static void msrle_decode_pal8(MsrleContext *s) { int stream_ptr = 0; unsigned char rle_code; unsigned char extra_byte; unsigned char stream_byte; int pixel_ptr = 0; int row_dec = s->frame.linesize[0]; int row_ptr = (s->avctx->height - 1) * row_dec; int 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 */ return; } 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 ((row_ptr + pixel_ptr + stream_byte > frame_size) || (row_ptr < 0)) { printf(" MS RLE: frame ptr just went out of bounds (1)\n"); return; } rle_code = stream_byte; extra_byte = stream_byte & 0x01; if (stream_ptr + rle_code + extra_byte > s->size) { printf(" MS RLE: stream ptr just went out of bounds (2)\n"); return; } while (rle_code--) { FETCH_NEXT_STREAM_BYTE(); s->frame.data[0][row_ptr + pixel_ptr] = stream_byte; 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) || (row_ptr < 0)) { printf(" MS RLE: frame ptr just went out of bounds (2)\n"); return; } FETCH_NEXT_STREAM_BYTE(); while(rle_code--) { s->frame.data[0][row_ptr + pixel_ptr] = stream_byte; pixel_ptr++; } } } /* make the palette available */ memcpy(s->frame.data[1], s->palette, 256 * 4); /* one last sanity check on the way out */ if (stream_ptr < s->size) printf(" MS RLE: ended frame decode with bytes left over (%d < %d)\n", stream_ptr, s->size); }