Posts by rpistutters

Huge thanks HiassofT

That's working brilliantly.

fantastic thank you for your time, effort and the feedback provided.

really appreciate it!

this thread looks interesting: LibreELEC Pi4 Refresh-rate problem

will try and test this weekend to see if I can correlate refresh rates to this issue between the two LE versions.

Hello,

I am experiencing artefacts and noise when playing back a range of different HEVC 4K videos. I've been unable to identify what makes one video faulty, while another one is fine.

This only occurs on LibreELEC 9.2.1. When running on LibreELEC 9.2.0 it's fine.

I'm using the Plex addon. The client (RPi4 on LE) is configured to 'direct play' and is marked as 'HEVC' and '4K' capable. The Plex server confirms it's direct playing to the client when I playback.

Sample 10sec clip that exhibits the problem (link should remain valid until May 28th): sample

Some pictures of the issue (taken while playing the sample clip from above) can also be seen at: Imgur: The magic of the Internet

Hope this helps to narrow down what's going on, and thanks for all your works.

EDIT: Resolution has been found! Huge thanks to HiassofT and the RPi devs.

Quote from HiassofT

Good news, RPi devs found the issue and fixed it in the latest firmware. I've just confirmed that the sample plays without artefacts with it.

Please switch to LE 9.2.1 again and run these commands to update to the latest firmware:

Code

mount -o remount,rw /flash
wget -O /flash/start.elf https://github.com/raspberrypi/firmware/raw/a6c9b6b/boot/start4x.elf
wget -O /flash/fixup.dat https://github.com/raspberrypi/firmware/raw/a6c9b6b/boot/fixup4x.dat 

After rebooting the firmware version should be May 22 2020:

Code

xbmc:~ # vcgencmd version
May 22 2020 21:12:25 
Copyright (c) 2012 Broadcom
version 4da3e1264076308eda90652cb98b553ae0586390 (clean) (release) (start_x)

Please also check with your other problematic files that showed artefacts if they are fine, too.

so long,

Hias

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Quote from Da Flex

It's better to create a new thread, instead of permanently kidnapping and updating a solved one.

Fair point. I misread initially when going through this thread, and mistakenly concluded that it was marked as 'resolved' because the author had simply downgraded. I now see that was someone else.

Thank for your suggestion. I will open a new thread now.

EDIT: Pending moderator approval, there is a new thread: Noise / artefacts when playing back 4K HEVC video on RPi4 + LE 9.2.1 (no problems on LE 9.2.0)

Bump as the sample link will only remain active for another 7 days.

sample

Link should be active for 14 days

Not sure how to remove the first phantom link, there was an error with that upload, but the one labelled 'sample' should be fine.

And here's some still images too: Imgur: The magic of the Internet

Thank you for this thread!

I've been experiencing the same issue with some 4K videos. I was trying to narrow it down to what it was, but I couldn't find anything that was obviously different between some videos that did work fine (level 5.0, level 5.1, 10 bit HDR) and those that didn't (level 5.0, level 5.1, 10 bit HDR).

I since stuck the 9.2.0.img.gz into the upgrade folder, rebooted, and now they're all playing fine. I was on 9.2.1 prior to that.

Hoping this gets resolved in 9.2.3!