Re: [tlug] OGG & MP3

[Godwin Stewart <godwin.stewart@example.com>]

On Sat, 20 May 2006 09:37:10 -0400, Jim <jep200404@example.com>
wrote:

> Each time you compress and decompress audio with lossy formats, 
> such as MP3 or Ogg Vorbis, the quality is degraded, 
> so when using lossy compression, you want to compress as few 
> times as possible, preferably just once. 

Agreed.

However, the loss of quality when using OGG is far lower than with MP3
at equivalent bitrates.

MP3 sounds horrible at anything less than 160kbps. OGG is already
perfectly acceptable at 128kbps ("-q 3", the default in oggenc).

IIRC, it has something to do with the algorithms which determine
exactly which harmonics are adjusted after the Fourier transformation
occurs.

> Lossless compression does not have that quality degradation concern. 

But does it really exist? Is FLAC, for example, *really* lossless in
absolute terms or are the losses outside the human audible range (much
like they are in OGG)? IOW, if you compress an uncompressed stream such
as PCM WAV and then re-uncompress the compressed stream, do you get
back exactly the same data as you started with?

-- 
G. Stewart - godwin.stewart@example.com

The most difficult years of marriage are those following the wedding.

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