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Diffstat (limited to 'alc/effects/autowah.cpp')
| -rw-r--r-- | alc/effects/autowah.cpp | 298 |
1 files changed, 298 insertions, 0 deletions
diff --git a/alc/effects/autowah.cpp b/alc/effects/autowah.cpp new file mode 100644 index 00000000..96292636 --- /dev/null +++ b/alc/effects/autowah.cpp @@ -0,0 +1,298 @@ +/** + * OpenAL cross platform audio library + * Copyright (C) 2018 by Raul Herraiz. + * 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 <algorithm> + +#include "alcmain.h" +#include "alcontext.h" +#include "alAuxEffectSlot.h" +#include "alError.h" +#include "alu.h" +#include "filters/biquad.h" +#include "vecmat.h" + +namespace { + +#define MIN_FREQ 20.0f +#define MAX_FREQ 2500.0f +#define Q_FACTOR 5.0f + +struct ALautowahState final : public EffectState { + /* Effect parameters */ + ALfloat mAttackRate; + ALfloat mReleaseRate; + ALfloat mResonanceGain; + ALfloat mPeakGain; + ALfloat mFreqMinNorm; + ALfloat mBandwidthNorm; + ALfloat mEnvDelay; + + /* Filter components derived from the envelope. */ + struct { + ALfloat cos_w0; + ALfloat alpha; + } mEnv[BUFFERSIZE]; + + struct { + /* Effect filters' history. */ + struct { + ALfloat z1, z2; + } Filter; + + /* Effect gains for each output channel */ + ALfloat CurrentGains[MAX_OUTPUT_CHANNELS]; + ALfloat TargetGains[MAX_OUTPUT_CHANNELS]; + } mChans[MAX_AMBI_CHANNELS]; + + /* Effects buffers */ + alignas(16) ALfloat mBufferOut[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(ALautowahState) +}; + +ALboolean ALautowahState::deviceUpdate(const ALCdevice*) +{ + /* (Re-)initializing parameters and clear the buffers. */ + + mAttackRate = 1.0f; + mReleaseRate = 1.0f; + mResonanceGain = 10.0f; + mPeakGain = 4.5f; + mFreqMinNorm = 4.5e-4f; + mBandwidthNorm = 0.05f; + mEnvDelay = 0.0f; + + for(auto &e : mEnv) + { + e.cos_w0 = 0.0f; + e.alpha = 0.0f; + } + + for(auto &chan : mChans) + { + std::fill(std::begin(chan.CurrentGains), std::end(chan.CurrentGains), 0.0f); + chan.Filter.z1 = 0.0f; + chan.Filter.z2 = 0.0f; + } + + return AL_TRUE; +} + +void ALautowahState::update(const ALCcontext *context, const ALeffectslot *slot, const EffectProps *props, const EffectTarget target) +{ + const ALCdevice *device{context->Device}; + + const ALfloat ReleaseTime{clampf(props->Autowah.ReleaseTime, 0.001f, 1.0f)}; + + mAttackRate = expf(-1.0f / (props->Autowah.AttackTime*device->Frequency)); + mReleaseRate = expf(-1.0f / (ReleaseTime*device->Frequency)); + /* 0-20dB Resonance Peak gain */ + mResonanceGain = std::sqrt(std::log10(props->Autowah.Resonance)*10.0f / 3.0f); + mPeakGain = 1.0f - std::log10(props->Autowah.PeakGain/AL_AUTOWAH_MAX_PEAK_GAIN); + mFreqMinNorm = MIN_FREQ / device->Frequency; + mBandwidthNorm = (MAX_FREQ-MIN_FREQ) / device->Frequency; + + mOutTarget = target.Main->Buffer; + for(size_t i{0u};i < slot->Wet.Buffer.size();++i) + { + auto coeffs = GetAmbiIdentityRow(i); + ComputePanGains(target.Main, coeffs.data(), slot->Params.Gain, mChans[i].TargetGains); + } +} + +void ALautowahState::process(const ALsizei samplesToDo, const FloatBufferLine *RESTRICT samplesIn, const ALsizei numInput, const al::span<FloatBufferLine> samplesOut) +{ + const ALfloat attack_rate = mAttackRate; + const ALfloat release_rate = mReleaseRate; + const ALfloat res_gain = mResonanceGain; + const ALfloat peak_gain = mPeakGain; + const ALfloat freq_min = mFreqMinNorm; + const ALfloat bandwidth = mBandwidthNorm; + + ALfloat env_delay{mEnvDelay}; + for(ALsizei i{0};i < samplesToDo;i++) + { + ALfloat w0, sample, a; + + /* Envelope follower described on the book: Audio Effects, Theory, + * Implementation and Application. + */ + sample = peak_gain * std::fabs(samplesIn[0][i]); + a = (sample > env_delay) ? attack_rate : release_rate; + env_delay = lerp(sample, env_delay, a); + + /* Calculate the cos and alpha components for this sample's filter. */ + w0 = minf((bandwidth*env_delay + freq_min), 0.46f) * al::MathDefs<float>::Tau(); + mEnv[i].cos_w0 = cosf(w0); + mEnv[i].alpha = sinf(w0)/(2.0f * Q_FACTOR); + } + mEnvDelay = env_delay; + + ASSUME(numInput > 0); + for(ALsizei c{0};c < numInput;++c) + { + /* This effectively inlines BiquadFilter_setParams for a peaking + * filter and BiquadFilter_processC. The alpha and cosine components + * for the filter coefficients were previously calculated with the + * envelope. Because the filter changes for each sample, the + * coefficients are transient and don't need to be held. + */ + ALfloat z1{mChans[c].Filter.z1}; + ALfloat z2{mChans[c].Filter.z2}; + + for(ALsizei i{0};i < samplesToDo;i++) + { + const ALfloat alpha = mEnv[i].alpha; + const ALfloat cos_w0 = mEnv[i].cos_w0; + ALfloat input, output; + ALfloat a[3], b[3]; + + b[0] = 1.0f + alpha*res_gain; + b[1] = -2.0f * cos_w0; + b[2] = 1.0f - alpha*res_gain; + a[0] = 1.0f + alpha/res_gain; + a[1] = -2.0f * cos_w0; + a[2] = 1.0f - alpha/res_gain; + + input = samplesIn[c][i]; + output = input*(b[0]/a[0]) + z1; + z1 = input*(b[1]/a[0]) - output*(a[1]/a[0]) + z2; + z2 = input*(b[2]/a[0]) - output*(a[2]/a[0]); + mBufferOut[i] = output; + } + mChans[c].Filter.z1 = z1; + mChans[c].Filter.z2 = z2; + + /* Now, mix the processed sound data to the output. */ + MixSamples(mBufferOut, samplesOut, mChans[c].CurrentGains, mChans[c].TargetGains, + samplesToDo, 0, samplesToDo); + } +} + + +void ALautowah_setParamf(EffectProps *props, ALCcontext *context, ALenum param, ALfloat val) +{ + switch(param) + { + case AL_AUTOWAH_ATTACK_TIME: + if(!(val >= AL_AUTOWAH_MIN_ATTACK_TIME && val <= AL_AUTOWAH_MAX_ATTACK_TIME)) + SETERR_RETURN(context, AL_INVALID_VALUE,,"Autowah attack time out of range"); + props->Autowah.AttackTime = val; + break; + + case AL_AUTOWAH_RELEASE_TIME: + if(!(val >= AL_AUTOWAH_MIN_RELEASE_TIME && val <= AL_AUTOWAH_MAX_RELEASE_TIME)) + SETERR_RETURN(context, AL_INVALID_VALUE,,"Autowah release time out of range"); + props->Autowah.ReleaseTime = val; + break; + + case AL_AUTOWAH_RESONANCE: + if(!(val >= AL_AUTOWAH_MIN_RESONANCE && val <= AL_AUTOWAH_MAX_RESONANCE)) + SETERR_RETURN(context, AL_INVALID_VALUE,,"Autowah resonance out of range"); + props->Autowah.Resonance = val; + break; + + case AL_AUTOWAH_PEAK_GAIN: + if(!(val >= AL_AUTOWAH_MIN_PEAK_GAIN && val <= AL_AUTOWAH_MAX_PEAK_GAIN)) + SETERR_RETURN(context, AL_INVALID_VALUE,,"Autowah peak gain out of range"); + props->Autowah.PeakGain = val; + break; + + default: + alSetError(context, AL_INVALID_ENUM, "Invalid autowah float property 0x%04x", param); + } +} +void ALautowah_setParamfv(EffectProps *props, ALCcontext *context, ALenum param, const ALfloat *vals) +{ ALautowah_setParamf(props, context, param, vals[0]); } + +void ALautowah_setParami(EffectProps*, ALCcontext *context, ALenum param, ALint) +{ alSetError(context, AL_INVALID_ENUM, "Invalid autowah integer property 0x%04x", param); } +void ALautowah_setParamiv(EffectProps*, ALCcontext *context, ALenum param, const ALint*) +{ alSetError(context, AL_INVALID_ENUM, "Invalid autowah integer vector property 0x%04x", param); } + +void ALautowah_getParamf(const EffectProps *props, ALCcontext *context, ALenum param, ALfloat *val) +{ + switch(param) + { + case AL_AUTOWAH_ATTACK_TIME: + *val = props->Autowah.AttackTime; + break; + + case AL_AUTOWAH_RELEASE_TIME: + *val = props->Autowah.ReleaseTime; + break; + + case AL_AUTOWAH_RESONANCE: + *val = props->Autowah.Resonance; + break; + + case AL_AUTOWAH_PEAK_GAIN: + *val = props->Autowah.PeakGain; + break; + + default: + alSetError(context, AL_INVALID_ENUM, "Invalid autowah float property 0x%04x", param); + } + +} +void ALautowah_getParamfv(const EffectProps *props, ALCcontext *context, ALenum param, ALfloat *vals) +{ ALautowah_getParamf(props, context, param, vals); } + +void ALautowah_getParami(const EffectProps*, ALCcontext *context, ALenum param, ALint*) +{ alSetError(context, AL_INVALID_ENUM, "Invalid autowah integer property 0x%04x", param); } +void ALautowah_getParamiv(const EffectProps*, ALCcontext *context, ALenum param, ALint*) +{ alSetError(context, AL_INVALID_ENUM, "Invalid autowah integer vector property 0x%04x", param); } + +DEFINE_ALEFFECT_VTABLE(ALautowah); + + +struct AutowahStateFactory final : public EffectStateFactory { + EffectState *create() override { return new ALautowahState{}; } + EffectProps getDefaultProps() const noexcept override; + const EffectVtable *getEffectVtable() const noexcept override { return &ALautowah_vtable; } +}; + +EffectProps AutowahStateFactory::getDefaultProps() const noexcept +{ + EffectProps props{}; + props.Autowah.AttackTime = AL_AUTOWAH_DEFAULT_ATTACK_TIME; + props.Autowah.ReleaseTime = AL_AUTOWAH_DEFAULT_RELEASE_TIME; + props.Autowah.Resonance = AL_AUTOWAH_DEFAULT_RESONANCE; + props.Autowah.PeakGain = AL_AUTOWAH_DEFAULT_PEAK_GAIN; + return props; +} + +} // namespace + +EffectStateFactory *AutowahStateFactory_getFactory() +{ + static AutowahStateFactory AutowahFactory{}; + return &AutowahFactory; +} |