Recordings truncated for no apparent reason (1 Viewer)

[nick8571]

I have a completely baffling problem where recordings of a particular show are repeatedly stopping prematurely. The show is the UK news program "BBC Breakfast," broadcast daily from 6.00am to 9.15am on the BBC1 HD channel, and I receive it via Freesat from the Astra 1N satellite at 28E, using a TBS 6981 DVB-S2 card. I'm running MP 1.2.3 on Windows 7 x64, using the StreamedMP skin.

The time at which the recording stops appears to happen more or less randomly - today for instance it stopped at 2:00:58 in, but it can stop at more or less any time, and once or twice the recording has even completed correctly. At the point of failure, MediaPortal *seems* to be continuing to record, and correctly shows the expected length of the recording as 3h 27 mins (including 3 and 10 mins pre & post record), but nothing is actually being written to disk from that point (several hundred GB free space BTW). There are no crashes, hangs or any other unusual behaviour.

The weird thing is that the problem *only* happens with this one show, at least so far - all other recordings, including those from BBC1 HD recorded at different times are carried out without any problems. I've also recorded several other channels over the same three-hour time period, and again they complete without problems.

For what it's worth, W7MC records the show correctly without any issues.

I can't see anything obvious in TsWriter.log or tv.log - I've attached the relevant snippets from today (the recording started at 05:57, and stopped writing to disk 2:00:58 later, according to the length of the file as shown in Windows Explorer). I did wonder if "Heartbeat transmitter thread" in tv.log might be involved, but it doesn't seem to bear any relation to the time at which the recording stopped.

If anyone can shed any light on this, it would be much appreciated - I'm not too bothered about this one particular show, but I'd like to know what's happening just in case the problem starts manifesting itself at other times.

Many thanks in advance.

 

[JimCatMP]

Hi

When you have a failed recording, how big are the files (not that you'll be reaching Windows 7 files size limit at 16T) - as you say other content records fine, but have you tried it HD for programs of equivalent duration (Wimbledon coverage tomorrow - 13:45 -> 18:00 for example) as a test.

Also, is all of Breakfast HD content - as the skip to regional news desks twice an hour?

Cheers - J.

 

[nick8571]

Thanks for the response and suggestions. Yup, already tried the Wimbledon transmissions on BBC1 HD, several days running (they were the obvious test candidates) - each time they've recorded perfectly OK for the full scheduled duration with no issues.

On the (rare) occasions when Breakfast has recorded OK for the full length, it produces a .ts file size of just under 11GB (duration as expected, 3hr 27min), but today it stopped at 6.4 GB (duration 2hrs 1min). Yesterday it was 4.3 GB (1hr 18min), and the day before it was 5.6GB (1hr 44min). As you can see, there doesn't seem to be any obvious pattern or consistency, and there's nothing in the log files that seems to make any sense either.

Breakfast on BBC1 HD is all continuous content - there's a placeholder clip when the regional news (SD only) is transmitted, but the broadcast itself isn't interrupted. There's no apparent correlation between the regional news times and the times of the recording failure anyway, so I wouldn't have thought there was a connection there.

It's a flipping mystery, I've been googling till my eyes are raw, without any success... I suppose I could try an uninstall/reinstall of MP and ultimately Windows if need be, but I'd rather avoid that if possible for obvious reasons.

 

[JimCatMP]

Ah - so great (but still in the dark) minds think alike:->

I can't think of anything more to suggest, but there are lots of bods on the forum who have far more experience than me, I'd hang fire on the reinstall if you can for a little while.

Only question I can still think to ask, your disk system, is it local the server or networked - as from your post, you provide the tuner card, a single seat setup (as you refer to the skin) and disk isn't SSD (from size reference).

Hopefully someone has more ideas - it seems unlikely that MePo has it in for Breakfast TV from BBC.

TTFN - JCMP

 

[nick8571]

It's a single-seat setup, everything is local - the PC has a dedicated 500GB HDD used solely for TV recordings, and it's only about a third full.

It's funny you should mention MP "having it in" for Breakfast, as that's exactly the impression which comes across. Logically, something must be happening in the BBC1 HD stream during the time Breakfast airs (and seemingly *only* then) which causes MediaPortal to spit the dummy, but I'm damned if I can think what it could be - whatever it is, W7MC seems unaffected as I mentioned earlier.

For my next trick I'll set MP recording BBC1 HD manually at around midnight tonight, and leave it recording all night up to and including Breakfast at 6.00 am, and see if anything interesting happens during that time.

Thanks for your replies, I do realise this is a peculiar one and I'm not expecting a solution right away (if at all)...

 

[mm1352000]

Hmmm, *very* strange issue. And WMC records it fine...
I know it would be an early start, but would it be possible to monitor the recording in the "manual control" section of TV Server configuration and check when the TS packet count stops increasing. That may help to identify a possible cause/event.

mm

 

[nick8571]

Yes, I can certainly do that, but what exactly am I looking for in the "manual control" screen? I don't see anything that will explicitly tell me when the TS packet count stops increasing, unless you're referring to the "state" column... am I looking in the right place?

I can already pinpoint the exact times at which TsWriter previously stopped writing, by adding the duration of the (truncated) files to the scheduled start time as per TsWriter.log... there's nothing in the MP logs to indicate anything unusual at those points (I'm now going through the Windows event viewer more in hope than expectation). MediaPortal itself thinks it's still recording beyond the failure points - the red indicator continues pulsing, "Breakfast" shows up under "Active Recordings," and the only indication that anything's wrong is that the filesize is not increasing.

FWIW the scheduled recording this morning stopped after 1hr 18mins 18 secs (4.322 GB filesize) - very similar to the day before yesterday, but it's been pretty random up until now, so I don't think it's anything more than a coincidence. I did originally try to set BBC1 HD to record all night, but the "Until manual stop" option seems to be unavailable, and it only allows you to record specific shows (which I've done already without finding out anything useful).

Needless to say, nothing of any note in the log files at 07:15 or thereabouts, when TsWriter decided it wasn't going to play anymore...

 

[mm1352000]

Hi again

Yes, I can certainly do that, but what exactly am I looking for in the "manual control" screen? I don't see anything that will explicitly tell me when the TS packet count stops increasing, unless you're referring to the "state" column... am I looking in the right place?

When you select a channel that is recording/timeshifting, the upper area is filled with the tuning details, signal level and quality... and "TS packets processed" and "discontinuities". Those last two stats are what you should look at. You want the TS packet count to keep increasing and the discontinuities to be at zero.

I can already pinpoint the exact times at which TsWriter previously stopped writing, by adding the duration of the (truncated) files to the scheduled start time as per TsWriter.log... there's nothing in the MP logs to indicate anything unusual at those points (I'm now going through the Windows event viewer more in hope than expectation). MediaPortal itself thinks it's still recording beyond the failure points - the red indicator continues pulsing, "Breakfast" shows up under "Active Recordings," and the only indication that anything's wrong is that the filesize is not increasing.

Okay. Well at least in manual control you can see if it is a signal dropout or something (the signal level and quality readings might drop off) or something else entirely (which would be indicated by the sudden stopping of the TS packed counter).

FWIW the scheduled recording this morning stopped after 1hr 18mins 18 secs (4.322 GB filesize) - very similar to the day before yesterday, but it's been pretty random up until now, so I don't think it's anything more than a coincidence. I did originally try to set BBC1 HD to record all night, but the "Until manual stop" option seems to be unavailable, and it only allows you to record specific shows (which I've done already without finding out anything useful).

To record until manually stopped you should be able to just hit "record now" in the MP front end.

Needless to say, nothing of any note in the log files at 07:15 or thereabouts, when TsWriter decided it wasn't going to play anymore...

On a bit of a tangent here... I know you said this works fine in WMC. I wonder if the tuner demodulator is just loosing lock for whatever reason. Are you using the latest TBS driver?

mm

 

[nick8571]

Hi again
When you select a channel that is recording/timeshifting, the upper area is filled with the tuning details, signal level and quality... and "TS packets processed" and "discontinuities". Those last two stats are what you should look at. You want the TS packet count to keep increasing and the discontinuities to be at zero.

Okay. Well at least in manual control you can see if it is a signal dropout or something (the signal level and quality readings might drop off) or something else entirely (which would be indicated by the sudden stopping of the TS packed counter).

Gotcha.

I guess ideally I'll need to keep a constant eye on the display to see what's happening at any given point - might be tricky as I'm generally chasing around a fair bit in the mornings, but I'll do my best.

To record until manually stopped you should be able to just hit "record now" in the MP front end.

hmmm... when I hit "Record now" I get the submenu with the two choices "Current program" and "Until manual stop". "Current program" works on all channels, but "Until manual stop" *doesn't* work on certain channels (nothing happens), including BBC1 HD. Picking a few channels, this is what I get:

BBC HD (DVB-S2) - "Until manual stop" doesn't work
BBC1 HD (DVB-S2) - doesn't work
BBC2 (DVB-T) - doesn't work
ITV1 HD (DVB-S) - doesn't work
Channel 4 HD (DVB-S) - works
Channel 5 (DVB-T) - doesn't work
ITV2 (DVB-T) - works
ITV3 (DVB-T) - works

Strange, although I guess it's unlikely to be connected to the original problem.

On a bit of a tangent here... I know you said this works fine in WMC. I wonder if the tuner demodulator is just loosing lock for whatever reason. Are you using the latest TBS driver?

mm

There is in fact a later driver than the one I've been using, I guess that's one of the first things I should have done. I was a bit reluctant as everything's been working fine in other respects, and the problem didn't seem obviously driver-related, but I'll give the new one a whirl.

 

[nick8571]

Well, just to close this off, just before 6am yesterday I started recording BBC1 HD via the manual control screen and used CamStudio to record the output. The TS packet count stopped increasing at 07:10 am, but there was no drop in signal strength or quality, and nothing else happened to indicate any sort of problem.

Yesterday evening I completely purged my system of any traces of MediaPortal (and MySql as well for good measure) and did a clean reinstall... this morning "Breakfast" recorded for the full allotted length (4hrs on a Saturday) with no issues. I'm a bit disappointed not to have identified the problem, but I'd run out of lines of enquiry and at the end of the day life's too short.

I'm running a minimal install of MePo for the time being with the default skin and no additional plugins, I guess I'll see if things go pear-shaped once I start getting it back the way I like it.

Thanks to both of you for your responses.