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FFmpeg/libavcodec/msp2dec.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

104 lines
3.2 KiB
C

/*
* Microsoft Paint (MSP) version 2 decoder
* Copyright (c) 2020 Peter Ross (pross@xvid.org)
*
* 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
*/
/**
* @file
* Microsoft Paint (MSP) version 2 decoder
*/
#include "avcodec.h"
#include "bytestream.h"
#include "internal.h"
static int msp2_decode_frame(AVCodecContext *avctx,
void *data, int *got_frame,
AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
AVFrame *p = data;
int ret;
unsigned int x, y, width = (avctx->width + 7) / 8;
GetByteContext idx, gb;
if (buf_size <= 2 * avctx->height)
return AVERROR_INVALIDDATA;
avctx->pix_fmt = AV_PIX_FMT_MONOBLACK;
if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
return ret;
p->pict_type = AV_PICTURE_TYPE_I;
p->key_frame = 1;
bytestream2_init(&idx, buf, 2 * avctx->height);
buf += 2 * avctx->height;
buf_size -= 2 * avctx->height;
for (y = 0; y < avctx->height; y++) {
unsigned int pkt_size = bytestream2_get_le16(&idx);
if (!pkt_size) {
memset(p->data[0] + y * p->linesize[0], 0xFF, width);
continue;
}
if (pkt_size > buf_size) {
av_log(avctx, AV_LOG_WARNING, "image probably corrupt\n");
pkt_size = buf_size;
}
bytestream2_init(&gb, buf, pkt_size);
x = 0;
while (bytestream2_get_bytes_left(&gb) && x < width) {
int size = bytestream2_get_byte(&gb);
if (size) {
size = FFMIN(size, bytestream2_get_bytes_left(&gb));
memcpy(p->data[0] + y * p->linesize[0] + x, gb.buffer, FFMIN(size, width - x));
bytestream2_skip(&gb, size);
} else {
int value;
size = bytestream2_get_byte(&gb);
if (!size)
avpriv_request_sample(avctx, "escape value");
value = bytestream2_get_byte(&gb);
memset(p->data[0] + y * p->linesize[0] + x, value, FFMIN(size, width - x));
}
x += size;
}
buf += pkt_size;
buf_size -= pkt_size;
}
*got_frame = 1;
return buf_size;
}
const AVCodec ff_msp2_decoder = {
.name = "msp2",
.long_name = NULL_IF_CONFIG_SMALL("Microsoft Paint (MSP) version 2"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_MSP2,
.decode = msp2_decode_frame,
.capabilities = AV_CODEC_CAP_DR1,
};