FFmpeg
ivfdec.c
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1 /*
2  * Copyright (c) 2010 David Conrad
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include "avformat.h"
22 #include "demux.h"
23 #include "internal.h"
24 #include "riff.h"
25 #include "libavutil/intreadwrite.h"
26 
27 static int probe(const AVProbeData *p)
28 {
29  if (AV_RL32(p->buf) == MKTAG('D','K','I','F')
30  && !AV_RL16(p->buf+4) && AV_RL16(p->buf+6) == 32)
31  return AVPROBE_SCORE_MAX-2;
32 
33  return 0;
34 }
35 
37 {
38  AVStream *st;
39  AVRational time_base;
40 
41  avio_rl32(s->pb); // DKIF
42  avio_rl16(s->pb); // version
43  avio_rl16(s->pb); // header size
44 
45  st = avformat_new_stream(s, NULL);
46  if (!st)
47  return AVERROR(ENOMEM);
48 
49 
51  st->codecpar->codec_tag = avio_rl32(s->pb);
53  st->codecpar->width = avio_rl16(s->pb);
54  st->codecpar->height = avio_rl16(s->pb);
55  time_base.den = avio_rl32(s->pb);
56  time_base.num = avio_rl32(s->pb);
57  st->nb_frames = avio_rl32(s->pb);
58  avio_skip(s->pb, 4); // unused
59 
60  // Infer duration from nb_frames, in order to be backward compatible with
61  // previous IVF demuxer.
62  // It is popular to configure time_base to 1/frame_rate by IVF muxer, that
63  // the duration happens to be the same with nb_frames. See
64  // `https://chromium.googlesource.com/webm/vp8-test-vectors/+/refs/heads/main`
65  st->duration = st->nb_frames;
66 
68 
69  if (!time_base.den || !time_base.num) {
70  av_log(s, AV_LOG_ERROR, "Invalid frame rate\n");
71  return AVERROR_INVALIDDATA;
72  }
73 
74  avpriv_set_pts_info(st, 64, time_base.num, time_base.den);
75 
76  return 0;
77 }
78 
80 {
81  int ret, size = avio_rl32(s->pb);
82  int64_t pts = avio_rl64(s->pb);
83 
84  ret = av_get_packet(s->pb, pkt, size);
85  pkt->stream_index = 0;
86  pkt->pts = pts;
87  pkt->pos -= 12;
88 
89  return ret;
90 }
91 
93  .p.name = "ivf",
94  .p.long_name = NULL_IF_CONFIG_SMALL("On2 IVF"),
95  .p.flags = AVFMT_GENERIC_INDEX,
96  .p.codec_tag = (const AVCodecTag* const []){ ff_codec_bmp_tags, 0 },
97  .read_probe = probe,
98  .read_header = read_header,
99  .read_packet = read_packet,
100 };
AVERROR
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
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:51
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const struct AVCodec *c)
Add a new stream to a media file.
read_header
static int read_header(AVFormatContext *s)
Definition: ivfdec.c:36
probe
static int probe(const AVProbeData *p)
Definition: ivfdec.c:27
AVCodecParameters::codec_tag
uint32_t codec_tag
Additional information about the codec (corresponds to the AVI FOURCC).
Definition: codec_par.h:59
read_packet
static int read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: ivfdec.c:79
AVPROBE_SCORE_MAX
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:463
avpriv_set_pts_info
void avpriv_set_pts_info(AVStream *st, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: avformat.c:853
ffstream
static av_always_inline FFStream * ffstream(AVStream *st)
Definition: internal.h:417
AVFMT_GENERIC_INDEX
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:480
pts
static int64_t pts
Definition: transcode_aac.c:644
AVStream::duration
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:802
avio_rl16
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:714
AVRational::num
int num
Numerator.
Definition: rational.h:59
pkt
AVPacket * pkt
Definition: movenc.c:60
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
AVCodecTag
Definition: internal.h:42
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:198
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:553
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:453
AVCodecParameters::width
int width
Video only.
Definition: codec_par.h:134
AV_RL16
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_RL16
Definition: bytestream.h:94
ff_ivf_demuxer
const FFInputFormat ff_ivf_demuxer
Definition: ivfdec.c:92
FFStream::need_parsing
enum AVStreamParseType need_parsing
Definition: internal.h:386
AVFormatContext
Format I/O context.
Definition: avformat.h:1255
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:766
NULL
#define NULL
Definition: coverity.c:32
AVRational
Rational number (pair of numerator and denominator).
Definition: rational.h:58
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:451
AVStream::nb_frames
int64_t nb_frames
number of frames in this stream if known or 0
Definition: avformat.h:804
avio_rl32
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:730
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:94
ff_codec_get_id
enum AVCodecID ff_codec_get_id(const AVCodecTag *tags, unsigned int tag)
Definition: utils.c:133
size
int size
Definition: twinvq_data.h:10344
FFInputFormat::p
AVInputFormat p
The public AVInputFormat.
Definition: demux.h:41
AVPacket::pts
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:517
AVCodecParameters::height
int height
Definition: codec_par.h:135
demux.h
av_get_packet
int av_get_packet(AVIOContext *s, AVPacket *pkt, int size)
Allocate and read the payload of a packet and initialize its fields with default values.
Definition: utils.c:91
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:743
AVSTREAM_PARSE_HEADERS
@ AVSTREAM_PARSE_HEADERS
Only parse headers, do not repack.
Definition: avformat.h:594
avformat.h
AV_RL32
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:92
ff_codec_bmp_tags
const AVCodecTag ff_codec_bmp_tags[]
Definition: riff.c:36
AVRational::den
int den
Denominator.
Definition: rational.h:60
AVPacket::stream_index
int stream_index
Definition: packet.h:526
avio_skip
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:318
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:55
AVPacket
This structure stores compressed data.
Definition: packet.h:501
riff.h
AVPacket::pos
int64_t pos
byte position in stream, -1 if unknown
Definition: packet.h:544
FFInputFormat
Definition: demux.h:37
avio_rl64
uint64_t avio_rl64(AVIOContext *s)
Definition: aviobuf.c:738
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
MKTAG
#define MKTAG(a, b, c, d)
Definition: macros.h:55