/* | |
** 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); | |
} | |