Yes, 0.5 doesn't look correct but is used as default by other elements too. So if we're going to change it here we should change it elsewhere too.

Other elements using 0.5 are:

jp2kdec, jpegdec, shapewipe, deinterlace, videomixer, ffdec_*

But all of these are not using the proportion either.

Why do we have properties that don't work?

(In reply to comment #3)
> Why do we have properties that don't work?

Hm? They're values from the QoS events, that could be used by elements to change their behaviour. If the proportion is bad you could switch to a worse but faster algorithm for example. If the time is ahead you can as well drop frames. These are not properties or anything, some elements just parse and store them for completeness or future use.

The thing is that a value of 1.0 means that the decoder is operating at exactly the right speed to make things still work realtime. What you usually want is a value much less than 1.0 so that you have planty of CPU headroom. Some decoders, for example, start dropping frames when they get close to 1.0. So, 0.5 is a safer value, I guess.

Let's close this as NOTABUG then.