path: root/libavformat/filmstripdec.c (plain)
blob: 0bf5a80830322318922cf75283ebb82494ab49d8

1	/*
2	* Adobe Filmstrip demuxer
3	* Copyright (c) 2010 Peter Ross
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	/**
23	* @file
24	* Adobe Filmstrip demuxer
25	*/
26
27	#include "libavutil/intreadwrite.h"
28	#include "libavutil/imgutils.h"
29	#include "avformat.h"
30	#include "internal.h"
31
32	#define RAND_TAG MKBETAG('R','a','n','d')
33
34	typedef struct FilmstripDemuxContext {
35	int leading;
36	} FilmstripDemuxContext;
37
38	static int read_header(AVFormatContext *s)
39	{
40	FilmstripDemuxContext *film = s->priv_data;
41	AVIOContext *pb = s->pb;
42	AVStream *st;
43
44	if (!(s->pb->seekable & AVIO_SEEKABLE_NORMAL))
45	return AVERROR(EIO);
46
47	avio_seek(pb, avio_size(pb) - 36, SEEK_SET);
48	if (avio_rb32(pb) != RAND_TAG) {
49	av_log(s, AV_LOG_ERROR, "magic number not found\n");
50	return AVERROR_INVALIDDATA;
51	}
52
53	st = avformat_new_stream(s, NULL);
54	if (!st)
55	return AVERROR(ENOMEM);
56
57	st->nb_frames = avio_rb32(pb);
58	if (avio_rb16(pb) != 0) {
59	avpriv_request_sample(s, "Unsupported packing method");
60	return AVERROR_PATCHWELCOME;
61	}
62
63	avio_skip(pb, 2);
64	st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
65	st->codecpar->codec_id = AV_CODEC_ID_RAWVIDEO;
66	st->codecpar->format = AV_PIX_FMT_RGBA;
67	st->codecpar->codec_tag = 0; /* no fourcc */
68	st->codecpar->width = avio_rb16(pb);
69	st->codecpar->height = avio_rb16(pb);
70	film->leading = avio_rb16(pb);
71
72	if (av_image_check_size(st->codecpar->width, st->codecpar->height, 0, s) < 0)
73	return AVERROR_INVALIDDATA;
74
75	avpriv_set_pts_info(st, 64, 1, avio_rb16(pb));
76
77	avio_seek(pb, 0, SEEK_SET);
78
79	return 0;
80	}
81
82	static int read_packet(AVFormatContext *s,
83	AVPacket *pkt)
84	{
85	FilmstripDemuxContext *film = s->priv_data;
86	AVStream *st = s->streams[0];
87
88	if (avio_feof(s->pb))
89	return AVERROR(EIO);
90	pkt->dts = avio_tell(s->pb) / (st->codecpar->width * (int64_t)(st->codecpar->height + film->leading) * 4);
91	pkt->size = av_get_packet(s->pb, pkt, st->codecpar->width * st->codecpar->height * 4);
92	avio_skip(s->pb, st->codecpar->width * (int64_t) film->leading * 4);
93	if (pkt->size < 0)
94	return pkt->size;
95	pkt->flags |= AV_PKT_FLAG_KEY;
96	return 0;
97	}
98
99	static int read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
100	{
101	AVStream *st = s->streams[stream_index];
102	if (avio_seek(s->pb, FFMAX(timestamp, 0) * st->codecpar->width * st->codecpar->height * 4, SEEK_SET) < 0)
103	return -1;
104	return 0;
105	}
106
107	AVInputFormat ff_filmstrip_demuxer = {
108	.name = "filmstrip",
109	.long_name = NULL_IF_CONFIG_SMALL("Adobe Filmstrip"),
110	.priv_data_size = sizeof(FilmstripDemuxContext),
111	.read_header = read_header,
112	.read_packet = read_packet,
113	.read_seek = read_seek,
114	.extensions = "flm",
115	};
116