| Chisato Kenmochi | 9470443 | 2017-01-10 11:56:48 +0900 | [diff] [blame] | 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 | |