filter_fn        1993 libavcodec/vp9dsp.c filter_fn(64, avg) \
filter_fn        1994 libavcodec/vp9dsp.c filter_fn(32, avg) \
filter_fn        1995 libavcodec/vp9dsp.c filter_fn(16, avg) \
filter_fn        1996 libavcodec/vp9dsp.c filter_fn(8,  avg) \
filter_fn        1997 libavcodec/vp9dsp.c filter_fn(4,  avg)
filter_fn        2002 libavcodec/vp9dsp.c #undef filter_fn