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 Libav.
6  *
7  * Libav 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  * Libav 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 Libav; 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 #include "avformat.h"
24 #include "internal.h"
25 
26 static int dfa_probe(AVProbeData *p)
27 {
28  if (p->buf_size < 4 || AV_RL32(p->buf) != MKTAG('D', 'F', 'I', 'A'))
29  return 0;
30 
31  return AVPROBE_SCORE_MAX;
32 }
33 
36 {
37  AVIOContext *pb = s->pb;
38  AVStream *st;
39  int frames;
40  uint32_t mspf;
41 
42  if (avio_rl32(pb) != MKTAG('D', 'F', 'I', 'A')) {
43  av_log(s, AV_LOG_ERROR, "Invalid magic for DFA\n");
44  return AVERROR_INVALIDDATA;
45  }
46  avio_skip(pb, 2); // unused
47  frames = avio_rl16(pb);
48 
49  st = avformat_new_stream(s, NULL);
50  if (!st)
51  return AVERROR(ENOMEM);
52 
55  st->codec->width = avio_rl16(pb);
56  st->codec->height = avio_rl16(pb);
57  mspf = avio_rl32(pb);
58  if (!mspf) {
59  av_log(s, AV_LOG_WARNING, "Zero FPS reported, defaulting to 10\n");
60  mspf = 100;
61  }
62  avpriv_set_pts_info(st, 24, mspf, 1000);
63  avio_skip(pb, 128 - 16); // padding
64  st->duration = frames;
65 
66  return 0;
67 }
68 
70 {
71  AVIOContext *pb = s->pb;
72  uint32_t frame_size;
73  int ret, first = 1;
74 
75  if (pb->eof_reached)
76  return AVERROR_EOF;
77 
78  if (av_get_packet(pb, pkt, 12) != 12)
79  return AVERROR(EIO);
80  while (!pb->eof_reached) {
81  if (!first) {
82  ret = av_append_packet(pb, pkt, 12);
83  if (ret < 0) {
84  av_free_packet(pkt);
85  return ret;
86  }
87  } else
88  first = 0;
89  frame_size = AV_RL32(pkt->data + pkt->size - 8);
90  if (frame_size > INT_MAX - 4) {
91  av_log(s, AV_LOG_ERROR, "Too large chunk size: %d\n", frame_size);
92  return AVERROR(EIO);
93  }
94  if (AV_RL32(pkt->data + pkt->size - 12) == MKTAG('E', 'O', 'F', 'R')) {
95  if (frame_size) {
96  av_log(s, AV_LOG_WARNING, "skipping %d bytes of end-of-frame marker chunk\n",
97  frame_size);
98  avio_skip(pb, frame_size);
99  }
100  return 0;
101  }
102  ret = av_append_packet(pb, pkt, frame_size);
103  if (ret < 0) {
104  av_free_packet(pkt);
105  return ret;
106  }
107  }
108 
109  return 0;
110 }
111 
113  .name = "dfa",
114  .long_name = NULL_IF_CONFIG_SMALL("Chronomaster DFA"),
115  .read_probe = dfa_probe,
116  .read_header = dfa_read_header,
117  .read_packet = dfa_read_packet,
118  .flags = AVFMT_GENERIC_INDEX,
119 };
Bytestream IO Context.
Definition: avio.h:68
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:54
void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the pts for a given stream.
Definition: utils.c:3828
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:117
int size
Definition: avcodec.h:909
Format I/O context.
Definition: avformat.h:863
uint8_t * data
Definition: avcodec.h:908
void av_free_packet(AVPacket *pkt)
Free a packet.
Definition: avpacket.c:151
#define AVERROR_EOF
End of file.
Definition: error.h:51
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:269
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:287
static int dfa_read_header(AVFormatContext *s, AVFormatParameters *ap)
Definition: dfa.c:34
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:738
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:191
AV_RL32
Definition: bytestream.h:89
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:140
AVStream * avformat_new_stream(AVFormatContext *s, AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:2776
AVCodecContext * codec
codec context
Definition: avformat.h:623
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:342
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:341
int width
picture width / height.
Definition: avcodec.h:1408
static av_always_inline int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: avio.h:483
Stream structure.
Definition: avformat.h:620
NULL
Definition: eval.c:50
enum AVMediaType codec_type
Definition: avcodec.h:1574
AVIOContext * pb
Definition: avformat.h:896
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:111
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:376
AVInputFormat ff_dfa_demuxer
Definition: dfa.c:112
This structure contains the data a format has to probe a file.
Definition: avformat.h:339
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:684
#define AVPROBE_SCORE_MAX
maximum score, half of that is used for file-extension-based detection
Definition: avformat.h:345
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:722
Main libavformat public API header.
static int dfa_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: dfa.c:69
static int dfa_probe(AVProbeData *p)
Definition: dfa.c:26
int eof_reached
true if eof reached
Definition: avio.h:98
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:460
#define MKTAG(a, b, c, d)
Definition: common.h:231
enum CodecID codec_id
Definition: avcodec.h:1575