libavformat/oggparseopus.c

   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 "libavutil/mem.h"
  26 #include "avformat.h"
  27 #include "internal.h"
  28 #include "oggdec.h"
  29
  30 struct oggopus_private {
  31     int need_comments;
  32     unsigned pre_skip;
  33     int64_t cur_dts;
  34 };
  35
  36 #define OPUS_SEEK_PREROLL_MS 80
  37 #define OPUS_HEAD_SIZE 19
  38
  39 static int parse_opus_header(AVFormatContext *avf, AVStream *st, struct ogg_stream *os,
  40                              struct oggopus_private *priv, uint8_t *packet,
  41                              size_t psize)
  42 {
  43     int channels;
  44     int ret;
  45
  46     if (psize < OPUS_HEAD_SIZE || (AV_RL8(packet + 8) & 0xF0) != 0)
  47         return AVERROR_INVALIDDATA;
  48
  49     st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
  50     st->codecpar->codec_id   = AV_CODEC_ID_OPUS;
  51
  52     channels = AV_RL8(packet + 9);
  53     if (st->codecpar->ch_layout.nb_channels &&
  54         channels != st->codecpar->ch_layout.nb_channels) {
  55         av_log(avf, AV_LOG_ERROR, "Channel change is not supported\n");
  56         return AVERROR_PATCHWELCOME;
  57     }
  58
  59     st->codecpar->ch_layout.nb_channels = channels;
  60
  61     priv->pre_skip        = AV_RL16(packet + 10);
  62     st->codecpar->initial_padding = priv->pre_skip;
  63     os->start_trimming = priv->pre_skip;
  64     /*orig_sample_rate    = AV_RL32(packet + 12);*/
  65     /*gain                = AV_RL16(packet + 16);*/
  66     /*channel_map         = AV_RL8 (packet + 18);*/
  67
  68     ret = ff_alloc_extradata(st->codecpar, os->psize);
  69     if (ret < 0)
  70         return ret;
  71
  72     memcpy(st->codecpar->extradata, packet, os->psize);
  73
  74     st->codecpar->sample_rate = 48000;
  75     st->codecpar->seek_preroll = av_rescale(OPUS_SEEK_PREROLL_MS,
  76                                             st->codecpar->sample_rate, 1000);
  77     avpriv_set_pts_info(st, 64, 1, 48000);
  78
  79     priv->need_comments = 1;
  80
  81     return 1;
  82 }
  83
  84 static int opus_header(AVFormatContext *avf, int idx)
  85 {
  86     struct ogg *ogg              = avf->priv_data;
  87     struct ogg_stream *os        = &ogg->streams[idx];
  88     AVStream *st                 = avf->streams[idx];
  89     struct oggopus_private *priv = os->private;
  90     uint8_t *packet              = os->buf + os->pstart;
  91
  92     if (!priv) {
  93         priv = os->private = av_mallocz(sizeof(*priv));
  94         if (!priv)
  95             return AVERROR(ENOMEM);
  96     }
  97
  98     if (os->flags & OGG_FLAG_BOS)
  99         return parse_opus_header(avf, st, os, priv, packet, os->psize);
 100
 101     if (priv->need_comments) {
 102         if (os->psize < 8 || memcmp(packet, "OpusTags", 8))
 103             return AVERROR_INVALIDDATA;
 104         ff_vorbis_stream_comment(avf, st, packet + 8, os->psize - 8);
 105         priv->need_comments--;
 106         return 1;
 107     }
 108
 109     return 0;
 110 }
 111
 112 static int opus_duration(uint8_t *src, int size)
 113 {
 114     unsigned nb_frames  = 1;
 115     unsigned toc        = src[0];
 116     unsigned toc_config = toc >> 3;
 117     unsigned toc_count  = toc & 3;
 118     unsigned frame_size = toc_config < 12 ? FFMAX(480, 960 * (toc_config & 3)) :
 119                           toc_config < 16 ? 480 << (toc_config & 1) :
 120                                             120 << (toc_config & 3);
 121     if (toc_count == 3) {
 122         if (size<2)
 123             return AVERROR_INVALIDDATA;
 124         nb_frames = src[1] & 0x3F;
 125     } else if (toc_count) {
 126         nb_frames = 2;
 127     }
 128
 129     return frame_size * nb_frames;
 130 }
 131
 132 static int opus_packet(AVFormatContext *avf, int idx)
 133 {
 134     struct ogg *ogg              = avf->priv_data;
 135     struct ogg_stream *os        = &ogg->streams[idx];
 136     AVStream *st                 = avf->streams[idx];
 137     struct oggopus_private *priv = os->private;
 138     uint8_t *packet              = os->buf + os->pstart;
 139     int ret;
 140
 141     if (!os->psize)
 142         return AVERROR_INVALIDDATA;
 143     if (os->granule > (1LL << 62)) {
 144         av_log(avf, AV_LOG_ERROR, "Unsupported huge granule pos %"PRId64 "\n", os->granule);
 145         return AVERROR_INVALIDDATA;
 146     }
 147
 148      if (os->psize > 8 && !memcmp(packet, "OpusHead", 8)) {
 149         ret = parse_opus_header(avf, st, os, priv, packet, os->psize);
 150         if (ret < 0)
 151             return ret;
 152
 153         return 1;
 154     }
 155
 156     if (os->psize > 8 && !memcmp(packet, "OpusTags", 8)) {
 157         ret = ff_vorbis_update_metadata(avf, st, os->buf + os->pstart + 8,
 158                                         os->psize - 8);
 159         if (ret < 0)
 160             return ret;
 161
 162         priv->need_comments = 0;
 163         return 1;
 164     }
 165
 166     if ((!os->lastpts || os->lastpts == AV_NOPTS_VALUE) && !(os->flags & OGG_FLAG_EOS)) {
 167         int seg, d;
 168         int duration;
 169         uint8_t *last_pkt  = os->buf + os->pstart;
 170         uint8_t *next_pkt  = last_pkt;
 171
 172         duration = 0;
 173         seg = os->segp;
 174         d = opus_duration(last_pkt, os->psize);
 175         if (d < 0) {
 176             os->pflags |= AV_PKT_FLAG_CORRUPT;
 177             return 0;
 178         }
 179         duration += d;
 180         last_pkt = next_pkt =  next_pkt + os->psize;
 181         for (; seg < os->nsegs; seg++) {
 182             next_pkt += os->segments[seg];
 183             if (os->segments[seg] < 255 && next_pkt != last_pkt) {
 184                 int d = opus_duration(last_pkt, next_pkt - last_pkt);
 185                 if (d > 0)
 186                     duration += d;
 187                 last_pkt = next_pkt;
 188             }
 189         }
 190         os->lastpts                 =
 191         os->lastdts                 = os->granule - duration;
 192     }
 193
 194     if ((ret = opus_duration(packet, os->psize)) < 0)
 195         return ret;
 196
 197     os->pduration = ret;
 198     if (os->lastpts != AV_NOPTS_VALUE) {
 199         if (st->start_time == AV_NOPTS_VALUE)
 200             st->start_time = os->lastpts;
 201         priv->cur_dts = os->lastdts = os->lastpts -= priv->pre_skip;
 202     }
 203
 204     priv->cur_dts += os->pduration;
 205     if ((os->flags & OGG_FLAG_EOS)) {
 206         int64_t skip = priv->cur_dts - os->granule + priv->pre_skip;
 207         skip = FFMIN(skip, os->pduration);
 208         if (skip > 0) {
 209             os->pduration = skip < os->pduration ? os->pduration - skip : 1;
 210             os->end_trimming = skip;
 211             av_log(avf, AV_LOG_DEBUG,
 212                    "Last packet was truncated to %d due to end trimming.\n",
 213                    os->pduration);
 214         }
 215     }
 216
 217     return 0;
 218 }
 219
 220 const struct ogg_codec ff_opus_codec = {
 221     .name             = "Opus",
 222     .magic            = "OpusHead",
 223     .magicsize        = 8,
 224     .header           = opus_header,
 225     .packet           = opus_packet,
 226     .nb_header        = 1,
 227 };