Let's develop an open-source media archive standard

[Roger Merchberger]

Rumor has it that der Mouse may have mentioned these words:
> > What shall we do with analog audio?  Sample at 44.1KHz / 16-bit PCM
> > and call it done?
>
>No!  Please!  Not for archival purposes!  44.1KHz is good enough for
>casual listening, for most people, but it is not good enough for
>archival - and for a serious audiophile, it's not enough even for
>listening.

Just checking, but are we on the same page? If you're talking *music* then 
I'd agree with you, but if we're talking computer "cassette audio data 
storage" formats, then I would think 44.1KHz would be more than ample, as 
standard (or even "data") cassette tapes had nowhere near this quality...

... and it's not like many people would just sit around listing to it on 
their hi-fi... ;-)

>Of course, this is a choice to be made by the person converting the
>analog data to digital.  I think the format spec should be able to
>describe whatever that person chooses; I think it would be a _very_ bad
>idea to assume anything about what that choice will be.  The format
>should be able to handle anything from 3 bits/sample compressed sound
>such as I get from my voice modem, or even less, to multi-MHz sample
>rates at hundreds of bits per sample (8-eg, channel 32bpp = 256 bits
>per sampling tick).  For audio, you probably could get away with
>capping it at a few GHz sample rate - I'm not sure air can carry
>frequences that high - but I see no reason to impose any limit.

Well, maybe I'm wrong, but "audio" would assume "audible"... as in you need 
to be able to hear it. Standards say that would be 20Hz->20KHz, but I'd say 
DC->25KHz would be better...

... If this archive data is to be around long enough that humans have wiped 
themselves off the map, and dogs eventually evolve to sentience (assuming 
they haven't already, and are taking the "perma-retirement" path to 
enlightment... ;-) then DC->35KHz would probably be about right.

Altho I agree that we shouldn't "impose limits" - and the spec should 
handle as much as possible, I would doubt that there's much analog data out 
there that would exceed 100KHz; and for audio 35KHz would probably be the max.

YMMV, Salt to taste and all that jazz,
Roger "Merch" Merchberger

--
Roger "Merch" Merchberger   | "Profile, don't speculate."
sysadmin, Iceberg Computers |     Daniel J. Bernstein
zmerch at 30below.com          |