Add Haivision SRT protocol
[libav.git] / libavformat / cdg.c
1 /*
2 * CD Graphics Demuxer
3 * Copyright (c) 2009 Michael Tison
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 "avformat.h"
23 #include "internal.h"
24
25 #define CDG_PACKET_SIZE 24
26 #define CDG_COMMAND 0x09
27 #define CDG_MASK 0x3F
28
29 typedef struct CDGContext {
30 int got_first_packet;
31 } CDGContext;
32
33 static int read_header(AVFormatContext *s)
34 {
35 AVStream *vst;
36 int ret;
37
38 vst = avformat_new_stream(s, NULL);
39 if (!vst)
40 return AVERROR(ENOMEM);
41
42 vst->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
43 vst->codecpar->codec_id = AV_CODEC_ID_CDGRAPHICS;
44
45 /// 75 sectors/sec * 4 packets/sector = 300 packets/sec
46 avpriv_set_pts_info(vst, 32, 1, 300);
47
48 ret = avio_size(s->pb);
49 if (ret < 0)
50 return ret;
51
52 vst->duration = (ret * vst->time_base.den) / (CDG_PACKET_SIZE * 300);
53 return 0;
54 }
55
56 static int read_packet(AVFormatContext *s, AVPacket *pkt)
57 {
58 CDGContext *priv = s->priv_data;
59 int ret;
60
61 while (1) {
62 ret = av_get_packet(s->pb, pkt, CDG_PACKET_SIZE);
63 if (ret < 1 || (pkt->data[0] & CDG_MASK) == CDG_COMMAND)
64 break;
65 av_packet_unref(pkt);
66 }
67
68 if (!priv->got_first_packet) {
69 pkt->flags |= AV_PKT_FLAG_KEY;
70 priv->got_first_packet = 1;
71 }
72
73 pkt->stream_index = 0;
74 return ret;
75 }
76
77 AVInputFormat ff_cdg_demuxer = {
78 .name = "cdg",
79 .long_name = NULL_IF_CONFIG_SMALL("CD Graphics"),
80 .priv_data_size = sizeof(CDGContext),
81 .read_header = read_header,
82 .read_packet = read_packet,
83 .extensions = "cdg",
84 };