[alsa-devel] Onkyo SE-200PCI : What can the first pair of RCA output do?

[Takashi Iwai]

At Tue, 3 Feb 2009 04:22:45 +0000 (GMT),
tycordinal wrote:
> 
> Hi,
>  
> I am running on Fedora 9 / Alsa 1.0.18a. I have tried
> to play 24bits 6ch PCM file on Onkyo SE-200PCI and the
> 6ch output from VGA-like connector are very good.
> 
> Thanks for the good work!
>  
> I would like to know what is the intention for the
> first pair of RCA output? Apparently, I am able to get
>  the first two channels out of the 6 channels audio
> file when I play through plug:surround51, but the
> remaining four channels were not able to get heard.
>  
> Could alsamixer or any asound.rc options can make
> Onkyo SE-200PCI to produce a downmix of 6ch on the
> first pair of RCA output? Can this be done through the
> hardware chips themselves, or any asound.rc options
> can make this work?
> 
> Or could it be, the first pair of RCA output is really
> hardwired, like ice1712/se.c has suggested because of
> WM8740 chip, to always give an exact copy of the first
> 2 channels out of the 6 channels playback?

It's rather a restriction of envy24-HT (ice1724).  The controller chip
has no mix support.

You can downmix, however, easily via alsa-lib plugin by adjusting the
routing table.


Takashi