Hardware decode acceleration of MPEG-2 is of dubious importance
..
. Decode acceleration for H264 and WMV can be very important for HD video decoding (even with some of the lower-end Core2 and Athlon X2 CPUs), but it is only really helpful on a very limited range of recent video cards.
Thanks for your perfectly clear post
On my previous desktop HTPC (XP SP2, PIV 3.2c@3.5, 2 g ram, AGP ..) I tested the following AGP Nvidia graphic cards :
AGP4X 6600 GT 128, AGP8X 7800 GS 256, and the upper AGP8X Nvidia GC found at this time: 7600 GT 256
I tested Mpeg-2, WMV and H264 decoding with 3 different HD videos downloaded from the net
I used PVDV7 deluxe codecs and compared with the last Nvidia Purevideo Codec
On each codec, I set "ON" the Nvidia hardware acceleration
and I compared the result with Nvidia hardw acceler "OFF"
In the Nvidia (last) XP driver of the PC, I set all for "HTPC only" use (Max performance setup, no 3D enhancements etc..)
The codecs setup were the same (Bob deinterlacing, VMR9 etc..)
The results :
- The 3 HD video playing formats (Mpeg-2, WMV and H264) had a signifiant good benefit on the 3 Graphic cards with the hardware acceleration activated
- The "best results" were with the 7600 GT (remember: higest AGP model):
that's why this CG model was the last installed on my previous (AGP) HTPC
nb: I called "best result": Less CPU % utilization + Framerate nearer to the optimum following the video file (25, or 30 fps) + less lost frames + less desync, etc..)
- On MY system, PVDV7 codecs gave better results than Nvidia PureVideo codec
(it was surprising for me, on.. Nvidia cards.!)
- The Hardware acceleration was very useful for my previous HTPC because it as not powerful
Now, as I said before, it's not so important on a more powerful PC :
The results are perfect on my new Vista Laptop HTPC (Core2duo, Nvidia 8400..), but...
... I cannot use Hardware acceleration because...
... None of te codecs which come with CCP codec can activate this hdw. acceleration !!
(MPV mpeg2-codec, FFDshow video codec..)
... and my tests with the new Vista PVDV7 codecs which can activate this acceleration, are not good at all
That' was my 2 cents