0,0 → 1,155 |
/* |
* various filters for ACELP-based codecs |
* |
* Copyright (c) 2008 Vladimir Voroshilov |
* |
* This file is part of FFmpeg. |
* |
* FFmpeg is free software; you can redistribute it and/or |
* modify it under the terms of the GNU Lesser General Public |
* License as published by the Free Software Foundation; either |
* version 2.1 of the License, or (at your option) any later version. |
* |
* FFmpeg is distributed in the hope that it will be useful, |
* but WITHOUT ANY WARRANTY; without even the implied warranty of |
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
* Lesser General Public License for more details. |
* |
* You should have received a copy of the GNU Lesser General Public |
* License along with FFmpeg; if not, write to the Free Software |
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
*/ |
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#include <inttypes.h> |
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#include "libavutil/avassert.h" |
#include "libavutil/common.h" |
#include "avcodec.h" |
#include "acelp_filters.h" |
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const int16_t ff_acelp_interp_filter[61] = { /* (0.15) */ |
29443, 28346, 25207, 20449, 14701, 8693, |
3143, -1352, -4402, -5865, -5850, -4673, |
-2783, -672, 1211, 2536, 3130, 2991, |
2259, 1170, 0, -1001, -1652, -1868, |
-1666, -1147, -464, 218, 756, 1060, |
1099, 904, 550, 135, -245, -514, |
-634, -602, -451, -231, 0, 191, |
308, 340, 296, 198, 78, -36, |
-120, -163, -165, -132, -79, -19, |
34, 73, 91, 89, 70, 38, |
0, |
}; |
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void ff_acelp_interpolate(int16_t* out, const int16_t* in, |
const int16_t* filter_coeffs, int precision, |
int frac_pos, int filter_length, int length) |
{ |
int n, i; |
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av_assert1(frac_pos >= 0 && frac_pos < precision); |
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for (n = 0; n < length; n++) { |
int idx = 0; |
int v = 0x4000; |
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for (i = 0; i < filter_length;) { |
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/* The reference G.729 and AMR fixed point code performs clipping after |
each of the two following accumulations. |
Since clipping affects only the synthetic OVERFLOW test without |
causing an int type overflow, it was moved outside the loop. */ |
|
/* R(x):=ac_v[-k+x] |
v += R(n-i)*ff_acelp_interp_filter(t+6i) |
v += R(n+i+1)*ff_acelp_interp_filter(6-t+6i) */ |
|
v += in[n + i] * filter_coeffs[idx + frac_pos]; |
idx += precision; |
i++; |
v += in[n - i] * filter_coeffs[idx - frac_pos]; |
} |
if (av_clip_int16(v >> 15) != (v >> 15)) |
av_log(NULL, AV_LOG_WARNING, "overflow that would need cliping in ff_acelp_interpolate()\n"); |
out[n] = v >> 15; |
} |
} |
|
void ff_acelp_interpolatef(float *out, const float *in, |
const float *filter_coeffs, int precision, |
int frac_pos, int filter_length, int length) |
{ |
int n, i; |
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for (n = 0; n < length; n++) { |
int idx = 0; |
float v = 0; |
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for (i = 0; i < filter_length;) { |
v += in[n + i] * filter_coeffs[idx + frac_pos]; |
idx += precision; |
i++; |
v += in[n - i] * filter_coeffs[idx - frac_pos]; |
} |
out[n] = v; |
} |
} |
|
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void ff_acelp_high_pass_filter(int16_t* out, int hpf_f[2], |
const int16_t* in, int length) |
{ |
int i; |
int tmp; |
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for (i = 0; i < length; i++) { |
tmp = (hpf_f[0]* 15836LL) >> 13; |
tmp += (hpf_f[1]* -7667LL) >> 13; |
tmp += 7699 * (in[i] - 2*in[i-1] + in[i-2]); |
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/* With "+0x800" rounding, clipping is needed |
for ALGTHM and SPEECH tests. */ |
out[i] = av_clip_int16((tmp + 0x800) >> 12); |
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hpf_f[1] = hpf_f[0]; |
hpf_f[0] = tmp; |
} |
} |
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void ff_acelp_apply_order_2_transfer_function(float *out, const float *in, |
const float zero_coeffs[2], |
const float pole_coeffs[2], |
float gain, float mem[2], int n) |
{ |
int i; |
float tmp; |
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for (i = 0; i < n; i++) { |
tmp = gain * in[i] - pole_coeffs[0] * mem[0] - pole_coeffs[1] * mem[1]; |
out[i] = tmp + zero_coeffs[0] * mem[0] + zero_coeffs[1] * mem[1]; |
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mem[1] = mem[0]; |
mem[0] = tmp; |
} |
} |
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void ff_tilt_compensation(float *mem, float tilt, float *samples, int size) |
{ |
float new_tilt_mem = samples[size - 1]; |
int i; |
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for (i = size - 1; i > 0; i--) |
samples[i] -= tilt * samples[i - 1]; |
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samples[0] -= tilt * *mem; |
*mem = new_tilt_mem; |
} |
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void ff_acelp_filter_init(ACELPFContext *c) |
{ |
c->acelp_interpolatef = ff_acelp_interpolatef; |
c->acelp_apply_order_2_transfer_function = ff_acelp_apply_order_2_transfer_function; |
|
if(HAVE_MIPSFPU) |
ff_acelp_filter_init_mips(c); |
} |