[linux-audio-dev] Re: Any interest in DVD-Audio?

Erik de Castro Lopo erikd-lad at mega-nerd.com
Mon Mar 14 17:29:49 EST 2005


On Mon, 14 Mar 2005 20:49:03 +0200
Jussi Laako <jussi.laako at pp.inet.fi> wrote:

> Typical newsgroup FUD.

The paper referenced is this one:

   http://sjeng.org/ftp/SACD.pdf

by Lipshitz and Vanderkooy, two absolute *GIANTS* in the field of digital
audio theory and practice.

> First of all, most of current A/D and D/A converters are delta sigma
> modulators. 

Yes, but from what I've heard, with modern delta-simga converters, 
the minimum bit width is 4 bits, not one bit.

> If you record something at for example 24-bit 192 kHz (using
> typical delta sigma converter),

The A/D converters now use a minimum of 4 bits.

> do some editing (in float format) 

Ie it gets convertered to PCM.

> and
> then output the master as PWM for SACD.

They *may* be some advantage here in that you can pay for a very 
expensive PCM -> SACD converter at the mastering stage and the 
playback system becomes simpler.

However, Sony is pushing SACD as a complete solution for the whole
audio chain. Sony and others are working on SACD multi track recorders
and so on. It is this in particular that Lipshitz and Vanderkooy and
trying to address.

Erik
-- 
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  Erik de Castro Lopo  nospam at mega-nerd.com (Yes it's valid)
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