This is too off-topic for RSU so I’m moving it out of the thread about Tony’s trials videos.
I found the cause for why I’m no longer able to play MJPG videos in Windows Media Player. In my case it is because of Nero 6 (CD/DVD burning software suite). If I uninstall Nero 6 I’m able to play MJPG videos in Windows Media Player. When I reinstall Nero 6 I can no longer play MJPG videos in WMP. Something in Nero 6 is messing up the video codecs involved.
The error I was getting in Windows Media Player was “Windows Media Player encountered an unknown error”. A dialog box with that error message would pop up when I tried to play an MJPG video.
The codecs involved in playing MJPG video are DirectShow filters. Nero installs a bunch of DirectShow filters for its video playback and editing features. One of those filters tells Windows that it can play MJPG video but when it actually tries it fails with an error. The problem is that the Nero filter is taking precedence over the Microsoft supplied DirectX filter that usually plays MJPG videos.
There is a fix of sorts. The fix is to increase the “merit” of the Microsoft supplied filter so it takes precedence over the broken Nero supplied filter. Windows chooses which filters to use based on a merit system. The filter with the most merit gets to play the video.
Download the Radlight Filter Manager ver. 1.4. It’s a small freeware utility.
Launch the RadLight Filter Manager
Go down to “DirectShow Filters”
Expand the branch for “DirectShow Filters”
Go down to “MJPEG Decompressor”
Expand the branch for “MJPEG Decompressor”
In the dropdown listbox select “MERIT_NORMAL + 1”
Click on the Set Value button to set the new value
Close RadLight Filter Manager
You may have to reboot or log off and log back on to get the changes to propagate. I didn’t have to, but ya never know. Some registry changes don’t always take effect till you shut everything down.
Now try to play an MJPG video file in Windows Media Player. It should now work if the cause of the problem was the same as it was for me.
Be very very careful with RadLight Filter Manager. It can make changes that will break video playback, audio playback, and other features relying on various filters. Playing with RadLight Filter Manager is just like playing with your registry. You can make changes that will totally break things to the point that you may have to reinstall Windows from scratch to recover.
The Microsoft supplied MJPG codec gets installed as part of the DirectX 9 (and possibly DirectX 8) install. If you want to be able to play MJPG videos in Windows Media Player you’ll need to install DirectX 9.
To get back to the default settings for the MJPEG Decompressor filter you can follow the following steps:
Open a command prompt
CD to your Windows directory
CD to the System32 directory
There should be a file named “quartz.dll” in that directory
Run the following command: REGSVR32 quartz.dll
You should get a dialog saying “DllRegisterServer in quartz.dll succeeded.”
The settings for the MJPEG Decompressor filter will now be back to normal
Now to complain to Nero about their buggy set of filters.
