Video Studdering

[Partyasaurus]

My feed is from HDHomeRun using an OTA antennae. It works fine using the HDHomeRun tools, but when I watch or record live TV in SageTV, the feed for several channels are choppy, stutter, and are unwatchable. It also happens via the SageTV Extender (HD200). I've had SAGETV for over a year and had attributed the problem to poor reception, however I have upgraded and reception is not the issue.

I have updated to the latest version of SageTV, tried every combination of filters and decoders with no success.

I'm running a dedicated server on WinXP sp3, Dell Optiplex GX280, P4 2.8 GHz HT, 2 GB Ram, Memory and CPU utilization don't seem very high.

Any suggestions? (Significant other is currently writing the epitaph for SageTV)

[sainswor99]

Are you running any sort of defragging tools on your recording drive? I recently had problems because I had started defragging my drives DURING recording (d'oh!). Once I turned defrag off, my video quality improved immensely.

[MitchSchaft]

That or commercial skipping or bad TV signal. What kind of video card do you have?

[Partyasaurus]

Thanks for the replies.

No, I'm not defragging or using any other utility.

Reception is also not an issue. All signals are strong, and display works fine using HDHomerun tools alone.

The video card is the default integrated card which i understand could be problematic except I am not using this card for display. The reception on my extenders is my primary concern (I can simply duplicate the issue using the local display). Note: issue was the same when using dual core processor with 7600GT card

[MitchSchaft]

oops, didn't realize it was to an HD200. Are you using wireless or wired for the connection?

[Opus4]

Are the recording drives formatted using 64K clusters? If not, that is likely the cause of stuttering.

Do you have an antivirus app that is scanning the recording dirs? If so, exclude those dirs from scans.

- Andy

[Partyasaurus]

Thanks-
Wired network and yes the drive is formatted 64K clusters. Checking virus software, but I believe it is set to scan main drive only.

[SWKerr]

You might have a multi-path problem with your antenna. Multi-path is when the signal bounces of a building, hill or tree and gets reflected back to the tuner a fraction of a second later than the real signal. I the old days it would show up as ghosting. Now the digital tuner is just confused and the picture will go in and out. The HDHR is one of the best tuners I have found for multi-path. (and I have a box of them)

I have had this problem for years because my house is surrounded by tall pines an is also has a large hill about a quarter mile away.

Usually a HDTV tuner is better at dealing with this issue than a tuner card but it would most likely be apparent there as well. Can you get good TV with the Antenna connected directly to the TV?

The cure is usually a highly directional antenna.

[TwistedMelon]

Here we are, posting this for the second time due to a previous accident.

From the details in the opening post, it's obvious this is nothing to do with multi-path or other broadcast/antenna problems. The native software would not be able to produce clean results if these problems existed. One thing I will advocate right up front is that it's a potentially a bad idea to use a Windows PC for playback. One is much better off using a dedicated playback device such as an HD200 extender for many reasons. That said....

The problem is moot until you've identified if it's an issue in the recording or whether it's a playback issue. There are a few tests to do to positively identify what's going wrong, then someone can look at how to get it fixed.

In Sage, make some recordings. Note if you are seeing pixelation or stuttering while watching as it records (just like you've mentioned in the initial post).

Next, play this recording back in an alternate video player, such as VLC or MPlayer. In fact, play it back in multiple players. This should tell you if the file contains damaged contents which cause the issue you're seeing.

You should also look at the issue from the other side. Using the default software that comes with your capture device, make a similar recording. This should, according to the original post, look fine as it's being made.

Next play this file in SageTV either through the Browse interface or by importing it into your media library. Does it show a problem with stuttering? Check the file using the other players you previously used.

You should be able to tell if the issue is with the file (happened at recording time) or with playback in SageTV.


I'm seeing stutters of audio and video as well as quick bursts of pixelation on some of my ATSC recordings. I'm using a dual tuner HVR-2250 and an HVR-1600 for ATSC HD and a PVR-500 for analog NTSC SD. I've verified it's an issue with the contents of the recording, not a playback issue. And I've also verified that it only seems to happen when recording multiple streams at the same time. For instance, 3 ATSC 720p/1080i streams and 0-2 NTSC 480i streams.

Recording only a single HD stream doesn't cause any issues. The signal strength is very high for all stations on all tuners. The weather outside isn't responsible for temporary reception issues because I can replicate the problem and then immediately make it go away when dropping down to one recording. The issue is not seen in every concurrent recording and is transitory. It might happen every minute or it might only happen every 10. It is also not specific to one particular tuner nor to one particular destination hard drive

Recording is being done to three 7200rpm SATA drives - all with 64K cluster size. Two of them are dedicated to recordings and the third is actually a single partition from the same drive being used for bootup. The "partition" volume is actually only for fall-back if the other drives get full. It is NOT normally being used for recordings and isn't a factor in this issue - none of the files get recorded to it.

I am doing some tests right now to remove some questions out of the way, such as clearing space on all the drives and defragmenting to group all the empty space together. The system is a relatively fast 2.8Ghz Core2Duo with 4GB of memory.

[paulbeers]

Originally Posted by TwistedMelon

Recording is being done to three 7200rpm SATA drives. Two of them are dedicated to recordings and the third is actually a single partition from the same drive being used for bootup.
y.

Well heck there's half your problem. So you are using the same drive as your OS drive and a recording drive? All it takes is Windows to start hitting the Page File and anything being recorded to that drive would be toast.

OS should always be on a separate drive! Not just a separate partition!

[TwistedMelon]

Originally Posted by paulbeers

OS should always be on a separate drive! Not just a separate partition!

It's almost as if I started doing this yesterday, isn't it? Trust me, that's not the case. You do have a valid point, but it's irrelevant in this case because of the way that Sage handles recordings. The two big drives, with a lot of empty space, are the primary recording devices. Sage puts recordings where the most space is available.

That partition is a worst-case fall-back device and none of the affected recordings are ever being made to it. Perhaps you missed the part where I said that the issues are not volume specific?

[paulbeers]

Originally Posted by TwistedMelon

It's almost as if I started doing this yesterday, isn't it? Trust me, that's not the case. You do have a valid point, but it's irrelevant in this case because of the way that Sage handles recordings. The two big drives, with a lot of empty space, are the primary recording devices. Sage puts recordings where the most space is available.

That partition is a worst-case fall-back device and none of the affected recordings are ever being made to it. Perhaps you missed the part where I said that the issues are not volume specific?

So then the other issue, is that you have one large hard drive and one small partition, and because they aren't the same size, Sage would record all streams to the larger partition until it hit the point where both had the same free space. So now you basically are recording all streams to the same drive most of the time, that's also a big no-no. And then when you fill up the first one so that Sage can use the second one, you are now recording to the OS drive! You need to use two (or more) non-OS drives that are the same size so that Sage will "usually" split the recordings to both drives. I use two 640GB drives for my recordings. Sage is constantly recording to both drives and with this setup I have had no problems recording up to 4 HD streams (1 OTA, 2 QAM and 1 HDPVR).

Oh and I did read your whole post, notice I said "Half your problem"...meaning the OS drive being an issue. Thanks for playing.

[DocDJ]

I too have Sage stuttering problems. HD200+SagetvMC 6.6. Playback on the server PC (Win7 Pro) works perfectly. Sage Extender playback stutters when 30 feet horizontally and 10 feet down from router.
Belkin F5D8236-4 wireless-N router on Ch. 6, WPA security.
"approved" USB N-adapter from Sage
Anti-virus not scanning the playback folders.
Swap drive is a separate drive.
Playback drives are 7200 RPM Sata. Cluster size=4K.
Playback in basement/den horizontally 0 feet and 30 feet vertically, works perfectly. Woodframe house. Problem is any time of day. Only one other broadcasting SSID in neighborhood outside town. Same effect when playing back over wireless-G with my laptop and SageTV Client software.

[DocDJ]

Just bought a new wireless-N (3ooMbps) adapter for my laptiop. It came with some pretty good signal-strength s/w. At anything less than 65% the Sage Client could not process the datastream. Audio was clipped and video stuttering. I may have to move my router to a more central location.

[davephan]

Originally Posted by DocDJ

I too have Sage stuttering problems. HD200+SagetvMC 6.6. Playback on the server PC (Win7 Pro) works perfectly. Sage Extender playback stutters when 30 feet horizontally and 10 feet down from router.
Belkin F5D8236-4 wireless-N router on Ch. 6, WPA security.
"approved" USB N-adapter from Sage
Anti-virus not scanning the playback folders.
Swap drive is a separate drive.
Playback drives are 7200 RPM Sata. Cluster size=4K.
Playback in basement/den horizontally 0 feet and 30 feet vertically, works perfectly. Woodframe house. Problem is any time of day. Only one other broadcasting SSID in neighborhood outside town. Same effect when playing back over wireless-G with my laptop and SageTV Client software.

It looks like you are using 4k blocks instead of 64k blocks as Andy mentioned above. Can you use a separate drive for the video files formatted with 64k blocks?

You might try using a cross over cable or a Eithernet cables and a switch to isolate the problem as a wireless problem.

Your stuttering might be from both the small block size and wireless.

Dave

[DocDJ]

By forcing my router to ONLY work in N-mode, I was able to stop the stuttering. Next I will take your advice and build a partition with 64K blocks, just to be safe.

[davephan]

It would be better to use a separate drive(s) for the video storage then the drive that contains the operating system. Your video drive can also storage the images of your operating system/programs drive, if you use disk imaging for backup / recovery.

Dave

[Fuzzy]

You really ought to look into running a cable. With wireless, even if you ARE working right now, you're just a few steps away from, say, a neighbor getting a new router, or even a new wireless phone, and that may be enough to throw off your signal again, complete with another rash of troubleshooting. Enjoy it while it works, but in the meantime, you really ought to look at hardwiring options.

[MitchSchaft]

Man, everytime I ran my microwave I would get a drop in signal . Wish they would hurry and move to the 5GHz channels!

[xls]

There's some great info in this thread, thank you!

Originally Posted by paulbeers

... You need to use two (or more) non-OS drives that are the same size so that Sage will "usually" split the recordings to both drives. ...

So if multiple drives are available, sage will put two simultaneous recording on two different drives? You wrote ' "usually" '... under what conditions does this not happen? I assume if one drive is near full and the other has a lot more space, it puts simultaneous recoding on the drive with more space.

Is there a way to test the network speed between the sage server and the HD200? I have a wired connection and in theory all HW is GBit capable (I think the HD200 is).