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; 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_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; 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_NEXT_STREAM_BYTE(); if (stream_byte == 0) {   row_ptr -= row_dec; pixel_ptr = 0; } else if (stream_byte == 1) {   return 0; } else if (stream_byte == 2) {   FETCH_NEXT_STREAM_BYTE(); pixel_ptr += stream_byte; FETCH_NEXT_STREAM_BYTE(); row_ptr -= stream_byte * row_dec; } else {  