SIZE_MACROBLOCK
unsigned int size_mb = SIZE_MACROBLOCK;
unsigned int num_blocks = DIV_ROUND_UP(width, SIZE_MACROBLOCK) *
DIV_ROUND_UP(height, SIZE_MACROBLOCK);
unsigned int pic_width_in_mb = DIV_ROUND_UP(width, SIZE_MACROBLOCK);
unsigned int frame_height_in_mb = DIV_ROUND_UP(height, SIZE_MACROBLOCK);