[Interest] QML profiling shows scene graph not rendering

[Luca Carlon]

Hello!
My app is affected by some stuttering and I'm trying to investigate the
reason through the profiler. I'm attaching a shot of what I see with the
profiler in vaapi.png. What I see is that there is a hole in the scene
graph row, but just a few milliseconds of execution of JS. As I know some
MediaPlayer's are restarted in that instant, I created some tests to
reproduce the behavior, and what I notice is that one video player stops
rendering for some ms when another MediaPlayer is set to another media. I
attach my test code in test.qml. The stuttering is not very noticeable with
only two players, but I have more than two.
I did the same test without the use of gstreamer vaapi (I'm using nVidia
decoding here through the gstreamer vaapi plugin), using software decoding,
and in that case the situation seems a bit better: attachment software.png.
So is it possible that the scene graph is stuck waiting for something in
QtMultimedia being done/allocated? Is there any way to move that
"processing" in another thread?
Thank you!
Regards.

Luca
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