Comment 37 for bug 1498129

Raymond:

>Why are three playback devices?

1) is analog output
2) is digital S/PDIF stereo output
3) some other digital output

Playing to the third device lights the "digital output" indicator, but I do not get any sound.
Looks like some sort of S/PDIF output, not supported by my external DAC.

Reading documentation I'd guess it is "Dolby Digital or DTS output", because the manual reads "For Dolby Digital or DTS output, check that the AV receiver is in the correct decoding mode." Also, searching on the Internet suggests that it is DDL: Dolby Digital Live, which can be selected for the S/PDIF output when using Windows software.