4K video issue on iPhone 5S and iPad Air 2

[Mikhail Kolesov]

Hello,
I have an issue with a large mp4 video (4K) captured by Go Pro. At launching, I can see first frame of video. After that video stuck and I can hear only audio.
Here is a debug log of Dropin-Player example app https://www.dropbox.com/s/5bqjy7ez7gwfm ... s.txt?dl=0
Here is a mediainfo info about 4K mp4 file https://www.dropbox.com/s/0306gy3uo6v1d ... o.txt?dl=0
Here is the video file (450MB, 1 min long) https://www.dropbox.com/s/lk8gutij4gbnj ... o.mp4?dl=0

At first I noticed this issue with my custom build of MobileVLCKit (3.1.4) on iPhone 5S (iOS 10.3) and iPad Air 2 (iOS 11.4). But later I checked with AppStore VLC for iOS(3.1.0) and it reproduced on the stock app as well.
For reproduction you need to copy video file using File Sharing in iTunes and open in VLC app on iPhone 5S or iPad Air 2 or (I guess) simular HW devices.

It looks like a regression issue. I had checked the same video with a half year ago VLC[Kit] (at the start of January 2018) and it was fine for same devices (OS version).
Also it looks like closer to a hardware related issue since it happened on iOS 10 and 11 but with simular HW (just an idea).

Regards,
Mikhail Kolesov

[tguillem]

Hello,

The profile of this video is too high for old devices: 51 (0x33).
It may work on old devices but it's not officially supported. We can't really enable it since it may cause more HW decoder crashes.

If you want to force it on your own build, you can modify the deviceSupportsAdvancedLevels() function in videotoolbox.m and always return YES.

[Mikhail Kolesov]

Thank you.It helped forcing deviceSupportsAdvancedLevels() to return YES.
It looks like it works fine. How is "HW decoder crash" looks like? Is it a crash at app side? Or is it a system wide decoder daimon(?) crash?
I mean how did you notice that?