summaryrefslogtreecommitdiff
path: root/third_party/ilbc/LPCdecode.c
diff options
context:
space:
mode:
authorBenny Prijono <bennylp@teluu.com>2007-04-07 12:47:34 +0000
committerBenny Prijono <bennylp@teluu.com>2007-04-07 12:47:34 +0000
commit81d1b2797aa3945c529d57f9ddf6179ec2b392a4 (patch)
tree2ae3b710e8152fb1140653473fbc338a6638178e /third_party/ilbc/LPCdecode.c
parent3ade1510e72926d02d7c7d4416257449bc0cd3f3 (diff)
Moved ilbc to third_party directory
git-svn-id: http://svn.pjsip.org/repos/pjproject/branches/split-3rd-party@1169 74dad513-b988-da41-8d7b-12977e46ad98
Diffstat (limited to 'third_party/ilbc/LPCdecode.c')
-rw-r--r--third_party/ilbc/LPCdecode.c158
1 files changed, 158 insertions, 0 deletions
diff --git a/third_party/ilbc/LPCdecode.c b/third_party/ilbc/LPCdecode.c
new file mode 100644
index 00000000..81bab904
--- /dev/null
+++ b/third_party/ilbc/LPCdecode.c
@@ -0,0 +1,158 @@
+
+ /******************************************************************
+
+ iLBC Speech Coder ANSI-C Source Code
+
+ LPC_decode.c
+
+ Copyright (C) The Internet Society (2004).
+ All Rights Reserved.
+
+ ******************************************************************/
+
+ #include <math.h>
+ #include <string.h>
+
+ #include "helpfun.h"
+ #include "lsf.h"
+ #include "iLBC_define.h"
+ #include "constants.h"
+
+ /*---------------------------------------------------------------*
+ * interpolation of lsf coefficients for the decoder
+ *--------------------------------------------------------------*/
+
+ void LSFinterpolate2a_dec(
+ float *a, /* (o) lpc coefficients for a sub-frame */
+ float *lsf1, /* (i) first lsf coefficient vector */
+ float *lsf2, /* (i) second lsf coefficient vector */
+ float coef, /* (i) interpolation weight */
+ int length /* (i) length of lsf vectors */
+ ){
+ float lsftmp[LPC_FILTERORDER];
+
+ interpolate(lsftmp, lsf1, lsf2, coef, length);
+ lsf2a(a, lsftmp);
+ }
+
+ /*---------------------------------------------------------------*
+ * obtain dequantized lsf coefficients from quantization index
+ *--------------------------------------------------------------*/
+
+ void SimplelsfDEQ(
+ float *lsfdeq, /* (o) dequantized lsf coefficients */
+ int *index, /* (i) quantization index */
+ int lpc_n /* (i) number of LPCs */
+ ){
+ int i, j, pos, cb_pos;
+
+
+
+
+
+ /* decode first LSF */
+
+ pos = 0;
+ cb_pos = 0;
+ for (i = 0; i < LSF_NSPLIT; i++) {
+ for (j = 0; j < dim_lsfCbTbl[i]; j++) {
+ lsfdeq[pos + j] = lsfCbTbl[cb_pos +
+ (long)(index[i])*dim_lsfCbTbl[i] + j];
+ }
+ pos += dim_lsfCbTbl[i];
+ cb_pos += size_lsfCbTbl[i]*dim_lsfCbTbl[i];
+ }
+
+ if (lpc_n>1) {
+
+ /* decode last LSF */
+
+ pos = 0;
+ cb_pos = 0;
+ for (i = 0; i < LSF_NSPLIT; i++) {
+ for (j = 0; j < dim_lsfCbTbl[i]; j++) {
+ lsfdeq[LPC_FILTERORDER + pos + j] =
+ lsfCbTbl[cb_pos +
+ (long)(index[LSF_NSPLIT + i])*
+ dim_lsfCbTbl[i] + j];
+ }
+ pos += dim_lsfCbTbl[i];
+ cb_pos += size_lsfCbTbl[i]*dim_lsfCbTbl[i];
+ }
+ }
+ }
+
+ /*----------------------------------------------------------------*
+ * obtain synthesis and weighting filters form lsf coefficients
+ *---------------------------------------------------------------*/
+
+ void DecoderInterpolateLSF(
+ float *syntdenum, /* (o) synthesis filter coefficients */
+ float *weightdenum, /* (o) weighting denumerator
+ coefficients */
+ float *lsfdeq, /* (i) dequantized lsf coefficients */
+ int length, /* (i) length of lsf coefficient vector */
+ iLBC_Dec_Inst_t *iLBCdec_inst
+ /* (i) the decoder state structure */
+ ){
+ int i, pos, lp_length;
+ float lp[LPC_FILTERORDER + 1], *lsfdeq2;
+
+
+
+
+
+
+ lsfdeq2 = lsfdeq + length;
+ lp_length = length + 1;
+
+ if (iLBCdec_inst->mode==30) {
+ /* sub-frame 1: Interpolation between old and first */
+
+ LSFinterpolate2a_dec(lp, iLBCdec_inst->lsfdeqold, lsfdeq,
+ lsf_weightTbl_30ms[0], length);
+ memcpy(syntdenum,lp,lp_length*sizeof(float));
+ bwexpand(weightdenum, lp, LPC_CHIRP_WEIGHTDENUM,
+ lp_length);
+
+ /* sub-frames 2 to 6: interpolation between first
+ and last LSF */
+
+ pos = lp_length;
+ for (i = 1; i < 6; i++) {
+ LSFinterpolate2a_dec(lp, lsfdeq, lsfdeq2,
+ lsf_weightTbl_30ms[i], length);
+ memcpy(syntdenum + pos,lp,lp_length*sizeof(float));
+ bwexpand(weightdenum + pos, lp,
+ LPC_CHIRP_WEIGHTDENUM, lp_length);
+ pos += lp_length;
+ }
+ }
+ else {
+ pos = 0;
+ for (i = 0; i < iLBCdec_inst->nsub; i++) {
+ LSFinterpolate2a_dec(lp, iLBCdec_inst->lsfdeqold,
+ lsfdeq, lsf_weightTbl_20ms[i], length);
+ memcpy(syntdenum+pos,lp,lp_length*sizeof(float));
+ bwexpand(weightdenum+pos, lp, LPC_CHIRP_WEIGHTDENUM,
+ lp_length);
+ pos += lp_length;
+ }
+ }
+
+ /* update memory */
+
+ if (iLBCdec_inst->mode==30)
+ memcpy(iLBCdec_inst->lsfdeqold, lsfdeq2,
+ length*sizeof(float));
+ else
+ memcpy(iLBCdec_inst->lsfdeqold, lsfdeq,
+ length*sizeof(float));
+
+ }
+
+
+
+
+
+