diff options
Diffstat (limited to 'codecs/ilbc/LPCdecode.c')
| -rwxr-xr-x | codecs/ilbc/LPCdecode.c | 273 |
1 files changed, 151 insertions, 122 deletions
diff --git a/codecs/ilbc/LPCdecode.c b/codecs/ilbc/LPCdecode.c index b0d273b32..680ebdfac 100755 --- a/codecs/ilbc/LPCdecode.c +++ b/codecs/ilbc/LPCdecode.c @@ -1,122 +1,151 @@ - -/****************************************************************** - - iLBC Speech Coder ANSI-C Source Code - - LPC_decode.c - - Copyright (c) 2001, - Global IP Sound AB. - All rights reserved. - -******************************************************************/ - -#include <math.h> -#include <string.h> - -#include "helpfun.h" -#include "lsf.h" -#include "iLBC_define.h" -#include "constants.h" -#include "LPCdecode.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 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]; - } - - /* 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; - - /* subframe 1: Interpolation between old and first */ - - LSFinterpolate2a_dec(lp, (*iLBCdec_inst).lsfdeqold, lsfdeq, - lsf_weightTbl[0], length); - memcpy(syntdenum,lp,lp_length*sizeof(float)); - bwexpand(weightdenum, lp, LPC_CHIRP_WEIGHTDENUM, lp_length); - - /* subframes 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[i], - length); - memcpy(syntdenum + pos,lp,lp_length*sizeof(float)); - bwexpand(weightdenum + pos, lp, - LPC_CHIRP_WEIGHTDENUM, lp_length); - pos += lp_length; - } - - /* update memory */ - - memcpy((*iLBCdec_inst).lsfdeqold, lsfdeq2, length*sizeof(float)); - -} - - + +/****************************************************************** + + 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)); + +} + + |