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 Libav.
6  *
7  * Libav 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  * Libav 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 Libav; 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;
54 
57  st->codec->channels = AV_RL8(packet + 9);
58  priv->pre_skip = AV_RL16(packet + 10);
59 
60  extradata = av_malloc(os->psize + FF_INPUT_BUFFER_PADDING_SIZE);
61  if (!extradata)
62  return AVERROR(ENOMEM);
63 
64  memcpy(extradata, packet, os->psize);
65  st->codec->extradata = extradata;
66  st->codec->extradata_size = os->psize;
67 
68  st->codec->sample_rate = 48000;
69  avpriv_set_pts_info(st, 64, 1, 48000);
70  priv->need_comments = 1;
71  return 1;
72  }
73 
74  if (priv->need_comments) {
75  if (os->psize < 8 || memcmp(packet, "OpusTags", 8))
76  return AVERROR_INVALIDDATA;
77  ff_vorbis_comment(avf, &st->metadata, packet + 8, os->psize - 8);
78  priv->need_comments--;
79  return 1;
80  }
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 
97  toc = *packet;
98  toc_config = toc >> 3;
99  toc_count = toc & 3;
100  frame_size = toc_config < 12 ? FFMAX(480, 960 * (toc_config & 3)) :
101  toc_config < 16 ? 480 << (toc_config & 1) :
102  120 << (toc_config & 3);
103  if (toc_count == 3) {
104  if (os->psize < 2)
105  return AVERROR_INVALIDDATA;
106  nb_frames = packet[1] & 0x3F;
107  } else if (toc_count) {
108  nb_frames = 2;
109  }
110 
111  os->pduration = frame_size * nb_frames;
112  if (os->lastpts != AV_NOPTS_VALUE) {
113  if (st->start_time == AV_NOPTS_VALUE)
114  st->start_time = os->lastpts;
115  priv->cur_dts = os->lastdts = os->lastpts -= priv->pre_skip;
116  }
117 
118  priv->cur_dts += os->pduration;
119  if ((os->flags & OGG_FLAG_EOS)) {
120  int64_t skip = priv->cur_dts - os->granule + priv->pre_skip;
121  skip = FFMIN(skip, os->pduration);
122  if (skip > 0) {
123  os->pduration = skip < os->pduration ? os->pduration - skip : 1;
124  av_log(avf, AV_LOG_WARNING,
125  "Last packet is truncated to %d (because of unimplemented end trim support).\n",
126  os->pduration);
127  return AVERROR_PATCHWELCOME;
128  }
129  }
130 
131  return 0;
132 }
133 
134 const struct ogg_codec ff_opus_codec = {
135  .name = "Opus",
136  .magic = "OpusHead",
137  .magicsize = 8,
138  .header = opus_header,
139  .packet = opus_packet,
140  .granule_is_start = 1,
141  .nb_header = 1,
142 };