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

1 files changed, 241 insertions, 0 deletions

diff --git a/codecs/ilbc/LPCencode.c b/codecs/ilbc/LPCencode.c
new file mode 100644
index 000000000..19695c0fa
--- /dev/null
+++ b/codecs/ilbc/LPCencode.c
@@ -0,0 +1,241 @@
+
+   /******************************************************************
+
+       iLBC Speech Coder ANSI-C Source Code
+
+       LPCencode.c
+
+       Copyright (C) The Internet Society (2004).
+       All Rights Reserved.
+
+   ******************************************************************/
+
+   #include <string.h>
+
+   #include "iLBC_define.h"
+   #include "helpfun.h"
+   #include "lsf.h"
+   #include "constants.h"
+
+
+
+
+
+   /*----------------------------------------------------------------*
+    *  lpc analysis (subrutine to LPCencode)
+    *---------------------------------------------------------------*/
+
+   void SimpleAnalysis(
+       float *lsf,         /* (o) lsf coefficients */
+       float *data,    /* (i) new data vector */
+       iLBC_Enc_Inst_t *iLBCenc_inst
+                           /* (i/o) the encoder state structure */
+   ){
+       int k, is;
+       float temp[BLOCKL_MAX], lp[LPC_FILTERORDER + 1];
+       float lp2[LPC_FILTERORDER + 1];
+       float r[LPC_FILTERORDER + 1];
+
+       is=LPC_LOOKBACK+BLOCKL_MAX-iLBCenc_inst->blockl;
+       memcpy(iLBCenc_inst->lpc_buffer+is,data,
+           iLBCenc_inst->blockl*sizeof(float));
+
+       /* No lookahead, last window is asymmetric */
+
+       for (k = 0; k < iLBCenc_inst->lpc_n; k++) {
+
+           is = LPC_LOOKBACK;
+
+           if (k < (iLBCenc_inst->lpc_n - 1)) {
+               window(temp, lpc_winTbl,
+                   iLBCenc_inst->lpc_buffer, BLOCKL_MAX);
+           } else {
+               window(temp, lpc_asymwinTbl,
+                   iLBCenc_inst->lpc_buffer + is, BLOCKL_MAX);
+           }
+
+           autocorr(r, temp, BLOCKL_MAX, LPC_FILTERORDER);
+           window(r, r, lpc_lagwinTbl, LPC_FILTERORDER + 1);
+
+           levdurb(lp, temp, r, LPC_FILTERORDER);
+           bwexpand(lp2, lp, LPC_CHIRP_SYNTDENUM, LPC_FILTERORDER+1);
+
+           a2lsf(lsf + k*LPC_FILTERORDER, lp2);
+       }
+       is=LPC_LOOKBACK+BLOCKL_MAX-iLBCenc_inst->blockl;
+       memmove(iLBCenc_inst->lpc_buffer,
+           iLBCenc_inst->lpc_buffer+LPC_LOOKBACK+BLOCKL_MAX-is,
+           is*sizeof(float));
+   }
+
+   /*----------------------------------------------------------------*
+
+
+
+
+
+    *  lsf interpolator and conversion from lsf to a coefficients
+    *  (subrutine to SimpleInterpolateLSF)
+    *---------------------------------------------------------------*/
+
+   void LSFinterpolate2a_enc(
+       float *a,       /* (o) lpc coefficients */
+       float *lsf1,/* (i) first set of lsf coefficients */
+       float *lsf2,/* (i) second set of lsf coefficients */
+       float coef,     /* (i) weighting coefficient to use between
+                              lsf1 and lsf2 */
+       long length      /* (i) length of coefficient vectors */
+   ){
+       float  lsftmp[LPC_FILTERORDER];
+
+       interpolate(lsftmp, lsf1, lsf2, coef, length);
+       lsf2a(a, lsftmp);
+   }
+
+   /*----------------------------------------------------------------*
+    *  lsf interpolator (subrutine to LPCencode)
+    *---------------------------------------------------------------*/
+
+   void SimpleInterpolateLSF(
+       float *syntdenum,   /* (o) the synthesis filter denominator
+                                  resulting from the quantized
+                                  interpolated lsf */
+       float *weightdenum, /* (o) the weighting filter denominator
+                                  resulting from the unquantized
+                                  interpolated lsf */
+       float *lsf,         /* (i) the unquantized lsf coefficients */
+       float *lsfdeq,      /* (i) the dequantized lsf coefficients */
+       float *lsfold,      /* (i) the unquantized lsf coefficients of
+                                  the previous signal frame */
+       float *lsfdeqold, /* (i) the dequantized lsf coefficients of
+                                  the previous signal frame */
+       int length,         /* (i) should equate LPC_FILTERORDER */
+       iLBC_Enc_Inst_t *iLBCenc_inst
+                           /* (i/o) the encoder state structure */
+   ){
+       int    i, pos, lp_length;
+       float  lp[LPC_FILTERORDER + 1], *lsf2, *lsfdeq2;
+
+       lsf2 = lsf + length;
+       lsfdeq2 = lsfdeq + length;
+       lp_length = length + 1;
+
+       if (iLBCenc_inst->mode==30) {
+           /* sub-frame 1: Interpolation between old and first
+
+
+
+
+
+              set of lsf coefficients */
+
+           LSFinterpolate2a_enc(lp, lsfdeqold, lsfdeq,
+               lsf_weightTbl_30ms[0], length);
+           memcpy(syntdenum,lp,lp_length*sizeof(float));
+           LSFinterpolate2a_enc(lp, lsfold, lsf,
+               lsf_weightTbl_30ms[0], length);
+           bwexpand(weightdenum, lp, LPC_CHIRP_WEIGHTDENUM, lp_length);
+
+           /* sub-frame 2 to 6: Interpolation between first
+              and second set of lsf coefficients */
+
+           pos = lp_length;
+           for (i = 1; i < iLBCenc_inst->nsub; i++) {
+               LSFinterpolate2a_enc(lp, lsfdeq, lsfdeq2,
+                   lsf_weightTbl_30ms[i], length);
+               memcpy(syntdenum + pos,lp,lp_length*sizeof(float));
+
+               LSFinterpolate2a_enc(lp, lsf, lsf2,
+                   lsf_weightTbl_30ms[i], length);
+               bwexpand(weightdenum + pos, lp,
+                   LPC_CHIRP_WEIGHTDENUM, lp_length);
+               pos += lp_length;
+           }
+       }
+       else {
+           pos = 0;
+           for (i = 0; i < iLBCenc_inst->nsub; i++) {
+               LSFinterpolate2a_enc(lp, lsfdeqold, lsfdeq,
+                   lsf_weightTbl_20ms[i], length);
+               memcpy(syntdenum+pos,lp,lp_length*sizeof(float));
+               LSFinterpolate2a_enc(lp, lsfold, lsf,
+                   lsf_weightTbl_20ms[i], length);
+               bwexpand(weightdenum+pos, lp,
+                   LPC_CHIRP_WEIGHTDENUM, lp_length);
+               pos += lp_length;
+           }
+       }
+
+       /* update memory */
+
+       if (iLBCenc_inst->mode==30) {
+           memcpy(lsfold, lsf2, length*sizeof(float));
+           memcpy(lsfdeqold, lsfdeq2, length*sizeof(float));
+       }
+       else {
+           memcpy(lsfold, lsf, length*sizeof(float));
+           memcpy(lsfdeqold, lsfdeq, length*sizeof(float));
+
+
+
+
+
+       }
+   }
+
+   /*----------------------------------------------------------------*
+    *  lsf quantizer (subrutine to LPCencode)
+    *---------------------------------------------------------------*/
+
+   void SimplelsfQ(
+       float *lsfdeq,    /* (o) dequantized lsf coefficients
+                              (dimension FILTERORDER) */
+       int *index,     /* (o) quantization index */
+       float *lsf,      /* (i) the lsf coefficient vector to be
+                              quantized (dimension FILTERORDER ) */
+       int lpc_n     /* (i) number of lsf sets to quantize */
+   ){
+       /* Quantize first LSF with memoryless split VQ */
+       SplitVQ(lsfdeq, index, lsf, lsfCbTbl, LSF_NSPLIT,
+           dim_lsfCbTbl, size_lsfCbTbl);
+
+       if (lpc_n==2) {
+           /* Quantize second LSF with memoryless split VQ */
+           SplitVQ(lsfdeq + LPC_FILTERORDER, index + LSF_NSPLIT,
+               lsf + LPC_FILTERORDER, lsfCbTbl, LSF_NSPLIT,
+               dim_lsfCbTbl, size_lsfCbTbl);
+       }
+   }
+
+   /*----------------------------------------------------------------*
+    *  lpc encoder
+    *---------------------------------------------------------------*/
+
+   void LPCencode(
+       float *syntdenum, /* (i/o) synthesis filter coefficients
+                                  before/after encoding */
+       float *weightdenum, /* (i/o) weighting denumerator
+                                  coefficients before/after
+                                  encoding */
+       int *lsf_index,     /* (o) lsf quantization index */
+       float *data,    /* (i) lsf coefficients to quantize */
+       iLBC_Enc_Inst_t *iLBCenc_inst
+                           /* (i/o) the encoder state structure */
+   ){
+       float lsf[LPC_FILTERORDER * LPC_N_MAX];
+       float lsfdeq[LPC_FILTERORDER * LPC_N_MAX];
+       int change=0;
+
+       SimpleAnalysis(lsf, data, iLBCenc_inst);
+       SimplelsfQ(lsfdeq, lsf_index, lsf, iLBCenc_inst->lpc_n);
+
+
+
+
+
+       change=LSF_check(lsfdeq, LPC_FILTERORDER, iLBCenc_inst->lpc_n);
+       SimpleInterpolateLSF(syntdenum, weightdenum,
+           lsf, lsfdeq, iLBCenc_inst->lsfold,
+           iLBCenc_inst->lsfdeqold, LPC_FILTERORDER, iLBCenc_inst);
+   }
+