Problems playing webm files

When I try to play a bunch of webm files (per videos-archives-select a directory-Play) sequentally, some files don´t play (a screen of rubbish rainbow lines appears) and I have to reboot.
Any ideas? Bad video codec?
The directory plays well on Kodi pc brand and also on Kodi Ipad installation

Well to judge that you should tell us which codec they are.
It would be good if we could find out more about the file you are having issues playing. Please see the ‘Playback related issues: using MediaInfo’ section in this Wiki resource for further help https://osmc.tv/wiki/general/how-to-submit-a-useful-support-request

And logs in general help us to help you.

Webms typically use vp8 video. This codec cannot be decoded in hardware on a raspberry pi.
When the pi has to decode the stream in software, it will be pushed very hard if the resolution is too high.

I am seeing this issue as well. When playing the webm video the screen displays static multicolored lines covering the whole screen, and it is not possible to get the UI back.
SSH works without problem, and there is no CPU load. The only way to get the UI to work again is to reboot.

The problem is 100% reproducible with e.g.:
http://cdn.media.ccc.de/congress/2016/webm-hd/33c3-8167-eng-deu-Everything_you_always_wanted_to_know_about_Certificate_Transparency_webm-hd.webm

The video is valid when playing it on an Ubuntu desktop.

Movie name : Everything you always wanted to know about Certificate Transparency
Writing application : Lavf56.40.101
Writing library : Lavf56.40.101

Video
ID : 1
Format : VP8
Codec ID : V_VP8

I understand that this codec cannot be decoded on the GPU.

I would expect the playback to be choppy with many dropped frames when decoding on the CPU, but I do not expect the UI to stop functioning all together and only show screen artifacts reminiscent of the c64 loading screen.

To me it looks looks like the graphics stack crashes somewhere. I do not see anything interesting in dmesg relating to playback of the video.

Some other notes:

  1. I seem to be wrong about it being 100% reproducible, the link i gave sometimes works. I have more luck reproducing the problem with this link:
    http://cdn.media.ccc.de/congress/2016/webm-hd/33c3-8315-eng-deu-A_world_without_blockchain_webm-hd.webm
  2. Audio playback continues without a hitch
  3. The CPU is not under load (16%)

Kodi log looks sane…:
22:29:57 106.679771 T:1956643760 WARNING: CDVDMessageQueue(player)::Put MSGQ_NOT_INITIALIZED
22:29:57 106.680992 T:1557132272 NOTICE: Creating InputStream
22:29:57 106.683624 T:1557132272 NOTICE: Creating Demuxer
22:29:57 106.721611 T:1557132272 NOTICE: Opening stream: 0 source: 256
22:29:58 106.727989 T:1557132272 NOTICE: Creating video codec with codec id: 141
22:29:58 106.737511 T:1557132272 NOTICE: Creating video thread
22:29:58 106.737679 T:1557132272 NOTICE: Opening stream: 1 source: 256
22:29:58 106.737740 T:1557132272 NOTICE: Finding audio codec for: 86021
22:29:58 106.737846 T:1548743664 NOTICE: running thread: video_thread
22:29:58 106.741295 T:1557132272 NOTICE: Creating audio thread
22:29:58 106.741562 T:1661727728 NOTICE: running thread: CDVDPlayerAudio::Process()
22:29:58 106.750618 T:1661727728 NOTICE: Creating audio stream (codec id: 86021, channels: 1, sample rate: 48000, no pass-through)
22:29:58 106.751053 T:1661727728 NOTICE: CDVDPlayerAudio::OutputPacket duplicate 8 packets of duration 12
22:29:58 106.894493 T:1661727728 NOTICE: CDVDPlayerAudio::OutputPacket duplicate 4 packets of duration 21
22:29:58 106.944031 T:1661727728 NOTICE: Previous line repeats 1 times.
22:29:58 106.944130 T:1661727728 NOTICE: CDVDPlayerAudio::OutputPacket skipping a packets of duration 12
22:29:58 106.944267 T:1661727728 NOTICE: CDVDPlayerAudio::OutputPacket skipping a packets of duration 2
22:29:58 106.944954 T:1661727728 NOTICE: Previous line repeats 6 times.
22:29:58 106.944992 T:1661727728 NOTICE: CDVDPlayerAudio::OutputPacket skipping a packets of duration 12
22:29:58 106.945175 T:1661727728 NOTICE: CDVDPlayerAudio::OutputPacket skipping a packets of duration 21
22:29:58 106.945297 T:1661727728 NOTICE: CDVDPlayerAudio::OutputPacket skipping a packets of duration 12
22:29:58 107.014839 T:1523577840 ERROR: CWebServer: failed to handle HTTP request for /image/
22:29:58 107.414696 T:1548743664 NOTICE: fps: 25.000000, pwidth: 1920, pheight: 1080, dwidth: 1920, dheight: 1080
22:29:58 107.414963 T:1548743664 NOTICE: Display resolution DESKTOP : 1360x768 (1360x768) @ 60.00 - Full Screen (16)
22:30:00 109.598747 T:1956643760 NOTICE: CDVDPlayer::CloseFile()
22:30:00 109.598938 T:1956643760 NOTICE: DVDPlayer: waiting for threads to exit
22:30:00 109.605545 T:1557132272 NOTICE: CDVDPlayer::OnExit()
22:30:00 109.605690 T:1557132272 NOTICE: Closing stream player 1
22:30:00 109.605774 T:1557132272 NOTICE: Waiting for audio thread to exit
22:30:00 109.638626 T:1661727728 NOTICE: thread end: CDVDPlayerAudio::OnExit()
22:30:00 109.638847 T:1557132272 NOTICE: Closing audio device
22:30:00 109.691025 T:1557132272 NOTICE: Deleting audio codec
22:30:00 109.691254 T:1557132272 NOTICE: Closing stream player 2
22:30:00 109.691307 T:1557132272 NOTICE: waiting for video thread to exit
22:30:01 109.728653 T:1548743664 NOTICE: thread end: video_thread
22:30:01 109.729591 T:1557132272 NOTICE: deleting video codec