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/*
* 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
*/
#include "opusdsp.h"
static void postfilter_c(float *data, int period, float *gains, int len)
{
const float g0 = gains[0];
const float g1 = gains[1];
const float g2 = gains[2];
float x4 = data[-period - 2];
float x3 = data[-period - 1];
float x2 = data[-period + 0];
float x1 = data[-period + 1];
for (int i = 0; i < len; i++) {
float x0 = data[i - period + 2];
data[i] += g0 * x2 +
g1 * (x1 + x3) +
g2 * (x0 + x4);
x4 = x3;
x3 = x2;
x2 = x1;
x1 = x0;
}
}
static float deemphasis_c(float *y, float *x, float coeff, int len)
{
float state = coeff;
for (int i = 0; i < len; i++) {
const float tmp = x[i] + state;
state = tmp * CELT_EMPH_COEFF;
y[i] = tmp;
}
return state;
}
av_cold void ff_opus_dsp_init(OpusDSP *ctx)
{
ctx->postfilter = postfilter_c;
ctx->deemphasis = deemphasis_c;
if (ARCH_X86)
ff_opus_dsp_init_x86(ctx);
}
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