Tim Crist wrote:
>
> Help.
>
> I'm trying to reproduce low fi of 300 to 8Khz while using a minimal amount
> of flash memory to do so.  I also want to keep the code simple, and within
> the confines of an 8 bit processor if possible.
>
> I've looked at MP3 and other compression techniques, but most of them
> require a large amount of processing.
>
> First a sanity check:  If I want 3 minutes of 8 bit sound reproduced with
> the max freq. of 8Khz I'll get:
>
> (180 seconds) * (8 bits) * (16000 pulses/ second) = 23.04 megbits of memory
> required
>
> right?
>
> Is there an easy method to half, quarter, or more this audio info to save on
> memory space?


Yes. Use a skilled sound engineer and good recording
equipment. If you have a decent analog "compressor"
to compress the dynamic range of the sound, especially
speech, and a REAL good microphone, you can get excellent
quality at 8bit 5000Hz or even 2000Hz. I have personally
recorded CD music to 8bit 10kHz and almost sounded
CD quality, but you need to know all the tricks.

You didn't mention if this was speech?? If so, a
trained speech person (Radio DJ etc) will help a huge
amount and usually have their own mic and know all the
tricks for pop suppresion and leveling. Contact local
small recording studios, they have local speech people
on file for pay per hour stuff.

If you state your exact needs i'm sure there are lots
of people here with experience who can offer suggestions.
:o)
-Roman

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