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

Fons Adriaensen fons.adriaensen at skynet.be
Mon Mar 14 20:54:02 UTC 2005


On Mon, Mar 14, 2005 at 10:13:59PM +0200, Jussi Laako wrote:

> See http://www.cirrus.com/en/images/product_diagrams/4398blkdiag_mag.gif
> and "Direct DSD" path. Which one of the paths, the "Direct DSD" or the
> "PCM" you think is easier and cheaper to make good quality?

This confirms that you can't even have a digital volume control without
going back to some form of pseudo-PCM. How do you control volume on your
all digital DSD-to-PWM amplifier ?  

The 'pure DSD' way of course can be quite simple, but with all the
limitations that simplicity brings along. 

For example, high quality surround should use a format that is independent
of speaker layout (such as Ambisonics), and have the decoding done in the
player, using information about the listener's speaker setup. Just to do
this, DSD would have to be recoded to PCM (unless you do it in the analog
domain). Just from the practical side, distributng audio in PCM format is
much more flexible.

As to pure quality, DSD has an incredible resolution at low frequencies,
but that goes down rapidly as frequency rises. With PCM you get the same
resolution over the entire frequency range. And with 24 bits, you have
a coding space that is much bigger than what your ears are capable of 
decoding.

-- 
FA





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