Little help about graphic card HD hardware decoding

[Hallucino]

Hi everyone :)

I already read this thread (url=http://forum.doom9.org/showthread.php?t=130269) about GeForce 8xxx hardware decoding, which gave me advices, but I'd like to get more info about my "case" :)

I'm running Vista Media Center on a P5B/e6600/2Gb Ram/8600GT, and I'm wondering if hardware video decoding would be a benefit for me.
I often watch HD videos while recording with 2 DVB-T tuners (multiple hard drives w. good speeds) and other tasks simulteanoulsy, and I'm wondering if getting a Radeon HD 2600XT (can replace my 8600GT with it for free) to get hardware decoding would be helping, in performance and also quality.
The videos I watch are some HD Xvid, and I'll soon try also BR/HD-DVD rips, so I guess I'll have to get some PowerDVD to configure this.
What do you think ? Is CPU decoding is still the best choice for quality and speed ? (I'm only using ffdshow and don't really know how to configure it properly according to my PC specs, never found any tutorial really explaining everything, I like to understand what I'm doing when touching buttons and sliders :p)

Thanks for your help, and excuse for the big thing to read :)
Also I'm french, so excuse my english, mistakes are to be forgotten :)

Hallucino

[lucassp]

This will help you:
http://www.tomshardware.com/2007/10/26/avivo_hd_vs_purevideo/

[Hallucino]

Thanks for the link, I studied it, and it convinced me to get a 2600XT :)
Do you know if it is possible to let the 2600XT help to decode all video media using Vista Media Center (DVD, HD-DVD, Blu-Ray, Xvid HD video H.264) and how ? Is the codec from latest PowerDVD Ultra suitable for this task ?
Thanks again, help appreciated :)

[Shakey_Jake33]

I don't think it'll help XviD files. PureVideo2 and AVIVO supports hardware assisted decoding of Mpeg2, VC-1 and H.264, but only on the codecs which support such functionality, which is the Cyberlink codec and that's it basically. CoreAVC still uses far less CPU for decoding H.264, and that uses no hardware acceleration at all.

[Blue_MiSfit]

Ok. Here's the deal.

As Shakey_Jake33 says, PureVideo2 / AVIVO do decode H.264, MPEG-2, and VC-1 in hardware - provided you have the Cyberlink decoder.

They do NOT decode MPEG-4 ASP in hardware - so forget about Xvid / DivX acceleration.

The Cyberlink decoder is pretty slow if it's running on the CPU, but if it's running on the GPU (hardware) it's VERY fast. Cyberlink in hardware is much much faster (in terms of CPU time) than CoreAVC in software.

That said, CoreAVC in software is much much faster than Cyberlink in software, IIRC.

Some people have made hardware acceleration work for self-generated H.264 video (x264 video stored inside an MKV container and played in a DirectShow media player for example). From what I've read, it's a bit tricky and not a sure thing.

I'm delving headfirst into this madness soon, as my GeForce 8800gts 320MB is elegible for a free step-up (from eVGA) to an 8800gt 512MB. This new card has PureVideo2, which the GTS lacked.

I will be picking up an HD-DVD drive, and having fun with HD backups soon!

~MiSfit