FFmpeg4/libavformat/img2_alias_pix.c

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2023-07-02 12:20:28 +00:00
/*
* Alias PIX image demuxer
* Copyright (c) 2014 Michael Niedermayer
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "img2.h"
#include "libavcodec/bytestream.h"
static int alias_pix_read_probe(const AVProbeData *p)
{
const uint8_t *b = p->buf;
const uint8_t *end = b + p->buf_size;
int width = bytestream_get_be16(&b);
int height = bytestream_get_be16(&b);
av_unused int ox = bytestream_get_be16(&b);
av_unused int oy = bytestream_get_be16(&b);
int bpp = bytestream_get_be16(&b);
int x, y;
if (!width || !height)
return 0;
if (bpp != 24 && bpp != 8)
return 0;
for (y=0; y<2 && y<height; y++) {
for (x=0; x<width; ) {
int count = *b++;
if (count == 0 || x + count > width)
return 0;
if (b > end)
return AVPROBE_SCORE_MAX / 8;
b += bpp / 8;
x += count;
}
}
return AVPROBE_SCORE_EXTENSION + 1;
}
static const AVClass image2_alias_pix_class = {
.class_name = "alias_pix demuxer",
.item_name = av_default_item_name,
.option = ff_img_options,
.version = LIBAVUTIL_VERSION_INT,
};
AVInputFormat ff_image2_alias_pix_demuxer = {
.name = "alias_pix",
.long_name = NULL_IF_CONFIG_SMALL("Alias/Wavefront PIX image"),
.priv_data_size = sizeof(VideoDemuxData),
.read_probe = alias_pix_read_probe,
.read_header = ff_img_read_header,
.read_packet = ff_img_read_packet,
.raw_codec_id = AV_CODEC_ID_ALIAS_PIX,
.priv_class = &image2_alias_pix_class,
};