Video stutters with 1GHz processor - why ?

[smdear]

Hello,

I am trying to see if SageTV server will work as expected on an older PC.

The candidate machine has an Asus CUSL-2 motherboard (http://www.motherboard.cz/mb/asus/CUSL2-C.htm)

It has 512Mb of RAM and a 1.0 Ghz Pentium 3 processor.

My graphics card is an ATI All-In-Wonder with a Rage Fury Pro/Xpert 2000 Pro engine.

My sound card is a Sound Blaster Xi-Fi Extreme Audio.

My video capture card is a WinTV PVR-150.

As input files, I have tried the following :
- a downloaded video (350MB in size for a 42 minute show).
* Sage TV is able to transcode and display this correctly. No problems.

- a home video produced by my Sony digital video camera. These files are much larger, and have the following specifications:
Audio: Dolby Digital, 6 channels, 448 kbit/s
Video: 720 x 480, MPEG-2, 9.7 Mbit/s
* Sage TV server behaves erratically when playing back these files. The video and audio start to stutter immediately after playback starts. Let's say I let the player stutter for 20 seconds, then if I rewind 20 seconds I get 20 seconds of perfectly fine video/audio playback, and then we're back to stuttering (I suppose there is some buffering occuring which can explain this).
- The curious thing is that my Sage TV server is only at 70% CPU utilization, and we're nowhere near exhausting available RAM, so my thinking is that I am lacking hardware resources to perform the required transcoding.

- I have tried setting various options under Sage TV server advanced setup Video/Audio section, with no change in results.

- I have tried the registry setting change recommended by Sage in their FAQ, with no change in results.

- I have even tried playing my home movie with another player (Nero Showtime), and the video stutters on playback there as well.

- Can anybody suggest where the bottleneck could be occuring, and if I would need to upgrade some piece of hardware in my system to support transcoding of these video files?

- Or, do you think my problem can be addressed by software alone ?

[Opus4]

I would say the cpu is underpowered, but since you said the cpu usage isn't maxed out, then maybe the video file is fragmented on a drive with a small cluster size -- videos should be on drives formatted with a 64K cluster size.

- Andy

[CollinR]

Which product are you using?

1Ghz is not enough for much of a server, but if you do you probably can't watch on it at the same time.

Placeshifter and Client should run but you will need to make sure you have hardware support from your display adapter.
(I am anti-ATI so I know nothing about them, oddly I think it was your exact video card that made me an ATI hater.)

[gplasky]

Your video card is pretty old and underpowered. If I'm not mistaken those came with about 64 MB of RAM and doesn't even support DirectX 7 so you are getting absolutely no help in the graphic acceleration dept. And even though the cpu isn't maxed out the sse instruction set won't help you alot with today's video needs. And as opus mentioned your default 4 k clusters slows down the disk read and contributes to that stutter.

Gerry

[Slipshod]

That first file is around 1.1Mbps, while your Sony file is 9.7 w/ AC3 audio. BIG difference in relative difficulty to play each of those.

Try defragging your hard disk to see if that improves playback. This is a short-term test, not a long-term fix. If this does help then the hardware *might *be OK as long as you use 64K cluster sizes on a dedicated video hard disk.

Cheers,
Slipshod

P.S. If you are playing back the file locally (as opposed to with an SD video extender), it's not being "transcoded". "decoded" would probably be a better term. Transcoding is when you take a file which is encoded with one codec (like MPEG-2) and convert it to another codec (like H.264).

[GTwannabe]

You need a better video card and more RAM (1 gig, minimum)

[smdear]

Thanks for the replies so far. I'll provide a little more information.

I'm only running Sage TV Server on my system.

I've since defragmented and then partitioned my USB hard drive, now I have a video partition with 64 KB cluster sizes.

Unfortunately, I'm still getting stuttering when I play a home movie file from this partition.

Unfortunately, my motherboard doesn't allow any more than 512MB of RAM to be installed, so I'm trying to determine if I can work within the RAM that I have (and avoid running many programs on startup to maximize the available RAM).

Do you suspect that my problem will go away if I upgrade my video card? Which video card would you recommend for my motherboard ?

I'm seeing stuttering whether I play the video from the Sage TV Server, or from another machine on the network using Sage TV Client. The CPU is not maxed out on either system.

[Opus4]

Originally Posted by smdear

I've since defragmented and then partitioned my USB hard drive, now I have a video partition with 64 KB cluster sizes.

USB 1 or 2?

Can the USB connection handle the throughput? Do you have a different USB controller to connect it to? I seem to remember that some are better than others from posts here long ago.

Is there an internal hard drive you can try using for comparison? What type of hard drive connection does that older system have?

I originally used a P2-400 (with an Xcard for hardware decoded playback) & had to get an ATA/100 add-on card -- the system's original ATA/33 worked, but just barely. After a year, I finally got tired of the old/slow P2-400 system & decided it was better to just build an all-around faster PC & be done with it.

- Andy

[davephan]

Smdear

It sounds like the whole system is a bottleneck! I used to have SageTV setup on an Athlon XP 2800 which was barely useable. When the system board died, I had to use an older computer with an Athlon XP 2100 CPU while I waited for the E6850 CPU to take a big price drop. Those older computers are just too weak for demanding video applications. I used to use 512 meg RAM, it is not enough, since my old system was caching to disk continuously. I boosted it up to 1 gig RAM and it worked much better. My new system, a 3.0 gig dual-core with 2 gigs RAM works far better. My normal RAM usage is about 1 gig continuously.

SageTV drastically improves the Television viewing experience. I think you'll only be disappointed using that obsolete hardware. I'm sorry to say that I think the only way to have a successful SageTV installation would be to replace everything, except for the PVR-150.


Dave

[amac]

I think it may be your video card that lacks the necessary hardware acceleration (of if it has the capability, then it's not turned on). My config is similar to yours with less ram.

I do not get stutters other than a momentary blip every 6 minutes or so (likely caused by Sage's scheduler process checking to see if anything has changed).

My config is in my signature.

[smdear]

OK - a few new updates for my problem (thanks for the replies so far) :

WMP over external USB hard drive - no stuttering
Sage from internal hard drive - no stuttering

Firstly, I put Windows Media Player head-to-head with SageTV and played a home movie file from my external USB hard drive (this is my 300GB drive where I'm storing all my media, since my computer's 20GB drive is not sufficient).

The video/audio stutters under Sage TV, but DOES NOT STUTTER under WMP.

I have tried changing various settings under Video/Audio config, but no significant change (Sage TV still stutters)

Secondly, I tried copying a home movie file to my internal hard drive, and in this case Sage TV server (and Sage client too) plays the file smoothly, without stutter.

So, it looks as though the USB and Sage TV's decoder are acting as co-bottlenecks.

Do we believe there is a software solution to my problem? If not, then I suppose I'd have to consider upgrading my internal hard drive.

Regards,
<Myles>

[paulbeers]

Originally Posted by smdear

OK - a few new updates for my problem (thanks for the replies so far) :

WMP over external USB hard drive - no stuttering
Sage from internal hard drive - no stuttering

Firstly, I put Windows Media Player head-to-head with SageTV and played a home movie file from my external USB hard drive (this is my 300GB drive where I'm storing all my media, since my computer's 20GB drive is not sufficient).

The video/audio stutters under Sage TV, but DOES NOT STUTTER under WMP.

I have tried changing various settings under Video/Audio config, but no significant change (Sage TV still stutters)

Secondly, I tried copying a home movie file to my internal hard drive, and in this case Sage TV server (and Sage client too) plays the file smoothly, without stutter.

So, it looks as though the USB and Sage TV's decoder are acting as co-bottlenecks.

Do we believe there is a software solution to my problem? If not, then I suppose I'd have to consider upgrading my internal hard drive.

Regards,
<Myles>

Seeing as how you are using a Pentium III, I would assume that you only have USB 1.1 on your motherboard which only has a maximum transfer rate of 12mbps. Your home video especially would basically max out the transfer rate. You might be able to get away with an add on USB 2.0 card.....but I think your video card also will need to be upgraded.

[amac]

Given that the large file actually plays fine when it's on the local (presumably IDE) drive, I think that rules out the video card as the main issue. It definitely sounds like a high-speed USB2.0 card would solve the problem.

As to why it plays fine with WMP and not Sage, perhaps it's a buffering problem where WMP buffers a larger amount in advance. Out of my depth on that one as I would think that it would still stutter but perhaps further down the timeline.

Bottom line is your definitely close to the theoretical limits of USB1.1

Originally Posted by paulbeers

Seeing as how you are using a Pentium III, I would assume that you only have USB 1.1 on your motherboard which only has a maximum transfer rate of 12mbps. Your home video especially would basically max out the transfer rate. You might be able to get away with an add on USB 2.0 card.....but I think your video card also will need to be upgraded.

[pjwerdna]

Originally Posted by smdear

So, it looks as though the USB and Sage TV's decoder are acting as co-bottlenecks.

Youre using the SageTV decoder within SageTV?

I dont think this uses hardware decoding so the CPU will be decoding the file with no help from the graphics card. I dont think WMP can use the Sage decoder so its probably using the one installed with the Hauppauge tuner.

Using the Sage decoder probably makes the USB transfer solwer as well.

[Opus4]

Originally Posted by pjwerdna

Youre using the SageTV decoder within SageTV?

I dont think this uses hardware decoding so the CPU will be decoding the file with no help from the graphics card.

There is an option to enable hardware acceleration when using the SageTV decoder.


But, I asked about the USB version above & others mentioned it too -- I just looked it up to confirm & the board specs say it is not USB 2.

- Andy

[amac]

Hmm, perhaps turning on hardware acceleration IS ALSO part of the issue (and would explain why WMP plays the file fine when Sage doesn't). My 1Ghz Duron only ever reaches 23% utilization on playback. I'm using the Hauppauge decoder with registry setting hwmc and dxvA on (i think those are the names in the Frey segment of the registry).

[autoboy]

You keep saying "transcoding." This has me confused. Transcoding is converting one format to another. SageTV server transcodes Dixv videos to mpeg2 to play over a MVP extender which can only play mpeg2 files. Are you using a MVP?

Decoding is probably the word you are looking for. Decoding is playing back the video in its native format. A 1ghz machine should be able to play the file. First, your video card is very old and does not support hardware acceleration. You will need to make sure you have VMR9 turned off in the settings. Use overlay instead. Then, you need to make sure that the file is not limited by the 1.1 USB connection. If those both fail, I might try a few other mpeg2 decoders.

[smdear]

Thanks for everybody's help.

First, the reason I've been using the term "transcoding" is because when I have my Sage TV client playing back a home movie, I see that a process called "SageTvTranscoder.exe" is running on the server and consuming CPU resources.

Second, I have VMR9 turned off and am using Overlap video renderer.

Third, I replaced my USB1.1 with a USB2 connection, and the system is performing acceptably well (not perfect, but at least watchable until such time as I can upgrade my server system).