Dxva

[jcjefferies]

Does anyone have experience using DXVA or other video accelerators like Pure Video with NPVR? My setup is all SD at the moment but I am looking to upgrade to HD soon. I am trying to work out if I just need to upgrade the motherboard or if a DXVA video card will allow a more modest motherboard upgrade. I have downloaded several H264 1080P video clips to test the current setup on my NPVR server and two clients.

My client is a 2GHZ P4 333Mhz RAM with Geforce 6600 video which supports DXVA and Pure video. Playing SD it runs at around 20% but playing 1080p it runs at 100% although a Cinemascope film runs at around 80% as there is less to process so was watchable most of the time. Although the Cyberlink decoders have DXVA selected in NPVR they are ignored and ffdshow are used instead. Even when the ffdshow DXVA decoder is selected for H264 the same ffdshow video filter is used. I suspect from using DXVA Checker that the card only supports DXVA for MPEG2 but not at 720p or 1080p.

The video card also supports Nvidia’s video accelerator Pure Video but as you have to buy the decoders I downloaded the time limited test decoders. DXVA Checker lists this under H264 at both 720p and 1080p but in NPVR is only listed under MPEG2 decoders and not under H264 decoders and the decoder is not used by NPVR. As two other media players both use the same decoders to play the videos I assume that that the Windows settings are overriding the NPVR settings. My other client is 3GHZ P4 366MHZ RAM but has no AGP slot so has PCI video card. This processes 1080p at around 60% but the video soon lags well behind the voice presumable because the PCI data rate is not fast enough.

[sub]

The Nvidia 6600 doesnt do hardware acceleration of H.264. Hardware acceleration of H.264 needs an Nvidia 8500/8600 or higher.

It usually via DXVA2, usingh the EVR renderer on Vista or Win7. There is some exceptions on XP though.

[ga_mueller]

or 8400gs... selling locally for $10 AR...

[jcjefferies]

I cannot see any mention of DXVA in the spec of any of the Nvidia cards, only their own Pure Video for which you have to buy decoders from Nvidia.

[ga_mueller]

Yes it is confusing. But the fact is, only very few presently manufactured cards support DXVA with a PCI interface. I'm using an 8400gs-PCI and it works great. Other cards would also work, like a 9500GT-PCI, for instance, but they are hard to find anymore. If you did buy an 8400gs-PCI, the Cyberlink decoder would definitely use DXVA for MPEG2. For h264, several free decoders are available. I'm using the one from MPC-HC (mpcvideodec.ax) and it works great for h264... good luck.

[jcjefferies]

Thanks for the help. The Cyberlink H264 decoders have a optional DXVA tick box. My two higher spec spare motherboards both failed recently but my SD setup works well with 6-8 year old technology I am left with. Before I invest in higher spec computer bits I wanted to check I could see the higher quality in normal use on my current displays. My 2GHZ Athlon 3000 NPVR server runs at less than 50% decoding a Cinamascope H264 clip but 90-100% when playing a full 1080P clip. So perhaps a motherboard upgrade is the easiest solution as none of my current spares have PCI Express slots needed by the modern graphics cards.

[rookie]

Hopefully this isn't too off topic. I've noticed that for 1080P I have a higher load with NPVR(35-40%) vs GBPVR(15-20%) using fddshow on the same machine. With GBPVR the load is only one one core. With NPVR the load is balanced among the two cores. I was wondering if there could be a thread affinity difference in NPVR? Either mutliplie threads or something in the code causing a context switch to another core. Maybe the decode thread hasn't been tied to a processor? I am using FSE in GBPVR; so maybe that is what allows the load to be only on a single core.

[Deev8]

So perhaps a motherboard upgrade is the easiest solution as none of my current spares have PCI Express slots needed by the modern graphics cards.

If you do decide on a motherboard upgrade, you could get one with an onboard graphics processor that supports hardware acceleration of H.264 video and avoid the need for a seperate video card. My two year old HTPC was built on a Gigabyte GA-MA78GM-US2H motherboard. Its onboard ATI Radeon HD 3200 graphics provides very satisfactory hardware acceleration for my (H.264 video) HD TV recordings.

[jcjefferies]

I am not familiar with the AMD video cards as all mine just happen to be Nvidia. Does your card use DXVA decoders as there is no mention in the HD3200 spec, or does it use AMD's own system. I was looking at a Gigabyte motherboard but with a Nvidia 7025 processor which only supports Nvidia own Pure Video acceleration for which you have to buy decoders. Can you give me some idea what the processor load runs at when decoding H264 video with and without video acceleration.

[stustunz]

h264 is pretty much done on all cards after 8XXX for nvidia and hd2xxx for ati so pretty much all cards on sale now
if they say they will decode h264 your pretty safe
you dont have to use their decoders cyberlink and other will work also
I think you have to be on W7 to get full use of the newer cards decoding

dxva2 is only on vista and w7

as for dxva you can use cyberlink decoder to do that only SD though

if your getting cpu usage above about 30% you can assume that all processing is been done by the cpu not the gpu(video card)

to get full acceleration of h264 i think you have to use dxva2 which is only on vista/w7 with cards above 8xxx nvidia and ati2xxx