FFmpeg
img2_alias_pix.c
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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 
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 
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 
65  .name = "alias_pix",
66  .long_name = NULL_IF_CONFIG_SMALL("Alias/Wavefront PIX image"),
67  .priv_data_size = sizeof(VideoDemuxData),
71  .raw_codec_id = AV_CODEC_ID_ALIAS_PIX,
72  .priv_class = &image2_alias_pix_class,
73 };
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
AVInputFormat ff_image2_alias_pix_demuxer
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:191
const AVOption ff_img_options[]
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:72
uint8_t
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
#define height
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
GLsizei count
Definition: opengl_enc.c:108
static int alias_pix_read_probe(const AVProbeData *p)
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:449
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:448
#define b
Definition: input.c:41
#define width
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:530
int ff_img_read_packet(AVFormatContext *s1, AVPacket *pkt)
Definition: img2dec.c:377
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
Describe the class of an AVClass context structure.
Definition: log.h:67
#define AVPROBE_SCORE_EXTENSION
score for file extension
Definition: avformat.h:456
This structure contains the data a format has to probe a file.
Definition: avformat.h:446
static const AVClass image2_alias_pix_class
static int read_probe(const AVProbeData *pd)
Definition: jvdec.c:55
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:458
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:654
int ff_img_read_header(AVFormatContext *s1)
Definition: img2dec.c:182
#define av_unused
Definition: attributes.h:125