Running Filters on WMV?

I've managed to get the x86 ffdshow "picture properties" filter running in Winamp on every video type I have except for WMV.

Is this possible in the DirectShow settings?

Enable the WMV formats on the "codecs" page in ffdshow settings.

Not sure how I missed that, thanks!

Another question: Is there any way to enable these filters for HEVC MP4 files, or is that codec unsupported by ffdshow?

Is there any way to run the filters on videos decoded by LAV?

ffdshow does not support HEVC and VP9 video. It is not possible to use ffdshow in Winamp for such videos.

If you use the MPC-HC player from the codec pack, then it is possible to use LAV Video decoder in combination with ffdshow video processor. That player also provides its own settings for adjusting Brightness/Contract/Hue/Saturation.