Stuttering Video on Raspi 4 with TvHeadend

1st Official Post

    Hi All

    I am running a TV-Headend Server on a Synology Box to feed several devices in my home.

    Lately I did an upgrade to Raspi 4 on a TV. Installation is Ok, the Raspi is capable of running up to 4k Video; BUT:

    SD-Video from TV-Headend has major problems, The picture is stuttering and lagging behind the Audio Stream.

    As TV-Headend was working perfectly on all other Devices (Android, Windows, Odroid/Librelec 8 ) It surely did look like a Codec Problem on the Raspi for me...

    So I checked the Raspi Homepage for the MPEG-1 Codec; not available anymore for Raspi 4.

    I think the Raspi 4 does have enough Power to decode MPEG-1 in Software, So maybe somebody knows a Workaround or can implement a permanent solution.

    OR, if a am totally wrong, maybe somebody can tell what the real problem is and how to fix it :)

    CU Frank

    Edited 2 times, last by fzwo (June 6, 2020 at 1:56 PM).

    Did you try to change Deinterlacing settings?I have to do that on all my HD streams..tough not on SD..just try.

    Hi, found the solution, after changing everything from Network Cable to MicroSD.

    Libreelec on Raspi 4 is not able to upscale SD-Television to 4k Screen resolution.

    If you reduce the Screen resolution, the stuttering and delay stops.

    Fun fact, I had to go down to 720p and then could go up to 1080p; simply downgrading to 1080p was not successful.

    Result: You have to decide currently which is more needed; SD-Television or 4k Videos. Upgrading to as Raspberry Pi for 4k reasons does not make Sense as long as You are watching SD-Television. Also 720p-TV, (Standard for german public HD-TV) shows some minor glitches

    CU Frank

    P.S. Initial Testing was done with 9.2.1; 9,2,3 was reacting exactly the same..

    • Official Post

    Recommentded settings for RPi4 devices are 1080@60 desktop resolution and [email protected]/24/50/59.95/60 and [email protected]/24/25/29.97/30 modes whitelisted. This ensures SD content is scaled to 1080p max and only 4K content is played at 4K, and we scale 720p skins to 1080p (which still ooks good) and leave scaling the 1080p GUI firther (to 4K) to the TV which does a better job than Kodi on any ARM hardware device. Almost nobody needs 4K60 modes as very little content exists in that format, so there's no real-world need to force that in config.txt (hence it is not our default). In some cases the best option is to revert Kodi to defaults again and resist the urge to fiddle with things that don't really need fiddling with :)

    Hi Thanks for the hints, but to my Understanding I was doing neither nor.

    I kept the Kodi resolution to 1080p, as I know, that this might improve the performance of the Interface itself. The only thing I did was to increase the screen resolution to 3840x2160. This is even possible in Standard Mode of Settings.

    How to whitelist Videomodes, I have not the slightest clue.

    Maybe it would be good to add these settings already in the installation package so everybody who makes a plain install like me is benefitting from them ?!?

    Edited once, last by fzwo (June 10, 2020 at 1:34 PM).

    • Official Post

    The skin might be at 1080p but you set the Desktop to 4K and the whitelist is not used so everything will be scaled to 4K. In other words, roughly the opposite of what I described. Kodi has to work on everything from Android phones to small embedded ARM boards, to high-end Intel chips. Hence it deliberately starts with neutral defaults.

    Please take some time to read the Kodi manual Official Kodi Wiki

    Thanks for the hint

    Instead of browsing through the Kodi Wiki, I tried installing Coreelec on my 4 Years old Odroid2.

    Surprisingly it was able to run both 4k Video and SD-Television with the 3840x2160 resolution selected.

    So I leave Libreelec for now and hope for a similar functionality in the future

    Thanks again and hopefully until the near future

    Frank

    • Official Post

    FYI, Amlogic fakes "4K" desktop in their 3.14 BSP kernel because the HDMI chip can output 4K resolution but only on the video plane. The OSD plane that renders the Kodi GUI cannot do more than 1080p. RPi4 can at least render the GUI at 4K, but it will suck at it, and (again) you're better off running the GUI at 1080p and allowing the TV to upscale to 4K (as Amlogic does) .. it will do a better job.