2.7.3 - 2.7.5 Avidemux becomes unresponsive for 4s after playback started

[OutOfSpace]

AMD Ryzen 7 3700X
32GB RAM
NVIDIA GeForce RTX 2060 SUPER

I'm having an issue where the application becomes unresponsive for about 4 seconds after playback has started. The video plays fine, but the UI cannot be interacted with. Everything that has been interacted with during those 4 seconds will suddenly trigger once the UI freeze is over.

This is a screencast of the issue : https://knowledge.autodesk.com/community/screencast/2eb556c3-0df0-4f03-a150-a66796cc6e96

This screencast shows the application being skinned by WindowBlinds, however the issue also happens when it is excluded from WindowBlinds skinning.

[eumagga0x2a]

Are you immediately stopping playback (klicking Play/Pause the second time) and then trying to interact with the GUI? Can't reproduce with just starting playback and immediately changing encoder or muxer after that on macOS and on Windows 10 with samples up to 1080p.

With 4k samples which Avidemux can't decode in real time anyway, everything is laggy (this is nothing new).

[OutOfSpace]

I am pressing play and then attempting to press stop. The video won't stop right away because the UI is unresponsive after playback has started. Clicking the other UI elements was just to show that the whole UI becomes unresponsive.
I am not playing 4k video. This is 720p.

[eumagga0x2a]

What is the size of the cache?

[OutOfSpace]

16

[eumagga0x2a]

Okay, then WFM.

(Avidemux seeks back to the last displayed picture on stopping playback, this picture is normally still in the cache, otherwise stopping may be not immediate)

[OutOfSpace]

Same hardware?

[eumagga0x2a]

No, a MBP (i.e. just a fraction of the resources your system has)

[OutOfSpace]

Okay so will this be considered not an issue because it works on your hardware? It also works fine on my laptop with different specs but not on this computer which is a fresh system and fresh install.

[eumagga0x2a]

Do you experience the same issue with WindowBlinds compeltely uninstalled? And with a different video output (enable OpenGL and select OpenGL output or simply with unaccelerated Qt)? And with DXVA2 hw accelerated decoding disabled?

I need to be able to reproduce (don't think I would be able to do anything about it...). Might be something related to graphics drivers.

[OutOfSpace]

Alright! The UI reacts normally when video display is set to Qt or OpenGL. So I guess the issue is fixed! Thank you!

[eumagga0x2a]

Good, we've identified the trigger. Will try something later, thank you.

[OutOfSpace]

Good, we've identified the trigger. Will try something later, thank you.

I can test builds on my machine if you need me to.

[eumagga0x2a]

Could you please clarify whether the issue is really tied to the DXVA2 output only or rather to the combination of DXVA2 decoding AND output? If you disable just the hw accelerated decoding and keep DXVA2 output, is it enough to trigger the problem? Have you tried completely uninstalling WindowBlinds?

[OutOfSpace]

"Decode video using DXVA2 (windows)" was never enabled.

I have not tried uninstalling WindowBlinds. That would have required a restart which I couldn't do at the time. However unloading WindowBlinds removes all the hooks from the system so uninstalling should not be necessary. If you really want me to try uninstalling it, I can do that later.