Home | History | Annotate | Download | only in src
      1 /* ------------------------------------------------------------------
      2  * Copyright (C) 1998-2009 PacketVideo
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
     13  * express or implied.
     14  * See the License for the specific language governing permissions
     15  * and limitations under the License.
     16  * -------------------------------------------------------------------
     17  */
     18 /****************************************************************************************
     19 Portions of this file are derived from the following 3GPP standard:
     20 
     21     3GPP TS 26.173
     22     ANSI-C code for the Adaptive Multi-Rate - Wideband (AMR-WB) speech codec
     23     Available from http://www.3gpp.org
     24 
     25 (C) 2007, 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TTA, TTC)
     26 Permission to distribute, modify and use this file under the standard license
     27 terms listed above has been obtained from the copyright holder.
     28 ****************************************************************************************/
     29 /*
     30 ------------------------------------------------------------------------------
     31 
     32 
     33 
     34  Filename: interpolate_isp.cpp
     35 
     36      Date: 05/08/2004
     37 
     38 ------------------------------------------------------------------------------
     39  REVISION HISTORY
     40 
     41 
     42  Description:
     43 
     44 ------------------------------------------------------------------------------
     45  INPUT AND OUTPUT DEFINITIONS
     46 
     47      int16 isp_old[],         input : isps from past frame
     48      int16 isp_new[],         input : isps from present frame
     49      const int16 frac[],      input : fraction for 3 first subfr (Q15)
     50      int16 Az[]               output: LP coefficients in 4 subframes
     51 
     52 
     53 ------------------------------------------------------------------------------
     54  FUNCTION DESCRIPTION
     55 
     56     Interpolation of the LP parameters in 4 subframes
     57 
     58 
     59 ------------------------------------------------------------------------------
     60  REQUIREMENTS
     61 
     62 
     63 ------------------------------------------------------------------------------
     64  REFERENCES
     65 
     66 ------------------------------------------------------------------------------
     67  PSEUDO-CODE
     68 
     69 ------------------------------------------------------------------------------
     70 */
     71 
     72 
     73 /*----------------------------------------------------------------------------
     74 ; INCLUDES
     75 ----------------------------------------------------------------------------*/
     76 
     77 #include "pv_amr_wb_type_defs.h"
     78 #include "pvamrwbdecoder_basic_op.h"
     79 #include "pvamrwbdecoder_cnst.h"
     80 #include "pvamrwbdecoder_acelp.h"
     81 
     82 /*----------------------------------------------------------------------------
     83 ; MACROS
     84 ; Define module specific macros here
     85 ----------------------------------------------------------------------------*/
     86 
     87 
     88 /*----------------------------------------------------------------------------
     89 ; DEFINES
     90 ; Include all pre-processor statements here. Include conditional
     91 ; compile variables also.
     92 ----------------------------------------------------------------------------*/
     93 
     94 #define MP1 (M+1)
     95 
     96 /*----------------------------------------------------------------------------
     97 ; LOCAL STORE/BUFFER/POINTER DEFINITIONS
     98 ; Variable declaration - defined here and used outside this module
     99 ----------------------------------------------------------------------------*/
    100 
    101 /*----------------------------------------------------------------------------
    102 ; EXTERNAL FUNCTION REFERENCES
    103 ; Declare functions defined elsewhere and referenced in this module
    104 ----------------------------------------------------------------------------*/
    105 
    106 /*----------------------------------------------------------------------------
    107 ; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES
    108 ; Declare variables used in this module but defined elsewhere
    109 ----------------------------------------------------------------------------*/
    110 
    111 /*----------------------------------------------------------------------------
    112 ; FUNCTION CODE
    113 ----------------------------------------------------------------------------*/
    114 
    115 void interpolate_isp(
    116     int16 isp_old[],       /* input : isps from past frame              */
    117     int16 isp_new[],       /* input : isps from present frame           */
    118     const int16 frac[],    /* input : fraction for 3 first subfr (Q15)  */
    119     int16 Az[]             /* output: LP coefficients in 4 subframes    */
    120 )
    121 {
    122     int16 i, k, fac_old, fac_new;
    123     int16 isp[M];
    124     int32 L_tmp;
    125 
    126     for (k = 0; k < 3; k++)
    127     {
    128         fac_new = frac[k];
    129         fac_old = add_int16(sub_int16(32767, fac_new), 1);  /* 1.0 - fac_new */
    130 
    131         for (i = 0; i < M; i++)
    132         {
    133             L_tmp = mul_16by16_to_int32(isp_old[i], fac_old);
    134             L_tmp = mac_16by16_to_int32(L_tmp, isp_new[i], fac_new);
    135             isp[i] = amr_wb_round(L_tmp);
    136         }
    137         Isp_Az(isp, Az, M, 0);
    138         Az += MP1;
    139     }
    140 
    141     /* 4th subframe: isp_new (frac=1.0) */
    142 
    143     Isp_Az(isp_new, Az, M, 0);
    144 
    145     return;
    146 }
    147