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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(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;
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->codec->width = avio_rl16(pb);
62  st->codec->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 (ff_alloc_extradata(st->codec, 2))
73  return AVERROR(ENOMEM);
74  AV_WL16(st->codec->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  av_free_packet(pkt);
97  return ret;
98  }
99  } else
100  first = 0;
101  frame_size = AV_RL32(pkt->data + pkt->size - 8);
102  if (frame_size > INT_MAX - 4) {
103  av_log(s, AV_LOG_ERROR, "Too large chunk size: %"PRIu32"\n", frame_size);
104  return AVERROR(EIO);
105  }
106  if (AV_RL32(pkt->data + pkt->size - 12) == MKTAG('E', 'O', 'F', 'R')) {
107  if (frame_size) {
109  "skipping %"PRIu32" bytes of end-of-frame marker chunk\n",
110  frame_size);
111  avio_skip(pb, frame_size);
112  }
113  return 0;
114  }
115  ret = av_append_packet(pb, pkt, frame_size);
116  if (ret < 0) {
117  av_free_packet(pkt);
118  return ret;
119  }
120  }
121 
122  return 0;
123 }
124 
126  .name = "dfa",
127  .long_name = NULL_IF_CONFIG_SMALL("Chronomaster DFA"),
128  .read_probe = dfa_probe,
129  .read_header = dfa_read_header,
130  .read_packet = dfa_read_packet,
131  .flags = AVFMT_GENERIC_INDEX,
132 };