TV Server channel change performance degrading and continuity errors in tswriter (1 Viewer)

[bermag]

TV-Server Version: TVE3 1.0 RC3
MediaPortal Version: 1.0 RC3
MediaPortal Skin: Blue 3
Windows Version: Win XP SP2
CPU Type: AMD AThlon 64 X2 4200+
HDD: Western Digital 200 GB
Memory: 2 GB DDR2
Motherboard: Asus NF8-E
Video Card: Nvidia Geforce 6600LE
Video Card Driver: 6.14.11.6218
Sound Card: Realtek Ac'97
Sound Card AC3:
Sound Card Driver:
1. TV Card: Terratec 2400i
1. TV Card Type: DVB-T (dual)
1. TV Card Driver: 1.0.3.260
2. TV Card:
2. TV Card Type:
2. TV Card Driver:
3. TV Card:
3. TV Card Type:
3. TV Card Driver:
4. TV Card:
4. TV Card Type:
4. TV Card Driver:
MPEG2 Video Codec:
MPEG2 Audio Codec:
h.264 Video Codec:
Satelite/CableTV Provider:
HTPC Case:
Cooling:
Power Supply:
Remote: MCE
TV: Samsung 50c96
TV - HTPC Connection: VGA

I have problem with MP/TV Server sometimes crashing and having other problems. In an attempt trying to test I have been running TvServerStressTest program to test if TV Server alone is crashing or if it is a client problem.

That channel change is getting slower is not the problem but probably the symptom of the problem I guess.

Anway, I first run a test serie of 100 channel changes. All was fine and had an average response time of less than 2sec. Run another test of 500 overnight and noticed at the end some channel changes taking longer time so I started a new batch in the morning. Now I got a response time of 15-20 sec or so. All reported succesful though.

I also started TV Server configuration and when I used manual control to turn on timeshifting it used Tuner 2 even if Tuner 1 has higher priority. Maybe this is an indication of the first tuner card to be in some faulty staty. I disabled Tuner 2 trying to force it to use Tuner 1 but then it failed (got an "unknown error") and could not preview either so I guess this is a good indication that it could not use Tuner 1 at all. Eventually server could not be used at all.

In the tswriter.log you can see there is a bunch of "Continuity errors".

I have attached log but those logs was when problem has already started so you will not see when the problem started.

I am trying to cause it to fail again to have som better logs

 

[bermag]

I was runnign another set of tests and after 186 channel changes problem started. I have the logs from start this time. I think problem started around 20:16 where this pops up in tv.log "Controller: Timeshifting failed, lets try next available card."

 

[tourettes]

There is huge amount of "continuity errors". This means that either the signal DVB card is receiving is bad quality or there is some HW issue that causes TS packets to be dropped on the way from DVB card to TsWriter.

 

[bermag]

Thank you for replying.

Can you give any advice how to track down what is causing this? Log file says signal strength/quality is 100 but I am not sure if that is reliable information.

Can you give any example of what might cause TS packets to be dropped?

Anyway if it is a bad signal should really TV Server crash because of that? Shouldn't it just report "bad signal" or something?

Do you think there might be a problem with the card? I know there have been some faulty Terratec 2400i cards.

The strange thing is that it might work for a long time but then suddenly it crashes. I left MP runnign for 8 hours or so without any problems (however it was showing same channel so the problems might be related to channel switching).

The Terratec software seems to run fine (not sure if it use BDA drivers though).

Any test program you can run to test if the crad and/or drivers are working properly?

Next thing to try is to make a clean XP installation from start. I think that is the only thing I haven't tried yet.

 

[bermag]

I have now tried dvbviewer pro and it has worked without any problems for a day. Never had MP up that long ever and I have been abusing it as much I can with simultanous recording/timeshift and viewing etc.

I I have a theory about why TV server crash and dvbviewer works fine: I think the problem has to do with how TV server deals with problems that might be happening in my environment. Dvbviewer is probably able to recover from these problems while tv server doesn't. Maybe something is needed (resetting card or whatever) to do after you recieve errors like this which is not done in tv server but dvbviewer do it.

When I look in the log file which dvbviewer creates when recording there are for some recordings a bunch of "discontinuities" (guess that is perhaps the same thing as a continuity error).

I understand this might be hard to track down especially when not having the same configuration which is causing the problems. Anything I can do to help debugging this further?

 

[tourettes]

You could try to generate a memory dump of TVE3 process when it crashes:

Debugging/MemoryDump - MediaPortal Manual Documentation

 

[bermag]

I am not sure that a memory dump will help you much though. Usually TV server doesn't really crash when I get into this stage. It has crasahed a few times but then the system is already in an unstable state. TV Service is running but channel change is slow. I think what happens is that server is trying to start accessing tuner 1 which doesn't responf and will wait until "wait for time shift" timeout and then try using tuner 2. It was only when I "abused" the server further by doing stuff like disabling tuner etc in tv server setup when it really crashed.

Tuner 1 was not working and when starting timeshift it would use Tuner 2. The reason why it take so long time for eacgh channel change was probably that TV Server didn't realize that Tuner 1 was not longer working and is trying to start timeshift whuich would timeout and then continue with Tuner 2.

So there is a problem but it will not cause a complete crash. When it becomes complety unusable (with or without crashing) is probably when same thing happen to Tuner 2 as well.

Anyway, I tried another thing. I noticed that DVBViewer had a default setting of giving high CPU priority, so I decided to try doing the same with TV Server and set TV Service priority to high. Seems to make a difference because I have now run 3000 channel shifts with TvServerStressTest without it crashing. I have seen a few channel changes that took 18 sec or so but the next would go with normal speed.

I even tried to show preview in TV Setup and it worked however Preview windows was jerky and hardly usable (however the load which stress test put on tv server is not typical).

However there are still a lot of "continuity errors" but at least it still runs. Not sure why setting high priority would help but maybe tv service needs more cpu time to be able to cope with the continuity errors.

Can you please explain a bit more about the cause of continuity errors. What kind of HW issues might affect them?

I am suspecting the motherboard. This is an Asus A8N-E, I know that at least on the SLI model there is a problem with weak power supply for PCI. For example some PCI tuner card will not run on these boards even causing damage to motherboard. Maybe not exactly my problem (and this is PCI-express card and the problems was for PCI) but maybe it might cause other problems. If it is taht then it will be no problem since I will use a new machine as htpc.

But I am not 100% sure it is working reliable yet. Need to do more tesring.

 

[corvy]

I have had similar problems like you for a long time, and I want to do the same test as you. Thanks, will report back my findings.

When it comes to the stress tool I have never tried that, but I find that over time one of my tuners just stop working and I do not notice cause the other one is fine. The only evidence is that scheduled recordings fail when they try to initiate on the faulty tuner and fail with an empty file. This has irritated the hell out of my wife as she is not getting her favourite shows recorded so we have also tested DVBviewer. This error never happens there, so there is some truth to the fact that TVserver does not handle HW exceptions in a good way like DVBviewer manages to do.

I love MP interface and functionality so I want this to work! .. fingers crossed .. will test tonight and the next few days.

 

[bermag]

Hmm and you are using FloppyDVD which is considered the most stable tv-card/drivers for MP. In the past I have been suspecting the tv card/drivers to be the problem but since dvbviewer (and Terratec's own software) had always worked flawless I am now sure it has to do with MP.

One theory I have is that it might have to do with bad reception or somethign which maybe is causing problems with MP. Perhaps it will cause the tuner to be locked or something. I have noticed that I sometimes get transmission problems (when watching normal tv), like today when several times the picture and sound just freeze for like 5 seconds. Maybe this will cause problems which MP is not able to deal with.

I should probably try to test signal quality but on TV (and also the tv card report good signal quality). However there might be other problems. I am using an amplifier for signal (without the amplifier I get no picture at all) and it is pretty old and maybe there are some problem with it causing loss of signal.

 

[corvy]

I found that I had problems with the signal on one of the cards. After I did some fixing with the coax connection it is now much better. In adition to this I had some stability issues with the CAMs, and after I changed them also it seems to finally be stable. Changing the priority alone did not fix the problems but it seems to be a bit more snappier though ...

At lest it seems my MP setup now is more stable and working better than ever. Have not misses a recording in 4-5 days, happpy about that