[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: Re[2]: copy protected audio cds with linux ?

On Mon, Mar 25, 2002 at 07:43:30PM -0500, Sean wrote:
| Of course the thing that just baffles my mind during this whole mp3
| nonsense is the fact that an mp3 is _not_ an exact digital copy of the
| original.

True, but notice too that a CD is not an exact copy of the sound
created by the artist.  Sound is analog energy; the vibration of
particles at any possible frequency.  A digital encoding is inherently
limited to representing only a subset of all the potential sound
waves.  The key to all this, though, is that the sensitivity of humans
ears is limited (some more so than others, like mine ;-)).  If the
digital encoding can represent _enough_ of the sound waves then the
human ear can't tell the difference between that and the original
sound the artist generated in the studio.  This is the whole idea
behind jpeg and mp3 and ogg.  If you can throw away some of the data
then you can reduce storage requirements.  If you don't throw away too
much data, then human ears (eyes in the case of jpeg) can't tell the
difference.  If you study, for example, PCM or v.90 you'll see the
same issues.  With POTS, though, the requirements are merely to be
intelligible and recognizable, thus a 8KHz sample rate is sufficient.
(Have you ever wondered where the 56Kpbs limit comes from?)

| If I want to listen to a
| massive collection of songs via the DVD player in the living room, I'll
| use a different compression level than if I want to listen to a massive
| collection of songs on my computer speakers.

If you're talking about laptop speakers, then you really don't need
wav quality :-).



The heart is deceitful above all things
    and beyond cure.
    Who can understand it?

I the Lord search the heart
    and examine the mind,
to reward a man according to his conduct,
    according to what his deeds deserve.

        Jeremiah 17:9-10

To UNSUBSCRIBE, email to debian-user-request@lists.debian.org 
with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org

Reply to: