FFmpeg: libavformat/ingenientdec.c Source File

FFmpeg
ingenientdec.c
Go to the documentation of this file.
1 /*
2  * RAW Ingenient MJPEG demuxer
3  * Copyright (c) 2005 Alex Beregszaszi
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 "avformat.h"
23 #include "rawdec.h"
24 #include "libavutil/intreadwrite.h"
25 
26 // http://multimedia.cx/ingenient.txt
27  static int ingenient_probe(const AVProbeData *p)
28 {
29  if ( AV_RN32(p->buf) != AV_RN32("MJPG")
30  || p->buf_size < 50
31  || AV_RB16(p->buf + 48) != 0xffd8)
32  return 0;
33  return AVPROBE_SCORE_MAX * 3 / 4;
34 }
35 
36  static int ingenient_read_packet(AVFormatContext *s, AVPacket *pkt)
37 {
38  int ret, size, w, h, unk1, unk2;
39 
40  if (avio_rl32(s->pb) != MKTAG('M', 'J', 'P', 'G'))
41  return AVERROR(EIO); // FIXME
42 
43  size = avio_rl32(s->pb);
44 
45  w = avio_rl16(s->pb);
46  h = avio_rl16(s->pb);
47 
48  avio_skip(s->pb, 8); // zero + size (padded?)
49  avio_skip(s->pb, 2);
50  unk1 = avio_rl16(s->pb);
51  unk2 = avio_rl16(s->pb);
52  avio_skip(s->pb, 22); // ASCII timestamp
53 
54  av_log(s, AV_LOG_DEBUG, "Ingenient packet: size=%d, width=%d, height=%d, unk1=%d unk2=%d\n",
55  size, w, h, unk1, unk2);
56 
57  ret = av_get_packet(s->pb, pkt, size);
58  if (ret < 0)
59  return ret;
60  pkt->stream_index = 0;
61  return ret;
62 }
63 
64  const AVInputFormat ff_ingenient_demuxer = {
65  .name = "ingenient",
66  .long_name = NULL_IF_CONFIG_SMALL("raw Ingenient MJPEG"),
67  .priv_data_size = sizeof(FFRawVideoDemuxerContext),
68  .read_probe = ingenient_probe,
69  .read_header = ff_raw_video_read_header,
70  .read_packet = ingenient_read_packet,
71  .flags = AVFMT_GENERIC_INDEX,
72  .extensions = "cgi", // FIXME
73  .raw_codec_id = AV_CODEC_ID_MJPEG,
74  .priv_class = &ff_rawvideo_demuxer_class,
75 };
ff_raw_video_read_header
int ff_raw_video_read_header(AVFormatContext *s)
Definition: rawdec.c:70
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
ff_rawvideo_demuxer_class
const AVClass ff_rawvideo_demuxer_class
Definition: rawdec.c:129
w
uint8_t w
Definition: llviddspenc.c:38
AVProbeData::buf_size
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:454
AVPROBE_SCORE_MAX
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:463
AVFMT_GENERIC_INDEX
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:480
avio_rl16
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:735
ingenient_read_packet
static int ingenient_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: ingenientdec.c:36
pkt
AVPacket * pkt
Definition: movenc.c:59
AVInputFormat
Definition: avformat.h:546
read_packet
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_read_callback.c:41
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:256
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:551
ff_ingenient_demuxer
const AVInputFormat ff_ingenient_demuxer
Definition: ingenientdec.c:64
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:453
AV_LOG_DEBUG
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:201
AVFormatContext
Format I/O context.
Definition: avformat.h:1104
read_header
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:545
rawdec.h
AV_RN32
#define AV_RN32(p)
Definition: intreadwrite.h:364
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:451
avio_rl32
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:751
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:115
size
int size
Definition: twinvq_data.h:10344
FFRawVideoDemuxerContext
Definition: rawdec.h:28
AV_CODEC_ID_MJPEG
@ AV_CODEC_ID_MJPEG
Definition: codec_id.h:59
ingenient_probe
static int ingenient_probe(const AVProbeData *p)
Definition: ingenientdec.c:27
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:102
ret
ret
Definition: filter_design.txt:187
avformat.h
AVPacket::stream_index
int stream_index
Definition: packet.h:376
avio_skip
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:339
read_probe
static int read_probe(const AVProbeData *p)
Definition: cdg.c:29
AVPacket
This structure stores compressed data.
Definition: packet.h:351
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:561
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
MKTAG
#define MKTAG(a, b, c, d)
Definition: macros.h:55
h
h
Definition: vp9dsp_template.c:2038
AV_RB16
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:98
Generated on Tue Feb 28 2023 21:34:05 for FFmpeg by   doxygen 1.8.17

AltStyle によって変換されたページ (->オリジナル) /