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
........

Merged revisions 351450 from http://svn.asterisk.org/svn/asterisk/branches/1.8
........

Merged revisions 351451 from http://svn.asterisk.org/svn/asterisk/branches/10


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@351452 65c4cc65-6c06-0410-ace0-fbb531ad65f3

codecs/ilbc/iCBConstruct.h

@@ -0,0 +1,40 @@
+
+   /******************************************************************
+
+       iLBC Speech Coder ANSI-C Source Code
+
+       iCBConstruct.h
+
+       Copyright (C) The Internet Society (2004).
+       All Rights Reserved.
+
+
+
+
+
+
+   ******************************************************************/
+
+   #ifndef __iLBC_ICBCONSTRUCT_H
+   #define __iLBC_ICBCONSTRUCT_H
+
+   void index_conv_enc(
+       int *index          /* (i/o) Codebook indexes */
+   );
+
+   void index_conv_dec(
+       int *index          /* (i/o) Codebook indexes */
+   );
+
+   void iCBConstruct(
+       float *decvector,   /* (o) Decoded vector */
+       int *index,         /* (i) Codebook indices */
+       int *gain_index,/* (i) Gain quantization indices */
+       float *mem,         /* (i) Buffer for codevector construction */
+       int lMem,           /* (i) Length of buffer */
+       int veclen,         /* (i) Length of vector */
+       int nStages         /* (i) Number of codebook stages */
+   );
+
+   #endif
+