diff options
Diffstat (limited to 'media/libstagefright/codecs/amrwbenc/src/hp400.c')
-rw-r--r-- | media/libstagefright/codecs/amrwbenc/src/hp400.c | 212 |
1 files changed, 106 insertions, 106 deletions
diff --git a/media/libstagefright/codecs/amrwbenc/src/hp400.c b/media/libstagefright/codecs/amrwbenc/src/hp400.c index 463a53a..fa66f1a 100644 --- a/media/libstagefright/codecs/amrwbenc/src/hp400.c +++ b/media/libstagefright/codecs/amrwbenc/src/hp400.c @@ -1,106 +1,106 @@ -/*
- ** 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: hp400.c *
-* *
-* Description: *
-* 2nd order high pass filter with cut off frequency at 400 Hz. *
-* Designed with cheby2 function in MATLAB. *
-* Optimized for fixed-point to get the following frequency response: *
-* *
-* frequency: 0Hz 100Hz 200Hz 300Hz 400Hz 630Hz 1.5kHz 3kHz *
-* dB loss: -infdB -30dB -20dB -10dB -3dB +6dB +1dB 0dB *
-* *
-* Algorithm: *
-* *
-* y[i] = b[0]*x[i] + b[1]*x[i-1] + b[2]*x[i-2] *
-* + a[1]*y[i-1] + a[2]*y[i-2]; *
-* *
-* Word16 b[3] = {3660, -7320, 3660}; in Q12 *
-* Word16 a[3] = {4096, 7320, -3540}; in Q12 *
-* *
-* float --> b[3] = {0.893554687, -1.787109375, 0.893554687}; *
-* a[3] = {1.000000000, 1.787109375, -0.864257812}; *
-* *
-************************************************************************/
-
-#include "typedef.h"
-#include "basic_op.h"
-#include "oper_32b.h"
-#include "acelp.h"
-
-/* filter coefficients */
-static Word16 b[3] = {915, -1830, 915}; /* Q12 (/4) */
-static Word16 a[3] = {16384, 29280, -14160}; /* Q12 (x4) */
-/* Initialization of static values */
-
-void Init_HP400_12k8(Word16 mem[])
-{
- Set_zero(mem, 6);
-}
-
-
-void HP400_12k8(
- Word16 signal[], /* input signal / output is divided by 16 */
- Word16 lg, /* lenght of signal */
- Word16 mem[] /* filter memory [6] */
- )
-{
- Word16 x2;
- Word16 y2_hi, y2_lo, y1_hi, y1_lo, x0, x1;
- Word32 L_tmp;
- Word32 num;
- y2_hi = *mem++;
- y2_lo = *mem++;
- y1_hi = *mem++;
- y1_lo = *mem++;
- x0 = *mem++;
- x1 = *mem;
- num = (Word32)lg;
- do
- {
- x2 = x1;
- x1 = x0;
- x0 = *signal;
- /* y[i] = b[0]*x[i] + b[1]*x[i-1] + b140[2]*x[i-2] */
- /* + a[1]*y[i-1] + a[2] * y[i-2]; */
- L_tmp = 8192L; /* rounding to maximise precision */
- L_tmp += y1_lo * a[1];
- L_tmp += y2_lo * a[2];
- L_tmp = L_tmp >> 14;
- L_tmp += (y1_hi * a[1] + y2_hi * a[2] + (x0 + x2)* b[0] + x1 * b[1]) << 1;
- L_tmp <<= 1; /* coeff Q12 --> Q13 */
- y2_hi = y1_hi;
- y2_lo = y1_lo;
- y1_hi = (Word16)(L_tmp>>16);
- y1_lo = (Word16)((L_tmp & 0xffff)>>1);
-
- /* signal is divided by 16 to avoid overflow in energy computation */
- *signal++ = (L_tmp + 0x8000) >> 16;
- }while(--num !=0);
-
- *mem-- = x1;
- *mem-- = x0;
- *mem-- = y1_lo;
- *mem-- = y1_hi;
- *mem-- = y2_lo;
- *mem = y2_hi;
- return;
-}
-
-
-
+/* + ** 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: hp400.c * +* * +* Description: * +* 2nd order high pass filter with cut off frequency at 400 Hz. * +* Designed with cheby2 function in MATLAB. * +* Optimized for fixed-point to get the following frequency response: * +* * +* frequency: 0Hz 100Hz 200Hz 300Hz 400Hz 630Hz 1.5kHz 3kHz * +* dB loss: -infdB -30dB -20dB -10dB -3dB +6dB +1dB 0dB * +* * +* Algorithm: * +* * +* y[i] = b[0]*x[i] + b[1]*x[i-1] + b[2]*x[i-2] * +* + a[1]*y[i-1] + a[2]*y[i-2]; * +* * +* Word16 b[3] = {3660, -7320, 3660}; in Q12 * +* Word16 a[3] = {4096, 7320, -3540}; in Q12 * +* * +* float --> b[3] = {0.893554687, -1.787109375, 0.893554687}; * +* a[3] = {1.000000000, 1.787109375, -0.864257812}; * +* * +************************************************************************/ + +#include "typedef.h" +#include "basic_op.h" +#include "oper_32b.h" +#include "acelp.h" + +/* filter coefficients */ +static Word16 b[3] = {915, -1830, 915}; /* Q12 (/4) */ +static Word16 a[3] = {16384, 29280, -14160}; /* Q12 (x4) */ +/* Initialization of static values */ + +void Init_HP400_12k8(Word16 mem[]) +{ + Set_zero(mem, 6); +} + + +void HP400_12k8( + Word16 signal[], /* input signal / output is divided by 16 */ + Word16 lg, /* lenght of signal */ + Word16 mem[] /* filter memory [6] */ + ) +{ + Word16 x2; + Word16 y2_hi, y2_lo, y1_hi, y1_lo, x0, x1; + Word32 L_tmp; + Word32 num; + y2_hi = *mem++; + y2_lo = *mem++; + y1_hi = *mem++; + y1_lo = *mem++; + x0 = *mem++; + x1 = *mem; + num = (Word32)lg; + do + { + x2 = x1; + x1 = x0; + x0 = *signal; + /* y[i] = b[0]*x[i] + b[1]*x[i-1] + b140[2]*x[i-2] */ + /* + a[1]*y[i-1] + a[2] * y[i-2]; */ + L_tmp = 8192L; /* rounding to maximise precision */ + L_tmp += y1_lo * a[1]; + L_tmp += y2_lo * a[2]; + L_tmp = L_tmp >> 14; + L_tmp += (y1_hi * a[1] + y2_hi * a[2] + (x0 + x2)* b[0] + x1 * b[1]) << 1; + L_tmp <<= 1; /* coeff Q12 --> Q13 */ + y2_hi = y1_hi; + y2_lo = y1_lo; + y1_hi = (Word16)(L_tmp>>16); + y1_lo = (Word16)((L_tmp & 0xffff)>>1); + + /* signal is divided by 16 to avoid overflow in energy computation */ + *signal++ = (L_tmp + 0x8000) >> 16; + }while(--num !=0); + + *mem-- = x1; + *mem-- = x0; + *mem-- = y1_lo; + *mem-- = y1_hi; + *mem-- = y2_lo; + *mem = y2_hi; + return; +} + + + |