HD streams show artefacts

Rainer Dorsch

Hi,

I have a cubox-i with a PCTV 461e (DVB-S2) and openelec 6.0 with tvheadend 4.0.8. When I view a HD stream, it has artefacts (maybe very 10-15 seconds for a short moment).

An example artefact is shown here:

http://netcup.bokomoko.de/~rd/vlcsnap_tvheadend_artefact.png

When I record the stream (w/o viewing it) and view it afterwards the artefacts are there as well. When I view the recorded file with vlc on a PC, the artefacts are there and repro exactly at the same position each time I view it. This implies for me that the recording is alreading broken.

The reported signal quality is 100% or sometimes very close to 100%

Any hint is welcome.

Thanks
Rainer

Rainer Dorsch

I just noticed there is a similar thread here:

http://forum.kodi.tv/showthread.php?tid=220129

Andy Furniss

You could try spinning up you cpu(s) with

nice -19 dd if=/dev/urandom of=/dev/null

If you have multiple cores maybe start more than one.

I have a couple of DVB-T2 PCTV sticks and got some usb/power save/xhci issues on my h/w.

Above would mostly fix. Rather than do that I found that the issue was far less if I disabled USB3 in bios to avoid using the xhci driver.

Of course your issue may be totally different - but it's worth a try.

Your symptoms do point to ts packet loss - which I know from my experience can be at usb level. There are posts on here from the past where people with PCIE cards also had to do similar.

Rainer Dorsch

This did not help.

I found in /storage/.kodi/userdata/addon_data/service.multimedia.tvheadend/service.log these entries:

2016-01-17 22:38:55.142 [WARNING] eit: invalid checksum (len 615, errors 77)
2016-01-17 22:39:27.703 [WARNING] eit: invalid checksum (len 412, errors 78)
2016-01-17 22:39:57.151 [WARNING] eit: invalid checksum (len 684, errors 79)
2016-01-17 22:40:08.199 [WARNING] eit: invalid checksum (len 2355, errors 80)
2016-01-17 22:40:22.070 [WARNING] eit: invalid checksum (len 91, errors 82)
2016-01-17 22:40:50.616 [WARNING] eit: invalid checksum (len 3163, errors 84)

2016-01-17 22:41:09.110 [WARNING] eit: invalid checksum (len 3229, errors 85)

Are they related to the issue I see?

I was searching for continuity error, but did not find them. In which file would they be logged?

Thanks
Rainer