ptrdiff_t width, ptrdiff_t height, \
int factor1, int factor2, int half
-#define BLEND_FACTOR_DEPTH8 7
-#define BLEND_FACTOR_DEPTH16 15
+#define BLEND_FACTOR_DEPTH(n) (n-1)
typedef void (*blend_func)(BLEND_FUNC_PARAMS);
int interp_end; ///< end of range to apply linear interpolation
int line_size[4]; ///< bytes of pixel data per line for each plane
+ int height[4]; ///< height of each plane
int vsub;
AVRational srce_time_base; ///< timebase of source