1/*
2 * Adobe Filmstrip demuxer
3 * Copyright (c) 2010 Peter Ross
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/**
23 * @file
24 * Adobe Filmstrip demuxer
25 */
26
27#include "libavutil/intreadwrite.h"
28#include "avformat.h"
29#include "internal.h"
30
31#define RAND_TAG MKBETAG('R','a','n','d')
32
33typedef struct {
34    int leading;
35} FilmstripDemuxContext;
36
37static int read_header(AVFormatContext *s,
38                       AVFormatParameters *ap)
39{
40    FilmstripDemuxContext *film = s->priv_data;
41    AVIOContext *pb = s->pb;
42    AVStream *st;
43
44    if (!s->pb->seekable)
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");
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        av_log_ask_for_sample(s, "unsupported packing method\n");
60        return AVERROR_INVALIDDATA;
61    }
62
63    avio_skip(pb, 2);
64    st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
65    st->codec->codec_id   = CODEC_ID_RAWVIDEO;
66    st->codec->pix_fmt    = PIX_FMT_RGBA;
67    st->codec->codec_tag  = 0; /* no fourcc */
68    st->codec->width      = avio_rb16(pb);
69    st->codec->height     = avio_rb16(pb);
70    film->leading         = avio_rb16(pb);
71    avpriv_set_pts_info(st, 64, 1, avio_rb16(pb));
72
73    avio_seek(pb, 0, SEEK_SET);
74
75    return 0;
76}
77
78static int read_packet(AVFormatContext *s,
79                       AVPacket *pkt)
80{
81    FilmstripDemuxContext *film = s->priv_data;
82    AVStream *st = s->streams[0];
83
84    if (s->pb->eof_reached)
85        return AVERROR(EIO);
86    pkt->dts = avio_tell(s->pb) / (st->codec->width * (st->codec->height + film->leading) * 4);
87    pkt->size = av_get_packet(s->pb, pkt, st->codec->width * st->codec->height * 4);
88    avio_skip(s->pb, st->codec->width * film->leading * 4);
89    if (pkt->size < 0)
90        return pkt->size;
91    pkt->flags |= AV_PKT_FLAG_KEY;
92    return 0;
93}
94
95static int read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
96{
97    AVStream *st = s->streams[stream_index];
98    avio_seek(s->pb, FFMAX(timestamp, 0) * st->codec->width * st->codec->height * 4, SEEK_SET);
99    return 0;
100}
101
102AVInputFormat ff_filmstrip_demuxer = {
103    .name           = "filmstrip",
104    .long_name      = NULL_IF_CONFIG_SMALL("Adobe Filmstrip"),
105    .priv_data_size = sizeof(FilmstripDemuxContext),
106    .read_header    = read_header,
107    .read_packet    = read_packet,
108    .read_seek      = read_seek,
109    .extensions = "flm",
110};
111