct ogg_codec ff_opus_codec = { |
| 176 | .name = "Opus", |
| 177 | .magic = "OpusHead", |
| 178 | .magicsize = 8, |
| 179 | .header = opus_header, |
| 180 | .packet = opus_packet, |
| 181 | .nb_header = 1, |
| 182 | }; |