ff_init_vscale    366 libswscale/slice.c         res = ff_init_vscale(c, c->desc + index, c->slice + srcIdx, c->slice + dstIdx);
ff_init_vscale   1039 libswscale/swscale_internal.h int ff_init_vscale(SwsContext *c, SwsFilterDescriptor *desc, SwsSlice *src, SwsSlice *dst);