static int ipvideo_decode_block_opcode_0x4(IpvideoContext *s) { int x, y; unsigned char B, BL, BH; /* copy a block from the previous frame; need 1 more byte */ CHECK_STREAM_PTR(1); B = *s->stream_ptr++; BL = B & 0x0F; BH = (B >> 4) & 0x0F; x = -8 + BL; y = -8 + BH; debug_interplay (" motion byte = %d, (x, y) = (%d, %d)\n", B, x, y); return copy_from(s, &s->last_frame, x, y); }