Video stutter 25Hz Videoplayback with Hardwaredecoding Libreelec 9.0

SDSD · May 14, 2021 at 9:47 AM

I'm running an old Intel NUC DN2820 with Bay Trail processor and have run into this same frustrating issue with playback - very slight continuous stutter during playback on files requiring upscaling. Would anyone be kind enough to post a step by step guide on creating, saving and running these required bash scripts in order to find out the gpu max frequency, check the frequency during playback and then set the frequency to run at max to achieve the permanent fix please? I don't have any experience with bash scripts or SSH. I've successfully connected to my LibreElec system using ssh in putty after enabling SSH and setting a password inside LibreElec, but now I'm stuck Any help very much appreciated

SDSD · May 16, 2021 at 11:20 AM

I worked this out in the end and can confirm that this fix has resolved my video stutter issues on LibreElec Leia 9.2.6 My max gpu freq was 756. during playback of 720 content on my 1080 display, or any other media requiring upscaling, the gpu freq was dropping and staying at 200. I set the new min freq to be 750 and the stuttering is gone.

evil77 · September 14, 2021 at 1:40 PM

Just wanted to give feedback;

bossanova808s fix did the job on my old Intel NUC DN2820

so big thanks to bossanova808

Quote from bossanova808
Ok, more experimenting...and I think I have beaten it (or more to the point Ross Nicholson has it cracked, here: 111032 – Need to set gt_min_freq_mhz to max value to avoid sync issues on Gemini Lake N5000/J5005)
It seems this is (still) the problem. The GPU clock speed is not scaling up as it should under load.
With a NUC 2820, I added this `autostart.sh` script:
Bash
(
echo 750 > /sys/devices/pci0000:00/0000:00:02.0/drm/card0/gt_min_freq_mhz
) &
nohup script.sh &
The 750 comes from the output of this command (you should check if you have a different NUC)
Bash
cat /sys/bus/pci/devices/0000\:00\:02.0/drm/card0/gt_max_freq_mhz
This results in immediate playback improvement - the stutter is gone from all my 25p stuff.
(I updated the bios to 68, and I am in this test using the 9.2 alpha release but it was only this specific fix that had any impact on the issue).
If I test the GPU (i.e., specifically while playing a hardware decodedc video), with
Bash
cat /sys/bus/pci/devices/0000:00:02.0/drm/card0/gt_cur_freq_mhz
...it now shows 750 during playback (187 during the Kodi GUI still, though, which kinda surprises me but I guess the GPU is idle until playback occurs maybe?)
I shall report back if testing shows any/more issues, but I think that's a solid fix, if anyone is still following along.
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