772 after resuming app ios video displayed black

[BPerlakiH]

Fixes: #772

Note: So far I only found this "hacky" javascript solution to fix this issue.
The traditional "low memory" warning triggers are not called in this case, therefore this black screen side effect is not due to that.
By playing and pausing the video (one after another) fixes this.
The fix is applied if:

• we are not in picture in picture mode - here we do not have this problem
• we are not at the beginning of the video - here we also do not have this problem, plus if we apply it as we come back to the tab., it will change the "poster" of the video to the first frame of the video (which might be black)

[kelson42]

@BPerlakiH Any user visible side effect (beside the fix obviously)?

[BPerlakiH]

User impact: it is not fixing it immediately, there's a slight delay after re-opening the application, so the black screen is visible for a moment, after that it fixes the issue.

[kelson42]

@BPerlakiH There is way to trigger this earlier than ondisplay()? For example when the app gets out of hibernation?

[BPerlakiH]

Actually, I had to wrap the call into a "Task" so it executes slightly later (next run loop), as the "black screen" problem appears somewhat later than "onAppear".

[kelson42]

Hmmm, I guess we can still do better. Video.js has a feature to set a "poster" overlay. Would that not be a solution to capture the frame a put it on the top, so, even if video goes black, this will be hidden in the background. See https://stackoverflow.com/questions/27583937/how-can-i-make-a-css-glass-blur-effect-work-for-an-overlay/27592975#27592975

[BPerlakiH]

Yes, possibly we need further investigation why this is happening in the first place...
We have poster set at the start of the video, maybe we can use something similar.
I did checked the console output, but there are no errors no output whatsoever ever, when the video stops (eg. due to another streaming app).
Maybe there's a way to capture that moment in JS, and then we could do some fallback / overlay solution.

[kelson42]

I'm not very satisfied from current PR. Lets talk about that later this week.

[kelson42]

I'm a bit surprised about this, but it seems there is no way tomdo better. Merging.