PNG_FILTER_VALUE_SUB  262 libavcodec/pngdec.c     case PNG_FILTER_VALUE_SUB:
PNG_FILTER_VALUE_SUB  174 libavcodec/pngenc.c     case PNG_FILTER_VALUE_SUB:
PNG_FILTER_VALUE_SUB  200 libavcodec/pngenc.c         pred = PNG_FILTER_VALUE_SUB;
PNG_FILTER_VALUE_SUB 1118 libavcodec/pngenc.c         { "sub",   NULL, 0, AV_OPT_TYPE_CONST, { .i64 = PNG_FILTER_VALUE_SUB },   INT_MIN, INT_MAX, VE, "pred" },