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

Nicolas Dufresne nicolas at
Wed Jun 30 13:39:43 UTC 2021

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.

> Kind regards,
> Michiel
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