Why does GBPVR use so much video card gpu?

[Deusxmachina]

I think I just realized something about maxing out my ATI 2400pro. GBPVR is the only thing that maxes it out. I was thinking the card couldn't keep up with deinterlacing, Weave the gpu is around 50% and then Bob it can sit at 99.9% and cause a stutter every second.

But if I play the same recorded file in another media player, such as Windows Media Player Classic, and turning on VMR9 instead of Overlay, gpu usage is around 10%. CPU usage is within 2% or so of what GBPVR uses.

Is there a setting somewhere that GBPVR is making the video card do five times the work to play the same file? Live TV or just playing a recorded file, doesn't matter, it will use around at least 50% gpu. Using PVRx1 for overlay it does it as well. I thought maybe GBPVR is trying to accelerate the mpeg2, but the card has that turned off by default from the factory, and if it were accelerating mpeg2 the cpu usage should show some kind of change but if it does it's not noticeable.

[stefan]

gbpvr does not in itself try to use mpeg acceleration (nor does it try not to). gbpvr just asks your chosen mpeg decoder to play the file. If you have told gbpvr to use the same decoder that MPC does, then it should use about the same CPU.

That said, different decoders have different ways of enabling/disabling hardware acceleration. Some decoders provide a "settings" button when chosen in GBPVR. When you click that button you might or might not get the choice to enable hardware acceleration (depending on your decoder). With others you might have to do registry hacks to enable hardware acceleration.

Hope I make sense

[sub]

As stefan said, it sounds like whatever combination of decoders you're using is not utilizing the hardware acceleration features of your device. GB-PVR does really play much of role in playback, and it just asks directshow to play it with the specified decoders and renderers.

That said, I have seen several posts on the AVS forums indicating these ATI HD 2400/2600 devices often wont do MPEG2 acceleration (even though they're happy to do MPEG4/AVC/VC1 acceleration), but I didnt read the full details of why.

[zed]

I have a 2600XT PCIe card. Playing a 1080i HD file (dvr-ms) in PVRX2 using the Purevideo decoder runs the gpu at about 55%. If I use the ATI decoder and same file it uses over 90% of the gpu...and gets pretty warm, too. CPU (AMD X2 4200+) usage is pretty much the same with either decoder at 12-15%. PQ is great in both cases, very smooth and no stuttering at all that I can see. If I turn off hardware acceleration in Purevideo the cpu goes way up...55-60% and gpu goes way down so it appears that it is indeed using hardware acceleration. No explanation, just another data point...

Now if only I could get sound over HDMI to work...

[stustunz]

yeah zed but that doesnt help with playing dirty old mpeg2 which is what the problem with these cards is

you did load the seperate audio hdmi driver didnt you

[Deusxmachina]

I think 2600s have mpeg2 hardware acceleration enabled by default. 2400s have it turned off by default. I did the reg tweaks on the last install but not on this one. I don't want the card to do mpeg2 hardware acceleration, just the deinterlacing, and then the UVD chip that kicks in for .264 content.

The gpu seems to be in sync with what deinterlacing method I choose in the software decoders, (I only have Gabest MPV, Cyberlink DTV, and ATI at the moment). Going from Bob deinterlacing to Weave cuts the gpu in half, but it's still around 45%. The gpu isn't supposed to even do anything apparently unless it is accelerating the video, but that's still turned off, and when it was turned on with the last install it behaved this same way.

I then noticed how much gpu the screen resolution uses. With Bob and 1600x1200, it pegs the gpu at 99.9%. I only have Bob down to 85% now because the screen is set to 1280x1024. One guy said those are crazy-high numbers for not having the hardware acceleration reg tweak enabled.

Zed, what is your deinterlacing method for those %s you posted? I think the 2400s can't do better than Bob on 1080i no matter what (hardcoded that way), but 2600s can, and with Vista they have even more headroom, so it's hard to compare %s without knowing more details. I might be doing Bob while you are doing Vector Adaptive.

Also, check your gpu with PVRx2 but then compare that to VLC player or something else. Using VLC is a little strange since it's self-contained, but a file that GBPVR pegs the gpu, I can play it in VLC using any of the deinterlacing methods, and the gpu is like 10% and cpu stays similar. Same with Media Player Classic. Here I thought the card was broken, but maybe it and GBPVR just don't like each other.

[sub]

Remember, when you're using PVRX2.exe you're using the VMR9 Custom renderer, which uses Direct3D for displaying everying. This is why you're still seeing gpu activity.

GBPVR.exe on the other hand will use whatever renderer you have selected in the config app, so if you dont use VMR9 Custom it'll not require Direct3D and you'll most likely see less gpu - comparible with these other apps. It wasnt possible to provide these other renderer options in PVRX2 because its not possible to mix these with the new Direct3D user interface.

[Deusxmachina]

With GBPVR x1 set to Overlay Manager in config, I get the same gpu readings as with PVRx2. That's what really threw me off from the beginning. Also, switching Media Player Classic between Overlay and the various VMRs, the gpu stays way down. Strange stuff.

[sub]

Sorry, I dont know. GB-PVR just uses directshow to play these files.

[stustunz]

is there any way that gbpvr is still trying to write to the screen while playing a mpeg
thats what it seems like
if that makes any sense