Adobe Flash version 11 (& maybe earlier) claim hardware acceleration under Linux is available for modern nVidia cards. This is apparently achieved by Adobe's 'stage' video architecture and the VDPAU interface.

But I'm not sure I've got this working properly.

I'm on Ubuntu 11.10 (upgraded from 11.04) and using a GT250 card on an Intel i3 PC.

I have created the file /etc/adobe/mms.cfg with contents:
I'm using this video for testing:

Right click the video and choose the 'Show video info' menu option. You typically get a popup showing something like:

10 stage fps, 23 video fps
Software video rendering, accelerated video decoding
If I play the video at 1080p, all four cores of the i3 go to about 30% to 40% and the 'top' command shows about CPU = 65%.
My graphics card has a loud fan, and this does increase in noise showing the GPU is indeed doing something.

If I play a downloaded 1080p video using totem (no gpu acceleration) I get
the cores going between 20% to 40% and top shows 55% CPU.

If I play the same downloaded movie using gnome-mplayer with vdpau enabled, the cores show 10% to 20%, and top shows 12% (and the gpu fan noise increases).

To me, it doesn't look like the flash video is being accelerated to any significant extant.

I have tried the following advice, but made no difference:
The advice applied to 11.10 I believe should be modified to:
sudo ln -s /usr/lib/nvidia-current/vdpau/  /usr/lib32/
I note that my /usr/lib32 directory contains no files - just empty folders (maybe a left over from an upgrade?).

I tend to conclude that while there may be some flash video acceleration going one, it isn't doing the whole job.

I wonder if anyone using a low end CPU with a VDPAU capable card has had success in playing HD flash videos under Linux?