I don't know if there was similar question so I post this as new topic.
ffdshow has preset autoload, and I'm interested if it would be possible to switch in automatic between dxva and non dxva decoder.
Reason for this is that most dvb softwares have option to switch decoders depending if video signal is mpeg2 or h.264, but they don't have option to switch decoder depending on if video is SD or HD quality. ffdshow non dxva is excelent decoder for improving SD picture quality, but its CPU usage is terrible when it comes to HD signal (even if all postprocessing is deactivated).
You can use the profile/presets functionality for this. Create one with HWA enabled and one with HWA disabled.
I recommend using LAV Video decoder instead of ffdshow. That has much better DXVA implementation and also easier configuration.