SageTV Recording Errors

[Taddeusz]

I'm not exactly sure where to put this thread.

I have 2 HDHR's and a HD-PVR. In a nutshell it appears that my problem is that on nights when I have a lot of simultaneous recordings that the files invariably end up with all kinds of errors. I run them through VideoRedo and I get all kinds of errors. It appears as if it might be comskip causing the problem, an underpowered system, or both.

Today I ran a test where I recorded 3 channels with my HDHR's and an HD-PVR recording (it's very rare that we get 5 recordings going at the same time, 4 is a common occurrence). First without comskip running and the second time with comskip running.

The results were very telling. Recordings done with no comskip are as pristine as they are when I am doing testing with hdhomerun_config (I created a batch file to fire off all 4 tuners at the same time). I get a handful of audio errors and that's about it. However, when I have SJQ set to run comskip errors sometimes multiply into the hundreds.

Ultimately I believe my problem is one of processing power. That my little 2.33Ghz C2D is not quite enough to keep up with 4 recordings while simultaneously running comskip live on all of them. I am going to do another test to determine if having the live comskip detection of an HD-PVR recording is causing the issue for the rest.

What should I be looking at and changing to keep things as error free as possible? BTW, my comskip thread count is set to 2.

[MattHelm]

How many recording drives do you have? You could be causing errors there, too.

[nyplayer]

If you have more than 1 recording Hard drive make sure sage is set to record using the bandwidth method,.

[Taddeusz]

I have 2 recording drives and it is set to bandwidth.

[reggie14]

I've had some problems too, although its more playback problems. It's a little weird, because it just started happening, enough though nothing changed on my system.

I think its a a hard drive issue. Particularly when a recording drive gets moderately full, I think I have trouble recording, running SA, and playing it back at the same time. I can generally do those three things off a single drive, but things start going poorly if I get up to four (like if I'm driving two extenders off the same recording drive).

I switched DirMon2 so that it will only run SA after the show is over, but that actually just made it worse. Then I'd end up in situations where a new recording would start, and SA would end up running full speed. Running on live recordings kept it in check, since for mpeg2 recordings it can run much faster than real-time.

I switched it to only run when the drive in idle. That helps, but it doesn't fix it entirely. DirMon2 can't stop SA when a new recording starts on the same drive. It seemed to help though.

Are you ever playing stuff back while the recordings are going on?

[Taddeusz]

Originally Posted by reggie14

Are you ever playing stuff back while the recordings are going on?

All the time. Not sure if my daughter was watching anything while I was doing my tests today.

[BobPhoenix]

Set Commercial Detector to only process files with Comskip when nothing is recording also use the playnice parameter to comskip and a single instance.

[Taddeusz]

Originally Posted by BobPhoenix

Set Commercial Detector to only process files with Comskip when nothing is recording also use the playnice parameter to comskip and a single instance.

How do you detect if a recording is happening? The only method I can seem to find is GetCurrentlyRecordingMediaFiles(). The documentation doesn't say what it returns if there are no recordings being done.

[BobPhoenix]

Originally Posted by Taddeusz

How do you detect if a recording is happening? The only method I can seem to find is GetCurrentlyRecordingMediaFiles(). The documentation doesn't say what it returns if there are no recordings being done.

Not at home currently so can't check but there is a setting with the Commercial Detector plugin that prevents running comskip when a recording is going on. tmiranda could tell you the exact setting since he wrote the Commercial Detector plugin but he is probably using the API method you meantion internally in the plugin.


Edit:
I think this is the setting from Wiki:
•Use Intelligent Scheduling set it to true and you will only get comskip when recordings are NOT happening.

[Taddeusz]

Ok, I've switched my commercial detection to tmiranda's plug-in and restricted to one comskip instance. Hopefully that will do a better job.

One of these days, hopefully sooner than later, I'll get the money to buy new server hardware. I plan on virtualizing things. I already have VMWare running on another box. Just not enough RAM or processing power. Currently serving as a testing platform for learning Group Policy and Active Directory. I also have Ubuntu Server in a vm serving as an ssh tunnel and dev web server. One day I'll be able to get a much better machine.

[Taddeusz]

Well, the only thing new I have on this now is that I suspect that SageTV is somehow inducing errors into the stream. I say this because I can create near perfect "recordings" with hdhomerun_config that get either zero errors or a handful of transport errors. When I run those files through VideoReDo I get either a handful of audio errors which I personally chalk up to the network or Cox inserting commercials. I've gotten a few that have absolutely nothing wrong with them that is detectable by VideoReDo.

Throw SageTV into the mix and I start getting all kinds of errors. Now a lot fewer since increasing the receive buffers on my network card seemed to improve things. But I'm still getting what I think are statistically more errors than the hdhomerun_config baseline.

I don't think I should be getting any significant amount of errors but there also doesn't seem to be any way I can monitor hdhr streams that are not being initiated by hdhomerun_config.

I know I'm probably banging my head against the wall but it just seems frustrating when there seems to be such a large discrepancy between what hdhomerun_config and SageTV produce as output.

[KryptoNyte]

Fire up HDHomerun Config application, then do it again and again, one instance for each HDHR tuner. Get all four of them where you can see them on the screen at the same time and make sure each window has a different tuner selected.

Schedule a five minute manual timed recording on a channel you believe may have a problem. Schedule three more timed recordings, same time and channel. When the recordings start on all four tuners simultaneously, watch the signal status on each of the (4) HDHR config windows for issues.

By some web searches and some trial and error, I found that I can't have my HDHR units anywhere near my wireless router. Maybe there is an easier method, but this is the one I used.

[KryptoNyte]

I should probably note, I was originally having the same problems with VideoRedo finding massive errors in my videos, some of them wouldn't even QSF it was so bad. When I watched them, there was quite a bit of strange blocking. Since I straightened out the "proximity to other hardware" issue, the HDHR's are back to their good operation.

[Taddeusz]

How close to your router were your hdhr's? My router sits on a shelf that's about 1ft above the shelf that holds my hdhr's.

[KryptoNyte]

Mine were virtually in the same proximity as yours, and that's no good. I read that 3 to 5 feet was the minimum, so I moved the HDHR's out of the cabinet, and sure enough, the signals all cleared up. I don't know why this is, but if you monitor and screenshot/document your signal before and after, you'll probably see the same improvement (hopefully this will solve the issue that you are having).

I also played around with changing out the coax cables, those HDHR's seemed VERY finicky, even when putting a little force on the cable/coax connection input, it seems like it would alter the signal when watching the signal live.

[Taddeusz]

After some troubleshooting with Silicon Dust I think I've come to the conclusion that the errors I see are quite possibly receiving errors from Cox. I say that because I am still seeing errors even though my recordings are nearly pristine now. I get the occasional receive error on my end but for the most part they are perfect. That means the errors that VideoReDo sees must not be from my reception but from Cox Cable's reception of the local network stations. Meaning that they are just re-transmitting the errors they receive via their source for the local networks, quite possibly their own antenna.

I've been thinking about buying an antenna just in case Cox decides they need to encrypt everything. I may just go ahead and do that and see what kind of signal I can get. The one I want is only $40. I can mount it in my attic.