[vorbis-dev] Can compressed music sound better than uncompressed?

[David Balazic]

Robert Voigt (f1k at gmx.de) wrote :

> On Wednesday 09 May 2001 22:24, Greg Mayer wrote: 
> > Consider this: 
> > 
> > With digital encoding, we are limited to discrete values for signal 
> > representation. So if we increase the number of bits available to us in 
> > the encoding, then we can get a more accurate representation of the 
> > original analog signal. How can we increase the number of bits available? 
> > We free up bits that would have been used to store audio signals outside of 
> > the normal range of hearing or that were masked by other sounds. 
> > 
> > You are absolutely right that you cannot increase resolution beyond that of 
> > the original recording. But if you have a high quality analog recording, 
> > then you can more closely represent the analog signal digitally with more 
> > bits available to you. Although, in practice, this increase may not be 
> > perceivable to the listener. 
> 
> Ok, you mean feeding a high quality 24 bit PCM to a perceptual encoder may 
> sound better than 16 bit PCM. I agree, but I think the author of that book 
> means comparing 16 bit PCM to compressed music where the input to the encoder 
> was also 16 bit. 

Did you read the book ?

The piece mailed here doesn't mention PCM or even digital audio.
It mentions "perceptual coder" but the tranforms could be done
in a pure analog domain.

>  I quote from "Principles of Digital Audio" by Ken C. Pohlmann:
> 
>    "Because perceptual coders tailor the coded signal to the ear's acuity, they
>    similarly tailor the required response of the playback system itself. Live
>    music does not pass through amplifiers and loudspeakers, it goes directly to
>    the ear. But recorded music must pass through the playback signal chain. Much
>    of the original signal present in a live recording merely degrades the
>    playback system's ability to reproduce the audible signal.

How does it degrade ?
Is the level of degradation noticable or even measurable ?

> Because a
>    perceptual coder removes inaudible signal content, the playback system's
>    ability to convey audible music logically should improve.

He says "should improve", not "will improve".

> In short, a
>    perceptual coder more properly codes an audio signal for passage through an
>    audio system."

He doesn't say that any audio quality improvement should or does happen.
Maybe it only reduces the power consumption of the amplifier , now that sounds
logical ( less audio, less energy , less power )
 
>    Is this bullshit or an interesting thought?


-- 
David Balazic
--------------
"Be excellent to each other." - Bill & Ted
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