[ILUG] 5.1 surround sound via SPDIF

[Gareth Eason]

Mikhail Ramendik wrote:
[snip]
> I do not have analog 5.1 outputs on my motherboard, but I do have SPDIF 
> output, and the AVR has SPDIF input. A usual DVD player would send 5.1 sound 
> via SPDIF.
> 
> Question: is it possible to make Linux do the same, with any of the assorted 
> DVD playing programs?
[snip]

	   Hi,

	Yes, Linux will quite merrily do this. What you need to do is run raw 
AC-3 (or similar) encoded data over the optical port (the SP/DIF port.)

	ALSA on Linux supports multiple channels and raw digital, so the 
limitation you're going to hit, if any, is with your hardware. If you 
get something from RME or Terratec, who also deal with Pro audio cards 
and devices, it's likely that the card will support streaming AC-3, 
which can be decoded by your external amplifier to 5.1, 4.1, 4.0, 2.0 
(stereo) or 1.0 mono.

	Many hardware DVD players, IME, do NOT send 5.1 out through the SP/DIF 
port. They send stereo encoded PCM. Better models of DVD players will, 
of course, allow you to output the raw AC-3 to an external surround decoder.

	I suspect VLC and Xine on Linux will quite merrily allow you to stream 
AC-3 to a suitable digital interface, but I have not tested either. 
Without a doubt, others will point you in the direction of other DVD 
playing software that works equally as well on Linux :-)

	Best regards,
	-->Gar