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authorSven Gothel <[email protected]>2014-01-26 07:06:02 +0100
committerSven Gothel <[email protected]>2014-01-26 07:06:02 +0100
commite6f4251945c228a775649b5ccd7f11dd4519c28d (patch)
tree8454b34363358cf9bb502021a68c6985c97daac4 /Alc/effects/equalizer.c
parent389ae1f767bfad6116e21306fc3cdf89a4cbcc0a (diff)
parent49baa9128dd98e986639def4f24c7522d9ec6b56 (diff)
Merge branch 'UPSTREAM'
Diffstat (limited to 'Alc/effects/equalizer.c')
-rw-r--r--Alc/effects/equalizer.c337
1 files changed, 337 insertions, 0 deletions
diff --git a/Alc/effects/equalizer.c b/Alc/effects/equalizer.c
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+/**
+ * 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);