I have always used CoreAVC for rendering HD videos, mainly because it runs with mkvs that have multiple subtitles, and it was the only one I could find at the time.

CoreAVC isnt free, and it doesnt do acceleration on formats like WMV, just did a google again, and found this: http://myhpmini.com/forum/mpc-hc-for-hd-video-playback-guide-t2331.html

DXVA seems to be alot better than I last tried, it didnt work very well and was crashing left and right…

Anyway, below is a paste of the relevant content, for archiving purposes, credit of course goes to the original author

by NvIon » Thu Sep 24, 2009 8:20 am

As you all know, the Nvidia Ion chipset’s GPU supports full hardware acceleration for offloading the entire decoding process to the GPU. MPC-HC is a freeware, open source media player that has DXVA hardware accelerated decoder that can take full advantage of the Ion GPU to offload the decoding of HD video formats such as H.264 and VC-1 in MKV container format, which is very popular now & MP4 container format. This guide will help you configure MPC-HC to do it, as easy as possible without installing any codecs or other extra software, everything is contained in MPC-HC executable itself.

First you need to download and install the latest DirectX Redist, MPC-HC uses some update runtimes that are not included in any version of Windows including Windows 7.

http://www.microsoft.com/downloads/deta … ceb6d8fa8d

Now download MPC-HC, you need the 32bit version since Atom N270/N280 only runs 32bit code. I’d suggest download the zip archive and unzipping it, but the installer is fine too if you prefer that.

http://mpc-hc.sourceforge.net/download- … ic-hc.html

Now after you run MPC-HC, press O to enter Options. Go to Playback, make sure Auto-load subtitles is checked if unchecked. This will enable subtitles for foreign language films if the MKV video has embedded subtitles.

Then go to Output, on XP, select VMR9 Renderless, on Windows 7, EVR Custom Pres is what you should select.

Now go to Internal Filters and make sure Matroska & MP4/MOV is checked in Source Filters. Matroska is the full name of MKV, many just call it MKV for simplicity. In Transform Filters, make sure H264/AVC (DXVA) & VC1 (DXVA) is checked. This makes MPC-HC use its DXVA hardware accelerated decoders.

Go to Subtitles, and set Maximum texture resolution to Desktop and uncheck Round up to power of two. This will give you clear, sharp, crisp subtitles.

And you’re done. Now you can enjoy 720P & 1080P H.264 or VC-1 videos on your Mini 311 with the Ion GPU doing all the hard decoding work on the Mini’s screen or output it through the HDMI port to a external LCD-TV or LCD PC monitor. Again, no extra codecs or software needed to be installed, everything is in MPC-HC itself.