VAR_S2R_MAIN_HSUB  197 libavfilter/vf_scale.c          vars_w[VAR_S2R_MAIN_HSUB] || vars_h[VAR_S2R_MAIN_HSUB] ||
VAR_S2R_MAIN_HSUB  447 libavfilter/vf_scale.c         scale->var_values[VAR_S2R_MAIN_HSUB] = 1 << main_desc->log2_chroma_w;