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FFmpeg/libavcodec/bmp.c
Kostya Shishkov c5b2fe165a Some BMP files have file size declared in the header equal to headers size 
without image data, so try to correct that value before conducting checks on
declared file size.

Originally committed as revision 15924 to svn://svn.ffmpeg.org/ffmpeg/trunk
2008-11-24 11:24:02 +00:00

340 lines
9.4 KiB
C
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/*
* BMP image format decoder
* Copyright (c) 2005 Mans Rullgard
*
* 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 "avcodec.h"
#include "bytestream.h"
#include "bmp.h"
#include "msrledec.h"
static av_cold int bmp_decode_init(AVCodecContext *avctx){
BMPContext *s = avctx->priv_data;
avcodec_get_frame_defaults((AVFrame*)&s->picture);
avctx->coded_frame = (AVFrame*)&s->picture;
return 0;
}
static int bmp_decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
const uint8_t *buf, int buf_size)
{
BMPContext *s = avctx->priv_data;
AVFrame *picture = data;
AVFrame *p = &s->picture;
unsigned int fsize, hsize;
int width, height;
unsigned int depth;
BiCompression comp;
unsigned int ihsize;
int i, j, n, linesize;
uint32_t rgb[3];
uint8_t *ptr;
int dsize;
const uint8_t *buf0 = buf;
if(buf_size < 14){
av_log(avctx, AV_LOG_ERROR, "buf size too small (%d)\n", buf_size);
return -1;
}
if(bytestream_get_byte(&buf) != 'B' ||
bytestream_get_byte(&buf) != 'M') {
av_log(avctx, AV_LOG_ERROR, "bad magic number\n");
return -1;
}
fsize = bytestream_get_le32(&buf);
if(buf_size < fsize){
av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %d)\n",
buf_size, fsize);
return -1;
}
buf += 2; /* reserved1 */
buf += 2; /* reserved2 */
hsize = bytestream_get_le32(&buf); /* header size */
ihsize = bytestream_get_le32(&buf); /* more header size */
if(ihsize + 14 > hsize){
av_log(avctx, AV_LOG_ERROR, "invalid header size %d\n", hsize);
return -1;
}
/* sometimes file size is set to some headers size, set a real size in that case */
if(fsize == 14 || fsize == ihsize + 14)
fsize = buf_size - 2;
if(fsize <= hsize){
av_log(avctx, AV_LOG_ERROR, "declared file size is less than header size (%d < %d)\n",
fsize, hsize);
return -1;
}
switch(ihsize){
case 40: // windib v3
case 64: // OS/2 v2
case 108: // windib v4
case 124: // windib v5
width = bytestream_get_le32(&buf);
height = bytestream_get_le32(&buf);
break;
case 12: // OS/2 v1
width = bytestream_get_le16(&buf);
height = bytestream_get_le16(&buf);
break;
default:
av_log(avctx, AV_LOG_ERROR, "unsupported BMP file, patch welcome\n");
return -1;
}
if(bytestream_get_le16(&buf) != 1){ /* planes */
av_log(avctx, AV_LOG_ERROR, "invalid BMP header\n");
return -1;
}
depth = bytestream_get_le16(&buf);
if(ihsize == 40)
comp = bytestream_get_le32(&buf);
else
comp = BMP_RGB;
if(comp != BMP_RGB && comp != BMP_BITFIELDS && comp != BMP_RLE4 && comp != BMP_RLE8){
av_log(avctx, AV_LOG_ERROR, "BMP coding %d not supported\n", comp);
return -1;
}
if(comp == BMP_BITFIELDS){
buf += 20;
rgb[0] = bytestream_get_le32(&buf);
rgb[1] = bytestream_get_le32(&buf);
rgb[2] = bytestream_get_le32(&buf);
}
avctx->width = width;
avctx->height = height > 0? height: -height;
avctx->pix_fmt = PIX_FMT_NONE;
switch(depth){
case 32:
if(comp == BMP_BITFIELDS){
rgb[0] = (rgb[0] >> 15) & 3;
rgb[1] = (rgb[1] >> 15) & 3;
rgb[2] = (rgb[2] >> 15) & 3;
if(rgb[0] + rgb[1] + rgb[2] != 3 ||
rgb[0] == rgb[1] || rgb[0] == rgb[2] || rgb[1] == rgb[2]){
break;
}
} else {
rgb[0] = 2;
rgb[1] = 1;
rgb[2] = 0;
}
avctx->pix_fmt = PIX_FMT_BGR24;
break;
case 24:
avctx->pix_fmt = PIX_FMT_BGR24;
break;
case 16:
if(comp == BMP_RGB)
avctx->pix_fmt = PIX_FMT_RGB555;
if(comp == BMP_BITFIELDS)
avctx->pix_fmt = rgb[1] == 0x07E0 ? PIX_FMT_RGB565 : PIX_FMT_RGB555;
break;
case 8:
if(hsize - ihsize - 14 > 0)
avctx->pix_fmt = PIX_FMT_PAL8;
else
avctx->pix_fmt = PIX_FMT_GRAY8;
break;
case 4:
if(hsize - ihsize - 14 > 0){
avctx->pix_fmt = PIX_FMT_PAL8;
}else{
av_log(avctx, AV_LOG_ERROR, "Unknown palette for 16-colour BMP\n");
return -1;
}
break;
case 1:
avctx->pix_fmt = PIX_FMT_MONOBLACK;
break;
default:
av_log(avctx, AV_LOG_ERROR, "depth %d not supported\n", depth);
return -1;
}
if(avctx->pix_fmt == PIX_FMT_NONE){
av_log(avctx, AV_LOG_ERROR, "unsupported pixel format\n");
return -1;
}
if(p->data[0])
avctx->release_buffer(avctx, p);
p->reference = 0;
if(avctx->get_buffer(avctx, p) < 0){
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
return -1;
}
p->pict_type = FF_I_TYPE;
p->key_frame = 1;
buf = buf0 + hsize;
dsize = buf_size - hsize;
/* Line size in file multiple of 4 */
n = ((avctx->width * depth) / 8 + 3) & ~3;
if(n * avctx->height > dsize && comp != BMP_RLE4 && comp != BMP_RLE8){
av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %d)\n",
dsize, n * avctx->height);
return -1;
}
// RLE may skip decoding some picture areas, so blank picture before decoding
if(comp == BMP_RLE4 || comp == BMP_RLE8)
memset(p->data[0], 0, avctx->height * p->linesize[0]);
if(depth == 4 || depth == 8)
memset(p->data[1], 0, 1024);
if(height > 0){
ptr = p->data[0] + (avctx->height - 1) * p->linesize[0];
linesize = -p->linesize[0];
} else {
ptr = p->data[0];
linesize = p->linesize[0];
}
if(avctx->pix_fmt == PIX_FMT_PAL8){
buf = buf0 + 14 + ihsize; //palette location
if((hsize-ihsize-14)>>depth < 4){ // OS/2 bitmap, 3 bytes per palette entry
for(i = 0; i < (1 << depth); i++)
((uint32_t*)p->data[1])[i] = bytestream_get_le24(&buf);
}else{
for(i = 0; i < (1 << depth); i++)
((uint32_t*)p->data[1])[i] = bytestream_get_le32(&buf);
}
buf = buf0 + hsize;
}
if(comp == BMP_RLE4 || comp == BMP_RLE8){
ff_msrle_decode(avctx, p, depth, buf, dsize);
}else{
switch(depth){
case 1:
for(i = 0; i < avctx->height; i++){
memcpy(ptr, buf, n);
buf += n;
ptr += linesize;
}
break;
case 4:
for(i = 0; i < avctx->height; i++){
int j;
for(j = 0; j < n; j++){
ptr[j*2+0] = (buf[j] >> 4) & 0xF;
ptr[j*2+1] = buf[j] & 0xF;
}
buf += n;
ptr += linesize;
}
break;
case 8:
for(i = 0; i < avctx->height; i++){
memcpy(ptr, buf, avctx->width);
buf += n;
ptr += linesize;
}
break;
case 24:
for(i = 0; i < avctx->height; i++){
memcpy(ptr, buf, avctx->width*(depth>>3));
buf += n;
ptr += linesize;
}
break;
case 16:
for(i = 0; i < avctx->height; i++){
const uint16_t *src = (const uint16_t *) buf;
uint16_t *dst = (uint16_t *) ptr;
for(j = 0; j < avctx->width; j++)
*dst++ = le2me_16(*src++);
buf += n;
ptr += linesize;
}
break;
case 32:
for(i = 0; i < avctx->height; i++){
const uint8_t *src = buf;
uint8_t *dst = ptr;
for(j = 0; j < avctx->width; j++){
dst[0] = src[rgb[2]];
dst[1] = src[rgb[1]];
dst[2] = src[rgb[0]];
dst += 3;
src += 4;
}
buf += n;
ptr += linesize;
}
break;
default:
av_log(avctx, AV_LOG_ERROR, "BMP decoder is broken\n");
return -1;
}
}
*picture = s->picture;
*data_size = sizeof(AVPicture);
return buf_size;
}
static av_cold int bmp_decode_end(AVCodecContext *avctx)
{
BMPContext* c = avctx->priv_data;
if (c->picture.data[0])
avctx->release_buffer(avctx, &c->picture);
return 0;
}
AVCodec bmp_decoder = {
"bmp",
CODEC_TYPE_VIDEO,
CODEC_ID_BMP,
sizeof(BMPContext),
bmp_decode_init,
NULL,
bmp_decode_end,
bmp_decode_frame,
.long_name = NULL_IF_CONFIG_SMALL("BMP image"),
};
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