[LAU] What audio interface to use for a Linux-powered surround preamp?

[Johan Herland]

Thanks for your reply; some comments below.

2012/2/19 Kaza Kore <dj_kaza at hotmail.com>:
> As to video. There are some HDMI capture cards available, EG Black Magic if
> on a tight budget, but from a quick reading it seems they all only support
> the baseline of 2 channel audio on HDMI, rather than the possible 8
> channels.

[...]

An added complication here, is that I want something that will work
with HDCP (AFAICS, the prosumer video equipment you mention will not
accept HDCP signals). Also, I'm not really in the market for lots of
video equipment. I simply want something that can switch between
mutiple HDMI sources (including consumer equipment such as BluRay/DVD
players), and then split the chosen HDMI signal, so that video goes
directly to the screen, and audio goes to my computer for further
processing.

Hence, I'm not really in the market for prosumer/professional video
equipment. I don't actually want the video signal into my computer at
all. However, there is currently no (consumer-level) standard (except
HDMI) for transferring multi-channel uncompressed digital audio
between devices. Ideally, I'd want a device with HDMI input and
HDMI(video) output, along with outputs for transmitting 8ch LPCM
(decoded from the HDMI audio signal). The audio output could be
something like 1 x ADAT, or even 4 x SPDIF (or AES/EBU) - I don't
really care - as long as it could be straightforwardly connected to my
computer.

> Or has the HDMI switch done away with the need for a lot of this? I would of
> used a basic switch, which are available cheaply, then into the computer
> using one of the above methods...

For now, I am using a cheap HDMI switch with an audio de-multiplexer
that redirects the 2ch. bitstream to an SPDIF output. This is
obviously not ideal, since it cannot handle >2ch LPCM (including the
Dolby TrueHD or DTS-HD Master Audio formats), but it _is_ able to do
the Dolby Digital and DTS formats that are compressed into the 2ch.
stream. This is "good enough" for now, since most of my video material
is DVDs (although the BluRay collection is growing slowly), and most
of the high-quality audio is in computer files that I can play
directly from the computer and thus does not have to traverse the HDMI
switch.

Considering the direction technology is moving, I might have most
video and audio accessible directly from the computer in the future,
thus making the HDMI switch less important (only needed for things
like console games, etc.)


Have fun! :)

...Johan

-- 
Johan Herland, <jherland at gmail.com>
www.herland.net