<br><br><div><span class="gmail_quote">On 2/23/06, <b class="gmail_sendername">Bob</b> <<a href="mailto:spam@homeurl.co.uk">spam@homeurl.co.uk</a>> wrote:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Every now and then on the list, this page gets posted<br><a href="http://www.elecard.com/technology/dxva.shtml">http://www.elecard.com/technology/dxva.shtml</a><br>in threads about the hardware acceleration capabilities of various GPUs,
<br>with the explanation that DXVA is the Ms version of XvMC but that due to<br>poor support from manufacturers, you won't get some cards to work under<br>linux.<br><br>But my nVidia Geforce 2 MX/MX400 while claiming to support DXVA with
<br>HWMC doesn't support XvMC, is this just nVidia turning it of in the<br>drivers so I have to buy a new card, or does the MPEG acceleration under<br>windows for this card use a different technology not available under linux?
</blockquote><div><br><br>I don't know if/why Nvidia turns off support in their driver. But, the older cards like your GeForce2 as well as the GeForce4 Ti cards, only support the motion compensation portion of DxVA/XvMC. The GeForce4 MX, GeForce FX, and newer cards support motion compensation plus iDCT. Maybe only the cards supporting full MPEG2 acceleration in hardware are enabled by the Linux drivers.
<br><br>The iDCT portion is the much more CPU intensive part of the MPEG decoding offload. I tried DxVA under Windows, with my GeForce4 4200 card (which only supported motion compensation), and the CPU savings was not noticeable. With my GeForce FX 5200, XvMC with the full iDCT offload takes CPU usage from 70% down to 40% on my Athlon64 3200+.
<br><br></div></div>