FFmpeg
oggparseopus.c
Go to the documentation of this file.
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_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;
57  st->codecpar->channels = AV_RL8(packet + 9);
58 
59  priv->pre_skip = AV_RL16(packet + 10);
60  st->codecpar->initial_padding = priv->pre_skip;
61  /*orig_sample_rate = AV_RL32(packet + 12);*/
62  /*gain = AV_RL16(packet + 16);*/
63  /*channel_map = AV_RL8 (packet + 18);*/
64 
66  if (ff_alloc_extradata(st->codecpar, os->psize))
67  return AVERROR(ENOMEM);
68 
69  memcpy(st->codecpar->extradata, packet, os->psize);
70 
71  st->codecpar->sample_rate = 48000;
73  st->codecpar->sample_rate, 1000);
74  avpriv_set_pts_info(st, 64, 1, 48000);
75  priv->need_comments = 1;
76  return 1;
77  }
78 
79  if (priv->need_comments) {
80  if (os->psize < 8 || memcmp(packet, "OpusTags", 8))
81  return AVERROR_INVALIDDATA;
82  ff_vorbis_stream_comment(avf, st, packet + 8, os->psize - 8);
83  priv->need_comments--;
84  return 1;
85  }
86 
87  return 0;
88 }
89 
90 static int opus_duration(uint8_t *src, int size)
91 {
92  unsigned nb_frames = 1;
93  unsigned toc = src[0];
94  unsigned toc_config = toc >> 3;
95  unsigned toc_count = toc & 3;
96  unsigned frame_size = toc_config < 12 ? FFMAX(480, 960 * (toc_config & 3)) :
97  toc_config < 16 ? 480 << (toc_config & 1) :
98  120 << (toc_config & 3);
99  if (toc_count == 3) {
100  if (size<2)
101  return AVERROR_INVALIDDATA;
102  nb_frames = src[1] & 0x3F;
103  } else if (toc_count) {
104  nb_frames = 2;
105  }
106 
107  return frame_size * nb_frames;
108 }
109 
110 static int opus_packet(AVFormatContext *avf, int idx)
111 {
112  struct ogg *ogg = avf->priv_data;
113  struct ogg_stream *os = &ogg->streams[idx];
114  AVStream *st = avf->streams[idx];
115  struct oggopus_private *priv = os->private;
116  uint8_t *packet = os->buf + os->pstart;
117  int ret;
118 
119  if (!os->psize)
120  return AVERROR_INVALIDDATA;
121  if (os->granule > (1LL << 62)) {
122  av_log(avf, AV_LOG_ERROR, "Unsupported huge granule pos %"PRId64 "\n", os->granule);
123  return AVERROR_INVALIDDATA;
124  }
125 
126  if ((!os->lastpts || os->lastpts == AV_NOPTS_VALUE) && !(os->flags & OGG_FLAG_EOS)) {
127  int seg, d;
128  int duration;
129  uint8_t *last_pkt = os->buf + os->pstart;
130  uint8_t *next_pkt = last_pkt;
131 
132  duration = 0;
133  seg = os->segp;
134  d = opus_duration(last_pkt, os->psize);
135  if (d < 0) {
137  return 0;
138  }
139  duration += d;
140  last_pkt = next_pkt = next_pkt + os->psize;
141  for (; seg < os->nsegs; seg++) {
142  next_pkt += os->segments[seg];
143  if (os->segments[seg] < 255 && next_pkt != last_pkt) {
144  int d = opus_duration(last_pkt, next_pkt - last_pkt);
145  if (d > 0)
146  duration += d;
147  last_pkt = next_pkt;
148  }
149  }
150  os->lastpts =
151  os->lastdts = os->granule - duration;
152  }
153 
154  if ((ret = opus_duration(packet, os->psize)) < 0)
155  return ret;
156 
157  os->pduration = ret;
158  if (os->lastpts != AV_NOPTS_VALUE) {
159  if (st->start_time == AV_NOPTS_VALUE)
160  st->start_time = os->lastpts;
161  priv->cur_dts = os->lastdts = os->lastpts -= priv->pre_skip;
162  }
163 
164  priv->cur_dts += os->pduration;
165  if ((os->flags & OGG_FLAG_EOS)) {
166  int64_t skip = priv->cur_dts - os->granule + priv->pre_skip;
167  skip = FFMIN(skip, os->pduration);
168  if (skip > 0) {
169  os->pduration = skip < os->pduration ? os->pduration - skip : 1;
170  os->end_trimming = skip;
171  av_log(avf, AV_LOG_DEBUG,
172  "Last packet was truncated to %d due to end trimming.\n",
173  os->pduration);
174  }
175  }
176 
177  return 0;
178 }
179 
180 const struct ogg_codec ff_opus_codec = {
181  .name = "Opus",
182  .magic = "OpusHead",
183  .magicsize = 8,
184  .header = opus_header,
185  .packet = opus_packet,
186  .nb_header = 1,
187 };
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
Copyright (C) 2005 Michael Ahlberg, Måns Rullgård.
Definition: oggdec.h:31
#define OPUS_SEEK_PREROLL_MS
Definition: oggparseopus.c:35
unsigned int pflags
Definition: oggdec.h:67
static int opus_duration(uint8_t *src, int size)
Definition: oggparseopus.c:90
void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: utils.c:4884
static int opus_header(AVFormatContext *avf, int idx)
Definition: oggparseopus.c:38
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3953
void * av_mallocz(size_t size)
Allocate a memory block with alignment suitable for all memory accesses (including vectors if availab...
Definition: mem.c:236
int flags
Definition: oggdec.h:76
#define src
Definition: vp8dsp.c:254
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_RL16
Definition: bytestream.h:87
int64_t lastpts
Definition: oggdec.h:72
static int opus_packet(AVFormatContext *avf, int idx)
Definition: oggparseopus.c:110
Format I/O context.
Definition: avformat.h:1358
unsigned int psize
Definition: oggdec.h:66
uint8_t
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1426
int64_t duration
Definition: movenc.c:63
int initial_padding
Audio only.
Definition: avcodec.h:4082
int end_trimming
set the number of packets to drop from the end
Definition: oggdec.h:87
ptrdiff_t size
Definition: opengl_enc.c:100
#define av_log(a,...)
#define AV_RL8(x)
Definition: intreadwrite.h:398
unsigned pre_skip
Definition: oggparseopus.c:31
#define OPUS_HEAD_SIZE
Definition: oggparseopus.c:36
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
int ff_vorbis_stream_comment(AVFormatContext *as, AVStream *st, const uint8_t *buf, int size)
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:197
#define OGG_FLAG_EOS
Definition: oggdec.h:112
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3949
#define FFMAX(a, b)
Definition: common.h:94
uint8_t segments[255]
Definition: oggdec.h:80
int ff_alloc_extradata(AVCodecParameters *par, int size)
Allocate extradata with additional AV_INPUT_BUFFER_PADDING_SIZE at end which is always set to 0...
Definition: utils.c:3288
int64_t av_rescale(int64_t a, int64_t b, int64_t c)
Rescale a 64-bit integer with rounding to nearest.
Definition: mathematics.c:129
#define FFMIN(a, b)
Definition: common.h:96
uint64_t granule
Definition: oggdec.h:70
unsigned int pstart
Definition: oggdec.h:65
struct ogg_stream * streams
Definition: oggdec.h:102
int segp
Definition: oggdec.h:79
#define OGG_FLAG_BOS
Definition: oggdec.h:111
Stream structure.
Definition: avformat.h:881
int frame_size
Definition: mxfenc.c:2216
unsigned int pduration
Definition: oggdec.h:68
int nsegs
Definition: oggdec.h:79
const int8_t * name
Definition: oggdec.h:34
const struct ogg_codec ff_opus_codec
Definition: oggparseopus.c:180
void * private
Definition: oggdec.h:90
int64_t lastdts
Definition: oggdec.h:73
int seek_preroll
Audio only.
Definition: avcodec.h:4093
int sample_rate
Audio only.
Definition: avcodec.h:4063
uint8_t * buf
Definition: oggdec.h:62
Main libavformat public API header.
int64_t start_time
Decoding: pts of the first frame of the stream in presentation order, in stream time base...
Definition: avformat.h:920
#define AV_PKT_FLAG_CORRUPT
The packet content is corrupted.
Definition: avcodec.h:1510
Definition: oggdec.h:101
void * priv_data
Format private data.
Definition: avformat.h:1386
uint8_t * extradata
Extra binary data needed for initializing the decoder, codec-dependent.
Definition: avcodec.h:3967
int channels
Audio only.
Definition: avcodec.h:4059
#define av_freep(p)
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1028
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later.That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another.Frame references ownership and permissions
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:248