PNG_FILTER_VALUE_NONE 238 libavcodec/pngdec.c case PNG_FILTER_VALUE_NONE: PNG_FILTER_VALUE_NONE 142 libavcodec/pngenc.c case PNG_FILTER_VALUE_NONE: PNG_FILTER_VALUE_NONE 556 libavcodec/pngenc.c PNG_FILTER_VALUE_NONE, PNG_FILTER_VALUE_NONE 559 libavcodec/pngenc.c s->filter_type = PNG_FILTER_VALUE_NONE;