1 /* 2 * Copyright (C) 2003 - 2016 Sony Corporation 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 express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include "ldac.h" 18 19 /*************************************************************************************************** 20 Subfunction: Process MDCT Core 21 ***************************************************************************************************/ 22 static void proc_mdct_core_ldac( 23 SCALAR *p_x, 24 SCALAR *p_y, 25 int nlnn) 26 { 27 int i, j, k; 28 int loop1, loop2; 29 int coef, index0, index1, offset; 30 int nsmpl = npow2_ldac(nlnn); 31 const int *p_p; 32 const SCALAR *p_w, *p_c, *p_s; 33 SCALAR a_work[LDAC_MAXLSU]; 34 SCALAR *p_work = a_work; 35 SCALAR a, b, c, d, tmp; 36 SCALAR cc, cs; 37 38 i = nlnn - LDAC_1FSLNN; 39 p_w = gaa_fwin_ldac[i]; 40 p_c = gaa_wcos_ldac[i]; 41 p_s = gaa_wsin_ldac[i]; 42 p_p = gaa_perm_ldac[i]; 43 44 /* Windowing */ 45 for (i = 0; i < nsmpl>>1; i++) { 46 p_work[p_p[i]] = -p_x[3*nsmpl/2-1-i] * p_w[nsmpl/2+i] - p_x[3*nsmpl/2+i] * p_w[nsmpl/2-1-i]; 47 48 p_work[p_p[nsmpl/2+i]] = p_x[i] * p_w[i] - p_x[nsmpl-1-i] * p_w[nsmpl-1-i]; 49 } 50 51 /* Butterfly */ 52 coef = 0; 53 for (i = 0; i < nlnn-1; ++i) { 54 loop1 = 1 << (nlnn-2-i); 55 loop2 = 1 << i; 56 index0 = 0; 57 index1 = 1 << (i+1); 58 offset = 1 << (i+2); 59 60 for (k = 0; k < loop2; ++k) { 61 cc = p_c[coef]; 62 cs = p_s[coef++]; 63 for (j = 0; j < loop1; ++j) { 64 a = p_work[index0+0]; 65 b = p_work[index0+1]; 66 c = p_work[index1+0] * cc + p_work[index1+1] * cs; 67 d = p_work[index1+0] * cs - p_work[index1+1] * cc; 68 69 p_work[index0+0] = a + c; 70 p_work[index0+1] = b + d; 71 p_work[index1+0] = a - c; 72 p_work[index1+1] = b - d; 73 index0 += offset; 74 index1 += offset; 75 } 76 index0 += 2 - nsmpl; 77 index1 += 2 - nsmpl; 78 } 79 } 80 81 tmp = _scalar(1.0) / (SCALAR)(nsmpl>>1); 82 for (i = 0; i < nsmpl>>1; i++) { 83 cc = p_c[coef]; 84 cs = p_s[coef++]; 85 86 index0 = i << 1; 87 a = p_work[index0] * cc + p_work[index0+1] * cs; 88 b = p_work[index0] * cs - p_work[index0+1] * cc; 89 90 p_y[index0] = a * tmp; 91 p_y[nsmpl-index0-1] = b * tmp; 92 } 93 94 return; 95 } 96 97 /*************************************************************************************************** 98 Process MDCT 99 ***************************************************************************************************/ 100 DECLFUNC void proc_mdct_ldac( 101 SFINFO *p_sfinfo, 102 int nlnn) 103 { 104 AC *p_ac; 105 int ich; 106 int nchs = p_sfinfo->cfg.ch; 107 108 for (ich = 0; ich < nchs; ich++) { 109 p_ac = p_sfinfo->ap_ac[ich]; 110 proc_mdct_core_ldac(p_ac->p_acsub->a_time, p_ac->p_acsub->a_spec, nlnn); 111 } 112 113 return; 114 } 115 116
