I already wrote it here because somebody had a similar problem:
https://hydrogenaud.io/index.php/topic,113775.0.html
But now i saw it is the foobar forum and i guess it better fits here.
I did convert the PCM from a High Fidelity Pure Audio Blu-ray to FLAC.
First from the Blu-ray to wav with AudioMuxer and then with dBpoweramp to FLAC.
Foobar shows only 6 in the Channels field in Properties on the FLAC files.
If i play a file i have output on BL BR.
If i lock at the same file as wav the Channels field shows 6: FL FR FC LFE SL SR
So this is correct and also the sound output is SL SR.
But the funny thing is that MPC-HC plays the FLAC correct (SL SR).
Then i thought i try it with one pass in AudioMuxer.
AudioMuxer also does convert to wav first and then to FLAC.
But then the Channels field is filled correct.
Also foobar playes it right.
Now i see that AudioMuxer uses "libFLAC 1.2.1 20070917" and dBpoweramp "libFLAC 1.3.1 20141125".
Any special reason AudioMuxer is using such an old FLAC?
Any downside with the old libFLAC?
Why do i have different results - is the new libFLAC or dBpoweramp responsible for the mess up?
Ans why is MPC-HC playing the dBpoweramp FLAC right without the channels fields and foobar not?
MPC-HC (or rather LAV filters) convert 'back' 5.1 to 'side' 5.1.
Also, you can use foobar2000 to convert wav to FLAC. I think you'll get correct FLAC file too.