Thanks for this, I noticed the little black bars left and right on 25fps material and managed to fix this using this.
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:
Just registered to say thanks for this fix! Finally got my 25fps video's running smooth on the Intel NUC 2820. Seems my tv doesn't support 25fps but it does support 50 so LibreElec picks 50 for 25fps material.