libavcodec/opusdsp.c

   1 /*
   2  * This file is part of FFmpeg.
   3  *
   4  * FFmpeg is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * FFmpeg is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with FFmpeg; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  17  */
  18
  19 #include "config.h"
  20 #include "libavutil/attributes.h"
  21 #include "opusdsp.h"
  22
  23 static void postfilter_c(float *data, int period, float *gains, int len)
  24 {
  25     const float g0 = gains[0];
  26     const float g1 = gains[1];
  27     const float g2 = gains[2];
  28
  29     float x4 = data[-period - 2];
  30     float x3 = data[-period - 1];
  31     float x2 = data[-period + 0];
  32     float x1 = data[-period + 1];
  33
  34     for (int i = 0; i < len; i++) {
  35         float x0 = data[i - period + 2];
  36         data[i] += g0 * x2        +
  37                    g1 * (x1 + x3) +
  38                    g2 * (x0 + x4);
  39         x4 = x3;
  40         x3 = x2;
  41         x2 = x1;
  42         x1 = x0;
  43     }
  44 }
  45
  46 static float deemphasis_c(float *y, float *x, float coeff, int len)
  47 {
  48     for (int i = 0; i < len; i++)
  49         coeff = y[i] = x[i] + coeff*CELT_EMPH_COEFF;
  50
  51     return coeff;
  52 }
  53
  54 av_cold void ff_opus_dsp_init(OpusDSP *ctx)
  55 {
  56     ctx->postfilter = postfilter_c;
  57     ctx->deemphasis = deemphasis_c;
  58
  59 #if ARCH_AARCH64
  60     ff_opus_dsp_init_aarch64(ctx);
  61 #elif ARCH_X86
  62     ff_opus_dsp_init_x86(ctx);
  63 #endif
  64 }