AF_comp_u(3) AF_comp_u(3) NAME AF_comp_u, AF_comp_a - linear to ULAW and ALAW compression tables SYNTAX #include <AF/AFUtils.h> extern unsigned char AF_comp_u[]; extern unsigned char AF_comp_a[]; DESCRIPTION AF_comp_u and AF_comp_a are precomputed tables you can link with your application. Each is indexed by the low 14 bits of a linear twos- complement value in the range between -8192 and +8191. AF_comp_u contains the corresponding U255 law encoding while AF_comp_a contains the corresponding ALAW encoding. EXAMPLES Typical usage is: unsigned char ulaw; int input; /* first limit the signal to the proper range */ if (input > 8191) input = 8191; else if (input < -8181) input = -8191; /* then translate */ ulaw = AF_comp_u[ input & 0x3fff ]; DIAGNOSTICS If you index the table with an out-of-range linear value you may cause a protection fault and crash your application. SEE ALSO AF_exp_u(3), AF_exp_a(3), AF_cvt_u2s(3), AF_cvt_a2s(3), AF_cvt_u2f(3), AF_cvt_a2f(3) AF(1) BUGS If you encounter a reproducible bug, please submit a problem report to (af-bugs@crl.dec.com). COPYRIGHT Copyright 1990-1994, Digital Equipment Corporation. See AF(1) for a full statement of rights and permissions. AUTHORS Tom Levergood and Larry Stewart, Digital Cambridge Research Lab