KNOWN             185 libavfilter/formats.c                 if (KNOWN(b->channel_layouts[i]))
KNOWN             205 libavfilter/formats.c         if (!KNOWN(a->channel_layouts[i]))
KNOWN             219 libavfilter/formats.c             if (!fmt || !KNOWN(fmt))
KNOWN             231 libavfilter/formats.c         if (KNOWN(a->channel_layouts[i]))