Vista Media Center - Changing the Default MPEG-2 Decoder

I've been playing quite a bit with and like the new beta of Media Center on Vista.

One of the nice things Microsoft have done which will make life a lot easier is to include an Mpeg-2 Decoder with every copy of Vista. This is the bit of software that makes it possible to watch DVD's and view Live and Recorded TV. Those of you who have built your own Media Center Edition PC's using 2005 will know this is a big deal as previously you would have had to buy a decoder from a third-party like Nvidia or Cyberlink.

So all in all a good thing. Wait though, what if you like something the third party decoder does for you? Perhaps it has more settings than the default decoder. Maybe it handles sound better. You would probably guess you could just install your old decoder and Media Center would use that.

Hmmm not exactly!

I've been having performance issues with the default decoder so I thought I would try the Nvidia one instead (I have an Nvidia graphics card and prevously the nvidia PureVideo encoder has worked better with it than the Cyberlink one)

So I installed the Nvidia Encoder opened Media Center, played recorded TV and... no difference. Fair enough I thought maybe my hardware is just not up to Vista but then I realised that the Nvidia icon wasn't showing in the system tray which it usually would when playing video.

After doing some digging I discovered that Vista was still using the Microsoft decoder. Ok I thought, in XP you could use the Microsoft XP Decoder Checkup utility to change the default codec. So, wondering if it would work in Vista, I downloaded ran that utility and... the Nvidia was set as the default decoder - duh!

To cut a long story short Vista media Center stores its default decoder settings in a different place in the registry to XP.



In vista they are in HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Media Center\Decoder whereas in XP they were in
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Media Center\Service\Video

The actual key names are the same
PreferredMPEG2AudioDecoder and PreferredMPEG2VideoDecoder

The Nvidia install had populated the old XP values, so it was a 'simple' matter of copying the values from Service\Video to \Decoder using the registry editor and away I went. The Nvidia icon popped up when I played Recorded TV and there was an improvement in playback.

Now I am not going to suggest that anyone modifies their registry. Modifying the registry is a risky business and you could prevent your PC from working.

But I am working on something which will make this process a whole lot easier...