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Diffstat (limited to 'media/libstagefright/codecs/amrwbenc/src/hp6k.c')
| -rw-r--r-- | media/libstagefright/codecs/amrwbenc/src/hp6k.c | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/media/libstagefright/codecs/amrwbenc/src/hp6k.c b/media/libstagefright/codecs/amrwbenc/src/hp6k.c new file mode 100644 index 0000000..8e66eb0 --- /dev/null +++ b/media/libstagefright/codecs/amrwbenc/src/hp6k.c @@ -0,0 +1,93 @@ +/* + ** 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); + +} + + + |