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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 "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 
35 {
36  AVIOContext *pb = s->pb;
37  AVStream *st;
38  int frames;
39  uint32_t mspf;
40 
41  if (avio_rl32(pb) != MKTAG('D', 'F', 'I', 'A')) {
42  av_log(s, AV_LOG_ERROR, "Invalid magic for DFA\n");
43  return AVERROR_INVALIDDATA;
44  }
45  avio_skip(pb, 2); // unused
46  frames = avio_rl16(pb);
47 
48  st = avformat_new_stream(s, NULL);
49  if (!st)
50  return AVERROR(ENOMEM);
51 
54  st->codec->width = avio_rl16(pb);
55  st->codec->height = avio_rl16(pb);
56  mspf = avio_rl32(pb);
57  if (!mspf) {
58  av_log(s, AV_LOG_WARNING, "Zero FPS reported, defaulting to 10\n");
59  mspf = 100;
60  }
61  avpriv_set_pts_info(st, 24, mspf, 1000);
62  avio_skip(pb, 128 - 16); // padding
63  st->duration = frames;
64 
65  return 0;
66 }
67 
69 {
70  AVIOContext *pb = s->pb;
71  uint32_t frame_size;
72  int ret, first = 1;
73 
74  if (pb->eof_reached)
75  return AVERROR_EOF;
76 
77  if (av_get_packet(pb, pkt, 12) != 12)
78  return AVERROR(EIO);
79  while (!pb->eof_reached) {
80  if (!first) {
81  ret = av_append_packet(pb, pkt, 12);
82  if (ret < 0) {
83  av_free_packet(pkt);
84  return ret;
85  }
86  } else
87  first = 0;
88  frame_size = AV_RL32(pkt->data + pkt->size - 8);
89  if (frame_size > INT_MAX - 4) {
90  av_log(s, AV_LOG_ERROR, "Too large chunk size: %d\n", frame_size);
91  return AVERROR(EIO);
92  }
93  if (AV_RL32(pkt->data + pkt->size - 12) == MKTAG('E', 'O', 'F', 'R')) {
94  if (frame_size) {
95  av_log(s, AV_LOG_WARNING, "skipping %d bytes of end-of-frame marker chunk\n",
96  frame_size);
97  avio_skip(pb, frame_size);
98  }
99  return 0;
100  }
101  ret = av_append_packet(pb, pkt, frame_size);
102  if (ret < 0) {
103  av_free_packet(pkt);
104  return ret;
105  }
106  }
107 
108  return 0;
109 }
110 
112  .name = "dfa",
113  .long_name = NULL_IF_CONFIG_SMALL("Chronomaster DFA"),
114  .read_probe = dfa_probe,
115  .read_header = dfa_read_header,
116  .read_packet = dfa_read_packet,
117  .flags = AVFMT_GENERIC_INDEX,
118 };