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/*
* Microsoft RLE decoder
* Copyright (C) 2008 Konstantin Shishkov
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* MS RLE decoder based on decoder by Mike Melanson and my own for TSCC
* For more information about the MS RLE format, visit:
* http://www.multimedia.cx/msrle.txt
*/
#include "libavutil/intreadwrite.h"
#include "avcodec.h"
#include "msrledec.h"
#define FETCH_NEXT_STREAM_BYTE() \
if (stream_ptr >= data_size) \
{ \
av_log(avctx, AV_LOG_ERROR, " MS RLE: stream ptr just went out of bounds (1)\n"); \
return -1; \
} \
stream_byte = data[stream_ptr++];
static int msrle_decode_pal4(AVCodecContext *avctx, AVPicture *pic,
const uint8_t *data, int data_size)
{
int stream_ptr = 0;
unsigned char rle_code;
unsigned char extra_byte, odd_pixel;
unsigned char stream_byte;
unsigned int pixel_ptr = 0;
int row_dec = pic->linesize[0];
int row_ptr = (avctx->height - 1) * row_dec;
int frame_size = row_dec * avctx->height;
int i;
while (row_ptr >= 0) {
FETCH_NEXT_STREAM_BYTE();
rle_code = stream_byte;
if (rle_code == 0) {
/* fetch the next byte to see how to handle escape code */
FETCH_NEXT_STREAM_BYTE();
if (stream_byte == 0) {
/* line is done, goto the next one */
row_ptr -= row_dec;
pixel_ptr = 0;
} else if (stream_byte == 1) {
/* decode is done */
return 0;
} else if (stream_byte == 2) {
/* reposition frame decode coordinates */
FETCH_NEXT_STREAM_BYTE();
pixel_ptr += stream_byte;
FETCH_NEXT_STREAM_BYTE();
row_ptr -= stream_byte * row_dec;
} else {
// copy pixels from encoded stream
odd_pixel = stream_byte & 1;
rle_code = (stream_byte + 1) / 2;
extra_byte = rle_code & 0x01;
if (row_ptr + pixel_ptr + stream_byte > frame_size) {
av_log(avctx, AV_LOG_ERROR, " MS RLE: frame ptr just went out of bounds (1)\n");
return -1;
}
for (i = 0; i < rle_code; i++) {
if (pixel_ptr >= avctx->width)
break;
FETCH_NEXT_STREAM_BYTE();
pic->data[0][row_ptr + pixel_ptr] = stream_byte >> 4;
pixel_ptr++;
if (i + 1 == rle_code && odd_pixel)
break;
if (pixel_ptr >= avctx->width)
break;
pic->data[0][row_ptr + pixel_ptr] = stream_byte & 0x0F;
pixel_ptr++;
}
// if the RLE code is odd, skip a byte in the stream
if (extra_byte)
stream_ptr++;
}
} else {
// decode a run of data
if (row_ptr + pixel_ptr + stream_byte > frame_size) {
av_log(avctx, AV_LOG_ERROR, " MS RLE: frame ptr just went out of bounds (1)\n");
return -1;
}
FETCH_NEXT_STREAM_BYTE();
for (i = 0; i < rle_code; i++) {
if (pixel_ptr >= avctx->width)
break;
if ((i & 1) == 0)
pic->data[0][row_ptr + pixel_ptr] = stream_byte >> 4;
else
pic->data[0][row_ptr + pixel_ptr] = stream_byte & 0x0F;
pixel_ptr++;
}
}
}
/* one last sanity check on the way out */
if (stream_ptr < data_size) {
av_log(avctx, AV_LOG_ERROR, " MS RLE: ended frame decode with bytes left over (%d < %d)\n",
stream_ptr, data_size);
return -1;
}
return 0;
}
static int msrle_decode_8_16_24_32(AVCodecContext *avctx, AVPicture *pic, int depth,
const uint8_t *data, int srcsize)
{
uint8_t *output, *output_end;
const uint8_t* src = data;
int p1, p2, line=avctx->height - 1, pos=0, i;
uint16_t pix16;
uint32_t pix32;
unsigned int width= FFABS(pic->linesize[0]) / (depth >> 3);
output = pic->data[0] + (avctx->height - 1) * pic->linesize[0];
output_end = pic->data[0] + avctx->height * pic->linesize[0];
while(src < data + srcsize) {
p1 = *src++;
if(p1 == 0) { //Escape code
p2 = *src++;
if(p2 == 0) { //End-of-line
output = pic->data[0] + (--line) * pic->linesize[0];
if (line < 0 && !(src+1 < data + srcsize && AV_RB16(src) == 1)) {
av_log(avctx, AV_LOG_ERROR, "Next line is beyond picture bounds\n");
return -1;
}
pos = 0;
continue;
} else if(p2 == 1) { //End-of-picture
return 0;
} else if(p2 == 2) { //Skip
p1 = *src++;
p2 = *src++;
line -= p2;
pos += p1;
if (line < 0 || pos >= width){
av_log(avctx, AV_LOG_ERROR, "Skip beyond picture bounds\n");
return -1;
}
output = pic->data[0] + line * pic->linesize[0] + pos * (depth >> 3);
continue;
}
// Copy data
if ((pic->linesize[0] > 0 && output + p2 * (depth >> 3) > output_end)
||(pic->linesize[0] < 0 && output + p2 * (depth >> 3) < output_end)) {
src += p2 * (depth >> 3);
continue;
}
if ((depth == 8) || (depth == 24)) {
for(i = 0; i < p2 * (depth >> 3); i++) {
*output++ = *src++;
}
// RLE8 copy is actually padded - and runs are not!
if(depth == 8 && (p2 & 1)) {
src++;
}
} else if (depth == 16) {
for(i = 0; i < p2; i++) {
pix16 = AV_RL16(src);
src += 2;
*(uint16_t*)output = pix16;
output += 2;
}
} else if (depth == 32) {
for(i = 0; i < p2; i++) {
pix32 = AV_RL32(src);
src += 4;
*(uint32_t*)output = pix32;
output += 4;
}
}
pos += p2;
} else { //run of pixels
uint8_t pix[3]; //original pixel
switch(depth){
case 8: pix[0] = *src++;
break;
case 16: pix16 = AV_RL16(src);
src += 2;
break;
case 24: pix[0] = *src++;
pix[1] = *src++;
pix[2] = *src++;
break;
case 32: pix32 = AV_RL32(src);
src += 4;
break;
}
if ((pic->linesize[0] > 0 && output + p1 * (depth >> 3) > output_end)
||(pic->linesize[0] < 0 && output + p1 * (depth >> 3) < output_end))
continue;
for(i = 0; i < p1; i++) {
switch(depth){
case 8: *output++ = pix[0];
break;
case 16: *(uint16_t*)output = pix16;
output += 2;
break;
case 24: *output++ = pix[0];
*output++ = pix[1];
*output++ = pix[2];
break;
case 32: *(uint32_t*)output = pix32;
output += 4;
break;
}
}
pos += p1;
}
}
av_log(avctx, AV_LOG_WARNING, "MS RLE warning: no end-of-picture code\n");
return 0;
}
int ff_msrle_decode(AVCodecContext *avctx, AVPicture *pic, int depth,
const uint8_t* data, int data_size)
{
switch(depth){
case 4:
return msrle_decode_pal4(avctx, pic, data, data_size);
case 8:
case 16:
case 24:
case 32:
return msrle_decode_8_16_24_32(avctx, pic, depth, data, data_size);
default:
av_log(avctx, AV_LOG_ERROR, "Unknown depth %d\n", depth);
return -1;
}
}
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