Include iLBC source code for distribution with Asterisk

This patch includes the iLBC source code for distribution with Asterisk.
Clarification regarding the iLBC source code was provided by Google, and
the appropriate licenses have been included in the codecs/ilbc folder.

Review: https://reviewboard.asterisk.org/r/1675
Review: https://reviewboard.asterisk.org/r/1649

(closes issue: ASTERISK-18943)
Reporter: Leif Madsen
Tested by: Matt Jordan



git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.8@351450 65c4cc65-6c06-0410-ace0-fbb531ad65f3

codecs/ilbc/lsf.h

@@ -0,0 +1,27 @@
+
+   /******************************************************************
+
+       iLBC Speech Coder ANSI-C Source Code
+
+       lsf.h
+
+       Copyright (C) The Internet Society (2004).
+       All Rights Reserved.
+
+   ******************************************************************/
+
+   #ifndef __iLBC_LSF_H
+   #define __iLBC_LSF_H
+
+   void a2lsf(
+       float *freq,/* (o) lsf coefficients */
+       float *a    /* (i) lpc coefficients */
+   );
+
+   void lsf2a(
+       float *a_coef,  /* (o) lpc coefficients */
+       float *freq     /* (i) lsf coefficients */
+   );
+
+   #endif
+