DVBC issues, artefacts, clicks, stop-and-go stream

[RJ65]

Hi there,

being new here, first a short intro: my goal on the long run is to switch to an "integrated" full solution like e.g. Kodi and build a special skin to support all my specific needs and hardware (beamer, motorized screen, lights, etc.). The basic requirements are quite limited: must-haves are music, slideshow and live TV from cable. The rest, like recorded videos, Netflix and DVD are nice-to-have goodies, if somehow possible. Low resolution, 1024 x 768 native on the beamer, and stereo 2.1 sound only - so there is no need for anything "fancy" like 4k, HD, Surround, etc.

I am currently evaluating NextPVR to use with Kodi for DVBC reception. Generally I am impressed about the ease of use and installation (also when compared to other competitors I have checked until now), also your software seems to be unusually stable, so Kudos for the fine work done here!

Just two installation hints for other newbies, this information may come in useful to others:

1. During the installation I have encountered some issues about transcoders blocking and breaking up the initialization, but after having consulted many forum entries and looking in detail into the logs, it appeared to be rather user/rights related problems, possibly when trying to access the temporary folders for recording/timeshift. At the end reinstalling the software from scratch with administrator elevation seems to have solved those problems and finally I could setup the channels.
   
2. Next problem turned out to be Firefow related - looks like the browser disallows media autoplay by default, so the web frontend refused to work. Having found the well hidden setting in Firefox resolved also this problem.
   

...BUT, now to the "real" issue where I could not find any helpful hints yet:

• When using the Web Frontend, the streams are not perfect, but quite OK, I have some audio disturbances or rarely some artefacts in the video popping up, but the live TV experience is quite "fluid".
  
• In the Desktop Client, the situation is getting definitely worse and the streams are heavily disturbed (compression artefacts all over the screen, stop and go, sound with cracking and clicks).
  
• Using Kodi with the addon is similar or maybe even worse.
  

CPU is in average around 8-12% when streaming live TV, also RAM is still plenty available - so I hope not having hit the capabilities of the hardware available. 

I am well aware that I use a rather old PC as Media Center (Intel i3-3110M CPU 2.40 GHz, 4GB RAM and only an onboard Intel HD 4000, Windows 10), but the very same PC worked fluently and flawlessly for many years by now using the same tuner hardware (Elgato EyeTV Hybrid DVBC/DVBT with BDA drivers). All drivers are up-to-date (as far as possible with such old components), the hardware works with other software, also the recognition, channel scan and EPG load worked in NextPVR like a breeze.

Tried to reinstall all codecs (K-Lite Standard, all settings at default), also tried to change from the Microsoft codecs to LAV Filter (where I had good experiences in the past) only, but all in vain. Looked into the Codec settings also, but having been completely at a loss there, preferred to cancel the dialogue without changing anything there :-D

Any hints or ideas what or where I could tweak? 

Thank you very much, cheerio, R. from Vienna, Austria.

[mvallevand]

The web player transcodes files so it might fix bad quality recordings. NextPVR.exe and Kodi use direct play so if the source file is bad you will see penalization. If you post an external link to a recording we can confirm that. Also please upload the zipped logs as explained on the wiki https://github.com/sub3/NextPVR/wiki/get-help

If you install LAV makes sure you install the 32 bit version, the client is still 32bit.

Martin

[RJ65]

Hi Martin, thank you for the quick reply, an impressive reaction time indeed!

I try to attach the fresh logs as requested - hope that works.

I did some quick test runs with roughly these times (my local time is GMT+2 if this makes any difference):

15:22:00 Web Viewer started live TV - BTW, my first assessment was wrong, it seems to have the artefacts also in the web viewer :-(
15:25:00 NextPVR Desktop - started live TV
15:26:00 NextPVR Desktop quick record - uploaded to OneDrive
15:29:00 Kodi record - uploaded to OneDrive

Sample recordings should be available in OneDrive @ https://1drv.ms/f/s!Ajz9MK4x8DehgvkeXJw-...w?e=CF8zCo
Bear with me if I did not manage this right in the first run - honestly, I am not often sharing stuff over OneDrive

Thank you for your support, cheers, R.

PS: oh yes, I was aware of the 32bit restriction, thanks. I had an older 32bit Mega version of K-Lite on the machine, today replaced it with a fresh 32bit K-Lite Standard

PS2: checked the grabbed videos on another PC where I have no media playback issues - the differences are like I have seen on the original PC: webinterface is the best but still has some issues. When using NextPVR.exe it is getting worse. The last recording through Kodi seems to be the worst one (although as far as I understand this records the same way via NextPVR server...?) All recordings from the same channel within a few minutes - HD Cable channel from our main local broadcaster. Monitored CPU on the machine while recording - did not exceed 12% anytime.

[mvallevand]

Do you use a powered cable splitter? Your signal could be too high.

Martin

[sub]

Sample recordings should be available in OneDrive @ https://1drv.ms/f/s!Ajz9MK4x8DehgvkeXJw-...w?e=CF8zCo
Bear with me if I did not manage this right in the first run - honestly, I am not often sharing stuff over OneDrive

I took a quick look at your files. They're full of continuity errors indicating missing packets that were not received, and also some TEI errors indicating damaged packets.

Ultimately these are (almost certainly) reception issues, with less than ideal signal. Changing decoders or NextPVR settings etc really won't help much. To fix this, you'll need to work out what is going wrong with your signal and resolve that. For NextPVR to give you smooth video, it really needs to receive a nearly perfect stream from the tuner. Currently your stream is missing big chucks of data.

The only other (less likely) possibility, is that your machine is not keeping up. Make sure your CPU and disk access aren't maxed out when you're trying to receive these channels. (I'm leaning strongly toward signal rather machine not keeping up, because you wouldn't get TEI errors if the machine isn't keeping up)

[RJ65]

Ouch, I kind of feared to get an answer like this.

No power splitter that I am aware of - but who knows what the cable provider has put into the chain somewhere. I'd rather assume the signal is too low or simply bad quality, the settop box also has sometimes issues with that. Over 40 years old analogue antenna cables, that nobody ever cared to renew. Up to the property high quality fiber net, the last 50 yards is just bad luck. In the last years the cable provider and the property manager keep fingerpointing at each other without doing anything, so the "usual" situation where the customer either gets lost or lets the whole thing reinstalled at own costs.

My gut feeling agrees with your estimation: the hardware is old, but I did not see any bottlenecks, I have checked the CPU, memory and also the drive activities without seeing any alarming peaks. Also tried to change the recording/timeshift folder to SSD hoping it might help, but it did not improve anything.

Maybe a last try: is there any tool available that you can recommend to check/monitor/measure/capture signal quality?

Likely I will need to look into some other alternatives instead of DVB-C then, like some reliable streaming, IPTV or similar. I hoped to get the tuner running, because private hardware in the cupboard is normally more reliable and not continuously tampered with, like streaming providers tend to do - I know this part of the sad theater from Netflix and Co, where nothing works longer than two-three weeks without the need to tweak again...

Cheerio and many thanks again to both of you for your quick efforts, R.

[mvallevand]

I mentioned the powered splitter because your signal report high numbers, albeit that could be a driver issue. Try removing splitters if you can. Also if your TV supports DVB-C and it works then maybe a better DVB-C stick or tuner could help.

Subscription IPTV quality does vary a lot by provider or maybe better said by reseller since it is kind of pyramid system. We have many posts from users with bad providers so yes a good tuner is more reliable when it work. Not being able to open discuss

I don't have fiber to the home either (FTTH) or even fiber to the neighborhood but so far my 1.5 Gb is very reliable. I know the theory say fiber is better but here in Canada the main FTTH provider doesn't even provide ipv6 so I am happy with cable.

Martin