[Android Apps and Games] awaldram:
I'm having the same issue with BubbleUPnPServer on Debian so not WMP related.

When selecting a non subtitled track everything proceeds correctly

qtp3316214-1241 ] INFO - 14:31:48.377 - n : begin transcoding video... (http://192.168.0.10:6544/Content/GetRecording?ChanId=51903&StartTime=2013-08-29T10:59:00Z)

[qtp3316214-1241 ] INFO - 14:31:48.392 - n : transcode process started: ffmpeg -async 1 -i http://192.168.0.10:6544/Content/GetRecording?ChanId=51903&StartTime=2013-08-29T10:59:00Z -vf scale=trunc(oh*a/2)*2:240 -vcodec libx264 -preset medium -acodec libmp3lame -ac 2 -ab 128000 -f mpegts -

[qtp3316214-1241 ] INFO - 14:31:59.10 - n : finished transcoding (aborted)

But when selecting any source where Matroska will be used FFmpeg chokes

[libx264 @ 0xa6c2a40] 264 - core 124 - H.264/MPEG-4 AVC codec - Copyleft 2003-2012 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=6 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
[matroska @ 0xa6c1f00] Subtitle codec 94209 is not supported.
Output #0, matroska, to 'pipe:':
Metadata:
encoder : Lavf54.6.100
Stream #0:0(eng): Audio: mp3, 48000 Hz, stereo, s16, 128 kb/s
Stream #0:1: Video: h264, yuv420p, 226x240 [SAR 640:339 DAR 16:9], q=-1--1, 1k tbn, 25 tbc
Stream #0:2(eng): Subtitle: dvb_subtitle ([6][0][0][0] / 0x0006)
Stream mapping:
Stream #0:1 -> #0:0 (mp2 -> libmp3lame)
Stream #0:0 -> #0:1 (mpeg2video -> libx264)
Stream #0:3 -> #0:2 (copy)
Could not write header for output file #0 (incorrect codec parameters ?)

[qtp3316214-1241 ] INFO - 14:31:25.502 - n : transcode process started: ffmpeg -async 1 -i http://192.168.0.10:6544/Content/GetRecording?ChanId=2011&StartTime=2013-08-15T17:59:00Z -map 0:1 -map 0:0 -map 0:s -c:s copy -vf scale=trunc(oh*a/2)*2:240 -vcodec libx264 -fpre libx264-current.ffpreset -acodec libmp3lame -ac 2 -ab 128000 -f matroska -
[qtp3316214-1241 ] WARNING - 14:31:25.557 - n : ffmpeg error exit code=1
[qtp3316214-1241 ] WARNING - 14:31:25.557 - n : ffmpeg output:

I checked my ffmpeg has Matroska support compiled in

DE m4v raw MPEG-4 video

E matroska Matroska

D matroska,webm Matroska / WebM

E md5 MD5 testing

And also tried your statically compiled version both result in the same issue (no transcoding)

I have tried a number of source points from mythtv -> xbomc same results.

I have no means of changing my main source point as its a 15 encoder myth setup so if its a matroska feed issue from the source I need a mechanism to switch it off in BubbleUPnPServer at the expense of text.

As now 70% of my content will no longer function under BubbleUPnPServer :(

I'd guess this is the issue "[matroska @ 0xa6c1f00] Subtitle codec 94209 is not supported." matroska doe snot support UK DVB subtitles" ?