[TriLUG] Command line mp3 ripper

[Bradford Powell]

You hit the nail on the head. FLAC (and shorten too, I suppose though I
have done less reading on it) can encode audio better than bzip2 or gzip
because they take advantage of specific facts about audio. Two predominant
ones are the high autocorrelation between near samples (i.e., if one
sample is high, it is likely that the next one is too) and the often high
correlation between the left and right channels of sound. From my
understanding, the FLAC specification allows an encoder to try several
different methods (per frams) to encode the gestalt of the signal, then
uses a variant of Huffman encoding to compress the difference between the
approximated signal and the actual signal.

FLAC is designed to put much of the processing time on the encoding
side of things (since people generally play sounds back a lot more often
than they encode them). FLAC supports placing tags at various locations
in the file to allow the audio stream to be seekable.

And it is an open specification. (and has an OSI-approved license)

Good reading at: http://flac.sourceforge.net/documentation.html

Linked from their homepage they have a list of comparisons of speed and
compression ratios for various lossless audio compression programs (not
bzip2, though...)

-- Bradford Powell

On 8 May 2003, Jeremy Portzer wrote:

> That's cool -- thanks for the explanation.  Wouldn't it be simpler on a
> Linux system to compress the WAV file with bzip2 or gzip, however?  Or
> because these formats are tuned towards audio, they work better than the
> standard zip formats?  (I've heard that gzip is best on text, for
> example.)
> 
> --Jeremy