[Flac-dev] flac can occasionally be worse than shorten

[Mark Powell]

On Thu, 15 Feb 2001, Josh Coalson wrote:

> well, I took a look at the files.  from my
> knowledge of shorten there are two things it does
> that flac doesn't do:
> 
> BUT, you have stumbled on some recordings where the
> LSB is 0 for much of the file.  as a matter of fact,
> in
> the worse track (track 6) almost the entire signal in
> both channels is like that.  taking a 15
> bit-per-sample
> signal and just shifting it left one bit is worse
> than just adding 1 bit of noise, and as distortion
> goes may actually be more audible, so I'm not sure who
> engineered these tracks.

See what you mean. I've just looked at those tracks in a hex editor. Wow,
like you say they seem to have been engineered by Satan himself.

> I've never come across a sample like this which is
> why I thought it wasn't useful to add that
> functionality to FLAC... maybe if this is a common
> practice I should put it in.

Hmm. Does seem like a waste of time. Although it does seem strange that
shorten can out perform flac in these limited cases. When flac does get
out of beta and starts to be adopted by the etree folks (and all of us)
then you're going to get more and more people asking about this? I know my
statistics teacher would shake his head at this conlcusion , but I've
compressed around 50 albums with flac and found 1 where the LSB is 0. Even
if it's 1 in 200, that's going to be lots of cases where shorten out
performs it?
  But, hey I program too and this seems like a pain in the arse to code
just for these limited cases :) Glad you got to the bottom of it though.
Knew you would.
  Later.

Mark Powell - UNIX System Administrator - The University of Salford
Academic Information Services, Clifford Whitworth Building,
Salford University, Manchester, M5 4WT, UK.
Tel: +44 161 295 5936  Fax: +44 161 295 5888  www.pgp.com for PGP key