Troubleshooting SageTV client playback stutter

[Audacity]

I installed SageTV 7 on the same box that I was running Windows 7 Media Center on, so initially I was just using the same drive configuration that worked great for 7MC. Playback is smooth on that box.

Playback is not smooth on the two client machines. I'm getting stutter with both SD and HD recordings.

I did some searching and saw that 64k cluster size is recommended, so last night I copied off all of my files (overnight), formatted my data drives with 64k clusters. The drives that will be hosting the recorded content from SageTV is a pair of 2TB WD "green" drives (WD20EARS). I was hesitent to do this because the Resource Monitor application showed me that the "Activity Time (%)" column for the drives in question where actually very low (well under 50%) and the Disk Queue Length was always less than 1. Also, the Windows defrag tool was telling me that drive wasn't fragmented. Either way, I see it is a best practice so I reformatted with 64k clusters.

Today I'm having the same symptoms, unfortunately.

- Both "client" HTPCs see the same stuttering issue, one is a Core2 Duo-based machine, one is a Athlon 2 x4 machine.
- All three computers are connected by wired gigabit Ethernet, running through a central gigabit switch.
- If I pause the video for 5-10 seconds the client is able to buffer for a while and when I hit play the video playback is stutter-free for 10-15 seconds or so while it blows through it's read-ahead buffer.
- When a SageTV client is stuttering (and I'm watching the network bandwidth used in Performance Monitor) the network bandwidth is bursty (going from 0.9% - 2.0% utilization of the gigabit connection). When it's not stuttering (which happens on occasion, but I'm not sure why it's okay sometimes and not okay other times) the network traffic is pretty constant at ~1.7% utilization.
- While the Client is playing stuttering video and I check the disk utilization on the server using Resource Monitor, the disk in question is mostly idle.

I'm looking for ideas/tests that I can perform to try and solve this problem.

I'll summarize with the system specs of the three computers:

"Server" machine:
AMD Phenom X4 9550
780G-based motherboard: ATI Radeon™ HD 3200 Graphics
4GB RAM
1 x 1TB Caviar Black OS drive
2 x 2TB Caviar Green SageTV Recording drives


"Bedroom HTPC" machine:
Dell Studio Hybrid
Intel Core 2 Duo
Integrated Intel Graphics Media Accelerator X3100
4GB RAM
(some 320GB 5400RPM 2.5" laptop drive)


"Downstairs HTPC" machine:
AMD Athlon 2 X4
785G-based motherboard: ATI Radeon™ HD 4200 Graphics
4GB RAM
1 x 1TB Caviar Black OS drive

[panteragstk]

What is the memory and cpu usage on the server? My client playback stutters when my server either runs out of memory or the cpu usage is way too high.

[Audacity]

The server machine has a AMD Phenom x4 with 4GB RAM.

[jerryt]

What is the CPU % during stuttering on the client?

Also what video cards are in the clients?

[Audacity]

The files that are being played are 1080i MPEG2 recorded from a HDHR.

The server machine (that plays video back perfectly) is a AMD Phenom X4 9550, running on a 780G-based motherboard using the integrated Radeon graphics (I forget the version number, but the performance is about the same as my other 785G-based system).

My "bedroom htpc" is a Dell Studio Hybrid machine: Core 2 Duo (Integrated Intel Graphics Media Accelerator X3100) client the CPU is in the 40-50% range when playback is stuttering.

I would have suspected the CPU speed was the main culprit except my understand is that video decoders are generally multi threaded (as it is a "embarrassingly parallel" problem), and if I do the pause/resume thing I get 10-15 seconds of perfect video playback.

The "basement htpc" is a Athlon 2 x4, running on a 785G-based motherboard (ATI Radeon 4200 for integrated graphics). This machine should have comparable playback performance as the server machine, but it has stuttering problems as well. I didn't check the CPU use in this system, but I can do that later today. (edit: I just checked, and while stuttering through a recording this quad core's CPU graph hovers between 12-15%).

Also, since this is somewhat relevant I'll list more info: the Dell Studio Hybrid is plugged into a 32" 720p HDTV, the custom-built machine is plugged into a 1080p HDTV.

[panteragstk]

I was asking what percentage of cpu and memory usage there is on the server side when you have the stuttering issues. Sometimes that can be the problem.

[Audacity]

Originally Posted by panteragstk

I was asking what percentage of cpu and memory usage there is on the server side when you have the stuttering issues. Sometimes that can be the problem.

Oh, on the server the CPU use is negligible. Memory use, about 2GB of 4GB is allocated according to Task Manager.

[panteragstk]

Originally Posted by Audacity

One more data point: only recorded TV (MPEG2) video files are stuttering. XviD, h.264/MKV files that I have in my movie collection are fine.

What decoder are you using for mpeg 2? It sounds like some sort of decoder issue. Since you have to pause it and then it plays ok for a few seconds it is similar to my issue with h.264. It was resolved (so far) by updating to the latest video card drivers. Haven't had any stuttering since.

Edit: Hmmm...Apparently I anticipated your question before it was asked. Interesting.

[Audacity]

panteragstk,

Cool! You replied to my post about 45 minutes before I even posted it. Talk about timely responses!

On the client that uses a integrated Radeon HD 4200, I updated the drives about a month ago so they should be relatively new. On the Dell Studio Hybrid, well, to be honest I haven't paid much attention to Intel video drivers, but they are the latest that Windows Update has offered me.

If this is the problem, then software rendering should fix it, right? I can't remember if I had set the MPEG2 renderer to use hardware acceleration or not, I'll try flipping that setting back and forth and see if it makes a difference. If these computers can do 1080p H.264 in software then MPEG2 in software shouldn't be a problem at all.

[Audacity]

One more data point: only recorded TV (MPEG2) video files are stuttering. XviD, h.264/MKV files that I have in my movie collection are fine.

[jerryt]

Originally Posted by Audacity

One more data point: only recorded TV (MPEG2) video files are stuttering. XviD, h.264/MKV files that I have in my movie collection are fine.

What decoder are you selecting for MPEG 2?

[Audacity]

Originally Posted by jerryt

What decoder are you selecting for MPEG 2?

The SageTV decoder.

[panteragstk]

grab the avivo that matches your ati driver version. It is the best I've use regardless of video card type. The sage decoder is ok at best.

[rwc]

I'm using the integrated graphics (radeon hd 4230 (maybe it's 4290?) )...I've read about using avivo, but I can never find where to download it.... Does it work with all the cards?

Does it work (or look) better than ffdshow?

[panteragstk]

Originally Posted by rwc

I'm using the integrated graphics (radeon hd 4230 (maybe it's 4290?) )...I've read about using avivo, but I can never find where to download it.... Does it work with all the cards?

Does it work (or look) better than ffdshow?

If I'm not mistaken it is just a repackaged cyberlink mpeg2 decoder. It would only be for mpeg2, plus it works with dxva and yes it works with all cards.

Click this link and select your OS. Then go to optional downloads for the AMD Media Codec Package as it isn't called AVIVO anymore.

[Audacity]

Thanks for the link (I wasn't able to find these codecs yesterday when I was searching for them).

I'll give it a try tonight on my 785G-based system and see how it goes.

[Audacity]

I finally had time to do more troubleshooting.

Unfortunately, changing the ATI/Cyberlink codec didn't make any difference. I'm pretty sure it's not a MPEG-2 decoder issue because:

- Pausing the video and clicking play again (on the client) causes the problem to go away for ~15 seconds. This seems to indicate that the client is data starved, and that it can handle the data if it's available.

- The same stuttering problem is happening on two different clients that have very different hardware profiles, and that it never happens on the server, which has very similar hardware to one of the clients.

They more I do "is/is not" testing on this the more I'm convinced that the SageTV server must be starving the SageTV client of data. When nothing is recording tomorrow I'll load both clients, check that it is stuttering issue is happening, and then bounce the SageTV service and see if the stuttering clears up on the clients when the server's SageTV service comes back.

If that doesn't clear things up, I'll try the same test, but with a server reboot.

[Audacity]

So, I bounced the SageTV service, no change.

Then I rebooted the server it's running on, no change.

I think the next step is to order a HD Theater 300 to see if that experiences stuttering. If my theory is correct then it will.

I'm also going to submit a ticket to SageTV to see if they have any ideas.

[appelm]

what router are you using? You might try upgrading.. See this thread for a similar issue: http://forums.sagetv.com/forums/showthread.php?t=39023

[Audacity]

I'm using a Netgear WNDR3700 for my router, but that device doesn't sit between the client and server machines. I have a gigabit switch at a "home point" in my basement where all the Ethernet jacks in my house connect to, and the one of those ports are connected to the router. In other words, if I was streaming video from my SageTV server to a SageTV client and reboot the router, that stream wouldn't be interrupted.