Occassional caching and buffering, Pi4, 1080p source, 1080p output, 1Gbit ethernet, confused.

  • Does anyone smart people have any idea how to identify the cause?


    I have mounted a folder on my NAS and copied 300MB of files on to the /tmp directory. It did it in under 10 seconds, easily 30MB/s

    I also copied back at the same speed.


    The file which caused it this time is the following: (it's not even 265! it's 264)

    2flZtng.png

    (10.8GB, 95 minutes, approximately 113MB per minute or as little as 2MBytes per second needed!)

    I'm also a lowly 1080p user, 1080p files, 1080p television so I dunno!




    Here is some random pics of top while it's playing back:

    GdrTFgK.png

    bu72WFa.png

    JP5ITh8.png




    So I'm not sure what the problem is, it's very random!

    I use subtitles always, not hardcoded, so I guess that might introduce a small amount of processing.

    This problem is wildly random by the way.


    I will consider loading files to USB stick and testing but the problem is, you can watch a movie or tv show for 20+ minutes before it does it. (so this is particularly awkward to do!)



    Anyone got some tips? I mean maybe it's just my NAS being busy at the time but I don't think it is (I've tried reducing that and SURELY video playback doesn't need more than 5 or 10MB/s)

    Can I incease the network buffer significantly? I have a 4GB Pi, happy to blow 500MB memory on it!


    Thank you all.


    One more thing for the super smart folks who actually make LibreElec (??) is there a way to LOG 'caching events' somehow? So I can play a video back, walk away and check the log, so I don't have to watch the thing, to know if it occurred? It would help a lot.

    Edited 2 times, last by FeFiFoFum: Merged a post created by FeFiFoFum into this post. ().

  • Final pics - I feel like it's the Pi - or my config, not the network, not the NAS - but would love the smarter people to help :( (Chewitt?)


    Note the processor usage on a Pi3B+

    4vk3bmh.png



    vs a Pi 4

    Ww1BCUM.png



    I gotta fix this, it's taken years of work to make the wife not hate Kodi!! :)


    This is in the kodi.log file for the Pi4







    and here's the Pi3 for the same duration





    Apologies for the bombardment of information, hopefully the super smart people can make sense of it!.

    Edited once, last by FeFiFoFum: Merged a post created by FeFiFoFum into this post. ().

  • So I've tested again


    "CRenderManager::WaitForBuffer - timeout waiting for buffer"

    This occurs a total of 18 times, on RPi3b+ playing back file.

    It occurs in excess of 200 times, on RPi4, same file



    Also lots of

    "NOTICE: CVideoPlayerAudio::Process - stream stalled"

    (only on Pi4, *none* on Pi3B+)



    Furthermore

    "CMMALVideo::GetPicture - ret(0) pics(0) inputs(0) slept(500) queued(0.21) (982.56:982.36) full(0) flags(0) preroll(0) eos(0 2>"

    (only on Pi4, *none* on Pi3B+)



    Finally

    "WARNING: ActiveAE - large audio sync error: -89435.153837"

    (only on Pi4, *none* on Pi3B+)

  • What do the below commands tell you? You have H264 enabled? How much memory do you have allocated to the GPU (second command)?


    v4l2-ctl -d 10 --list-formats-out

    vcgencmd get_mem gpu

    • Official Post

    I see mention of MMAL so this must be LE 9.2. Go test LE10. Kodi 19 includes lots of feature/bug fixes, and RPi has an entirely different kernel driver stack. From our side of the fence there is no point (and thus not much interest) in investigating issues on LE 9.2 .. it's an effectively dead codebase now.

  • What do the below commands tell you? You have H264 enabled? How much memory do you have allocated to the GPU (second command)?


    v4l2-ctl -d 10 --list-formats-out

    vcgencmd get_mem gpu


    Did this - thank you!





    GPU = 320M (it's a 4GB, Pi4)


    I see mention of MMAL so this must be LE 9.2. Go test LE10. Kodi 19 includes lots of feature/bug fixes, and RPi has an entirely different kernel driver stack. From our side of the fence there is no point (and thus not much interest) in investigating issues on LE 9.2 .. it's an effectively dead codebase now.


    Sure but I (think) this used to be fine for me and I don't want to use LE10 for a very long time. I use the Aura Skin on Kodi and love the hell out of it, I need that skin fully functioning.


    Besides, a Pi3B+ is beating a Pi4, I'm pretty sure this is, somehow, my fault.

    Tonight, I build a perfectly fresh, 0 addons, raw Pi4 with stock 9.2.7 and attempt to play back the same file again.


    Also of note, in case this helps - the only difference I can think of, from my Pi3 to my Pi4 is the Pi4 is forcing display refresh rate to match video? Maybe that?

    Edited once, last by FeFiFoFum: Merged a post created by FeFiFoFum into this post. ().

  • Well that's a good start!

    Let me check what I'm currently using, which is critical to me.


    Critical:

    Opensubtitles

    LibreElec VNC (Tiger?)

    Library, auto update



    Not critical, wanted:

    Trakt

    Picture Slideshow Screensaver


    That being said, I can't recall my previous favourite skin, but I distinctly recall, it worked on Kodi 15, when they released it for 16 or 17 or whatever, despite the same name, it was vastly inferior :( I'd hope Aura is near identical.


    .


    .


    .


    I also didn't get time last night to re-cook an SD card and try a raw, fresh Pi4 9.2.7 build, with no addons just to see if that addressed the issue, so I will try that in the next 48 hours to see if this is a fundamental issue with 9.2 that I haven't noticed before or if it's just me 'breaking' something on my setup.

    Edited once, last by FeFiFoFum: Merged a post created by FeFiFoFum into this post. ().

  • Your GPU and video outputs look good. If you have a spare microSD card, I would try a LibreElec 10 test build and see if you are seeing the same issue. I suspect your Pi4 needs a kernel from 10 where as your 3+ needs one from 9.2.7.

  • I've done a 9.2.7 build now - I'll be able to test tomorrow morning.

    Thank you - I'll also try 10, too.


    P.S I assume the logs I provided indicate the install is ok?

  • I ran a fresh build of 9.2.7 and noticed no errors in the log, playing back the incriminating file on the Pi4.


    I am now running it on my old install, with MANY addons disabled.


    Getting this one only as a fault.


    2021-07-07 09:48:55.192 T:2433688432 WARNING: CMMALVideo::GetPicture - ret(0) pics(0) inputs(0) slept(500) queued(0.33) (484.44:484.11) full(0) flag>

    2021-07-07 09:48:57.851 T:2433688432 WARNING: Previous line repeats 4 times.