Libreelec 9 on Raspberry Pi3 B+ skipping frame

1st Official Post
    • Official Post

    One line of text. That's the best you can do?

    Please provide a full debug log.

    How to post a log (wiki)

    1. Enable debugging in Settings>System Settings>Logging
    2. Restart Kodi
    3. Replicate the problem
    4. Generate a log URL (do not post/upload logs to the forum)

    use "Settings > LibreELEC > System > Paste system logs" or run "pastekodi" over SSH, then post the URL link

    Hello,

    I'm taking the opportunity to post my logs in this thread instead of opening a new one.

    I get the same thing, but on a Pi 2 once I upgraded to 9.0.0.

    Happens while playing Mpeg2-TS via TVHeadEnd PVR Plugin

    v8.2.5 Worked perfectly with the same settings

    (Vanilla install, PVR Plugin added + MYSQL/MariaDB Advanced config)

    http://ix.io/1ajd

    I am running LibreElec 9.0 on a 3B+ using the unofficial SiliconDust PVR software with SiliconDust Quatro tuners and not having any frame skipping issues. These are MPEG-2 12mbps streams. Do you have the MPEG-2 decoder license on your Pi and have you looked at the CPU utilization when playing the MPEG2 streams ? I have the MPEG2 license on mine and CPU utilization is 12-14% with 1080P 12mbps live streams.

    Edited once, last by jbinkley60 (February 8, 2019 at 12:48 AM).

    Yes, I do have the MPEG2 License, and running vcgencmd codec_enabled mpg2 shows it is still enabled after the upgrade.

    From memory, CPU utilization wasn't over 15%... but I will recheck tonight to be sure.

    Other thing I might try is playing with the Network Buffer settings and see if it can improve things a bit.

    Is your connection wireless or wired ? I haven't upgraded my wireless connected Raspberry Pi 3B+ yet to 9.0 . It is still running 8.2.5. My 9.0 Raspberry Pi is on a wired connection. I'll upgrade the wireless one soon.

    Connection is Wired.

    Tried increasing the buffer settings - Same result

    Disabling the HW Acceleration for MMAL loaded all 4 cores to 85-90% (vs 15%). Result is still skipping frames, but less than when it is enabled.

    Enabling HW Acceleration for OMXPlayer is way better at frame skips, but audio can't stay sync'd.

    I suggest you back your settings before the upgrade. Easier to revert after ;)

    I'm concluding my tests with this release... as I just found this is not exclusive to LibreELEC.

    I just tested OSMC with latest nightly and I'm getting exactly the same result. So it must to be something in Kodi 18 (also 18.1RC1) instead.

    I have hardware acceleration disabled in OMXplayer because it interferes with the ability to change playback speed on YouTube. I still get smooth playback of MPEG-2 HD streams from TVheadend on a RPi 3 in LibreELEC 9, regardless of whether the factory MPEG-2 license key is installed. But I run the TVHeadend server on another machine, which could make a difference.

    Quote from jbinkley60

    I am running LibreElec 9.0 on a 3B+ using the unofficial SiliconDust PVR software with SiliconDust Quatro tuners and not having any frame skipping issues.

    Its probably worth pointing out that the SiliconDust PVR client does not have a companion server component which runs on the local network (except what is in the tuner - that does not support PSIP, multicast, or transcoding.) There are pros and cons to this arrangement, but suffice it to say that your CPU load will be lower compared to those who are running a PVR service on same machine as the client.

    Quote from MarioT

    I get the same thing, but on a Pi 2 once I upgraded to 9.0.0. Happens while playing Mpeg2-TS via TVHeadEnd PVR Plugin

    If you can find a build of TVheadend for your router or NAS device, it would be preferable to use that instead of running the server on your media player. (And since the MPEG-2 patent expired, I also think LibreELEC should include the patched GPU firmware that activates hardware acceleration automatically.)

    Update: I was able to reproduce this issue on the old 2-core Play 1. When I move the mouse rapidly, CPU usage nearly doubles. If I continue this for a while, it starts dropping frames and the audio loses sync. After about 10 - 20 seconds, CPU usage returns to normal but sometimes the audio remains silent until the channel is changed. It seems like the video player is running at a lower priority than it should - and if something pushes the CPU to 100%, sometimes it never recovers.

    Code
    WARNING: CRenderManager::WaitForBuffer - timeout waiting for buffer
WARNING: Previous line repeats 16 times.
WARNING: ActiveAE - large audio sync error: -1218.382589
WARNING: ActiveAE - large audio sync error: -1216.828077
WARNING: ActiveAE - large audio sync error: -1217.117625
WARNING: ActiveAE - large audio sync error: -1209.260177

    (repeats)

    Edited 4 times, last by LE23 (February 12, 2019 at 11:57 PM).

    Update: I finally found what's doing it on my setup.

    Video files I'm playing are mostly Mpeg2-TS 1080i

    The default de-interlace setting (Auto) doesn't work properly: skips frames and sound get out-of-sync most of the time.

    Manually trying each setting, I've found that both MMAL - Advanced are doing this, but the 2 MMAL - BOB work perfectly for what I need.

    I've upgraded my wireless connected Raspberry Pi 3B+ and am not seeing any issues with frame skips and similar for live streaming MPEG2 broadcast TV. I have seen the frame skipping audio/video sync issue playing MPEG2 recorded broadcast files especially when fast forwarding or rewinding and having HW decoding enabled. Adjusting the deinterlacing settings has helped but isn't perfect.