Posts by smp

RAM/GPU overclocking should help as well. Push it as far as possible.

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Can you point sakos at your build to see if it helps his issue too?

Dropbox - Link not found

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Which kernel does your custom build use?

4.8.13

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I can't think of a reason why an older kernel would work better, but if it does I'd like to know why.

I'd like to know this myself. I noticed the inferior performance of kernel 4.9 back in December with Milhouse build #1215. The issue is easy to reproduce as long as you have a DVB tuner connected to the Pi and PVR server/client are on the same Pi. The difference in performance is huge, with kernel 4.8 I can run this setup without a single issue (with Advanced deinterlacing enabled). With kernel 4.9 I absolutely have to disable Advanced deinterlacing (even increasing arm_uc doesn't help).

I also tested Milhouse's kernel 4.10-RC builds and they are just as bad as 4.9.x.

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- "vcgencmd arbiter set arm_uc 12 0" command improves the behavior but it is still present. Shall I try with other parameters?

No, other parameters will not improve anything.
With the latest LE builds that use Linux kernel 4.9.x - "arm_uc 12 0" will not fix those errors.
Use an older, pre-kernel 4.9 build (or my custom 7.95.2 build) + "arm_uc 12 0" and the errors should be gone.

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- "Switch from Advanced deinterlacing to Bob". There are only MMAL BOB and MMAL BOB halved options. By selecting them there is no picture. The configured HW acceleration is OMX and not MMAL. Does it matter?

Always use mmal. Never enable omx except for troubleshooting purposes.

I run VDR on my RPi3 24/7 for months without a reboot. It is rock stable, not a single crash.
Tvh crashes every chance it gets. It would *always* cause Kodi to crash when the signal is poor (e.g. during rain) but sometimes it crash for no apparent reason. I actually thought it was a Kodi issue until I switched to VDR.
The only nice thing about Tvh is it's web interface.

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I still see some sporadic artefacts while watching TV but the recorded streams are perfect.

Try to switch from Advanced to Bob deinterlacing. Advanced is using a lot of RAM bandwidth and it may cause issues (especially on HD channels) when both PVR client and server are on the same Pi.
Also, increasing "arm_uc" value should help a lot with sporadic artefacts. The default value is "10 0". To check the current value run "vcgencmd arbiter status".
"arm_uc 12 0" works great for me, anything higher will cause HDMI dropouts.
To change it to "12 0" run "vcgencmd arbiter set arm_uc 12 0", you can add it to autostart.sh to make the setting permanent.

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Will you provide one for the final release, too?

Sure.

I assume you're running both Tvheadend server and client on the same Pi.
I had the same issue with my DVBSky s960 + RPi3. Here's how you can fix it:

1) Switch from Advanced deinterlacing to Bob. Advanced deinterlace is using a lot of RAM bandwidth and it may cause issues (especially on HD channels) when both PVR client and server are on the same Pi. This is not the best solution because Advanced looks better than Bob.
2) Increase the "arm_uc" value (I use 12 0). The default value for Pi3 is "10 0". For Pi2 it is probably the same. Run "vcgencmd arbiter status" to check the current value.
To make the new setting permanent add this to autostart.sh file:

vcgencmd arbiter set arm_uc 12 0

^This setting completely fixed the issue for me, I didn't have to disable the Advanced deinterlacing.
RAM overclocking will also help a bit.

Also, see this thread - thread-4235.html
Linux kernel 4.9.x perform poorly on the Pi. The latest LibreELEC builds are based on kernel 4.9.x. Use a build based on pre-4.9 kernel.

I have no such issues here with Samba. Using RPi3, LE 7.95.2. Windows 10 PC as NAS.

No issues here with LE 7.95.3 + VDR + OSCam.

Oops, I forgot that there are other platforms...

Anyway, it's easy to compile it without media_build. Just edit the project options file.

Try my custom build that I posted here. I compiled it without media_build.

The multi-coloured-square at boot is a GPU test.

I could be mistaken but the green LED is disabled intentionally on release and release candidate builds.

Maybe a media_build issue? 7.90.010 didn't include it.

Doesn't Germany use HEVC for DVB-T2?

I decided to take the issue into my own hands and compiled a build using LE v.7.95.2 sources and linux kernel 4.8.13. As I expected this completely fixed the video corruption issue. IMO linux kernels 4.9.x/4.10.x are putting much more strain on low performance device such as RPi3.

If anyone wants to check out my custom build for RPi2/3 here's the link. I tested it for a few hours and it works great.

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No, this time deinterlace doesn't make much difference.
When back in summer I reported a similar issue there were 2 ways to fix it:
1) By switching from Advanced deinterlacing to Bob.
2) By raising "vcgencmd arbiter set arm_uc". Setting it to "12 0" completely fixed the issue.

Since the very first kernel 4.9 based build the video corruption dramatically increased with no apparent way fo fix it.