DECLARE_BLOCK_FUNCTIONS   50 libavutil/pixelutils.c DECLARE_BLOCK_FUNCTIONS(2)
DECLARE_BLOCK_FUNCTIONS   51 libavutil/pixelutils.c DECLARE_BLOCK_FUNCTIONS(4)
DECLARE_BLOCK_FUNCTIONS   52 libavutil/pixelutils.c DECLARE_BLOCK_FUNCTIONS(8)
DECLARE_BLOCK_FUNCTIONS   53 libavutil/pixelutils.c DECLARE_BLOCK_FUNCTIONS(16)