Occassional Video and Audio Playback Stuttering

[comedian999]

Until this past Saturday, I'd been running Sage 1.4.11 on an XP SP1 box with a Hauppauge 250 stably for two and a half years with no hardware or software changes beyond the Daylight Savings patches to Windows and Java in March.

In the past four or five months, I'd noticed that sometimes during playback or watching live TV (All standard def), the playback would stutter like a skipping record: Sage would play back about a second of video and sound, then skip back and repeat it four or five times, before getting past it and playing back normally afterwards.

This condition could be cured by skipping back 10 seconds, which would skip back normally and then play back the portion that stuttered normally, so this doesn't seem to be an encoding issue of the video file itself.

I always attributed this to an old Sage install with a 2.5 year bloated DB and / or rocking only 256 meg, but on Friday night, my old Sage setup finally crashed, so I took the opportunity to upgrade the memory from 256 to 512, and I did a clean install of the latest trial version of Sage on the existing install of Windows. The same playback skipping issue is occasionally occurring on the new install.

The drives I'm using are all formatted to NTFS with 64K blocks, and running scan discs on each of them returned no apparent issues. I reformatted the drives I use for video when I installed Sage 6.10, so I doubt this is a disc fragmentation issue.

Has anyone else experienced occasional video and audio skipping like this in playback? Right now this is only an occasional irritant, but I suspect this might be caused by some kind of impending hardware failure. If someone could point me in the direction of whatever might be causing this, I'd appreciate it.

Thanks!

[ntisdale]

These things are always hard to track down. I had power supply that was failing and before it finally gave up the picture quality from my two DVB-T cards really deteriorated. It's always worth testing your hardware if you have spares you can use - bad memory can cause all sorts of random mischief.

Neil

[SpiffyRex]

How old is your drive? I had a similar problem with a hard drive going bad. I was able to check the file system just fine although it will take a long time. The drive was S.M.A.R.T capable but the IDE controller in my old motherboard was not. So when I moved the drive to another computer the Bios gave me a boot warning telling me that the drive was about to fail and that it should be replaced. The reason the drive slows down is b/s an excessive number of retries to read or write. Also keep in mind that if your filesystem is > 90% full you will have some performance degradation.
Unfortunately there are so many things that could be doing this. You are going to have to go one by one. Hopefully it's not a combination of two or more problems.

[comedian999]

The drive that contains the system partition is just under 3 years old. I have a second drive that's a couple months younger. Since I reformatted all the partitions on each drive that I use for video prior to install, I think it's unlikely that it's an issue of the file system being too full (a few long-as-hell Red Sox games notwithstanding. )

In the few times the stutter's happened since I upgraded Sage this past weekend, it seems that all the recordings that display this behavior are on a partition on the main system drive, so I suspect I might have a drive going bad.

Unfortunately, I don't have another box I can drop the drive into to test it, so I guess I'll keep any eye on it and keep $150 and my Windows install disk in ready reach in case it goes toes up and needs to be replaced.

Thanks!

[davephan]

I found that Windows XP needs at least 750 megs to run decently. Windows XP will function with 128 megs, but it caches to disk continuously when only running the operating system. I ran SageTV on my old system with 512 megs RAM, and it wasn't enough. That system consumed about 500 megs most of the time. I increased the memory up to 1 gig. With the extra headroom, the memory consumption reduced to about 400 megs.

With my current system, I am running XP with 2 gigs of memory. I am running the current version of SageTV plus many other programs. My memory consumption is about 1 gig.

If you are using an MVP, make sure the ports are open in your router. I discovered that my MVPs would work when the ports were not open, but they stuttered.

Dave

[SpiffyRex]

Go to your drive properties and select the tools tab. In the Error-checking panel select "Check Now". Then check "Automatically fix file system errors" and "Scan for and attempt recovery of bad sectors". You will have to reboot for this to work. This might help for a while, but if the drive is going bad you are basically living in borrowed time...

I found that Windows XP needs at least 750 megs to run decently. Windows XP will function with 128 megs, but it caches to disk continuously when only running the operating system.

This is a very good point. Have you started recording to your primary drive (where XP is installed) recently? One possible scenario is that even though XP was paging quite a lot in your previous configuration, since it only had 256MB of memory, you never noticed it b/s all the recording was done in the other drive. Even your 512MB upgrade will still cause excessive paging. If you are running with < 1GB of memory you should have a dedicated drive for the OS and make sure the paging file is there too.
Also keep in mind that updating your JRE may cause more memory consumption. You did the right thing since you need the DST patch but the new JRE might have higher memory requirements for performance enhancements. I bet they assume everyone is running with 1GB or more of memory these days.

[comedian999]

SpiffyRex -

I did the full error check and bad sector recovery on all drives, and it seemed to run without any issue (Well, at least no bad sectors were reported as found).

I do record on the drive that has Windows on it, but I keep Windows and Sage on a separate partition upon which I don't do any recording.

And actually, I'm still running JRE 1.4. I only applied the single patch that that version needed to deal with DST. When your day gig is a software QA Engineer, you learn to appreciate the value of incremental changes on a stable system.

And actually, I had a stutter last night that occurred while recording on the *non* system drive, so maybe jacking the RAM to a gig might be the way to go.

Thanks!

[SpiffyRex]

I do record on the drive that has Windows on it, but I keep Windows and Sage on a separate partition upon which I don't do any recording.

Good, and as you mentioned before, the recording partition is 64K NTFS. Keep in mind that excessive paging might still interfere. Since both partitions are in the same drive, the disk drive arm will have to move back and forward between the sectors in the paging file and the sectors in the video file. However, this might not be the case since you noticed that you also get stutter when recording to the non-system drive.

And actually, I'm still running JRE 1.4. I only applied the single patch that that version needed to deal with DST. When your day gig is a software QA Engineer, you learn to appreciate the value of incremental changes on a stable system.

Very wise.

I agree bumping the memory to 1GB is the way to go. The only other optimization I might recommend is to defrag the XP partition and make sure the paging file is just one segment. You can do all of this by using XP's defrag utility, not the best one, but it has the right price. To do this, go to the advance system properties, Performance settings, Advance, change. Select no paging file for the XP partition. Select "System managed size" in any other partition. This is temporary, don't worry if it's in a recording drive. Reboot, defrag the XP partition, go back to change the virtual memory settings. This time (and after you upgrade to 1GB memory) you will see that the recommended paging size is something like 1534 (a bit less than 1GB x 1.5). Make the initial size and maximum size that number, or bigger if you like and remove the other paging file. Go back to the defrag utility and check to make sure the paging file in the XP partition is one big block (the green, unmovable files). After you reboot the temporary page file should go away, if not remove it to reclaim space. You might also consider putting the paging file in the second, recording file-system. This has two advantages, first the paging file is closer to the video files so if you have excessive paging the drive arm will not have to move too far. Also you have the performance advantage of having the paging file in a 64K file-system. However, it's a waste of space b/s you won't be using the allocated OS partition and consuming space from the never big enough recording partition. Don't think you need to do this but is something to try if the 1GB upgrade doesn't do the trick.

[comedian999]

The only other optimization I might recommend is to defrag the XP partition and make sure the paging file is just one segment.

This is an exceptional idea that hadn't occurred to me to try. I'll give it a shot while I wait for my next paycheck to cover the memory upgrade.

Thanks again! You've been a big help.