I am attempting to play an NDI source in a fairly standard Direct Show movie player. To test whether this can work, I installed the NDI Tools package and verified that it installed Direct Show NDI Source and SpeedHQ Decoder filters.

Ran up the NDI Test Pattern tool and selected the NewTek NDI pattern.
Ran up the Studio Monitor tool to check it was working and verified path.
Loaded Windows Media Player and selected Menu->File->Open URL... and entered:

ndi://{machine name}/TestPattern

This resulted in media player loading but showing a blank screen.

Is this correct? Is there a better way to test whether the DirectShow source is working?