diff options
Diffstat (limited to 'Alc/effects/distortion.cpp')
| -rw-r--r-- | Alc/effects/distortion.cpp | 269 |
1 files changed, 0 insertions, 269 deletions
diff --git a/Alc/effects/distortion.cpp b/Alc/effects/distortion.cpp deleted file mode 100644 index 59557395..00000000 --- a/Alc/effects/distortion.cpp +++ /dev/null @@ -1,269 +0,0 @@ -/** - * OpenAL cross platform audio library - * Copyright (C) 2013 by Mike Gorchak - * This library is free software; you can redistribute it and/or - * modify it under the terms of the GNU Library General Public - * License as published by the Free Software Foundation; either - * version 2 of the License, or (at your option) any later version. - * - * This library 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 - * Library General Public License for more details. - * - * You should have received a copy of the GNU Library General Public - * License along with this library; if not, write to the - * Free Software Foundation, Inc., - * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. - * Or go to http://www.gnu.org/copyleft/lgpl.html - */ - -#include "config.h" - -#include <cmath> -#include <cstdlib> - -#include <cmath> - -#include "alcmain.h" -#include "alcontext.h" -#include "alAuxEffectSlot.h" -#include "alError.h" -#include "alu.h" -#include "filters/biquad.h" - - -namespace { - -struct DistortionState final : public EffectState { - /* Effect gains for each channel */ - ALfloat mGain[MAX_OUTPUT_CHANNELS]{}; - - /* Effect parameters */ - BiquadFilter mLowpass; - BiquadFilter mBandpass; - ALfloat mAttenuation{}; - ALfloat mEdgeCoeff{}; - - ALfloat mBuffer[2][BUFFERSIZE]{}; - - - ALboolean deviceUpdate(const ALCdevice *device) override; - void update(const ALCcontext *context, const ALeffectslot *slot, const EffectProps *props, const EffectTarget target) override; - void process(const ALsizei samplesToDo, const FloatBufferLine *RESTRICT samplesIn, const ALsizei numInput, const al::span<FloatBufferLine> samplesOut) override; - - DEF_NEWDEL(DistortionState) -}; - -ALboolean DistortionState::deviceUpdate(const ALCdevice*) -{ - mLowpass.clear(); - mBandpass.clear(); - return AL_TRUE; -} - -void DistortionState::update(const ALCcontext *context, const ALeffectslot *slot, const EffectProps *props, const EffectTarget target) -{ - const ALCdevice *device{context->Device}; - - /* Store waveshaper edge settings. */ - const ALfloat edge{ - minf(std::sin(al::MathDefs<float>::Pi()*0.5f * props->Distortion.Edge), 0.99f)}; - mEdgeCoeff = 2.0f * edge / (1.0f-edge); - - ALfloat cutoff{props->Distortion.LowpassCutoff}; - /* Bandwidth value is constant in octaves. */ - ALfloat bandwidth{(cutoff / 2.0f) / (cutoff * 0.67f)}; - /* Multiply sampling frequency by the amount of oversampling done during - * processing. - */ - auto frequency = static_cast<ALfloat>(device->Frequency); - mLowpass.setParams(BiquadType::LowPass, 1.0f, cutoff / (frequency*4.0f), - mLowpass.rcpQFromBandwidth(cutoff / (frequency*4.0f), bandwidth)); - - cutoff = props->Distortion.EQCenter; - /* Convert bandwidth in Hz to octaves. */ - bandwidth = props->Distortion.EQBandwidth / (cutoff * 0.67f); - mBandpass.setParams(BiquadType::BandPass, 1.0f, cutoff / (frequency*4.0f), - mBandpass.rcpQFromBandwidth(cutoff / (frequency*4.0f), bandwidth)); - - ALfloat coeffs[MAX_AMBI_CHANNELS]; - CalcDirectionCoeffs({0.0f, 0.0f, -1.0f}, 0.0f, coeffs); - - mOutTarget = target.Main->Buffer; - ComputePanGains(target.Main, coeffs, slot->Params.Gain*props->Distortion.Gain, mGain); -} - -void DistortionState::process(const ALsizei samplesToDo, const FloatBufferLine *RESTRICT samplesIn, const ALsizei /*numInput*/, const al::span<FloatBufferLine> samplesOut) -{ - const ALfloat fc{mEdgeCoeff}; - for(ALsizei base{0};base < samplesToDo;) - { - /* Perform 4x oversampling to avoid aliasing. Oversampling greatly - * improves distortion quality and allows to implement lowpass and - * bandpass filters using high frequencies, at which classic IIR - * filters became unstable. - */ - ALsizei todo{mini(BUFFERSIZE, (samplesToDo-base) * 4)}; - - /* Fill oversample buffer using zero stuffing. Multiply the sample by - * the amount of oversampling to maintain the signal's power. - */ - for(ALsizei i{0};i < todo;i++) - mBuffer[0][i] = !(i&3) ? samplesIn[0][(i>>2)+base] * 4.0f : 0.0f; - - /* First step, do lowpass filtering of original signal. Additionally - * perform buffer interpolation and lowpass cutoff for oversampling - * (which is fortunately first step of distortion). So combine three - * operations into the one. - */ - mLowpass.process(mBuffer[1], mBuffer[0], todo); - - /* Second step, do distortion using waveshaper function to emulate - * signal processing during tube overdriving. Three steps of - * waveshaping are intended to modify waveform without boost/clipping/ - * attenuation process. - */ - for(ALsizei i{0};i < todo;i++) - { - ALfloat smp{mBuffer[1][i]}; - - smp = (1.0f + fc) * smp/(1.0f + fc*fabsf(smp)); - smp = (1.0f + fc) * smp/(1.0f + fc*fabsf(smp)) * -1.0f; - smp = (1.0f + fc) * smp/(1.0f + fc*fabsf(smp)); - - mBuffer[0][i] = smp; - } - - /* Third step, do bandpass filtering of distorted signal. */ - mBandpass.process(mBuffer[1], mBuffer[0], todo); - - todo >>= 2; - const ALfloat *outgains{mGain}; - for(FloatBufferLine &output : samplesOut) - { - /* Fourth step, final, do attenuation and perform decimation, - * storing only one sample out of four. - */ - const ALfloat gain{*(outgains++)}; - if(!(std::fabs(gain) > GAIN_SILENCE_THRESHOLD)) - continue; - - for(ALsizei i{0};i < todo;i++) - output[base+i] += gain * mBuffer[1][i*4]; - } - - base += todo; - } -} - - -void Distortion_setParami(EffectProps*, ALCcontext *context, ALenum param, ALint) -{ alSetError(context, AL_INVALID_ENUM, "Invalid distortion integer property 0x%04x", param); } -void Distortion_setParamiv(EffectProps*, ALCcontext *context, ALenum param, const ALint*) -{ alSetError(context, AL_INVALID_ENUM, "Invalid distortion integer-vector property 0x%04x", param); } -void Distortion_setParamf(EffectProps *props, ALCcontext *context, ALenum param, ALfloat val) -{ - switch(param) - { - case AL_DISTORTION_EDGE: - if(!(val >= AL_DISTORTION_MIN_EDGE && val <= AL_DISTORTION_MAX_EDGE)) - SETERR_RETURN(context, AL_INVALID_VALUE,, "Distortion edge out of range"); - props->Distortion.Edge = val; - break; - - case AL_DISTORTION_GAIN: - if(!(val >= AL_DISTORTION_MIN_GAIN && val <= AL_DISTORTION_MAX_GAIN)) - SETERR_RETURN(context, AL_INVALID_VALUE,, "Distortion gain out of range"); - props->Distortion.Gain = val; - break; - - case AL_DISTORTION_LOWPASS_CUTOFF: - if(!(val >= AL_DISTORTION_MIN_LOWPASS_CUTOFF && val <= AL_DISTORTION_MAX_LOWPASS_CUTOFF)) - SETERR_RETURN(context, AL_INVALID_VALUE,, "Distortion low-pass cutoff out of range"); - props->Distortion.LowpassCutoff = val; - break; - - case AL_DISTORTION_EQCENTER: - if(!(val >= AL_DISTORTION_MIN_EQCENTER && val <= AL_DISTORTION_MAX_EQCENTER)) - SETERR_RETURN(context, AL_INVALID_VALUE,, "Distortion EQ center out of range"); - props->Distortion.EQCenter = val; - break; - - case AL_DISTORTION_EQBANDWIDTH: - if(!(val >= AL_DISTORTION_MIN_EQBANDWIDTH && val <= AL_DISTORTION_MAX_EQBANDWIDTH)) - SETERR_RETURN(context, AL_INVALID_VALUE,, "Distortion EQ bandwidth out of range"); - props->Distortion.EQBandwidth = val; - break; - - default: - alSetError(context, AL_INVALID_ENUM, "Invalid distortion float property 0x%04x", - param); - } -} -void Distortion_setParamfv(EffectProps *props, ALCcontext *context, ALenum param, const ALfloat *vals) -{ Distortion_setParamf(props, context, param, vals[0]); } - -void Distortion_getParami(const EffectProps*, ALCcontext *context, ALenum param, ALint*) -{ alSetError(context, AL_INVALID_ENUM, "Invalid distortion integer property 0x%04x", param); } -void Distortion_getParamiv(const EffectProps*, ALCcontext *context, ALenum param, ALint*) -{ alSetError(context, AL_INVALID_ENUM, "Invalid distortion integer-vector property 0x%04x", param); } -void Distortion_getParamf(const EffectProps *props, ALCcontext *context, ALenum param, ALfloat *val) -{ - switch(param) - { - case AL_DISTORTION_EDGE: - *val = props->Distortion.Edge; - break; - - case AL_DISTORTION_GAIN: - *val = props->Distortion.Gain; - break; - - case AL_DISTORTION_LOWPASS_CUTOFF: - *val = props->Distortion.LowpassCutoff; - break; - - case AL_DISTORTION_EQCENTER: - *val = props->Distortion.EQCenter; - break; - - case AL_DISTORTION_EQBANDWIDTH: - *val = props->Distortion.EQBandwidth; - break; - - default: - alSetError(context, AL_INVALID_ENUM, "Invalid distortion float property 0x%04x", - param); - } -} -void Distortion_getParamfv(const EffectProps *props, ALCcontext *context, ALenum param, ALfloat *vals) -{ Distortion_getParamf(props, context, param, vals); } - -DEFINE_ALEFFECT_VTABLE(Distortion); - - -struct DistortionStateFactory final : public EffectStateFactory { - EffectState *create() override { return new DistortionState{}; } - EffectProps getDefaultProps() const noexcept override; - const EffectVtable *getEffectVtable() const noexcept override { return &Distortion_vtable; } -}; - -EffectProps DistortionStateFactory::getDefaultProps() const noexcept -{ - EffectProps props{}; - props.Distortion.Edge = AL_DISTORTION_DEFAULT_EDGE; - props.Distortion.Gain = AL_DISTORTION_DEFAULT_GAIN; - props.Distortion.LowpassCutoff = AL_DISTORTION_DEFAULT_LOWPASS_CUTOFF; - props.Distortion.EQCenter = AL_DISTORTION_DEFAULT_EQCENTER; - props.Distortion.EQBandwidth = AL_DISTORTION_DEFAULT_EQBANDWIDTH; - return props; -} - -} // namespace - -EffectStateFactory *DistortionStateFactory_getFactory() -{ - static DistortionStateFactory DistortionFactory{}; - return &DistortionFactory; -} |