(2/5 is just adding a test, I'll assume you mean 1/5.)
Yes, sorry.
Yeah, I'm not sure about that part either. I'm not sure about any of this, other than what BURIKO needs, and I have no idea about _why_ any of that.
As mentioned in bugzilla, using the MPEG splitter and decoders may have a performance impact, even in applications that don't care about compressed MPEG; that's why I chose this approach. And, as you said, changing filter priorities yields a regression risk.
But if you feel that the improved do-it-right-ness outweighs said drawbacks, then so be it. Please confirm which way you want it.
Yes, it makes performance worse and debugging harder, but at this point the ship has sailed; that's a problem we just need to deal with. That was one of the motivations for delaying doing the work to implement compressed output support, but now we've reached the point where we need it. I think the tradeoffs at this point are such that always using the real MPEG-1 splitter and AVI splitter is the right option.