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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 
dfa_probe(const AVProbeData * p)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 
dfa_read_header(AVFormatContext * s)39 static int dfa_read_header(AVFormatContext *s)
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 
59     st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
60     st->codecpar->codec_id   = AV_CODEC_ID_DFA;
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 
dfa_read_packet(AVFormatContext * s,AVPacket * pkt)81 static int dfa_read_packet(AVFormatContext *s, AVPacket *pkt)
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) {
107                 av_log(s, AV_LOG_WARNING,
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 
123 AVInputFormat ff_dfa_demuxer = {
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 };
131