I am seeing the "same" issue. I have an MKV with AC3 (french) and DTS (english).
Using a roVideoScreen and setting the videoItem.AudioLanguageSelected = "eng" doesn't seem to work. The MKV played from a HTTP url will only play the AC3 track.
Can anyone confirm that MKV over HTTP works with the AudioLanguageSelected option?
Source file audio streams:
Audio #1
ID : 2
Format : AC-3
Format/Info : Audio Coding 3
Mode extension : CM (complete main)
Format settings, Endianness : Big
Codec ID : A_AC3
Duration : 1h 44mn
Bit rate mode : Constant
Bit rate : 640 Kbps
Channel(s) : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Compression mode : Lossy
Stream size : 480 MiB (6%)
Title : AC3 5.1
Language : French
Default : Yes
Forced : Yes
Audio #2
ID : 3
Format : DTS
Format/Info : Digital Theater Systems
Mode : 16
Format settings, Endianness : Big
Codec ID : A_DTS
Duration : 1h 44mn
Bit rate mode : Constant
Bit rate : 1 509 Kbps
Channel(s) : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Sampling rate : 48.0 KHz
Bit depth : 24 bits
Compression mode : Lossy
Stream size : 1.11 GiB (14%)
Title : DTS 5.1
Language : English
Default : No
Forced : No