ffmpeg/libavcodec/aliaspixdec.c
Andreas Rheinhardt a247ac640d avcodec: Constify AVCodecs
Given that the AVCodec.next pointer has now been removed, most of the
AVCodecs are not modified at all any more and can therefore be made
const (as this patch does); the only exceptions are the very few codecs
for external libraries that have a init_static_data callback.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: James Almer <jamrial@gmail.com>
2021-04-27 10:43:15 -03:00

132 lines
3.9 KiB
C

/*
* Alias PIX image decoder
* Copyright (C) 2014 Vittorio Giovara <vittorio.giovara@gmail.com>
*
* 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 "libavutil/intreadwrite.h"
#include "avcodec.h"
#include "bytestream.h"
#include "internal.h"
#define ALIAS_HEADER_SIZE 10
static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
AVPacket *avpkt)
{
AVFrame *f = data;
GetByteContext gb;
int width, height, ret, bits_pixel, pixel;
uint8_t *out_buf;
uint8_t count;
int x, y;
bytestream2_init(&gb, avpkt->data, avpkt->size);
if (bytestream2_get_bytes_left(&gb) < ALIAS_HEADER_SIZE) {
av_log(avctx, AV_LOG_ERROR, "Header too small %d.\n", avpkt->size);
return AVERROR_INVALIDDATA;
}
width = bytestream2_get_be16u(&gb);
height = bytestream2_get_be16u(&gb);
bytestream2_skipu(&gb, 4); // obsolete X, Y offset
bits_pixel = bytestream2_get_be16u(&gb);
if (bits_pixel == 24)
avctx->pix_fmt = AV_PIX_FMT_BGR24;
else if (bits_pixel == 8)
avctx->pix_fmt = AV_PIX_FMT_GRAY8;
else {
av_log(avctx, AV_LOG_ERROR, "Invalid pixel format.\n");
return AVERROR_INVALIDDATA;
}
ret = ff_set_dimensions(avctx, width, height);
if (ret < 0)
return ret;
if (bytestream2_get_bytes_left(&gb) < width*height / 255)
return AVERROR_INVALIDDATA;
ret = ff_get_buffer(avctx, f, 0);
if (ret < 0)
return ret;
f->pict_type = AV_PICTURE_TYPE_I;
f->key_frame = 1;
x = 0;
y = 1;
out_buf = f->data[0];
while (bytestream2_get_bytes_left(&gb) > 0) {
int i;
/* set buffer at the right position at every new line */
if (x == avctx->width) {
x = 0;
out_buf = f->data[0] + f->linesize[0] * y++;
if (y > avctx->height) {
av_log(avctx, AV_LOG_ERROR,
"Ended frame decoding with %d bytes left.\n",
bytestream2_get_bytes_left(&gb));
return AVERROR_INVALIDDATA;
}
}
/* read packet and copy data */
count = bytestream2_get_byteu(&gb);
if (!count || x + count > avctx->width) {
av_log(avctx, AV_LOG_ERROR, "Invalid run length %d.\n", count);
return AVERROR_INVALIDDATA;
}
if (avctx->pix_fmt == AV_PIX_FMT_BGR24) {
pixel = bytestream2_get_be24(&gb);
for (i = 0; i < count; i++) {
AV_WB24(out_buf, pixel);
out_buf += 3;
}
} else { // AV_PIX_FMT_GRAY8
pixel = bytestream2_get_byte(&gb);
for (i = 0; i < count; i++)
*out_buf++ = pixel;
}
x += i;
}
if (x != width || y != height) {
av_log(avctx, AV_LOG_ERROR, "Picture stopped at %d,%d.\n", x, y);
return AVERROR_INVALIDDATA;
}
*got_frame = 1;
return avpkt->size;
}
const AVCodec ff_alias_pix_decoder = {
.name = "alias_pix",
.long_name = NULL_IF_CONFIG_SMALL("Alias/Wavefront PIX image"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_ALIAS_PIX,
.decode = decode_frame,
.capabilities = AV_CODEC_CAP_DR1,
};