[comp.dcom.telecom] PCM <-> 16 Bit Audio

JDurand@apple.com (09/26/89)

>rusty@garnet.berkeley.edu writes:
>>Does anybody have any code or know where I can get my hands on some
>>that would convert "normal" (uncompressed) 16 bit digital audio into
>>the 8 bit u-law (or A-law) compressed form that the AM79C30 uses?

>Chip Rosenthal / chip@vector.Dallas.TX.US / Dallas Semiconductor


There is no need to use an equation to generate "uncompressed" data
from PCM code, since there are only 256 possibilities, everyone just
uses a lookup table copied from any CODEC data sheet.  To convert
from "uncompresssed" to PCM, you don't need to be real accurate, just
scan the table for the first entry that is less than or equal to your
data.

Jerry Durand, Durand Interstellar, Inc., sun!cup.portal.com!jdurand