1 /* 2 ** Copyright 2003-2010, VisualOn, Inc. 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 /*********************************************************************** 18 * File: pred_lt4.c * 19 * * 20 * Description: Compute the result of long term prediction with * 21 * fractional interpolation of resolution 1/4 * 22 * on return exc[0..L_subr-1] contains the interpolated signal * 23 * (adaptive codebook excitation) * 24 * * 25 ************************************************************************/ 26 27 #include "typedef.h" 28 #include "basic_op.h" 29 30 #define UP_SAMP 4 31 #define L_INTERPOL2 16 32 33 /* 1/4 resolution interpolation filter (-3 dB at 0.856*fs/2) in Q14 */ 34 35 Word16 inter4_2[4][32] = 36 { 37 {0,-2,4,-2,-10,38,-88,165,-275,424,-619,871,-1207,1699,-2598,5531,14031,-2147,780,-249, 38 -16,153,-213,226,-209,175,-133,91,-55,28,-10,2}, 39 40 {1,-7,19,-33,47,-52,43,-9,-60,175,-355,626,-1044,1749,-3267,10359,10359,-3267,1749,-1044, 41 626,-355,175,-60,-9,43,-52,47,-33,19, -7, 1}, 42 43 {2,-10,28,-55,91,-133,175,-209,226,-213,153,-16,-249,780,-2147,14031,5531,-2598,1699,-1207, 44 871,-619,424,-275,165,-88,38,-10,-2,4,-2,0}, 45 46 {1,-7,22,-49,92,-153,231,-325,431,-544,656,-762,853,-923,968,15401,968,-923,853,-762, 47 656,-544,431,-325,231,-153,92,-49,22,-7, 1, 0} 48 49 }; 50 51 void Pred_lt4( 52 Word16 exc[], /* in/out: excitation buffer */ 53 Word16 T0, /* input : integer pitch lag */ 54 Word16 frac, /* input : fraction of lag */ 55 Word16 L_subfr /* input : subframe size */ 56 ) 57 { 58 Word16 j, k, *x; 59 Word32 L_sum; 60 Word16 *ptr, *ptr1; 61 Word16 *ptr2; 62 63 x = exc - T0; 64 frac = -frac; 65 if (frac < 0) 66 { 67 frac += UP_SAMP; 68 x--; 69 } 70 x -= 15; /* x = L_INTERPOL2 - 1 */ 71 k = 3 - frac; /* k = UP_SAMP - 1 - frac */ 72 73 ptr2 = &(inter4_2[k][0]); 74 for (j = 0; j < L_subfr; j++) 75 { 76 ptr = ptr2; 77 ptr1 = x; 78 L_sum = vo_mult32((*ptr1++), (*ptr++)); 79 L_sum += vo_mult32((*ptr1++), (*ptr++)); 80 L_sum += vo_mult32((*ptr1++), (*ptr++)); 81 L_sum += vo_mult32((*ptr1++), (*ptr++)); 82 L_sum += vo_mult32((*ptr1++), (*ptr++)); 83 L_sum += vo_mult32((*ptr1++), (*ptr++)); 84 L_sum += vo_mult32((*ptr1++), (*ptr++)); 85 L_sum += vo_mult32((*ptr1++), (*ptr++)); 86 L_sum += vo_mult32((*ptr1++), (*ptr++)); 87 L_sum += vo_mult32((*ptr1++), (*ptr++)); 88 L_sum += vo_mult32((*ptr1++), (*ptr++)); 89 L_sum += vo_mult32((*ptr1++), (*ptr++)); 90 L_sum += vo_mult32((*ptr1++), (*ptr++)); 91 L_sum += vo_mult32((*ptr1++), (*ptr++)); 92 L_sum += vo_mult32((*ptr1++), (*ptr++)); 93 L_sum += vo_mult32((*ptr1++), (*ptr++)); 94 L_sum += vo_mult32((*ptr1++), (*ptr++)); 95 L_sum += vo_mult32((*ptr1++), (*ptr++)); 96 L_sum += vo_mult32((*ptr1++), (*ptr++)); 97 L_sum += vo_mult32((*ptr1++), (*ptr++)); 98 L_sum += vo_mult32((*ptr1++), (*ptr++)); 99 L_sum += vo_mult32((*ptr1++), (*ptr++)); 100 L_sum += vo_mult32((*ptr1++), (*ptr++)); 101 L_sum += vo_mult32((*ptr1++), (*ptr++)); 102 L_sum += vo_mult32((*ptr1++), (*ptr++)); 103 L_sum += vo_mult32((*ptr1++), (*ptr++)); 104 L_sum += vo_mult32((*ptr1++), (*ptr++)); 105 L_sum += vo_mult32((*ptr1++), (*ptr++)); 106 L_sum += vo_mult32((*ptr1++), (*ptr++)); 107 L_sum += vo_mult32((*ptr1++), (*ptr++)); 108 L_sum += vo_mult32((*ptr1++), (*ptr++)); 109 L_sum += vo_mult32((*ptr1++), (*ptr++)); 110 111 L_sum = L_shl2(L_sum, 2); 112 exc[j] = extract_h(L_add(L_sum, 0x8000)); 113 x++; 114 } 115 116 return; 117 } 118 119 120 121
