Fun with DVR-MS
'Fun with DVR-MS'... this is the title of an article recently posted on Microsoft's MSDN website by Stephen Toub. In this Article Stephen discusses the DVR-MS file format generated by Windows XP Media Center 2005, provides an introduction to DirectShow, and shows how the latter can be used to work with the former. And that's not all! On the page a download can be found with in it all the programs he discusses in the article including the source code of the programs!
The part where Stephen discusses how to use the WmvConverter really caught our atention because there a great plug-in is introduced: WmvTranscoderPlugin. This plug-in enables you to pick up any recorded program and turn it into a wmv file.
So I've downloaded the package and I installed it on my Media Center and ran it. The first thing I saw when I ran the plug-in is that it in some way 'hacks' into the CD/DVD burning feature of my Media Center and uses it's interface, I already thought so when I looked at the screenshots in the articel on MSDN but because I run a Dutch Media Center I could clearly see it: the things different from the burning plug-in were in English, where the rest of the interface was in Dutch.
After you have given the the name of the target folder, which will end up in the root of the C: drive, you see the same selectionscreen you get when you make a selection for CD/DVD burning. When you click the 'Transcode' button the conversion starts and again you get a dialog box from the CD/DVD burning feature, and here you can really see this feature is used (at least on a Dutch system) because this dialog contains the exact same description as when you are burning a CD or DVD.
While the conversion process is running you can do other things with your Media Center, but unfortunately it's not a totally separate process, like in dCut for example, when you shut down Media Center the conversion also stops. I can't really judge the speed at which a recorded program is converted but it seems reasonably fast, a 40 minutes show recorded at the highest quality was converted in a little over 10 minutes and the file size shrunk from 2.5 Gb to 73 Mb. a good result, but unfortunately the resulting wmv file was only 320x240 so full screen playback on 1024x768 isn't really satisfying.
All in all I came to the conclusion that the WmvTranscoderPlugin is usable, but it is not a finished product ready to be used by every Media Center user to compress his or her recorded programs. But I also think that Stephen did not aim for this, he wrote a great article about the dvr-ms file format and provided some nice coding which other programmers can use for the plug-ins they are building. Maybe this version can be tweaked by editing the supplied prx file, I will certainly have a look at it and report all progress I make with it.
In the end I do want to thank Microsoft and specifically Stephen Toub for making this information available. It's been said a lot off times the support from Microsoft by 'revealing' information on Media Center specific functionality has been very bad, let's hope the publication of this article is the turning point!
LINK !
Wie der Filter, FilterGraphen und die ganzen Interfaces erklärt ist wirklich gut. 