Re: Observation about group

[mjmahon@aol.com (Michael J. Mahon)]

Scott Alfter wrote:

>><< You can get 11KHz sounds from almost everywhere.  Practically all
>>Mac sounds are 11KHz (or can easily be resampled to 11KHz).  The
>>trick is extracting the bits from their cozy little resource forks. >>
>>
>>	Give me a place to start looking.  I tried creating my own on the
>>Mac, but neither I nor the demonstrator could find the files in a file
>>search.
>
>WAVs are easier to deal with on an Apple II, as you don't have to deal with
>extracting them from resource forks.  There's a fairly nice utility called
>sox that you can build under Linux, *BSD (maybe this includes MacOS X now),
>Win32, DOS, etc. that will take a WAV (or many other formats) and convert to
>raw 11.025-kHz unsigned 8-bit mono, which is what SoftDAC and similar 8-bit
>Apple II audio players expect.  Back when I was using SoftDAC on a somewhat
>regular basis (read: before upgrading to a IIGS), I used sox all the time
>for that purpose.  I still use it today for other audio-editing purposes,
>such as slight rate changes to make audio length match video length...it's
>faster and easier than most of the WIMP sound-editing tools I've run across.

Yes, and .wav files can be used directly with Sound Editor, since it's
quite easy to trim the headers off.  Resampling to adjust pitch and length
is also straightforward on the //e, for sounds less than 20KB in size (a
little less than 2 seconds).

Sound Editor's uncompressed file load code (in Applesoft) can be easily
modified to load "chunks" of a large sound file in 16KB-20KB pieces,
for extracting the "sound bites" you'd like to save (usually in 2:1
compressed ADPCM format).  One of these days, I should clean up
my "sound explorer" modification of Sound Editor and post it so that
this kind of extraction could be easily done on the //e.

BTW, Scott, your 3-bit SoftDAC was the inspiration for my work.
Getting it up to 5-bit with 2x oversampling was great fun.  ;-)

-michael

 Email:  mjmahon@aol.com
 Home page:  http://members.aol.com/MJMahon/