| /* |
| ** Copyright 2003-2010, VisualOn, Inc. |
| ** |
| ** Licensed under the Apache License, Version 2.0 (the "License"); |
| ** you may not use this file except in compliance with the License. |
| ** You may obtain a copy of the License at |
| ** |
| ** http://www.apache.org/licenses/LICENSE-2.0 |
| ** |
| ** Unless required by applicable law or agreed to in writing, software |
| ** distributed under the License is distributed on an "AS IS" BASIS, |
| ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| ** See the License for the specific language governing permissions and |
| ** limitations under the License. |
| */ |
| |
| /*********************************************************************** |
| * File: pred_lt4.c * |
| * * |
| * Description: Compute the result of long term prediction with * |
| * fractional interpolation of resolution 1/4 * |
| * on return exc[0..L_subr-1] contains the interpolated signal * |
| * (adaptive codebook excitation) * |
| * * |
| ************************************************************************/ |
| |
| #include "typedef.h" |
| #include "basic_op.h" |
| |
| #define UP_SAMP 4 |
| #define L_INTERPOL2 16 |
| |
| /* 1/4 resolution interpolation filter (-3 dB at 0.856*fs/2) in Q14 */ |
| |
| Word16 inter4_2[4][32] = |
| { |
| {0,-2,4,-2,-10,38,-88,165,-275,424,-619,871,-1207,1699,-2598,5531,14031,-2147,780,-249, |
| -16,153,-213,226,-209,175,-133,91,-55,28,-10,2}, |
| |
| {1,-7,19,-33,47,-52,43,-9,-60,175,-355,626,-1044,1749,-3267,10359,10359,-3267,1749,-1044, |
| 626,-355,175,-60,-9,43,-52,47,-33,19, -7, 1}, |
| |
| {2,-10,28,-55,91,-133,175,-209,226,-213,153,-16,-249,780,-2147,14031,5531,-2598,1699,-1207, |
| 871,-619,424,-275,165,-88,38,-10,-2,4,-2,0}, |
| |
| {1,-7,22,-49,92,-153,231,-325,431,-544,656,-762,853,-923,968,15401,968,-923,853,-762, |
| 656,-544,431,-325,231,-153,92,-49,22,-7, 1, 0} |
| |
| }; |
| |
| void Pred_lt4( |
| Word16 exc[], /* in/out: excitation buffer */ |
| Word16 T0, /* input : integer pitch lag */ |
| Word16 frac, /* input : fraction of lag */ |
| Word16 L_subfr /* input : subframe size */ |
| ) |
| { |
| Word16 j, k, *x; |
| Word32 L_sum; |
| Word16 *ptr, *ptr1; |
| Word16 *ptr2; |
| |
| x = exc - T0; |
| frac = -frac; |
| if (frac < 0) |
| { |
| frac += UP_SAMP; |
| x--; |
| } |
| x -= 15; /* x = L_INTERPOL2 - 1 */ |
| k = 3 - frac; /* k = UP_SAMP - 1 - frac */ |
| |
| ptr2 = &(inter4_2[k][0]); |
| for (j = 0; j < L_subfr; j++) |
| { |
| ptr = ptr2; |
| ptr1 = x; |
| L_sum = vo_mult32((*ptr1++), (*ptr++)); |
| L_sum += vo_mult32((*ptr1++), (*ptr++)); |
| L_sum += vo_mult32((*ptr1++), (*ptr++)); |
| L_sum += vo_mult32((*ptr1++), (*ptr++)); |
| L_sum += vo_mult32((*ptr1++), (*ptr++)); |
| L_sum += vo_mult32((*ptr1++), (*ptr++)); |
| L_sum += vo_mult32((*ptr1++), (*ptr++)); |
| L_sum += vo_mult32((*ptr1++), (*ptr++)); |
| L_sum += vo_mult32((*ptr1++), (*ptr++)); |
| L_sum += vo_mult32((*ptr1++), (*ptr++)); |
| L_sum += vo_mult32((*ptr1++), (*ptr++)); |
| L_sum += vo_mult32((*ptr1++), (*ptr++)); |
| L_sum += vo_mult32((*ptr1++), (*ptr++)); |
| L_sum += vo_mult32((*ptr1++), (*ptr++)); |
| L_sum += vo_mult32((*ptr1++), (*ptr++)); |
| L_sum += vo_mult32((*ptr1++), (*ptr++)); |
| L_sum += vo_mult32((*ptr1++), (*ptr++)); |
| L_sum += vo_mult32((*ptr1++), (*ptr++)); |
| L_sum += vo_mult32((*ptr1++), (*ptr++)); |
| L_sum += vo_mult32((*ptr1++), (*ptr++)); |
| L_sum += vo_mult32((*ptr1++), (*ptr++)); |
| L_sum += vo_mult32((*ptr1++), (*ptr++)); |
| L_sum += vo_mult32((*ptr1++), (*ptr++)); |
| L_sum += vo_mult32((*ptr1++), (*ptr++)); |
| L_sum += vo_mult32((*ptr1++), (*ptr++)); |
| L_sum += vo_mult32((*ptr1++), (*ptr++)); |
| L_sum += vo_mult32((*ptr1++), (*ptr++)); |
| L_sum += vo_mult32((*ptr1++), (*ptr++)); |
| L_sum += vo_mult32((*ptr1++), (*ptr++)); |
| L_sum += vo_mult32((*ptr1++), (*ptr++)); |
| L_sum += vo_mult32((*ptr1++), (*ptr++)); |
| L_sum += vo_mult32((*ptr1++), (*ptr++)); |
| |
| L_sum = L_shl2(L_sum, 2); |
| exc[j] = extract_h(L_add(L_sum, 0x8000)); |
| x++; |
| } |
| |
| return; |
| } |
| |
| |
| |