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oggparseopus.c
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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 
31  unsigned pre_skip;
32  int64_t cur_dts;
33 };
34 
35 #define OPUS_HEAD_SIZE 19
36 
37 static int opus_header(AVFormatContext *avf, int idx)
38 {
39  struct ogg *ogg = avf->priv_data;
40  struct ogg_stream *os = &ogg->streams[idx];
41  AVStream *st = avf->streams[idx];
42  struct oggopus_private *priv = os->private;
43  uint8_t *packet = os->buf + os->pstart;
44  uint8_t *extradata;
45 
46  if (!priv) {
47  priv = os->private = av_mallocz(sizeof(*priv));
48  if (!priv)
49  return AVERROR(ENOMEM);
50  }
51  if (os->flags & OGG_FLAG_BOS) {
52  if (os->psize < OPUS_HEAD_SIZE || (AV_RL8(packet + 8) & 0xF0) != 0)
53  return AVERROR_INVALIDDATA;
56  st->codec->channels = AV_RL8 (packet + 9);
57  priv->pre_skip = AV_RL16(packet + 10);
58  /*orig_sample_rate = AV_RL32(packet + 12);*/
59  /*gain = AV_RL16(packet + 16);*/
60  /*channel_map = AV_RL8 (packet + 18);*/
61 
62  extradata = av_malloc(os->psize + FF_INPUT_BUFFER_PADDING_SIZE);
63  if (!extradata)
64  return AVERROR(ENOMEM);
65  memcpy(extradata, packet, os->psize);
66  st->codec->extradata = extradata;
67  st->codec->extradata_size = os->psize;
68 
69  st->codec->sample_rate = 48000;
70  avpriv_set_pts_info(st, 64, 1, 48000);
71  priv->need_comments = 1;
72  return 1;
73  }
74 
75  if (priv->need_comments) {
76  if (os->psize < 8 || memcmp(packet, "OpusTags", 8))
77  return AVERROR_INVALIDDATA;
78  ff_vorbis_comment(avf, &st->metadata, packet + 8, os->psize - 8);
79  priv->need_comments--;
80  return 1;
81  }
82  return 0;
83 }
84 
85 static int opus_packet(AVFormatContext *avf, int idx)
86 {
87  struct ogg *ogg = avf->priv_data;
88  struct ogg_stream *os = &ogg->streams[idx];
89  AVStream *st = avf->streams[idx];
90  struct oggopus_private *priv = os->private;
91  uint8_t *packet = os->buf + os->pstart;
92  unsigned toc, toc_config, toc_count, frame_size, nb_frames = 1;
93 
94  if (!os->psize)
95  return AVERROR_INVALIDDATA;
96  toc = *packet;
97  toc_config = toc >> 3;
98  toc_count = toc & 3;
99  frame_size = toc_config < 12 ? FFMAX(480, 960 * (toc_config & 3)) :
100  toc_config < 16 ? 480 << (toc_config & 1) :
101  120 << (toc_config & 3);
102  if (toc_count == 3) {
103  if (os->psize < 2)
104  return AVERROR_INVALIDDATA;
105  nb_frames = packet[1] & 0x3F;
106  } else if (toc_count) {
107  nb_frames = 2;
108  }
109  os->pduration = frame_size * nb_frames;
110  if (os->lastpts != AV_NOPTS_VALUE) {
111  if (st->start_time == AV_NOPTS_VALUE)
112  st->start_time = os->lastpts;
113  priv->cur_dts = os->lastdts = os->lastpts -= priv->pre_skip;
114  }
115  priv->cur_dts += os->pduration;
116  if ((os->flags & OGG_FLAG_EOS)) {
117  int64_t skip = priv->cur_dts - os->granule + priv->pre_skip;
118  skip = FFMIN(skip, os->pduration);
119  if (skip > 0) {
120  os->pduration = skip < os->pduration ? os->pduration - skip : 1;
121  av_log(avf, AV_LOG_WARNING,
122  "Last packet must be truncated to %d (unimplemented).\n",
123  os->pduration);
124  }
125  }
126  return 0;
127 }
128 
129 const struct ogg_codec ff_opus_codec = {
130  .name = "Opus",
131  .magic = "OpusHead",
132  .magicsize = 8,
133  .header = opus_header,
134  .packet = opus_packet,
135 };