Track Matte first frame flicker

[Wiethoofd]

When using a browser transition with track matte the first frame on repeat transitions flickers regardless of when you decide to reload the browser transition source each scene transition. Usually the first transition plays correctly and breaks on consecutive scene changes.

A user reported this earlier on the plugin forums discussion, and I also managed to record it with a bigger contrast between a full green and a blue color source scene and back:

2024-01-16.18-04-10.mp4

It does not matter if I use a white or inverted track matte layer or where the transition point is set (audio only?). And also occurs when you 'Refresh browser when scene becomes active'.

My suspicion is that it currently ignores the 'Shutdown source when not visible' setting as can be seen here in a debug transition showing the remote-console-port debugging screen (might need a frame by frame analysis):

browser.transition.unloading.mp4

Here you can see a single transition:

1. Scene A Blue
2. 1 frame of scene B containing OBS debug screen with 'the tab is inactive' and 4 lines in console
3. transition plays out
4. 6 lines in console (transitionStart + stinger run true) because it triggered stinger()
5. Finally on the last frame of this video it shows:
   'The tab is inactive' with 8 lines in console, 2 extra for the cleanup after transitionStop

Settings for the browser transition:

My dumb suggestion would be to default have the bottom half or right side (position of track matte) set with the color of the track matte (black or for inverted white) so even on refresh or inactivity the default state until the transition loads is always correct.

[Exeldro]

Thank you for the detailed description of the issue, this made it easy to replicate.
I made a fix, can you verify this also fixes it for you?
You can download the test build from the bottom of this page:
https://github.com/exeldro/obs-browser-transition/actions/runs/7556098237

[Wiethoofd]

The first transition directly after launching OBS still flickers or doesn't trigger properly for a newly added stinger, consecutive transitions are fine.

Debug console now also showed a OBS | Browser Source after first load of plugin (and I've seen multiple times where it had a duplicate of the transition source in the CEF debug list, where only 1 was added). It always adds a duplicate when you have the properties open, which I assume is expected so the preview works without disrupting live view, but sometimes creates another OBS | Browser Source and leaves it after closing the properties dialog.