[vorbis] Using oggenc

[Cameron Patrick]

<de-lurk>

On Thu, Jun 26, 2003 at 10:54:56AM +0530, Santosh Chandwani wrote:
| Actually, audio CD's do have a file format. Each track is burned as a
| *.cda file. There are restrictions on publishing/disclosing the format
| in order to discourage piracy and copyright violations.

I call "rubbish"!  First, the format of Audio CDs is documented
completely in the "Red Book" standard which is available to all and
sundry although at rather inflated prices.  Certainly there are no
restrictions on the format in order to control piracy - bearing in mind
that when audio CDs first came out, the CD-Rs were entirely non-existent
and very few would have been able to afford a computer which could hold
~700MB of audio data.

Audio CDs don't have a file format in the sense of being stored as
ordinary files, with names and sizes and so on, in a standard filesystem
layout such as FAT32 or ISO 9660.  They show up on Windows machines as
being a bunch of ".cda" files; these cda files are IIRC text files that
store information from the table of contents on the CD - more or less
"start playing for 4m:33s at 28m:15s into the CD".  These cda files
don't exist in any physical sense on the CD though, at least not in the
format that they are presented in.

Finally, you can think of the "file format" of audio CDs as the way in
which the audio data is encoded on the CD (i.e. the raw format which CD
burning programs must present to the drive) in which case it is no big
secret either: big endian 16-bit with a sample rate of 44100 Hz and the
left and right channels interleaved.

(N.B. Despite what it may sound like, I'm really no expert on the ins
and outs of CDs, so the specific details above are likely to be wrong.
Nevertheless I think I have the general gist more-or-less correct.)

Cheers,

Cameron.

<lurk>

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