#512 vaapi broken due to postprocessing

[Ilya]

smplayer 0.8.0 runs mplayer with "-vf-add pp" even when "enable postprocessing by default" isn't enabled in preferences->video
This behavior breaks vaapi. This happens on some MKV files, but on other there is no such problem

[Ricardo Villalba]

Could you send the smplayer log?