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FFmpeg/libavcodec/opusdsp.c
Andreas Rheinhardt 40e6575aa3 all: Replace if (ARCH_FOO) checks by #if ARCH_FOO
This is more spec-compliant because it does not rely
on dead-code elimination by the compiler. Especially
MSVC has problems with this, as can be seen in
https://ffmpeg.org/pipermail/ffmpeg-devel/2022-May/296373.html
or
https://ffmpeg.org/pipermail/ffmpeg-devel/2022-May/297022.html

This commit does not eliminate every instance where we rely
on dead code elimination: It only tackles branching to
the initialization of arch-specific dsp code, not e.g. all
uses of CONFIG_ and HAVE_ checks. But maybe it is already
enough to compile FFmpeg with MSVC with whole-programm-optimizations
enabled (if one does not disable too many components).

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2022-06-15 04:56:37 +02:00

65 lines
1.8 KiB
C

/*
* 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 "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)
{
for (int i = 0; i < len; i++)
coeff = y[i] = x[i] + coeff*CELT_EMPH_COEFF;
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_X86
ff_opus_dsp_init_x86(ctx);
#endif
}