The iLBC ANSI C Source code is available through IETF RFC page, which use is subject to the GIPS Royalty Free License and can be obtained here. In order to extract C code form the draft please use the following awk script (courtesy of Wenju Jiang, Columbia University) and for the command syntax check readme file.
The following package can be used to verify that your compiled iLBC code works correctly.
Included are:
Here is the list of available implementations of iLBC.
Demo
Applications/Systems
HW IP Phones / IADs
Chip
Open Source
Info