/* * 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 "config.h"#include "libavutil/attributes.h"#include "libavutil/mem_internal.h"#include "dsp.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, const float *weights, int len){    const float c = weights[0];    for (int i = 0; i < len; i++)        coeff = y[i] = x[i] + coeff*c;     return coeff;} av_cold void ff_opus_dsp_init(OpusDSP *ctx){    ctx->postfilter = postfilter_c;    ctx->deemphasis = deemphasis_c; #if ARCH_AARCH64    ff_opus_dsp_init_aarch64(ctx);#elif ARCH_RISCV    ff_opus_dsp_init_riscv(ctx);#elif ARCH_X86    ff_opus_dsp_init_x86(ctx);#endif}