FFmpeg
dfa.c
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1 /*
2  * Chronomaster DFA Format Demuxer
3  * Copyright (c) 2011 Konstantin Shishkov
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 <inttypes.h>
23 
24 #include "libavutil/intreadwrite.h"
25 #include "avformat.h"
26 #include "internal.h"
27 
28 static int dfa_probe(const AVProbeData *p)
29 {
30  if (p->buf_size < 4 || AV_RL32(p->buf) != MKTAG('D', 'F', 'I', 'A'))
31  return 0;
32 
33  if (AV_RL32(p->buf + 16) != 0x80)
34  return AVPROBE_SCORE_MAX / 4;
35 
36  return AVPROBE_SCORE_MAX;
37 }
38 
40 {
41  AVIOContext *pb = s->pb;
42  AVStream *st;
43  int frames, ret;
44  int version;
45  uint32_t mspf;
46 
47  if (avio_rl32(pb) != MKTAG('D', 'F', 'I', 'A')) {
48  av_log(s, AV_LOG_ERROR, "Invalid magic for DFA\n");
49  return AVERROR_INVALIDDATA;
50  }
51 
52  version = avio_rl16(pb);
53  frames = avio_rl16(pb);
54 
55  st = avformat_new_stream(s, NULL);
56  if (!st)
57  return AVERROR(ENOMEM);
58 
61  st->codecpar->width = avio_rl16(pb);
62  st->codecpar->height = avio_rl16(pb);
63  mspf = avio_rl32(pb);
64  if (!mspf) {
65  av_log(s, AV_LOG_WARNING, "Zero FPS reported, defaulting to 10\n");
66  mspf = 100;
67  }
68  avpriv_set_pts_info(st, 24, mspf, 1000);
69  avio_skip(pb, 128 - 16); // padding
70  st->duration = frames;
71 
72  if ((ret = ff_alloc_extradata(st->codecpar, 2)) < 0)
73  return ret;
74  AV_WL16(st->codecpar->extradata, version);
75  if (version == 0x100)
76  st->sample_aspect_ratio = (AVRational){2, 1};
77 
78  return 0;
79 }
80 
82 {
83  AVIOContext *pb = s->pb;
84  uint32_t frame_size;
85  int ret, first = 1;
86 
87  if (avio_feof(pb))
88  return AVERROR_EOF;
89 
90  if (av_get_packet(pb, pkt, 12) != 12)
91  return AVERROR(EIO);
92  while (!avio_feof(pb)) {
93  if (!first) {
94  ret = av_append_packet(pb, pkt, 12);
95  if (ret < 0) {
96  return ret;
97  }
98  } else
99  first = 0;
100  frame_size = AV_RL32(pkt->data + pkt->size - 8);
101  if (frame_size > INT_MAX - 4) {
102  av_log(s, AV_LOG_ERROR, "Too large chunk size: %"PRIu32"\n", frame_size);
103  return AVERROR(EIO);
104  }
105  if (AV_RL32(pkt->data + pkt->size - 12) == MKTAG('E', 'O', 'F', 'R')) {
106  if (frame_size) {
108  "skipping %"PRIu32" bytes of end-of-frame marker chunk\n",
109  frame_size);
110  avio_skip(pb, frame_size);
111  }
112  return 0;
113  }
114  ret = av_append_packet(pb, pkt, frame_size);
115  if (ret < 0) {
116  return ret;
117  }
118  }
119 
120  return 0;
121 }
122 
124  .name = "dfa",
125  .long_name = NULL_IF_CONFIG_SMALL("Chronomaster DFA"),
126  .read_probe = dfa_probe,
127  .read_header = dfa_read_header,
128  .read_packet = dfa_read_packet,
129  .flags = AVFMT_GENERIC_INDEX,
130 };
#define NULL
Definition: coverity.c:32
Bytestream IO Context.
Definition: avio.h:161
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
#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:4943
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:4036
AVRational sample_aspect_ratio
sample aspect ratio (0 if unknown)
Definition: avformat.h:937
int size
Definition: avcodec.h:1534
static int dfa_read_header(AVFormatContext *s)
Definition: dfa.c:39
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:329
int version
Definition: avisynth_c.h:858
static AVPacket pkt
if it could not because there are no more frames
Format I/O context.
Definition: avformat.h:1352
int width
Video only.
Definition: avcodec.h:4102
trying all byte sequences megabyte in length and selecting the best looking sequence will yield cases to try But first
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4524
uint8_t * data
Definition: avcodec.h:1533
#define AVERROR_EOF
End of file.
Definition: error.h:55
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:308
#define av_log(a,...)
int av_append_packet(AVIOContext *s, AVPacket *pkt, int size)
Read data and append it to the current content of the AVPacket.
Definition: utils.c:318
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:767
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:4032
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:444
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:443
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:3323
#define s(width, name)
Definition: cbs_vp9.c:257
Stream structure.
Definition: avformat.h:875
int frame_size
Definition: mxfenc.c:2140
static int dfa_probe(const AVProbeData *p)
Definition: dfa.c:28
AVIOContext * pb
I/O context.
Definition: avformat.h:1394
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:463
Rational number (pair of numerator and denominator).
Definition: rational.h:58
AVInputFormat ff_dfa_demuxer
Definition: dfa.c:123
This structure contains the data a format has to probe a file.
Definition: avformat.h:441
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:924
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:453
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:751
Main libavformat public API header.
static int dfa_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: dfa.c:81
#define AV_WL16(p, v)
Definition: intreadwrite.h:412
uint8_t * extradata
Extra binary data needed for initializing the decoder, codec-dependent.
Definition: avcodec.h:4050
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:649
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1022
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:356
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 MKTAG(a, b, c, d)
Definition: common.h:366
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:87
This structure stores compressed data.
Definition: avcodec.h:1510