Stuttery OTA playback @ 1080p - AVS Forum
Forum Jump: 
 
Thread Tools
post #1 of 7 Old 02-15-2008, 06:15 PM - Thread Starter
Newbie
 
Strik3r's Avatar
 
Join Date: Oct 2006
Posts: 9
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
So i've tried searching and I get the impression that the problem lies in refresh rate but wanted to confirm before i go playing.

I have the following PC setup as a HTPC:

AMD Athlon 64 3500+ (2200mhz)
2 * 512mg DDR400 (1gig) memory
ATI Radeon 3850 w/ HDMI output (including sound)
DVICO Fusion Dual Digital DVB tuner card.

The TV is a SONY SXRD 60" rear pro.

Currently, the output res is full 1920*1080*60hz. DVD's look fine as does my divx/xvid content, but when trying to watch OTA HD, the picture goes very stuttery. Still image or slow moving images look great, but as soon as there is any medium/fast motion (sports, even people walking in a movie) you can really notice a stutter/picture jumping. At first i thought it was just a lack of power in the rig to handle the real time deinterlacing and processing of the 1080i signal to 1080p, but my readings suggest that this PC should be able to handle mpeg 2 decoding fine (if not VC1 / .264 as well).. so is it this annoying refresh rate issue thats causing my stutter ? Im in Australia, so its PAL.. Blu-ray / HDDVD are not an issue for us YET, its just OTA that needs to work.. CPU usage seems to sit < 50% for most of the time.. certainly doesnt seem to max out.

any advice/feedback would be much appreciated.
Strik3r is offline  
Sponsored Links
Advertisement
 
post #2 of 7 Old 02-16-2008, 06:34 AM
AVS Addicted Member
 
walford's Avatar
 
Join Date: May 2003
Location: Orange County, CA
Posts: 16,789
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
Does the sound also stutter?
Does the same problem occur with recorded TV? If not then your tuner card and your graphics card may be sharing a resouce such as an IRQ. Try putting the tuner card in a different slot.
walford is offline  
post #3 of 7 Old 02-16-2008, 03:01 PM - Thread Starter
Newbie
 
Strik3r's Avatar
 
Join Date: Oct 2006
Posts: 9
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
sound does not stutter... Will have to record some TV and playback & let you know... Interesting RE: IRQ conflict.. will swap slots or muck around in BIOS and see if i can clear that up.
Strik3r is offline  
post #4 of 7 Old 02-18-2008, 05:29 PM - Thread Starter
Newbie
 
Strik3r's Avatar
 
Join Date: Oct 2006
Posts: 9
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
hmm, ok ive done more mucking around than i care to mention. Firstly, everything so far seems to point to an IRQ issue. When using the FusionHDTV app, I get about ~28% CPU usage while watching OTA HD using UVD as the decoder, yet the picture is incredibly jumpy. Deinterlacing looks great, as does pic quality on still images, but as soon as there is movement (particularly in sports) the picture goes very jumpy - makes it painful to watch, and definately unacceptable.

Now ive tried the card in all 3 PCI slots with no improvement. The DualDigital2 installs itself as a VIA USB Hub and 2 other VIA USB related things (will post exact names and pics when i get home tonight). The 2 tuners come up as USB devices. No matter which slot i put the capture card in, the video card is always sharing an IRQ with one of the 3 installed devices from the capture card.

Now i noticed that I could disable 2 of the 3 installed devices and still use the tuners but the 3rd one stopped the tuners from working (i think the one that is required is called VIA USB Root Hub and the other 2 were something similar - again will post details when i get home from work). Also at this point in time ive disabled like... everything that isnt required (COM ports, Serial ports etc.).

So i convert my PC from APCI Uniprocess to playin APCI. Now at least I have a proper IRQ listing (i think). Now i disable the Via Root Usb device and reenable it and it gets assigned a new (unique) IRQ under device manager, however the problem is still there when i try load up FusionHDTV. Im guessing that perhaps the device hasn't reallly been assigned a new IRQ because this is actually done by the BIOS during boot ? Unfortunately my Motherboard doesnt provide much in the way of PCI management.

Anyway, things to do this afternoon after work:

- Install MediaPortal and verify that the problem isnt just in FusionHDTV software.

- Flash mobo to latest BIOS and see if i can get any more control over IRQ assignments to PCI slots.

- Download demo files and see if playback stutter occurs there.

- Worst case scenario, reformat (again) and install Windows as Standard PC. I tried to convert to standard PC last time, but while i could still boot, all my USB function disappeared (including my mouse :P).

- failing above 4 steps, kill self. :P

If anyone has any ideas, feel free to post. I will update this thread tonight with any more info i get.
Strik3r is offline  
post #5 of 7 Old 02-18-2008, 07:09 PM
Senior Member
 
TheFranchise's Avatar
 
Join Date: Aug 2007
Posts: 229
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 29
Sounds like a deinterlacing problem, and not from being underpowered. I actually had PowerDVD's deinterlacing cause some stuttering like that on my Sony rear-pro even when I wasn't using PDVD as the viewer. I may have been using its decoder via another program, though. Can't remember. It's the checkbox in the PDVD options.

I also turned down or off all extra image quality options in the control panel. I don't think the deinterlacing setting did anything, but some other not-obvious setting did. I think I turned off anti-aliasing on the card, which was an ATI 2400pro.

Could also be if it's playing with Directshow filters that whatever decoder is being used has the deinterlacing at a bad setting for you. Later, I also got stutters from the 2400pro being at a high resolution and maxing out the gpu. I had to run the video decoder on Weave to not max the gpu, or cut the resolution down to 1280x1024. And then from there I went into all the hacks and tricks and things with the 2400pro in the 2400/2600/2900 owners' thread.

Anyway, sounds like a bad deinterlacing setting somewhere, or even the anti-aliasing setting like on mine. It sounds like it wouldn't affect it, but stranger things have happened.
TheFranchise is offline  
post #6 of 7 Old 02-18-2008, 08:07 PM - Thread Starter
Newbie
 
Strik3r's Avatar
 
Join Date: Oct 2006
Posts: 9
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
ill have a play around with the settings.. its currently using the AVIVO UVD to do its deinterlacing/processing. i could try an earlier driver (or a beta driver) easily enough.. or possibly another decoder.

Quote:
Later, I also got stutters from the 2400pro being at a high resolution and maxing out the gpu. I had to run the video decoder on Weave to not max the gpu, or cut the resolution down to 1280x1024.

yea i read that the 2400 pros would struggle with HD resolutions and that you needed the 2600xt to give you a bit more grunt.. But the ATI 3750 is definately capable of handling the high res's and deinterlacing.. how did you know you were maxing out the GPU ?
Strik3r is offline  
post #7 of 7 Old 02-18-2008, 08:39 PM
Senior Member
 
TheFranchise's Avatar
 
Join Date: Aug 2007
Posts: 229
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 29
Quote:
Originally Posted by Strik3r View Post

how did you know you were maxing out the GPU ?

Because the GPU meter on RivaTuner told me so. I could see small stutters when it bounced off 100%. I later linked it to only happening in one Directshow viewer, and that was with mpeg2 hardware acceleration supposedly turned off through the registry, so it was really odd. I know your card won't max out like that, I merely mentioned it while rambling.

If it wasn't the AA setting that finally fully fixed the big stutters, it was one of the deinterlacers. ...as if they were double-deinterlacing or something. That was awhile ago, so hard to remember exactly. There were multiple stutters at various points. Even not defragging for awhile could cause some small stutters.
TheFranchise is offline  
Reply Home Theater Computers

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off