How do I grab a PCM audio stream from Bluray

[aaron_w2]

I have a music bluray disk I recently purchased that has 5 tracks.
One track is 5.1 DTS audio and the other two are 24-bit 192KHz PCM streams.
I want one of the stereo PCM streams where I can later convert to flac without changing the sample rate, bit depth, etc.
This means that I don't want it watered down to 16-bit.
It seems that no matter what I do, VLC only dumps the dts stream. Is there a way to force VLC to dump another audio stream?
I've tried

:audio=track=X

and

:sub-track=X

in the edit options but it makes no difference and only dumps the first audio track which is DTS.
As far as I can tell, the audio track settings only work for DVDs and not bluray.