Both the DRM and
the MLP coding are optional, so in theory you could create
DVD-A disks using only open source software. The matter was
discussed some time ago on the surround sound list, as the
DVD-A format is the only 'mainstream' one allowing musicians
and composers to create their own multichannel recordings.
What concerns me is the output restrictions in place on *any* DVD player
which supports the DVD-Audio format.
As for digital outs - the industry has embraced the HDMI interface due to
its HDCP compatiblility.
HDCP licensees must agree to limit the capabilities of their products such
that DVD-Audio is restricted to DAT quality on non-HDCP digital audio
outputs and 'must design their products to "effectively frustrate attempts
to defeat the content protection requirements." '
High-resolution audio can only ouput through HDCP digital outs (i.e. HDMI)
or analog outs.
This shouldn't be a problem for digital output, but does limit the audio
receiver devices that can be used.
As for analog outs, it appears they're being phased out in the newer
DVD-Audio supporting players - almost certainly due to industry concerns
about the "analog hole" or "analog reconversion problem".
This is further muddied by the pending 'Broadcast Flag' legislation, which
if approved, will require digital output protection technologies on all
digital outs from HDTV signal demodulators and 'analog output must be
limited to a resolution of 480p, which effectively limits sets with analog
input to non-HD resolutions'.
It is not clear to me at this point if this has any bearing on DVD-Audio,
as it depends on what type of receiver system the player outputs to.
(If anyone can shed further illumination on this subject, I'm all ears.)
But real full-spec DVD-A players are rare, and the
future
of the format isn't very clear.
It doesn't look like HD-DVD will replace DVD-Audio, at least w/re to
high-resolution PCM, since it only supports MPEG compression.
What is more the question is - is there any real market interest in
DVD-Audio?
It appears to be a fringe audiophile market - but it is also a *paying*
one. ;)
- Maluvia