forked from sox_ng/sox_ng
56 lines
1.6 KiB
C
56 lines
1.6 KiB
C
/*
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* DiodeClip.c, part of libdolbyb.
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*
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* Copyright (C) 2025 Martin Guy <martinwguy@gmail.com>
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* based on dolbybcsoftwaredecode by Richard Evans 2018.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2
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* as published by the Free Software Foundation. See COPYING for details.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
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* Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#include "dolbyb.h"
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#include "DiodeClip.h"
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#include "Param.h"
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#include <math.h>
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/* This is not declared when compiling -ansi (C90) */
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extern double round(double x);
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void DiodeClipInit(dolbyb_t *Param)
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{
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double DioVal = ParamDioClp;
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if (Param->ThGain != 1.0) DioVal /= Param->ThGain;
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Param->DiodeClipMaxVal = round(DioVal * ParamVltMux);
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Param->DiodeClipMinVal = -Param->DiodeClipMaxVal;
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}
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int64_t DiodeClip(dolbyb_t *Param, int64_t InSamp)
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{
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/* Clip the output from the side channel if necessary */
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/* to avoid sudden brief overshoots */
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if (InSamp > Param->DiodeClipMaxVal) {
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Param->DiodeClipCliped = 1;
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return Param->DiodeClipMaxVal;
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}
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if (InSamp < Param->DiodeClipMinVal) {
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Param->DiodeClipCliped = 1;
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return Param->DiodeClipMinVal;
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}
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Param->DiodeClipCliped = 0;
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return InSamp;
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}
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