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) {
static int aasc_decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
const uint8_t *buf, int buf_size)
{
AascContext *s = 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;
}
