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FFmpeg/libavcodec/msp2dec.c
Andreas Rheinhardt 4243da4ff4 avcodec/codec_internal: Use union for FFCodec decode/encode callbacks
This is possible, because every given FFCodec has to implement
exactly one of these. Doing so decreases sizeof(FFCodec) and
therefore decreases the size of the binary.
Notice that in case of position-independent code the decrease
is in .data.rel.ro, so that this translates to decreased
memory consumption.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2022-04-05 20:02:37 +02:00

103 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 "codec_internal.h"
#include "internal.h"
static int msp2_decode_frame(AVCodecContext *avctx, AVFrame *p,
int *got_frame, AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
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 FFCodec ff_msp2_decoder = {
.p.name = "msp2",
.p.long_name = NULL_IF_CONFIG_SMALL("Microsoft Paint (MSP) version 2"),
.p.type = AVMEDIA_TYPE_VIDEO,
.p.id = AV_CODEC_ID_MSP2,
.p.capabilities = AV_CODEC_CAP_DR1,
FF_CODEC_DECODE_CB(msp2_decode_frame),
};