I was not aware that Roku supports DLNA, but I'm new to this area. Most of the forums say it does not, but there are hints Roku was planning to in the future.
I did some research on Windows Media Player and came across some information about URLs on their Wiki stating,
"As of 2012 Microsoft still recommends using "mms://" as a "protocol rollover URL".
I tried substituting http:// with mms:// in my links without success.
I was wondering if RokuChris or someone else might know how the Roku Media Player Channel App specifies the URL and whether any special API calls are required to stream from WMP.