[mythtv-users] More Digital Audio Q's

[Brian Foddy]

On Sunday 27 November 2005 04:10 pm, Steve Adeff wrote:
> On Sunday 27 November 2005 16:26, Michael T. Dean wrote:
> > Steve Adeff wrote:
> > >On Sunday 27 November 2005 14:19, Brian Foddy wrote:
> > >
> > >
> > >If you require bit-perfect SPDIF output (DVD's 5.1 HDTV) get a Chaintech
> > >AV710, they can be had for $25 from newegg
> > >http://www.newegg.com/Product/Product.asp?Item=N82E16829120103
> > >it does true 192/24 (which NONE of the Creative chips do) and does true
> > >bit-perfect optical digital output.
> > >Heres a thread about using it in linux:
> > >http://mysettopbox.tv/phpBB2/viewtopic.php?t=4132&
> > >
> > >really, any of the ENVY24HT based cards are what you want for
> > > bit-perfect, there are a few out there, with varying levels of SPDIF
> > > support (in/out, optical/coax) and with DAC of varying levels of
> > > quality. Google is your friend in this regard.
> >
> > What exactly does this mean?  If you're doing AC-3 passthrough from
> > Myth, won't the S/PDIF output be as bit-perfect as was sent to you by
> > the digital TV broadcaster/DVD production house?  Or, are you saying
> > that some sound card's mangle the stream they're attempting to pass
> > through?
> >
> > Mike
>
> Yes, 'mangle', because the chipset will do freq/bitrate conversion if
> needed to match the abilities of the output circuitry. If the output
> circuits can handle 24/196 then no change is needed and the chip just sends
> out the signal. Creative's output circuits can't handle 24/196 so the
> signal gets reprocessed to match its output (20/92 iirc). This is whether
> the signal is DD/DTS or PCM.

That's a bummer.  So either I need to look for better quality
onboard sound, or reserve a pci slot for a card...

Brian