diff options
author | Sven Gothel <[email protected]> | 2014-01-26 07:06:02 +0100 |
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committer | Sven Gothel <[email protected]> | 2014-01-26 07:06:02 +0100 |
commit | e6f4251945c228a775649b5ccd7f11dd4519c28d (patch) | |
tree | 8454b34363358cf9bb502021a68c6985c97daac4 /Alc/effects/equalizer.c | |
parent | 389ae1f767bfad6116e21306fc3cdf89a4cbcc0a (diff) | |
parent | 49baa9128dd98e986639def4f24c7522d9ec6b56 (diff) |
Merge branch 'UPSTREAM'
Diffstat (limited to 'Alc/effects/equalizer.c')
-rw-r--r-- | Alc/effects/equalizer.c | 337 |
1 files changed, 337 insertions, 0 deletions
diff --git a/Alc/effects/equalizer.c b/Alc/effects/equalizer.c new file mode 100644 index 00000000..d5bd2caf --- /dev/null +++ b/Alc/effects/equalizer.c @@ -0,0 +1,337 @@ +/** + * 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., 59 Temple Place - Suite 330, + * Boston, MA 02111-1307, USA. + * Or go to http://www.gnu.org/copyleft/lgpl.html + */ + +#include "config.h" + +#include <math.h> +#include <stdlib.h> + +#include "alMain.h" +#include "alFilter.h" +#include "alAuxEffectSlot.h" +#include "alError.h" +#include "alu.h" + + +/* The document "Effects Extension Guide.pdf" says that low and high * + * frequencies are cutoff frequencies. This is not fully correct, they * + * are corner frequencies for low and high shelf filters. If they were * + * just cutoff frequencies, there would be no need in cutoff frequency * + * gains, which are present. Documentation for "Creative Proteus X2" * + * software describes 4-band equalizer functionality in a much better * + * way. This equalizer seems to be a predecessor of OpenAL 4-band * + * equalizer. With low and high shelf filters we are able to cutoff * + * frequencies below and/or above corner frequencies using attenuation * + * gains (below 1.0) and amplify all low and/or high frequencies using * + * gains above 1.0. * + * * + * Low-shelf Low Mid Band High Mid Band High-shelf * + * corner center center corner * + * frequency frequency frequency frequency * + * 50Hz..800Hz 200Hz..3000Hz 1000Hz..8000Hz 4000Hz..16000Hz * + * * + * | | | | * + * | | | | * + * B -----+ /--+--\ /--+--\ +----- * + * O |\ | | | | | | /| * + * O | \ - | - - | - / | * + * S + | \ | | | | | | / | * + * T | | | | | | | | | | * + * ---------+---------------+------------------+---------------+-------- * + * C | | | | | | | | | | * + * U - | / | | | | | | \ | * + * T | / - | - - | - \ | * + * O |/ | | | | | | \| * + * F -----+ \--+--/ \--+--/ +----- * + * F | | | | * + * | | | | * + * * + * Gains vary from 0.126 up to 7.943, which means from -18dB attenuation * + * up to +18dB amplification. Band width varies from 0.01 up to 1.0 in * + * octaves for two mid bands. * + * * + * Implementation is based on the "Cookbook formulae for audio EQ biquad * + * filter coefficients" by Robert Bristow-Johnson * + * http://www.musicdsp.org/files/Audio-EQ-Cookbook.txt */ + +typedef struct ALequalizerState { + DERIVE_FROM_TYPE(ALeffectState); + + /* Effect gains for each channel */ + ALfloat Gain[MaxChannels]; + + /* Effect parameters */ + ALfilterState filter[4]; +} ALequalizerState; + +static ALvoid ALequalizerState_Destruct(ALequalizerState *UNUSED(state)) +{ +} + +static ALboolean ALequalizerState_deviceUpdate(ALequalizerState *UNUSED(state), ALCdevice *UNUSED(device)) +{ + return AL_TRUE; +} + +static ALvoid ALequalizerState_update(ALequalizerState *state, ALCdevice *device, const ALeffectslot *slot) +{ + ALfloat frequency = (ALfloat)device->Frequency; + ALfloat gain = sqrtf(1.0f / device->NumChan) * slot->Gain; + + SetGains(device, gain, state->Gain); + + /* Calculate coefficients for the each type of filter */ + ALfilterState_setParams(&state->filter[0], ALfilterType_LowShelf, + sqrtf(slot->EffectProps.Equalizer.LowGain), + slot->EffectProps.Equalizer.LowCutoff/frequency, + 0.0f); + + ALfilterState_setParams(&state->filter[1], ALfilterType_Peaking, + sqrtf(slot->EffectProps.Equalizer.Mid1Gain), + slot->EffectProps.Equalizer.Mid1Center/frequency, + slot->EffectProps.Equalizer.Mid1Width); + + ALfilterState_setParams(&state->filter[2], ALfilterType_Peaking, + sqrtf(slot->EffectProps.Equalizer.Mid2Gain), + slot->EffectProps.Equalizer.Mid2Center/frequency, + slot->EffectProps.Equalizer.Mid2Width); + + ALfilterState_setParams(&state->filter[3], ALfilterType_HighShelf, + sqrtf(slot->EffectProps.Equalizer.HighGain), + slot->EffectProps.Equalizer.HighCutoff/frequency, + 0.0f); +} + +static ALvoid ALequalizerState_process(ALequalizerState *state, ALuint SamplesToDo, const ALfloat *restrict SamplesIn, ALfloat (*restrict SamplesOut)[BUFFERSIZE]) +{ + ALuint base; + ALuint it; + ALuint kt; + ALuint ft; + + for(base = 0;base < SamplesToDo;) + { + ALfloat temps[64]; + ALuint td = minu(SamplesToDo-base, 64); + + for(it = 0;it < td;it++) + { + ALfloat smp = SamplesIn[base+it]; + + for(ft = 0;ft < 4;ft++) + smp = ALfilterState_processSingle(&state->filter[ft], smp); + + temps[it] = smp; + } + + for(kt = 0;kt < MaxChannels;kt++) + { + ALfloat gain = state->Gain[kt]; + if(!(gain > GAIN_SILENCE_THRESHOLD)) + continue; + + for(it = 0;it < td;it++) + SamplesOut[kt][base+it] += gain * temps[it]; + } + + base += td; + } +} + +static void ALequalizerState_Delete(ALequalizerState *state) +{ + free(state); +} + +DEFINE_ALEFFECTSTATE_VTABLE(ALequalizerState); + + +typedef struct ALequalizerStateFactory { + DERIVE_FROM_TYPE(ALeffectStateFactory); +} ALequalizerStateFactory; + +ALeffectState *ALequalizerStateFactory_create(ALequalizerStateFactory *UNUSED(factory)) +{ + ALequalizerState *state; + int it; + + state = malloc(sizeof(*state)); + if(!state) return NULL; + SET_VTABLE2(ALequalizerState, ALeffectState, state); + + /* Initialize sample history only on filter creation to avoid */ + /* sound clicks if filter settings were changed in runtime. */ + for(it = 0; it < 4; it++) + ALfilterState_clear(&state->filter[it]); + + return STATIC_CAST(ALeffectState, state); +} + +DEFINE_ALEFFECTSTATEFACTORY_VTABLE(ALequalizerStateFactory); + +ALeffectStateFactory *ALequalizerStateFactory_getFactory(void) +{ + static ALequalizerStateFactory EqualizerFactory = { { GET_VTABLE2(ALequalizerStateFactory, ALeffectStateFactory) } }; + + return STATIC_CAST(ALeffectStateFactory, &EqualizerFactory); +} + + +void ALequalizer_setParami(ALeffect *UNUSED(effect), ALCcontext *context, ALenum UNUSED(param), ALint UNUSED(val)) +{ SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM); } +void ALequalizer_setParamiv(ALeffect *effect, ALCcontext *context, ALenum param, const ALint *vals) +{ + ALequalizer_setParami(effect, context, param, vals[0]); +} +void ALequalizer_setParamf(ALeffect *effect, ALCcontext *context, ALenum param, ALfloat val) +{ + ALeffectProps *props = &effect->Props; + switch(param) + { + case AL_EQUALIZER_LOW_GAIN: + if(!(val >= AL_EQUALIZER_MIN_LOW_GAIN && val <= AL_EQUALIZER_MAX_LOW_GAIN)) + SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE); + props->Equalizer.LowGain = val; + break; + + case AL_EQUALIZER_LOW_CUTOFF: + if(!(val >= AL_EQUALIZER_MIN_LOW_CUTOFF && val <= AL_EQUALIZER_MAX_LOW_CUTOFF)) + SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE); + props->Equalizer.LowCutoff = val; + break; + + case AL_EQUALIZER_MID1_GAIN: + if(!(val >= AL_EQUALIZER_MIN_MID1_GAIN && val <= AL_EQUALIZER_MAX_MID1_GAIN)) + SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE); + props->Equalizer.Mid1Gain = val; + break; + + case AL_EQUALIZER_MID1_CENTER: + if(!(val >= AL_EQUALIZER_MIN_MID1_CENTER && val <= AL_EQUALIZER_MAX_MID1_CENTER)) + SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE); + props->Equalizer.Mid1Center = val; + break; + + case AL_EQUALIZER_MID1_WIDTH: + if(!(val >= AL_EQUALIZER_MIN_MID1_WIDTH && val <= AL_EQUALIZER_MAX_MID1_WIDTH)) + SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE); + props->Equalizer.Mid1Width = val; + break; + + case AL_EQUALIZER_MID2_GAIN: + if(!(val >= AL_EQUALIZER_MIN_MID2_GAIN && val <= AL_EQUALIZER_MAX_MID2_GAIN)) + SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE); + props->Equalizer.Mid2Gain = val; + break; + + case AL_EQUALIZER_MID2_CENTER: + if(!(val >= AL_EQUALIZER_MIN_MID2_CENTER && val <= AL_EQUALIZER_MAX_MID2_CENTER)) + SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE); + props->Equalizer.Mid2Center = val; + break; + + case AL_EQUALIZER_MID2_WIDTH: + if(!(val >= AL_EQUALIZER_MIN_MID2_WIDTH && val <= AL_EQUALIZER_MAX_MID2_WIDTH)) + SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE); + props->Equalizer.Mid2Width = val; + break; + + case AL_EQUALIZER_HIGH_GAIN: + if(!(val >= AL_EQUALIZER_MIN_HIGH_GAIN && val <= AL_EQUALIZER_MAX_HIGH_GAIN)) + SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE); + props->Equalizer.HighGain = val; + break; + + case AL_EQUALIZER_HIGH_CUTOFF: + if(!(val >= AL_EQUALIZER_MIN_HIGH_CUTOFF && val <= AL_EQUALIZER_MAX_HIGH_CUTOFF)) + SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE); + props->Equalizer.HighCutoff = val; + break; + + default: + SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM); + } +} +void ALequalizer_setParamfv(ALeffect *effect, ALCcontext *context, ALenum param, const ALfloat *vals) +{ + ALequalizer_setParamf(effect, context, param, vals[0]); +} + +void ALequalizer_getParami(const ALeffect *UNUSED(effect), ALCcontext *context, ALenum UNUSED(param), ALint *UNUSED(val)) +{ SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM); } +void ALequalizer_getParamiv(const ALeffect *effect, ALCcontext *context, ALenum param, ALint *vals) +{ + ALequalizer_getParami(effect, context, param, vals); +} +void ALequalizer_getParamf(const ALeffect *effect, ALCcontext *context, ALenum param, ALfloat *val) +{ + const ALeffectProps *props = &effect->Props; + switch(param) + { + case AL_EQUALIZER_LOW_GAIN: + *val = props->Equalizer.LowGain; + break; + + case AL_EQUALIZER_LOW_CUTOFF: + *val = props->Equalizer.LowCutoff; + break; + + case AL_EQUALIZER_MID1_GAIN: + *val = props->Equalizer.Mid1Gain; + break; + + case AL_EQUALIZER_MID1_CENTER: + *val = props->Equalizer.Mid1Center; + break; + + case AL_EQUALIZER_MID1_WIDTH: + *val = props->Equalizer.Mid1Width; + break; + + case AL_EQUALIZER_MID2_GAIN: + *val = props->Equalizer.Mid2Gain; + break; + + case AL_EQUALIZER_MID2_CENTER: + *val = props->Equalizer.Mid2Center; + break; + + case AL_EQUALIZER_MID2_WIDTH: + *val = props->Equalizer.Mid2Width; + break; + + case AL_EQUALIZER_HIGH_GAIN: + *val = props->Equalizer.HighGain; + break; + + case AL_EQUALIZER_HIGH_CUTOFF: + *val = props->Equalizer.HighCutoff; + break; + + default: + SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM); + } +} +void ALequalizer_getParamfv(const ALeffect *effect, ALCcontext *context, ALenum param, ALfloat *vals) +{ + ALequalizer_getParamf(effect, context, param, vals); +} + +DEFINE_ALEFFECT_VTABLE(ALequalizer); |