large numbers of artifacts in recordings since upgrade to 3.5.7

[TimB]

Hi,
I have recently upgraded to 3.5.7 (and installed the recommended codex pack) and now get lots of artifacts in my recordings- everything worked fine before. People turn blockly and blocky ghosts appear when the scene changes rapidly. Watching files within NPVR is so bad I have had to resort to other players (such as VLC). These display the corruption, but carry on going.
I have looked for any settings to change recording settings, but there do not seem to be any, so I am at a bit of a loss. While recording the processor is not maxed out or anything, according to task manager

My system: AMD Athlon Dual Core 5050e 2.60GHz, running windows 7 home premium, 4GB of RAM
recording hardware (as reported by NPVR): Hauppage WinTV MOD7700 DVB-T dual tuner card, REALTEK 2831U_BDA (a cheap USB tuner)
I have attached the logs.

Anyone have any ideas what can have happened?

Thanks,
Tim

[sub]

Given lack of other reports of the same problem, I'm inclined to believe it's probably related to your signal, and probably just coincidental that it happened around the time you upgraded to 3.5.7. (other things to check would be heavily fragmented disk, or high amounts of CPU being used by other things running at the time)

I'm not sure if this is one of the devices supported by the Hauppauge Signal Monitor, but if it is, it'd be worth trying this while recording. It'll show you whether you're getting acceptable signal, and how many errors are occurring.

Regarding the playback in NextPVR vs VLC, you'll find your choice of decoders will be the major factor. Different decoder cope differently when they encounter broken packets. Some just don't display broken frames. Some try, and show partial frame plus garbage. Some lockup.

[TimB]

Thanks for the quick reply and suggestions. Hmmm, my disk is not fragmented, CPU use is below 40%, RAM use 2.4GB, however Hauppauge signal monitor does work (even though I had never heard of it before!) and it reports about 10 correctable errors and between 5 and 20 uncorrectable errors, so signal looks like it might be the problem- I guess you are right that it is just a co-incidence on timing. Well that sucks.

Is it possible to use different decoders within NPVR, so I can make the best of a bad situation?

[sub]

Is it possible to use different decoders within NPVR, so I can make the best of a bad situation?

Yeah, sure - you choose what decoders get used. You can select them on Settings->Decoders screen.

[gEd]

Hi and welcome to the community.

your ndigitalhost log files have a huge number of "EPG event" related entries. This is a bit of a punt but I am wondering if all this logging might be affecting your disk i.o

2015-10-18 03:22:03.405 [DEBUG][21] Got 9 EPG Events
2015-10-18 03:22:03.709 [DEBUG][21] Got 2 EPG Events
2015-10-18 03:22:04.012 [DEBUG][21] Got 6 EPG Events
2015-10-18 03:22:04.314 [DEBUG][21] Got 3 EPG Events
2015-10-18 03:22:04.615 [DEBUG][21] Got 8 EPG Events
2015-10-18 03:22:04.917 [DEBUG][21] Got 8 EPG Events
2015-10-18 03:22:05.221 [DEBUG][21] Got 7 EPG Events
2015-10-18 03:22:05.525 [DEBUG][21] Got 10 EPG Events
2015-10-18 03:22:05.828 [DEBUG][21] No additional EPG events available
2015-10-18 03:22:06.132 [DEBUG][21] Got 3 EPG Events
2015-10-18 03:22:06.434 [DEBUG][21] No additional EPG events available
2015-10-18 03:22:06.735 [DEBUG][21] Got 1 EPG Events
2015-10-18 03:22:07.037 [DEBUG][21] Got 8 EPG Events
2015-10-18 03:22:07.341 [DEBUG][21] Got 22 EPG Events
2015-10-18 03:22:07.648 [DEBUG][21] Got 20 EPG Events
2015-10-18 03:22:07.956 [DEBUG][21] Got 3 EPG Events
2015-10-18 03:22:08.257 [DEBUG][21] Got 3 EPG Events

2015-10-16 21:43:23.025 [DEBUG][8] No additional EPG events available
2015-10-16 21:43:23.362 [DEBUG][8] No additional EPG events available
2015-10-16 21:43:23.662 [DEBUG][8] No additional EPG events available
2015-10-16 21:43:23.962 [DEBUG][8] No additional EPG events available
2015-10-16 21:43:24.262 [DEBUG][8] No additional EPG events available
2015-10-16 21:43:24.562 [DEBUG][8] No additional EPG events available
2015-10-16 21:43:24.862 [DEBUG][8] No additional EPG events available
2015-10-16 21:43:25.162 [DEBUG][8] No additional EPG events available
2015-10-16 21:43:25.462 [DEBUG][8] No additional EPG events available
2015-10-16 21:43:25.762 [DEBUG][8] No additional EPG events available
2015-10-16 21:43:26.062 [DEBUG][8] No additional EPG events available
2015-10-16 21:43:26.362 [DEBUG][8] No additional EPG events available

I would recommend that you change logging level down to INFO, restart the recording service and re-test.
To do this, you need to edit config.xml in notepad and change
<LogLevel>DEBUG</LogLevel>
to
<LogLevel>INFO</LogLevel>

Also, just make sure you don't have "Update DVD EPG during live TV" enabled in misc tab (it causes problems)

[Handy.Man]

...however Hauppauge signal monitor does work (even though I had never heard of it before!) and it reports about 10 correctable errors and between 5 and 20 uncorrectable errors, so signal looks like it might be the problem- I guess you are right that it is just a co-incidence on timing. Well that sucks. ...

Check or change the cable or splitter connetced to the tuners.

[TimB]

Thanks all, I have now removed a splitter connected to the tuner and this had nearly entirely solved my problem- uncorrectable errors are gone, hurray!

[gEd]

Yeh splitters are troublesome, I spent quite a while sorting out my aerial cabling. The signal is very weak and needs good cables and connectors and as few of the later as possible.

[Handy.Man]

I use a cable booster with a 3 ft cable to the antenna.

But cables also are tricky, you bend or move them and they loose signal strength, many of them went direct to the trash can.

[ACTCMS]

Working on the principle that that no amplifier is going to improve a bad signal, I bit the bullet a few years ago and had a new aerial installed which I then connected to an eight-way powered splitter in the loft. I didn't have to renew any of my existing co-ax cable throughout the house - I just renewed the cable connectors on any which still didn't give a good signal.

Alex