third_party_ffmpeg/libavcodec/msrle.c
Michael Niedermayer 754f84663e avcodec/msrle: check return code for success before use
The check is possibly redundant, but better to check for errors
that dont occur than to skip the check and crash

Fixes CID1197060

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
2014-04-06 04:01:24 +02:00

171 lines
4.8 KiB
C

/*
* Microsoft RLE video decoder
* Copyright (C) 2003 the ffmpeg project
*
* 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
* MS RLE video decoder by Mike Melanson (melanson@pcisys.net)
* For more information about the MS RLE format, visit:
* http://www.pcisys.net/~melanson/codecs/
*
* The MS RLE decoder outputs PAL8 colorspace data.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "avcodec.h"
#include "internal.h"
#include "msrledec.h"
#include "libavutil/imgutils.h"
typedef struct MsrleContext {
AVCodecContext *avctx;
AVFrame *frame;
GetByteContext gb;
const unsigned char *buf;
int size;
uint32_t pal[256];
} MsrleContext;
static av_cold int msrle_decode_init(AVCodecContext *avctx)
{
MsrleContext *s = avctx->priv_data;
int i;
s->avctx = avctx;
switch (avctx->bits_per_coded_sample) {
case 1:
avctx->pix_fmt = AV_PIX_FMT_MONOWHITE;
break;
case 4:
case 8:
avctx->pix_fmt = AV_PIX_FMT_PAL8;
break;
case 24:
avctx->pix_fmt = AV_PIX_FMT_BGR24;
break;
default:
av_log(avctx, AV_LOG_ERROR, "unsupported bits per sample\n");
return AVERROR_INVALIDDATA;
}
s->frame = av_frame_alloc();
if (!s->frame)
return AVERROR(ENOMEM);
if (avctx->extradata_size >= 4)
for (i = 0; i < FFMIN(avctx->extradata_size, AVPALETTE_SIZE)/4; i++)
s->pal[i] = 0xFFU<<24 | AV_RL32(avctx->extradata+4*i);
return 0;
}
static int msrle_decode_frame(AVCodecContext *avctx,
void *data, int *got_frame,
AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
MsrleContext *s = avctx->priv_data;
int istride = FFALIGN(avctx->width*avctx->bits_per_coded_sample, 32) / 8;
int ret;
s->buf = buf;
s->size = buf_size;
if ((ret = ff_reget_buffer(avctx, s->frame)) < 0)
return ret;
if (avctx->bits_per_coded_sample > 1 && avctx->bits_per_coded_sample <= 8) {
const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
if (pal) {
s->frame->palette_has_changed = 1;
memcpy(s->pal, pal, AVPALETTE_SIZE);
}
/* make the palette available */
memcpy(s->frame->data[1], s->pal, AVPALETTE_SIZE);
}
/* FIXME how to correctly detect RLE ??? */
if (avctx->height * istride == avpkt->size) { /* assume uncompressed */
int linesize = av_image_get_linesize(avctx->pix_fmt, avctx->width, 0);
uint8_t *ptr = s->frame->data[0];
uint8_t *buf = avpkt->data + (avctx->height-1)*istride;
int i, j;
if (linesize < 0)
return linesize;
for (i = 0; i < avctx->height; i++) {
if (avctx->bits_per_coded_sample == 4) {
for (j = 0; j < avctx->width - 1; j += 2) {
ptr[j+0] = buf[j>>1] >> 4;
ptr[j+1] = buf[j>>1] & 0xF;
}
if (avctx->width & 1)
ptr[j+0] = buf[j>>1] >> 4;
} else {
memcpy(ptr, buf, linesize);
}
buf -= istride;
ptr += s->frame->linesize[0];
}
} else {
bytestream2_init(&s->gb, buf, buf_size);
ff_msrle_decode(avctx, (AVPicture*)s->frame, avctx->bits_per_coded_sample, &s->gb);
}
if ((ret = av_frame_ref(data, s->frame)) < 0)
return ret;
*got_frame = 1;
/* report that the buffer was completely consumed */
return buf_size;
}
static av_cold int msrle_decode_end(AVCodecContext *avctx)
{
MsrleContext *s = avctx->priv_data;
/* release the last frame */
av_frame_free(&s->frame);
return 0;
}
AVCodec ff_msrle_decoder = {
.name = "msrle",
.long_name = NULL_IF_CONFIG_SMALL("Microsoft RLE"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_MSRLE,
.priv_data_size = sizeof(MsrleContext),
.init = msrle_decode_init,
.close = msrle_decode_end,
.decode = msrle_decode_frame,
.capabilities = CODEC_CAP_DR1,
};