mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-12-07 11:13:41 +02:00
5509bffa88
Originally committed as revision 4842 to svn://svn.ffmpeg.org/ffmpeg/trunk
175 lines
5.2 KiB
C
175 lines
5.2 KiB
C
/*
|
|
* Autodesc RLE Decoder
|
|
* Copyright (C) 2005 the ffmpeg project
|
|
*
|
|
* This library 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 of the License, or (at your option) any later version.
|
|
*
|
|
* This library 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 this library; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
/**
|
|
* @file aasc.c
|
|
* Autodesc RLE Video Decoder by Konstantin Shishkov
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
|
|
#include "common.h"
|
|
#include "avcodec.h"
|
|
#include "dsputil.h"
|
|
|
|
typedef struct AascContext {
|
|
AVCodecContext *avctx;
|
|
AVFrame frame;
|
|
} AascContext;
|
|
|
|
#define FETCH_NEXT_STREAM_BYTE() \
|
|
if (stream_ptr >= buf_size) \
|
|
{ \
|
|
av_log(s->avctx, AV_LOG_ERROR, " AASC: stream ptr just went out of bounds (fetch)\n"); \
|
|
break; \
|
|
} \
|
|
stream_byte = buf[stream_ptr++];
|
|
|
|
static int aasc_decode_init(AVCodecContext *avctx)
|
|
{
|
|
AascContext *s = (AascContext *)avctx->priv_data;
|
|
|
|
s->avctx = avctx;
|
|
|
|
avctx->pix_fmt = PIX_FMT_BGR24;
|
|
avctx->has_b_frames = 0;
|
|
s->frame.data[0] = NULL;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int aasc_decode_frame(AVCodecContext *avctx,
|
|
void *data, int *data_size,
|
|
uint8_t *buf, int buf_size)
|
|
{
|
|
AascContext *s = (AascContext *)avctx->priv_data;
|
|
int stream_ptr = 4;
|
|
unsigned char rle_code;
|
|
unsigned char stream_byte;
|
|
int pixel_ptr = 0;
|
|
int row_dec, row_ptr;
|
|
int frame_size;
|
|
int i;
|
|
|
|
s->frame.reference = 1;
|
|
s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
|
|
if (avctx->reget_buffer(avctx, &s->frame)) {
|
|
av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
|
|
return -1;
|
|
}
|
|
|
|
row_dec = s->frame.linesize[0];
|
|
row_ptr = (s->avctx->height - 1) * row_dec;
|
|
frame_size = row_dec * s->avctx->height;
|
|
|
|
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 */
|
|
break;
|
|
} 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 */
|
|
if ((pixel_ptr + stream_byte > avctx->width * 3) ||
|
|
(row_ptr < 0)) {
|
|
av_log(s->avctx, AV_LOG_ERROR, " AASC: frame ptr just went out of bounds (copy1)\n");
|
|
break;
|
|
}
|
|
|
|
rle_code = stream_byte;
|
|
if (stream_ptr + rle_code > buf_size) {
|
|
av_log(s->avctx, AV_LOG_ERROR, " AASC: stream ptr just went out of bounds (copy2)\n");
|
|
break;
|
|
}
|
|
|
|
for (i = 0; i < rle_code; i++) {
|
|
FETCH_NEXT_STREAM_BYTE();
|
|
s->frame.data[0][row_ptr + pixel_ptr] = stream_byte;
|
|
pixel_ptr++;
|
|
}
|
|
if (rle_code & 1)
|
|
stream_ptr++;
|
|
}
|
|
} else {
|
|
/* decode a run of data */
|
|
if ((pixel_ptr + rle_code > avctx->width * 3) ||
|
|
(row_ptr < 0)) {
|
|
av_log(s->avctx, AV_LOG_ERROR, " AASC: frame ptr just went out of bounds (run1)\n");
|
|
break;
|
|
}
|
|
|
|
FETCH_NEXT_STREAM_BYTE();
|
|
|
|
while(rle_code--) {
|
|
s->frame.data[0][row_ptr + pixel_ptr] = stream_byte;
|
|
pixel_ptr++;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* one last sanity check on the way out */
|
|
if (stream_ptr < buf_size)
|
|
av_log(s->avctx, AV_LOG_ERROR, " AASC: ended frame decode with bytes left over (%d < %d)\n",
|
|
stream_ptr, buf_size);
|
|
|
|
*data_size = sizeof(AVFrame);
|
|
*(AVFrame*)data = s->frame;
|
|
|
|
/* report that the buffer was completely consumed */
|
|
return buf_size;
|
|
}
|
|
|
|
static int aasc_decode_end(AVCodecContext *avctx)
|
|
{
|
|
AascContext *s = (AascContext *)avctx->priv_data;
|
|
|
|
/* release the last frame */
|
|
if (s->frame.data[0])
|
|
avctx->release_buffer(avctx, &s->frame);
|
|
|
|
return 0;
|
|
}
|
|
|
|
AVCodec aasc_decoder = {
|
|
"aasc",
|
|
CODEC_TYPE_VIDEO,
|
|
CODEC_ID_AASC,
|
|
sizeof(AascContext),
|
|
aasc_decode_init,
|
|
NULL,
|
|
aasc_decode_end,
|
|
aasc_decode_frame,
|
|
CODEC_CAP_DR1,
|
|
};
|