1 /*
2 * CCTV DAT demuxer
3 *
4 * Copyright (c) 2020 Paul B Mahol
5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23 #include "libavutil/intreadwrite.h"
24 #include "avio_internal.h"
25 #include "avformat.h"
26 #include "internal.h"
27
dat_probe(const AVProbeData * p)28 static int dat_probe(const AVProbeData *p)
29 {
30 if (p->buf_size < 0x2080)
31 return 0;
32
33 if (memcmp(p->buf, "luo ", 4))
34 return 0;
35
36 if (memcmp(p->buf + 0x1ffc, " oulliu ", 8))
37 return 0;
38
39 if (!AV_RL32(p->buf + 0x2004))
40 return 0;
41
42 if (memcmp(p->buf + 0x207c, " uil", 4))
43 return 0;
44
45 return AVPROBE_SCORE_MAX;
46 }
47
dat_read_header(AVFormatContext * s)48 static int dat_read_header(AVFormatContext *s)
49 {
50 s->ctx_flags |= AVFMTCTX_NOHEADER;
51
52 avio_seek(s->pb, 0x2000, SEEK_SET);
53
54 return 0;
55 }
56
dat_read_packet(AVFormatContext * s,AVPacket * pkt)57 static int dat_read_packet(AVFormatContext *s, AVPacket *pkt)
58 {
59 AVIOContext *pb = s->pb;
60 int index, ret, key, stream_id, stream_index, width, height, fps, pkt_size;
61 int64_t pts, pos = avio_tell(pb);
62
63 if (avio_feof(pb))
64 return AVERROR_EOF;
65
66 if (avio_rb32(pb) != MKBETAG('l', 'i', 'u', ' '))
67 return AVERROR_INVALIDDATA;
68 stream_id = avio_rl32(pb);
69 width = avio_rl32(pb);
70 height = avio_rl32(pb);
71 fps = avio_rl32(pb);
72 avio_skip(pb, 16);
73 key = avio_rl32(pb) == 1;
74 avio_skip(pb, 4);
75 index = avio_rl32(pb);
76 avio_skip(pb, 4);
77 pts = avio_rl64(pb);
78 pkt_size = avio_rl32(pb);
79 avio_skip(pb, 64);
80
81 if (pkt_size == 0)
82 return AVERROR_EOF;
83
84 for (stream_index = 0; stream_index < s->nb_streams; stream_index++) {
85 if (s->streams[stream_index]->id == stream_id)
86 break;
87 }
88
89 if (stream_index == s->nb_streams) {
90 AVStream *st = avformat_new_stream(s, NULL);
91
92 if (!st)
93 return AVERROR(ENOMEM);
94
95 st->id = stream_id;
96 st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
97 st->codecpar->codec_id = AV_CODEC_ID_H264;
98 st->codecpar->width = width;
99 st->codecpar->height = height;
100 avpriv_set_pts_info(st, 64, 1, fps);
101 }
102
103 if (index >= s->nb_streams)
104 av_log(s, AV_LOG_WARNING, "Stream index out of range.\n");
105
106 ret = av_get_packet(pb, pkt, pkt_size);
107 if (ret < 0)
108 return ret;
109 pkt->pos = pos;
110 pkt->pts = pts;
111 pkt->stream_index = stream_index;
112 if (key)
113 pkt->flags |= AV_PKT_FLAG_KEY;
114
115 return ret;
116 }
117
118 AVInputFormat ff_luodat_demuxer = {
119 .name = "luodat",
120 .long_name = NULL_IF_CONFIG_SMALL("Video CCTV DAT"),
121 .read_probe = dat_probe,
122 .read_header = dat_read_header,
123 .read_packet = dat_read_packet,
124 .extensions = "dat",
125 .flags = AVFMT_GENERIC_INDEX,
126 };
127