1 /*
2 * Alias PIX image demuxer
3 * Copyright (c) 2014 Michael Niedermayer
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 "img2.h"
23 #include "libavcodec/bytestream.h"
24
alias_pix_read_probe(const AVProbeData * p)25 static int alias_pix_read_probe(const AVProbeData *p)
26 {
27 const uint8_t *b = p->buf;
28 const uint8_t *end = b + p->buf_size;
29 int width = bytestream_get_be16(&b);
30 int height = bytestream_get_be16(&b);
31 av_unused int ox = bytestream_get_be16(&b);
32 av_unused int oy = bytestream_get_be16(&b);
33 int bpp = bytestream_get_be16(&b);
34 int x, y;
35
36 if (!width || !height)
37 return 0;
38
39 if (bpp != 24 && bpp != 8)
40 return 0;
41
42 for (y=0; y<2 && y<height; y++) {
43 for (x=0; x<width; ) {
44 int count = *b++;
45 if (count == 0 || x + count > width)
46 return 0;
47 if (b > end)
48 return AVPROBE_SCORE_MAX / 8;
49 b += bpp / 8;
50 x += count;
51 }
52 }
53
54 return AVPROBE_SCORE_EXTENSION + 1;
55 }
56
57 static const AVClass image2_alias_pix_class = {
58 .class_name = "alias_pix demuxer",
59 .item_name = av_default_item_name,
60 .option = ff_img_options,
61 .version = LIBAVUTIL_VERSION_INT,
62 };
63
64 AVInputFormat ff_image2_alias_pix_demuxer = {
65 .name = "alias_pix",
66 .long_name = NULL_IF_CONFIG_SMALL("Alias/Wavefront PIX image"),
67 .priv_data_size = sizeof(VideoDemuxData),
68 .read_probe = alias_pix_read_probe,
69 .read_header = ff_img_read_header,
70 .read_packet = ff_img_read_packet,
71 .raw_codec_id = AV_CODEC_ID_ALIAS_PIX,
72 .priv_class = &image2_alias_pix_class,
73 };
74