Re: Dot file element properties "atomicity"? Queue level time and buffers don't match

[Arun Raghavan]

On Wed, 30 Jun 2021, at 9:39 AM, Nicolas Dufresne via gstreamer-devel wrote:
> Le mercredi 30 juin 2021 à 10:09 +0200, Michiel Konstapel via gstreamer-devel a
> écrit :
> > I'm seeing some "impossible" values in my debug dot files, namely queues 
> > with current-level-buffers=1 and current-level-time=1_720_000_000, in a 
> > pipeline where every video buffer should be 40 ms (25 fps):
> > 
> > 
> > GstQueue
> > queue:video2-preview
> > [>]
> > current-level-buffers=1
> > current-level-bytes=8294400
> > current-level-time=1720000000
> > max-size-buffers=0
> > max-size-bytes=0
> > 
> > Are the property values shown in a dot file an "atomic" snapshot or is 
> > it possible it first read the current time, then a load of buffers got 
> > taken out, and then the current-level-buffers was read?
> 
> No, they are not atomic. This is fetch independently from a running pipeline.
> 
> > 
> > Then I still can't explain the picture, because the max-size-time of the 
> > queue is the default one second, so I don't understand how 1.7 seconds 
> > worth of buffers got in there.
> 
> I confirm the result does not seems logical, you'd need 43 buffers, which is too
> big of a difference. That being said, there is too little information here to
> help you investigate.

Possibly related: https://gitlab.freedesktop.org/gstreamer/gstreamer/-/issues/684

-- Arun