2 Tuners, Simultaneous recording problems (1 Viewer)

[mm1352000]

Hi folks
So this is still an issue for both of you?

I have some general questions first:
1. Is this a problem on all channels and combinations of channels, or only particular channels/combinations?
2. Is the issue only with HD, or does it also affect SD?

Generally speaking I think the issue could be caused by one or more of the following:
1. Bad signal
2. Bad HDD, or HDD not fast enough.
3. Bad drivers/codecs (least likely).

mundy5
Did you test your 2nd tuner by itself? From your logs, it looks like the signal strength/quality on that tuner isn't as good as the first tuner...
When you say that the picture stutters with both recordings in progress, do you check both recordings... or only one?
The "Program clock reference forward jump" and continuity errors that I can see in your TsReader logs often indicate bad signal, but it could be caused by an HDD that is struggling to keep up with the load that you're putting on it.

Ideally you want your timeshifting and recording folders to be on a separate HDD to your operating system. You should definitely make sure that nothing else is heavily using your recording/timeshifting drive like RobNorthcott suggested. In particular, exclude the recording and timeshifting folders from virus scans. Check whether your virus scanner is doing a scan when you are testing. The combined load of a virus scan and 2 HD streams may be enough to cause the HDD to struggle.

 

[mm1352000]

Did you ever find a reason or solution for this? Coincidentally my system has recently been doing the same thing. We've got more stuff being broadcast on HD now, so there have been times when I have had two overlapping HD recordings. When this happens, I get stuttering during the overlap just as you described (when playing back the recording, not just trying to watch it live while there is a recording going on). I'm wondering if it's just drive speed (my recording drive is a WD Green drive, so not the fastest, although not really slow). I can't try separating the recordings because they're both from the same tuner, so have to go to the same place.

Rob

Hi Rob

It is very likely that your drive is the culprit. Green drives are notorious for exactly these kinds of issues. Can you try timeshifting/recording off a 7200rpm drive?
The reason why you get stuttering in the playback is probably because the recording was bad. Of course I can only guess because you haven't posted logs. I'd expect to find continuity errors in the TsReader logs...

 

[RobNorthcott]

Hi Rob

It is very likely that your drive is the culprit. Green drives are notorious for exactly these kinds of issues. Can you try timeshifting/recording off a 7200rpm drive?

I haven't got one spare the moment so I can only speculate for now. The problem only occurs with two simultaneous HD recordings (off the same transponder, as I only have a single DVB-S tuner). I can record multiple SD streams at once (at least three) with no problem, or watch an HD recording while recording another, all from the same drive. But I'm not denying the possibility that a faster drive may help. Overlapping HD recordings are still pretty rare for me, so it's not worth me buying a faster drive at the moment just for that.

The reason why you get stuttering in the playback is probably because the recording was bad.

That's definitely true. Both files play back stuttery over the part where they overlapped during recording. The rest of the file is fine.

Of course I can only guess because you haven't posted logs. I'd expect to find continuity errors in the TsReader logs...

I didn't post logs because I was only mentioning the problem to see if the OP had found out what caused it on his system.

I've got a 1TB WD Black drive in another machine where it really doesn't need to be fast, so perhaps I'll try swapping it with the Green one in the MP machine when I get some time to transfer all the data over.

Rob

 

[mundy5]

Hi folks
So this is still an issue for both of you?

Thank you for responding. The answer to your first question is yes.

I have some general questions first:
1. Is this a problem on all channels and combinations of channels, or only particular channels/combinations?.

I have tried it with 2 different combinations. Have not had time to try too many others for now. In both cases, there was too much stutter on both channels.

2. Is the issue only with HD, or does it also affect SD?.

In all honesty, I have not tried it with SD, I was trying it with 2 HD shows during primetime.

Generally speaking I think the issue could be caused by one or more of the following:
1. Bad signal

I can agree with you here if I get the same problem with only one tuner operating on the channel in question. But when only 1 tuner is running, it works fine so that is the reason why I am not convinced that it is a bad signal issue.

2. Bad HDD, or HDD not fast enough.

I am currently using a 7200 rpm 64 MB cache 750GB hdd bought just recently. I am not sure how much faster the hdd can be.

3. Bad drivers/codecs (least likely).

I believe I am using the codecs supplied by the manufacturer.

@mundy5
Did you test your 2nd tuner by itself? From your logs, it looks like the signal strength/quality on that tuner isn't as good as the first tuner...

When you say that the picture stutters with both recordings in progress, do you check both recordings... or only one?

Yes, both tuners were testing individually with no issues with recording HD shows. After recording simultaneously, both recordings were problematic, not just one of them.

The "Program clock reference forward jump" and continuity errors that I can see in your TsReader logs often indicate bad signal, but it could be caused by an HDD that is struggling to keep up with the load that you're putting on it.

As I said earlier, I could understand if I am having issues with a single tuner running and recording, but I am not having any issues with a single tuner.

Ideally you want your timeshifting and recording folders to be on a separate HDD to your operating system. You should definitely make sure that nothing else is heavily using your recording/timeshifting drive like RobNorthcott suggested. In particular, exclude the recording and timeshifting folders from virus scans. Check whether your virus scanner is doing a scan when you are testing. The combined load of a virus scan and 2 HD streams may be enough to cause the HDD to struggle.

When recording both HD shows simulataneously, does it also timeshift? I'll try to isolate the recording on one hdd and the timeshifter on another.

Thank you for trying to help us out. I'd love to get it to work perfectly recording 2 HD shows simultaneously though it is not a deal breaker for now since many of the shows are on the web. But since I have 2 tuners, I'd love to use both of them.

btw, since my original post, I have now purchased an ATI TV Wonder 750 pcie card. So I have both the TV Wonder 600 and 750 pcie cards. I have removed the AVerMedia card.

 

[RobNorthcott]

I've decided I could do with more drive space on that machine anyway, so I've got a new faster (and bigger) drive on the way. When it arrives (should be some time next week) I'll post back and let you know if it cured the problem.

Rob

 

[mm1352000]

Cool
I'll keep an eye on this thread then...

 

[mm1352000]

Hi again mundy5

In all honesty, I have not tried it with SD, I was trying it with 2 HD shows during primetime.

I think it is important to try 2 SD recordings. Note that when I say SD, I mean SD in terms of the channel resolution. I'm *not* talking about SD programmes on a channel that broadcasts an HD resolution (upscales the SD to HD). The reason I think it is so important is that I can't see anything in your system specs that stands out as an obvious potential cause for the issue you experience. Aside from the causes I have already mentioned, I can only think of nasty causes like driver or hardware related issues...

How many HDDs do you have plugged into the motherboard?
At this stage I would be putting the recording/timeshifting folders for each tuner on physically different drives. In other words, I would put the recording and timeshifting folders for the TV Wonder 600 on one drive, and the recording and timeshifting folders for the TV Wonder 750 on a different drive. Ideally neither of the two drives would be the operating system drive. I don't think separating the timeshifting and recording folders onto separate drives would make much difference unless you plan to be timeshifting on one channel and recording another more often than you plan to be recording two channels (which may well be the case - just thought I should clarify).

Did you make sure that your recording/timeshifting folders are excluded from any virus scans?
Are you running your HDDs in AHCI mode, or legacy mode?

By the way, in answer to your question regarding timeshifting and recording: recording is just like timeshifting except that recording keeps the programme/s in one file and ensures that the file is kept. Timeshifting splits the programme over multiple files and throws away or overwrites the files when you get to the timeshifting file size and number quotas. So when you record a programme, you don't timeshift and record unless you are watching the said programme at the same time as you are recording it. Even then, MP may be smart enough to let you timeshift from the recording to reduce the load on the HDD.

 

[RobNorthcott]

I'd forgotten about this thread...
Just for information, swapping my WD Green drive for a new WD Black seems to have stopped the problems I was having with overlapping HD recordings. So the problem (in my case at least) appeared to be drive speed related.

Rob

 

[mundy5]

Rob, thank you for updating us on your transition. Do you by chance have that model # handy? I believe my new hdd is a pretty fast one and so I am not sure if speed is an issue for me.

Also are you having any issues with overlapping HD shows? That's where I was having issues.

 

[riksmith]

Because somebody mentioned that a faster harddisk helps this thread might be interesting (i am not involved so cannot be sure):
https://forum.team-mediaportal.com/...stuttering-corrupted-streaming-live-tv-91214/