VAR_CH            448 libavfilter/aeval.c             eval->var_values[VAR_CH] = j;
VAR_CH            645 libavfilter/af_firequalizer.c         vars[VAR_CH] = ch;
VAR_CH             84 libavfilter/boxblur.c     var_values[VAR_CH] = ch = h>>(desc->log2_chroma_h);