| /* |
| ** 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: hp6k.c * |
| * * |
| * Description:15th order band pass 6kHz to 7kHz FIR filter * |
| * frequency: 4kHz 5kHz 5.5kHz 6kHz 6.5kHz 7kHz 7.5kHz 8kHz * |
| * dB loss: -60dB -45dB -13dB -3dB 0dB -3dB -13dB -45dB * |
| * * |
| ************************************************************************/ |
| |
| #include "typedef.h" |
| #include "basic_op.h" |
| #include "acelp.h" |
| #include "cnst.h" |
| |
| #define L_FIR 31 |
| |
| /* filter coefficients (gain=4.0) */ |
| |
| Word16 fir_6k_7k[L_FIR] = |
| { |
| -32, 47, 32, -27, -369, |
| 1122, -1421, 0, 3798, -8880, |
| 12349, -10984, 3548, 7766, -18001, |
| 22118, -18001, 7766, 3548, -10984, |
| 12349, -8880, 3798, 0, -1421, |
| 1122, -369, -27, 32, 47, |
| -32 |
| }; |
| |
| |
| void Init_Filt_6k_7k(Word16 mem[]) /* mem[30] */ |
| { |
| Set_zero(mem, L_FIR - 1); |
| return; |
| } |
| |
| void Filt_6k_7k( |
| Word16 signal[], /* input: signal */ |
| Word16 lg, /* input: length of input */ |
| Word16 mem[] /* in/out: memory (size=30) */ |
| ) |
| { |
| Word16 x[L_SUBFR16k + (L_FIR - 1)]; |
| Word32 i, L_tmp; |
| |
| Copy(mem, x, L_FIR - 1); |
| for (i = lg - 1; i >= 0; i--) |
| { |
| x[i + L_FIR - 1] = signal[i] >> 2; /* gain of filter = 4 */ |
| } |
| for (i = 0; i < lg; i++) |
| { |
| L_tmp = (x[i] + x[i+ 30]) * fir_6k_7k[0]; |
| L_tmp += (x[i+1] + x[i + 29]) * fir_6k_7k[1]; |
| L_tmp += (x[i+2] + x[i + 28]) * fir_6k_7k[2]; |
| L_tmp += (x[i+3] + x[i + 27]) * fir_6k_7k[3]; |
| L_tmp += (x[i+4] + x[i + 26]) * fir_6k_7k[4]; |
| L_tmp += (x[i+5] + x[i + 25]) * fir_6k_7k[5]; |
| L_tmp += (x[i+6] + x[i + 24]) * fir_6k_7k[6]; |
| L_tmp += (x[i+7] + x[i + 23]) * fir_6k_7k[7]; |
| L_tmp += (x[i+8] + x[i + 22]) * fir_6k_7k[8]; |
| L_tmp += (x[i+9] + x[i + 21]) * fir_6k_7k[9]; |
| L_tmp += (x[i+10] + x[i + 20]) * fir_6k_7k[10]; |
| L_tmp += (x[i+11] + x[i + 19]) * fir_6k_7k[11]; |
| L_tmp += (x[i+12] + x[i + 18]) * fir_6k_7k[12]; |
| L_tmp += (x[i+13] + x[i + 17]) * fir_6k_7k[13]; |
| L_tmp += (x[i+14] + x[i + 16]) * fir_6k_7k[14]; |
| L_tmp += (x[i+15]) * fir_6k_7k[15]; |
| signal[i] = (L_tmp + 0x4000) >> 15; |
| } |
| |
| Copy(x + lg, mem, L_FIR - 1); |
| |
| } |
| |
| |
| |