FFmpeg
oggparsevp8.c
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1 /*
2  * On2 VP8 parser for Ogg
3  * Copyright (C) 2013 James Almer
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 "libavutil/intreadwrite.h"
23 
24 #include "avformat.h"
25 #include "internal.h"
26 #include "oggdec.h"
27 
28 #define VP8_HEADER_SIZE 26
29 
30 static int vp8_header(AVFormatContext *s, int idx)
31 {
32  struct ogg *ogg = s->priv_data;
33  struct ogg_stream *os = ogg->streams + idx;
34  uint8_t *p = os->buf + os->pstart;
35  AVStream *st = s->streams[idx];
37 
38  if (os->psize < 7 || p[0] != 0x4f)
39  return 0;
40 
41  switch (p[5]){
42  case 0x01:
43  if (os->psize < VP8_HEADER_SIZE) {
44  av_log(s, AV_LOG_ERROR, "Invalid OggVP8 header packet");
45  return AVERROR_INVALIDDATA;
46  }
47 
48  if (p[6] != 1) {
50  "Unknown OggVP8 version %d.%d\n", p[6], p[7]);
51  return AVERROR_INVALIDDATA;
52  }
53 
54  st->codecpar->width = AV_RB16(p + 8);
55  st->codecpar->height = AV_RB16(p + 10);
56  st->sample_aspect_ratio.num = AV_RB24(p + 12);
57  st->sample_aspect_ratio.den = AV_RB24(p + 15);
58  framerate.num = AV_RB32(p + 18);
59  framerate.den = AV_RB32(p + 22);
60 
61  avpriv_set_pts_info(st, 64, framerate.den, framerate.num);
65  break;
66  case 0x02:
67  if (p[6] != 0x20)
68  return AVERROR_INVALIDDATA;
69  ff_vorbis_stream_comment(s, st, p + 7, os->psize - 7);
70  break;
71  default:
72  av_log(s, AV_LOG_ERROR, "Unknown VP8 header type 0x%02X\n", p[5]);
73  return AVERROR_INVALIDDATA;
74  }
75 
76  return 1;
77 }
78 
79 static uint64_t vp8_gptopts(AVFormatContext *s, int idx,
80  uint64_t granule, int64_t *dts)
81 {
82  struct ogg *ogg = s->priv_data;
83  struct ogg_stream *os = ogg->streams + idx;
84 
85  int invcnt = !((granule >> 30) & 3);
86  // If page granule is that of an invisible vp8 frame, its pts will be
87  // that of the end of the next visible frame. We subtract 1 for those
88  // to prevent messing up pts calculations.
89  uint64_t pts = (granule >> 32) - invcnt;
90  uint32_t dist = (granule >> 3) & 0x07ffffff;
91 
92  if (!dist)
93  os->pflags |= AV_PKT_FLAG_KEY;
94 
95  if (dts)
96  *dts = pts;
97 
98  return pts;
99 }
100 
101 static int vp8_packet(AVFormatContext *s, int idx)
102 {
103  struct ogg *ogg = s->priv_data;
104  struct ogg_stream *os = ogg->streams + idx;
105  uint8_t *p = os->buf + os->pstart;
106 
107  if ((!os->lastpts || os->lastpts == AV_NOPTS_VALUE) &&
108  !(os->flags & OGG_FLAG_EOS)) {
109  int seg;
110  int duration;
111  uint8_t *last_pkt = p;
112  uint8_t *next_pkt;
113 
114  seg = os->segp;
115  duration = (last_pkt[0] >> 4) & 1;
116  next_pkt = last_pkt += os->psize;
117  for (; seg < os->nsegs; seg++) {
118  if (os->segments[seg] < 255) {
119  duration += (last_pkt[0] >> 4) & 1;
120  last_pkt = next_pkt + os->segments[seg];
121  }
122  next_pkt += os->segments[seg];
123  }
124  os->lastpts =
125  os->lastdts = vp8_gptopts(s, idx, os->granule, NULL) - duration;
126  if(s->streams[idx]->start_time == AV_NOPTS_VALUE) {
127  s->streams[idx]->start_time = os->lastpts;
128  if (s->streams[idx]->duration && s->streams[idx]->duration != AV_NOPTS_VALUE)
129  s->streams[idx]->duration -= s->streams[idx]->start_time;
130  }
131  }
132 
133  if (os->psize > 0)
134  os->pduration = (p[0] >> 4) & 1;
135 
136  return 0;
137 }
138 
139 const struct ogg_codec ff_vp8_codec = {
140  .magic = "OVP80",
141  .magicsize = 5,
142  .header = vp8_header,
143  .packet = vp8_packet,
144  .gptopts = vp8_gptopts,
145  .nb_header = 1,
146 };
#define NULL
Definition: coverity.c:32
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
#define VP8_HEADER_SIZE
Definition: oggparsevp8.c:28
Copyright (C) 2005 Michael Ahlberg, Måns Rullgård.
Definition: oggdec.h:31
unsigned int pflags
Definition: oggdec.h:67
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
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:4929
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3968
AVRational sample_aspect_ratio
sample aspect ratio (0 if unknown)
Definition: avformat.h:943
int num
Numerator.
Definition: rational.h:59
static uint64_t vp8_gptopts(AVFormatContext *s, int idx, uint64_t granule, int64_t *dts)
Definition: oggparsevp8.c:79
int flags
Definition: oggdec.h:76
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_WB32 unsigned int_TMPL AV_WB24 unsigned int_TMPL AV_RB16
Definition: bytestream.h:87
int framerate
Definition: h264_levels.c:65
int64_t lastpts
Definition: oggdec.h:72
Format I/O context.
Definition: avformat.h:1358
unsigned int psize
Definition: oggdec.h:66
uint8_t
int width
Video only.
Definition: avcodec.h:4034
enum AVStreamParseType need_parsing
Definition: avformat.h:1099
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_RB32
Definition: bytestream.h:87
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1426
int64_t duration
Definition: movenc.c:63
static int vp8_packet(AVFormatContext *s, int idx)
Definition: oggparsevp8.c:101
#define av_log(a,...)
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: avcodec.h:1512
#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 OGG_FLAG_EOS
Definition: oggdec.h:112
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3964
uint8_t segments[255]
Definition: oggdec.h:80
Only parse headers, do not repack.
Definition: avformat.h:801
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 s(width, name)
Definition: cbs_vp9.c:257
Stream structure.
Definition: avformat.h:881
unsigned int pduration
Definition: oggdec.h:68
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_WB32 unsigned int_TMPL AV_RB24
Definition: bytestream.h:87
int nsegs
Definition: oggdec.h:79
Rational number (pair of numerator and denominator).
Definition: rational.h:58
int64_t lastdts
Definition: oggdec.h:73
static int64_t pts
const int8_t * magic
Definition: oggdec.h:32
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:930
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
const struct ogg_codec ff_vp8_codec
Definition: oggparsevp8.c:139
int den
Denominator.
Definition: rational.h:60
Definition: oggdec.h:101
void * priv_data
Format private data.
Definition: avformat.h:1386
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1028
static int vp8_header(AVFormatContext *s, int idx)
Definition: oggparsevp8.c:30
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:248