BrightScript Debugger> ?cr.GetSubtitleTracks()
<Component: roAssociativeArray>
BrightScript Debugger> ?cr.GetSubtitleTracks()[0]
Language: eng
Description:
TrackName: mkv/3
BrightScript Debugger> cr.ChangeSubtitleTrack(cr.GetSubtitleTracks()[0].TrackName)
*** ERROR: Missing or invalid PHY: 'mkv/3'