Poor VMR performance with 98.08?

[acidfiend2003]

I upgraded my laptop to 98.08 yesterday and after a long process of fiddling with skins and plugins etc. I finally got it up and running.

After playing with it for a good few hours I have to say that I really like a lot of the new features and I definately want to take advantage of them but I noticed a major difference in performance in 98.08 that makes it unusable for me.

My laptop is a 1.6ghz Turion 64 with 1mb ram and the ATI Radeon Xpress 200 graphics chipset. In 96.08, I use VMR7 and the Nvidia Purevideo decoder and the CPU usage on average is around 30% when watching LiveTV. In 98.08 the CPU usage is double, and goes up to 90%+ when I use VMR9. In all of the VMR modes it drops frames like crazy.

I managed to get it to work in Overlay mode, but the CPU consumption is still much higher than before. Has anyone else noticed this? I've gone back to 96.08 in the meantime.

Regards
Dave

[sub]

GB-PVR itself doesnt consume the CPU while doing playback - thats just down to directshow. Its still using directshow in the same way as past releases, so unlikely to be any differences in the way the CPU is being used.

If the CPU seems to have increased, them it is most likely using different decoders than before, or using VMR9 Custom renderer instead of VMR9, or something similar.

[acidfiend2003]

The decoders are the same as before (nvidia purevideo/AC3 filter), checked and verified. As per my post I also checked VMR7, VMR9 custom renderer and plain VMR9. Those are in order of CPU consumption - ranging from 60% to maxing out the box. Only overlay gave acceptable, shudder-free video but at the loss of OSD transparency etc. etc.

By contrast, using the same codecs etc. and VMR7 in 96.x uses just 10-20% CPU to watch live TV. There must be something else in additional code that you've added since - are DVB subtitle support and auto-aspect-ratio accomplished entirely with external DirectShow filters??

Regards
Dave

[Ted the Penguin]

have you checked the graph that gbpvr is using to make sure that all the same codecs are being used?

[sub]

If you set <BDAEnableDvbSubtitles>false</BDAEnableDvbSubtitles> and <EnableTeleText>false</EnableTeleText> in config.xml, then these filters are not added to the graph and wont introduce extra overhead.

auto aspect ratio add no measurable overhead - only polls current media format every 5 sconds, and this consumes only a few cycles.

[acidfiend2003]

BDAEnableDvbSubtitles is definately false, I remember doing that as it was the only way I could shut off the subtitles. I don't know about EnableTeleText and without spending another afternoon reinstalling 98.08 I can't be sure.

Maybe I'll give it another go when the next version comes out.

Regards
Dave

[sub]

Honestly, nothing has changed. Its still just using directshow for playback, just as it has in every previous release. We'd be seeing a lot more reports of these types of CPU changes if it was occurring for everybody.

[acidfiend2003]

I guess it would depend on if you're on a "marginal" machine or not. My 1.6ghz Turion + integrated graphics must be quite slow for running GBPVR so I notice any change in CPU consumption more than other users with more powerful equipment.

If I spent the time to reinstall 98.08 and reconfigure it etc. so I could do a proper comparison would you look into my results? do you think, if I installed to different paths, that I could get the two versions to happily coexist on one box to save me a bit of time?

[sub]

I guess it would depend on if you're on a "marginal" machine or not. My 1.6ghz Turion + integrated graphics must be quite slow for running GBPVR so I notice any change in CPU consumption more than other users with more powerful equipment.

Yes, true.

Just so you know - if you configure GB-PVR to use the same video decoder and video renderer as Windows Media Player, then you'll get the exact same CPU usage. (it'll be using the exact same components)

do you think, if I installed to different paths, that I could get the two versions to happily coexist on one box to save me a bit of time?

No, only one version can be installed at a time.

[hick]

I've noticed something similar since upgrading to 98.08. When viewing videos using an nvidia card and the purevideo decoder under VMR9 mode my CPU is being eaten up. Only around 55% for me, but for me this is still like viewing a mpeg without hardware acceleration enabled even though checking the purevideo taskbar control while playing a video shows that hardware acceleration is enabled.

Using the VMR9 Custom Renderer the CPU is 15% usage, much closer to what i've previously experienced with hardware acceleration enabled, but the video tears and jumps too much.

Opening the Graphs created after a run in each mode in graphedit revealed that the graphs were the same, so it's strange that under the same graph but in the two different renderer modes I would experience such a difference in CPU utilization.