Line data    Source code

       1             : /******************************************************************************
       2             : *                        ETSI TS 103 634 V1.5.1                               *
       3             : *              Low Complexity Communication Codec Plus (LC3plus)              *
       4             : *                                                                             *
       5             : * Copyright licence is solely granted through ETSI Intellectual Property      *
       6             : * Rights Policy, 3rd April 2019. No patent licence is granted by implication, *
       7             : * estoppel or otherwise.                                                      *
       8             : ******************************************************************************/
       9             : 
      10             : #include "options.h"
      11             : #include "wmc_auto.h"
      12             : #include "functions.h"
      13             : 
      14           0 : void dct2_init(Dct2* dct, int length)
      15             : {
      16           0 :     assert(length <= MAX_LEN);
      17           0 :     dct->length = length;
      18           0 :     fft_init(&dct->fft, length);
      19           0 : }
      20             : 
      21           0 : void dct2_free(Dct2* dct)
      22             : {
      23           0 :     if (dct) {
      24           0 :         fft_free(&dct->fft);
      25           0 :         memset(dct, 0, sizeof(*dct));
      26             :     }
      27           0 : }
      28             : 
      29           0 : void dct2_apply(Dct2* dct, const LC3_FLOAT* input, LC3_FLOAT* output)
      30             : {
      31             :     Complex   tmp1[MAX_LEN];
      32             :     Complex   tmp2[MAX_LEN];
      33             :     int       i;
      34           0 :     assert(input != output);
      35             : 
      36           0 :     for (i = 0; i < 8; i++) {
      37           0 :         tmp1[i]           = cmplx(input[i * 2], 0);
      38           0 :         tmp1[16 - i - 1]  = cmplx(input[i * 2 + 1], 0);
      39             :     }
      40             : 
      41           0 :     fft_apply(&dct->fft, tmp1, tmp2);
      42             : 
      43           0 :     for (i = 0; i < 16; i++) {
      44           0 :         output[i] = cmul(tmp2[i], dct2_16[i]).r;
      45             :     }
      46           0 :     output[0] /= (LC3_FLOAT)1.414213562373095; /* SQRT(2) */
      47           0 : }
      48             : 
      49             : 
      50           0 : void dct4_init(Dct4* dct, int length)
      51             : {
      52             :     int i;
      53           0 :     assert(length <= MAX_LEN);
      54           0 :     dct->length = length;
      55           0 :     dct->twid1  = calloc(sizeof(*dct->twid1), length / 2);
      56           0 :     dct->twid2  = calloc(sizeof(*dct->twid2), length / 2);
      57           0 :     for (i = 0; i < length / 2; i++) {
      58           0 :         dct->twid1[i] = cexpi(-(LC3_FLOAT)M_PI_LC3PLUS * (i + (LC3_FLOAT)0.25) / length);
      59           0 :         dct->twid2[i] = cexpi(-(LC3_FLOAT)M_PI_LC3PLUS * i / length);
      60             :     }
      61           0 :     fft_init(&dct->fft, length / 2);
      62           0 : }
      63             : 
      64           0 : void dct4_free(Dct4* dct)
      65             : {
      66           0 :     if (dct) {
      67           0 :         free(dct->twid1);
      68           0 :         free(dct->twid2);
      69           0 :         fft_free(&dct->fft);
      70           0 :         memset(dct, 0, sizeof(*dct));
      71             :     }
      72           0 : }
      73             : 
      74           0 : void dct4_apply(Dct4* dct, const LC3_FLOAT* input, LC3_FLOAT* output)
      75             : {
      76             :     Complex     tmp2[MAX_LEN / 2];
      77           0 :     int         i    = 0;
      78           0 :     Complex*    tmp1 = (Complex*)output;
      79           0 :     const int   len  = dct->length;
      80           0 :     const LC3_FLOAT norm = (LC3_FLOAT)1.0 / LC3_SQRT((LC3_FLOAT)(len >> 1));
      81           0 :     assert(input != output);
      82             : 
      83           0 :     for (i = 0; i < len >> 1; i++) {
      84           0 :         tmp1[i] = cmul(cmplx(input[i * 2], input[len - i * 2 - 1]), dct->twid1[i]);
      85             :     }
      86             : 
      87           0 :     fft_apply(&dct->fft, tmp1, tmp2);
      88             : 
      89           0 :     for (i = 0; i < len >> 1; i++) {
      90           0 :         Complex t               = cmul(tmp2[i], dct->twid2[i]);
      91           0 :         output[i * 2]           = t.r * norm;
      92           0 :         output[len - i * 2 - 1] = -t.i * norm;
      93             :     }
      94           0 : }