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: syn_filt.c * 19 * * 20 * Description: Do the synthesis filtering 1/A(z) * 21 * * 22 ************************************************************************/ 23 24 #include "typedef.h" 25 #include "basic_op.h" 26 #include "math_op.h" 27 #include "cnst.h" 28 29 #define UNUSED(x) (void)(x) 30 31 void Syn_filt( 32 Word16 a[], /* (i) Q12 : a[m+1] prediction coefficients */ 33 Word16 x[], /* (i) : input signal */ 34 Word16 y[], /* (o) : output signal */ 35 Word16 lg, /* (i) : size of filtering */ 36 Word16 mem[], /* (i/o) : memory associated with this filtering. */ 37 Word16 update /* (i) : 0=no update, 1=update of memory. */ 38 ) 39 { 40 Word32 i, a0; 41 Word16 y_buf[L_SUBFR16k + M16k]; 42 Word32 L_tmp; 43 Word16 *yy, *p1, *p2; 44 yy = &y_buf[0]; 45 /* copy initial filter states into synthesis buffer */ 46 for (i = 0; i < 16; i++) 47 { 48 *yy++ = mem[i]; 49 } 50 a0 = (a[0] >> 1); /* input / 2 */ 51 /* Do the filtering. */ 52 for (i = 0; i < lg; i++) 53 { 54 p1 = &a[1]; 55 p2 = &yy[i-1]; 56 L_tmp = vo_mult32(a0, x[i]); 57 L_tmp -= vo_mult32((*p1++), (*p2--)); 58 L_tmp -= vo_mult32((*p1++), (*p2--)); 59 L_tmp -= vo_mult32((*p1++), (*p2--)); 60 L_tmp -= vo_mult32((*p1++), (*p2--)); 61 L_tmp -= vo_mult32((*p1++), (*p2--)); 62 L_tmp -= vo_mult32((*p1++), (*p2--)); 63 L_tmp -= vo_mult32((*p1++), (*p2--)); 64 L_tmp -= vo_mult32((*p1++), (*p2--)); 65 L_tmp -= vo_mult32((*p1++), (*p2--)); 66 L_tmp -= vo_mult32((*p1++), (*p2--)); 67 L_tmp -= vo_mult32((*p1++), (*p2--)); 68 L_tmp -= vo_mult32((*p1++), (*p2--)); 69 L_tmp -= vo_mult32((*p1++), (*p2--)); 70 L_tmp -= vo_mult32((*p1++), (*p2--)); 71 L_tmp -= vo_mult32((*p1++), (*p2--)); 72 L_tmp -= vo_mult32((*p1), (*p2)); 73 74 L_tmp = L_shl2(L_tmp, 4); 75 y[i] = yy[i] = extract_h(L_add(L_tmp, 0x8000)); 76 } 77 /* Update memory if required */ 78 if (update) 79 for (i = 0; i < 16; i++) 80 { 81 mem[i] = yy[lg - 16 + i]; 82 } 83 return; 84 } 85 86 87 void Syn_filt_32( 88 Word16 a[], /* (i) Q12 : a[m+1] prediction coefficients */ 89 Word16 m, /* (i) : order of LP filter */ 90 Word16 exc[], /* (i) Qnew: excitation (exc[i] >> Qnew) */ 91 Word16 Qnew, /* (i) : exc scaling = 0(min) to 8(max) */ 92 Word16 sig_hi[], /* (o) /16 : synthesis high */ 93 Word16 sig_lo[], /* (o) /16 : synthesis low */ 94 Word16 lg /* (i) : size of filtering */ 95 ) 96 { 97 Word32 i,a0; 98 Word32 L_tmp, L_tmp1; 99 Word16 *p1, *p2, *p3; 100 UNUSED(m); 101 102 a0 = a[0] >> (4 + Qnew); /* input / 16 and >>Qnew */ 103 /* Do the filtering. */ 104 for (i = 0; i < lg; i++) 105 { 106 L_tmp = 0; 107 L_tmp1 = 0; 108 p1 = a; 109 p2 = &sig_lo[i - 1]; 110 p3 = &sig_hi[i - 1]; 111 112 L_tmp -= vo_mult32((*p2--), (*p1)); 113 L_tmp1 -= vo_mult32((*p3--), (*p1++)); 114 L_tmp -= vo_mult32((*p2--), (*p1)); 115 L_tmp1 -= vo_mult32((*p3--), (*p1++)); 116 L_tmp -= vo_mult32((*p2--), (*p1)); 117 L_tmp1 -= vo_mult32((*p3--), (*p1++)); 118 L_tmp -= vo_mult32((*p2--), (*p1)); 119 L_tmp1 -= vo_mult32((*p3--), (*p1++)); 120 L_tmp -= vo_mult32((*p2--), (*p1)); 121 L_tmp1 -= vo_mult32((*p3--), (*p1++)); 122 L_tmp -= vo_mult32((*p2--), (*p1)); 123 L_tmp1 -= vo_mult32((*p3--), (*p1++)); 124 L_tmp -= vo_mult32((*p2--), (*p1)); 125 L_tmp1 -= vo_mult32((*p3--), (*p1++)); 126 L_tmp -= vo_mult32((*p2--), (*p1)); 127 L_tmp1 -= vo_mult32((*p3--), (*p1++)); 128 L_tmp -= vo_mult32((*p2--), (*p1)); 129 L_tmp1 -= vo_mult32((*p3--), (*p1++)); 130 L_tmp -= vo_mult32((*p2--), (*p1)); 131 L_tmp1 -= vo_mult32((*p3--), (*p1++)); 132 L_tmp -= vo_mult32((*p2--), (*p1)); 133 L_tmp1 -= vo_mult32((*p3--), (*p1++)); 134 L_tmp -= vo_mult32((*p2--), (*p1)); 135 L_tmp1 -= vo_mult32((*p3--), (*p1++)); 136 L_tmp -= vo_mult32((*p2--), (*p1)); 137 L_tmp1 -= vo_mult32((*p3--), (*p1++)); 138 L_tmp -= vo_mult32((*p2--), (*p1)); 139 L_tmp1 -= vo_mult32((*p3--), (*p1++)); 140 L_tmp -= vo_mult32((*p2--), (*p1)); 141 L_tmp1 -= vo_mult32((*p3--), (*p1++)); 142 L_tmp -= vo_mult32((*p2--), (*p1)); 143 L_tmp1 -= vo_mult32((*p3--), (*p1++)); 144 145 L_tmp = L_tmp >> 11; 146 L_tmp += vo_L_mult(exc[i], a0); 147 148 /* sig_hi = bit16 to bit31 of synthesis */ 149 L_tmp = L_tmp - (L_tmp1<<1); 150 151 L_tmp = L_tmp >> 3; /* ai in Q12 */ 152 sig_hi[i] = extract_h(L_tmp); 153 154 /* sig_lo = bit4 to bit15 of synthesis */ 155 L_tmp >>= 4; /* 4 : sig_lo[i] >> 4 */ 156 sig_lo[i] = (Word16)((L_tmp - (sig_hi[i] << 13))); 157 } 158 159 return; 160 } 161 162 163 164 165
