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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 "bitstream.h"
#include "bswap.h"
#include "bmp.h"
#define read16(bits) bswap_16(get_bits(bits, 16))
#define read32(bits) bswap_32(get_bits_long(bits, 32))
static 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,
uint8_t *buf, int buf_size)
{
BMPContext *s = avctx->priv_data;
AVFrame *picture = data;
AVFrame *p = &s->picture;
GetBitContext bits;
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;
if(buf_size < 14){
av_log(avctx, AV_LOG_ERROR, "buf size too small (%d)\n", buf_size);
return -1;
}
init_get_bits(&bits, buf, buf_size);
if(get_bits(&bits, 16) != 0x424d){ /* 'BM' */
av_log(avctx, AV_LOG_ERROR, "bad magic number\n");
return -1;
}
fsize = read32(&bits);
if(buf_size < fsize){
av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %d)\n",
buf_size, fsize);
return -1;
}
skip_bits(&bits, 16); /* reserved1 */
skip_bits(&bits, 16); /* reserved2 */
hsize = read32(&bits); /* header size */
if(fsize <= hsize){
av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %d)\n",
fsize, hsize);
return -1;
}
ihsize = read32(&bits); /* more header size */
if(ihsize + 14 > hsize){
av_log(avctx, AV_LOG_ERROR, "invalid header size %d\n", hsize);
return -1;
}
width = read32(&bits);
height = read32(&bits);
if(read16(&bits) != 1){ /* planes */
av_log(avctx, AV_LOG_ERROR, "invalid BMP header\n");
return -1;
}
depth = read16(&bits);
if(ihsize > 16)
comp = read32(&bits);
else
comp = BMP_RGB;
if(comp != BMP_RGB && comp != BMP_BITFIELDS){
av_log(avctx, AV_LOG_ERROR, "BMP coding %d not supported\n", comp);
return -1;
}
if(comp == BMP_BITFIELDS){
skip_bits(&bits, 20 * 8);
rgb[0] = read32(&bits);
rgb[1] = read32(&bits);
rgb[2] = read32(&bits);
}
avctx->codec_id = CODEC_ID_BMP;
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;
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 += hsize;
dsize = buf_size - hsize;
/* Line size in file multiple of 4 */
n = (avctx->width * (depth / 8) + 3) & ~3;
if(n * avctx->height > dsize){
av_log(avctx, AV_LOG_ERROR, "not enough data (%d < %d)\n",
dsize, n * avctx->height);
return -1;
}
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];
}
switch(depth){
case 24:
for(i = 0; i < avctx->height; i++){
memcpy(ptr, buf, n);
buf += n;
ptr += linesize;
}
break;
case 16:
for(i = 0; i < avctx->height; i++){
uint16_t *src = (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++){
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;
}
AVCodec bmp_decoder = {
"bmp",
CODEC_TYPE_VIDEO,
CODEC_ID_BMP,
sizeof(BMPContext),
bmp_decode_init,
NULL,
NULL,
bmp_decode_frame
};
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