Imported Debian version 2.5.2~trusty
[deb_ffmpeg.git] / ffmpeg / libavformat / cdg.c
... / ...
CommitLineData
1/*
2 * CD Graphics Demuxer
3 * Copyright (c) 2009 Michael Tison
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 "avformat.h"
23#include "internal.h"
24
25#define CDG_PACKET_SIZE 24
26#define CDG_COMMAND 0x09
27#define CDG_MASK 0x3F
28
29typedef struct CDGContext {
30 int got_first_packet;
31} CDGContext;
32
33static 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->codec->codec_type = AVMEDIA_TYPE_VIDEO;
43 vst->codec->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 av_log(s, AV_LOG_WARNING, "Cannot calculate duration as file size cannot be determined\n");
51 } else
52 vst->duration = (ret * vst->time_base.den) / (CDG_PACKET_SIZE * 300);
53
54 return 0;
55}
56
57static int read_packet(AVFormatContext *s, AVPacket *pkt)
58{
59 CDGContext *priv = s->priv_data;
60 int ret;
61
62 while (1) {
63 ret = av_get_packet(s->pb, pkt, CDG_PACKET_SIZE);
64 if (ret < 1 || (pkt->data[0] & CDG_MASK) == CDG_COMMAND)
65 break;
66 av_free_packet(pkt);
67 }
68
69 if (!priv->got_first_packet) {
70 pkt->flags |= AV_PKT_FLAG_KEY;
71 priv->got_first_packet = 1;
72 }
73
74 pkt->stream_index = 0;
75 pkt->dts=
76 pkt->pts= pkt->pos / CDG_PACKET_SIZE;
77
78 if(ret>5 && (pkt->data[0]&0x3F) == 9 && (pkt->data[1]&0x3F)==1 && !(pkt->data[2+2+1] & 0x0F)){
79 pkt->flags = AV_PKT_FLAG_KEY;
80 }
81 return ret;
82}
83
84AVInputFormat ff_cdg_demuxer = {
85 .name = "cdg",
86 .long_name = NULL_IF_CONFIG_SMALL("CD Graphics"),
87 .priv_data_size = sizeof(CDGContext),
88 .read_header = read_header,
89 .read_packet = read_packet,
90 .flags = AVFMT_GENERIC_INDEX,
91 .extensions = "cdg",
92};