My media center works fine when I want to play mp3's, but when I want to play a divx file it returns with a codec unknown message. However, the exact same divx file has no problem playing in my windows media player. I tried uninstalling the divx codec and reinstalling a codec pack from a different source, and I tried to install a different ffdshow filter, but neither worked. How can I get my media center to play my divx files?

My specs:
Vista Home Premium 64
Asus Pundit P1-AH2 barebone with integrated GeForce 6 GPU
AMD Athlon 64 3200+
1GB memory

I don't have a good answer for you, but I recently went through a very similar issue with trying to get Nero Digital MP4 files working under Media Center.

Besides the codec itself, there's a component called "ffdshow" that seems to be part of the codec packs floating around. I'm not exactly sure what it does but I get the impression that it acts as some kind of DirectShow interface that Media Center needs. (Someone else can surely speak to this more intelligently.) Did you try installing that along with your codec pack?

I did eventually get Nero Digital working. The problem was half with the codecs and half with my video card drivers under Vista.

Good luck!

I am having exactly the same problem with an xvid and haven't been able to find a solution yet.  The only thing I can see that is different about this video file compared to other files that will play is that it is encoded at a very high rate (1080p).

Paqratt:

Besides the codec itself, there's a component called "ffdshow" that seems to be part of the codec packs floating around. I'm not exactly sure what it does but I get the impression that it acts as some kind of DirectShow interface that Media Centre needs. (Someone else can surely speak to this more intelligently.) Did you try installing that along with your codec pack?

ffdshow is an open source codec that many believe (myself included) is all you will ever need to play the majority of video/music files.  In fact, most of the codec packs available for download bundle this codec along with a whole bunch of other stuff that is renowned for stuffing up media centre.

Sadly, I have ffdshow installed but still get the error 

If you no problem playing in my windows media player then,
Run regedit see if you have Content Type set to video/mp4 and PerceivedType set to "video"

[HKEY_CLASSES_ROOT\.mp4]
"PerceivedType"="video"
"Content Type"="video/mp4"

Problems could be

a) Too many different codec's installed.  This is way you NEVER install "Codec Packs".  You should have as few codec's installed as are needed.
b) The ffdshow-tryout builds are the best to use with Vista in my experience.
c) Just because it plays in Windows Media Player, doesn't mean it will play in Media Center at this point in Vista.  It should, but codec's still need to be updated.
d) While playing the video in Windows Media Player, right click on the file in the playlist and choose Properties.  It should tell you what codec is actually being used to decode it.

Chris has a good point.
"d) While playing the video in Windows Media Player, right click on the file in the playlist and choose Properties.  It should tell you what codec is actually being used to decode it."

This is how I found out that Media Player was using nero decoder 2 years ago, Nero was giving me problems.

Just played the video in WMP and the properties showed it using ffdshow video decoder as expected, so no further forward sadly.

What version ffdshow do you have?

Try updating it.

FFDSHOW rev. 1104 (20070415)
FFDSHOW rev. 1097 (200700413)
FFDSHOW rev. 1090 (20070405)
FFDSHOW rev. 1082 (200700328)
FFDSHOW rev. 1054 (20070319)
FFDSHOW rev. 1046 (200700317)
FFDSHOW rev. 1038 (20070315)
FFDSHOW rev. 1023 (200700312)
FFDSHOW rev. 1006 (20070307)
FFDSHOW rev. 979 (200700301)
FFDSHOW rev. 960(20070223)
FFDSHOW rev. 945 (20070220)
FFDSHOW rev. 896 (20070208)
FFDSHOW rev. 885 (20070205)
FFDSHOW rev. 866 (20070202)
FFDSHOW rev. 858 (20070130)
FFDSHOW rev. 843 (20070128)
FFDSHOW rev. 802 (20070120)
FFDSHOW rev. 788 (20070117)
FFDSHOW rev. 770 (20070113)
FFDSHOW rev. 756 (20070109)
FFDSHOW rev. 740 (20070105)
FFDSHOW rev. 736 (20070103)
FFDSHOW rev. 731 (20061230)
FFDSHOW rev. 723 (20061229)
FFDSHOW rev. 705 (20061222)
FFDSHOW rev. 696 (20061215)
FFDSHOW rev. 684 (20061211)
FFDSHOW rev. 673 (20061210)
FFDSHOW rev. 664 (20061209)
FFDSHOW rev. 657 (20061209)
FFDSHOW rev. 654 (20061207)
FFDSHOW rev. 641 (20061206)
FFDSHOW rev. 646 (20061207)
FFDSHOW rev. 610 (20061201)
FFDSHOW rev. 598 (20061127)
FFDSHOW rev. 584 (200611123)
FFDSHOW rev. 568 (20061119)
FFDSHOW rev. 529 (20061113)
FFDSHOW rev. 514
FFDSHOW rev420
FFDSHOW 2004-10-12

I use this VistaCodec pack.  They also have a 64bit add on.  (I only use the 32 though)  You need the 64bit version of the codec if you want it ot work in 64bit vista MCE's player.

Package: http://www.msfn.org/board/index.php?showtopic=66826&st=0&p=460040
64 bit ad on: http://www.msfn.org/board/index.php?showtopic=66826&st=0&p=460040&#entry460040

All my .avi xvid files play great.  I can even play them via xbox 360 in extender mode. (transcode360)

Make sure you uninstall ALL other codec packs before you try the above through.

Everybody thanks for the advice, and tanks for the vista codec packs S4Czech, they did help me somewhat. MCE is now able to make thumbnails out of the divx/xvid files. However my problem is not yet solved yet as my nVidia drivers are giving me problems. When they are not installed I am able to play most of the divx/xvid files, however the MCE is running annoyingly slow, with pauses during scrolling of menu items that last from a couple of seconds up to a minute. When I install the latest nVidia x64 drivers for vista the pauses are gone, but as soon as I want to play a file the screen turns black. I think in the background the movie is playing though (the HD is acting the same as how it acts as when I play a movie). After that my MCE is gone to. I have to end it through the taskmanager to get control back. How can I make this work?

My next piece of advice is don't use x64 Vista in the living room.  It's not worth it.  You don't need a 64 bit OS if all you're running is Media Center stuff.   I tried 64 bit for several weeks but gave up.   Too many strange issues, work around, or fun apps that only work in x86 32 bit.   So ask yourself, do you really "need" 64 bit MCE?    I'm happy 64 bit stuff is finally going main stream.  I'd rather my livingroom HTPC have full options, with solid drivers and be easy to maintain/setup though.   Leave 64 bit for your office/workstation/play machine.  If you're the type that likes to live on the edge, then keep on trucking!

MceExplorer:

MCE is now able to make thumbnails out of the divx/xvid files. However my problem is not yet solved yet as my nVidia drivers are giving me problems. When they are not installed I am able to play most of the divx/xvid files, however the MCE is running annoyingly slow, with pauses during scrolling of menu items that last from a couple of seconds up to a minute. When I install the latest nVidia x64 drivers for vista the pauses are gone, but as soon as I want to play a file the screen turns black. I think in the background the movie is playing though (the HD is acting the same as how it acts as when I play a movie). After that my MCE is gone to. I have to end it through the taskmanager to get control back. How can I make this work?

I have exactly the same issue on MCE2005, but only on certain files.

Some play without a problem, with others the screen turns black, I hear 2 seconds of the opening credit and that's it. I've opened them with Gspot to compare the codecs, but there are only minor differences. I'm also a fond believer in ffdshow and it has worked in the past, but it just stopped at a certain time. At the time I didn't feel like pulling the PC apart to find out what happened, WAF you know.

Bubble:

[

I have exactly the same issue on MCE2005, but only on certain files.

Some play without a problem, with others the screen turns black, I hear 2 seconds of the opening credit and that's it.

I've made a new effort this weekend. Deinstalled and reinstalled the ffdshow codec without selecting any sound filter (after a tip from a MCE forum somewhere) and now it works.