I've been able to address several DolbyTrueHD blurays made into MKV's and successfully played them via my BDT500. Wanted to get back to you on the steps.
As noted before I am making the mkv using DVDFab V126.96.36.199 and the mkv passthrough profile. Nothing fancy. Just use the passthrough.
Once made I open the MVK in MKVMerge. I tried just editing the audio track number and the "Default" setting via the header information. Doing such was suggested by another user. Despite changing the values in the header the resulting mkv still did not play on the BDT500 properly. The BDT500 said the audio track was unrecognized.
The information the BDT500 is looking for apparently is the track id information.
I found no way to change the ID information number in the header edit process. The only way I found to change it was to move it up the list and then change the Default setting and then remux the mkv. Only took a couple of minutes as this isn't changing a whole lot in the mkv file. The default setting for the DolbyTrueHD has to be removed of course.
The result is the AC3 track is now listed as the first audio, the default and has the track id 1.
Playback is perfect via the BDT500 and all I have to do with my other playback devices is select the HD Audio track. The default is now the AC3. Simply hitting the audio button for my AIOS, I have it programmed as an extra button on my touch screen display of my Harmony One, and I cycle to the HD audio.
There might be a way to do this track ID thing via the header edit process. I did not find one.
I grabbed all English audio tracks with DVDFab V8 but could have just kept the one English AC3 and been good to go.
Here's Brave playing through the BDT500 in the back of my house being fed off the NAS drive in my office that has Brave.mkv on it.Edited by jsmiddleton4 - 12/10/13 at 6:29pm