grayed out playback window filters

[bturkus]

i think it'd be nice to gray out playback filters when larger filter sets are disabled. for example, the various audio playback filters require Audio Phase Meter to be selected in preferences.

[metacynicv2]

+1

[richardpl]

Huh, this does not make sense, audio playback filters make sense only if there is audio and not if some option is set in preference.

[dericed]

I guess the filters could be greyed out if testing a media type that isn't in the file, such as if there's a video file with no audio, then the audio playback filters could be greyed out. But as @richardpl says the preferences won't impact the use of the playback filters.

[dericed]

closing, duplicate of https://github.com/bavc/qctools/issues/790