Changing playback rate is allowed or not?

[acbegen]

Is it allowed to slow down or speed up the playback rate to avoid a stall or reduce the latency, respectively? dash.js is capable of doing it, however, it is not clear whether this capability can be used or not.

[johnBartos]

It is allowed, because otherwise the player is limited to hard seeks to re-synchronize with latency (which is not always a great option). But we will account for this in the evaluation criteria. If rate manipulation produces a bad user experience that is not good.

[acbegen]

OK, but then the latency cannot be fixed, at least in the short term. Yes, indeed we want to avoid stalls but suppose one drops from 30 fps to 3fps, it is not stalling in theory but it is stalling in practice. I wonder how the evaluation will be done.