Selecting Decoder

[MasterYoda34]

I understand that WMP requires a decoder in order to play DVDs. I also know that you can have more than one decoder installed on a system.

My question is: How does WMP know which decoder to use? And how do you change this setting?

[LoRd_MuldeR]

Basically WMP let's DirectShow decide:
DirectShow will try to build a filter chain between the source (e.g. DVD) and the audio/video renderer.
This filter chain may contain source filters (e.g. file reader), splitters (e.g. AVI Demuxer), decoders (e.g. MPEG-2 Decoder) and more.
If there are several filters installed on your system, that could do the same job, DirectShow will choose the one with the highest "merit" value.
Also I guess that WMP will try to force M$ own filters into the filter chain and only falls back to third-party filters if needed...

BTW: You can use a DirectShow Filter Manager to check/edit the merit values...

[MasterYoda34]

Thanks, that clears up the confusion a bit. Is there any way to verify which filters are actually being used though?

[LoRd_MuldeR]

Thanks, that clears up the confusion a bit. Is there any way to verify which filters are actually being used though?

Good DirectShow-based players let you see which filters they currently use (e.g. Media Player Classic).
M$ prefers to keep that information in secret, there is no way to list the filters in WMP.

Nevertheless there are tools like GraphEdit or GraphStudio that let you show the entire Filter chain:

http://blog.monogram.sk/janos/download/tools/graphstudio.png

http://blog.monogram.sk/janos/tools/monogram-graphstudio/