[PLUG] CD player sound and aux. cable?

Fedor Pikus fedorp at wv.mentorg.com
Thu Nov 20 21:15:02 UTC 2003


On Thu, 20 Nov 2003, AthlonRob wrote:
> I was unaware of this connector - I've never seen any software that
> actually plays DVD audio this way... it's all been decoded in software
> and run through the sound drivers that I've seen.
Well, how many people have external amplifiers connected to digital out
of their sound cards? Without such connection, the best you can do is
"record" from S/PDIF and set it to "monitor" so the signal is sent through
the card's DAC to the analog outs, and that takes software support.

> Hmmmm... I always thought you needed drivers to run the S/PDIF stuff.  I
> know I certainly see more than a few messages on the Alsa-User and
> Alsa-Dev mailing lists about folks trying to get S/PDIF working, saying,
> "But it works in Windows..." ... which implies, to me, we're still
> looking at drivers (software).
No, you don't need drivers. What you do need is a mixer which can enable
the S/PDIF in and out (and the mixer, of course, talks to the low-level driver,
so you do need it, but not for playback itself). For some cards which come
with enough connectors digital in/out is just there, can't be enabled or
disabled, then you don't even need drivers.

> CD drives, on the other hand, don't need any software running on the
> machine.  I had a soundblaster compatable soundcard halfway plugged in
If your sound card has digital input enabled, and a receiver connected to
digital out, DVDs will play (the audio part) like that too. The reason it seems
unusual is a) SB does not enable digital in/out by default, and b) very
few people have external decoders, while analog CD input is always enabled,
and the card does not need any software to send the analog signal from inputs
to its amplifier and out to speakers.

-- 
                                  Fedor G. Pikus
Mentor Graphics Corporation         | Phone: (503) 685-4857
8405 SW Boeckman Road               | FAX:   (503) 685-1239
Wilsonville, Oregon 97070           | http://www.pikus.net/~pikus/




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