Alc/effects/compressor.c

   1 /**
   2  * OpenAL cross platform audio library
   3  * Copyright (C) 2013 by Anis A. Hireche
   4  * This library is free software; you can redistribute it and/or
   5  *  modify it under the terms of the GNU Library General Public
   6  *  License as published by the Free Software Foundation; either
   7  *  version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  *  Library General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Library General Public
  15  *  License along with this library; if not, write to the
  16  *  Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17  *  Boston, MA  02111-1307, USA.
  18  * Or go to http://www.gnu.org/copyleft/lgpl.html
  19  */
  20
  21 #include <stdlib.h>
  22
  23 #include "config.h"
  24 #include "alError.h"
  25 #include "alMain.h"
  26 #include "alAuxEffectSlot.h"
  27 #include "alu.h"
  28
  29
  30 typedef struct ALcompressorState {
  31     DERIVE_FROM_TYPE(ALeffectState);
  32
  33     /* Effect gains for each channel */
  34     ALfloat Gain[MaxChannels];
  35
  36     /* Effect parameters */
  37     ALboolean Enabled;
  38     ALfloat AttackRate;
  39     ALfloat ReleaseRate;
  40     ALfloat GainCtrl;
  41 } ALcompressorState;
  42
  43 static ALvoid ALcompressorState_Destruct(ALcompressorState *UNUSED(state))
  44 {
  45 }
  46
  47 static ALboolean ALcompressorState_deviceUpdate(ALcompressorState *state, ALCdevice *device)
  48 {
  49     const ALfloat attackTime = device->Frequency * 0.2f; /* 200ms Attack */
  50     const ALfloat releaseTime = device->Frequency * 0.4f; /* 400ms Release */
  51
  52     state->AttackRate = 1.0f / attackTime;
  53     state->ReleaseRate = 1.0f / releaseTime;
  54
  55     return AL_TRUE;
  56 }
  57
  58 static ALvoid ALcompressorState_update(ALcompressorState *state, ALCdevice *Device, const ALeffectslot *Slot)
  59 {
  60     ALfloat gain;
  61
  62     state->Enabled = Slot->EffectProps.Compressor.OnOff;
  63
  64     gain = sqrtf(1.0f / Device->NumChan) * Slot->Gain;
  65     SetGains(Device, gain, state->Gain);
  66 }
  67
  68 static ALvoid ALcompressorState_process(ALcompressorState *state, ALuint SamplesToDo, const ALfloat *SamplesIn, ALfloat (*SamplesOut)[BUFFERSIZE])
  69 {
  70     ALuint it, kt;
  71     ALuint base;
  72
  73     for(base = 0;base < SamplesToDo;)
  74     {
  75         ALfloat temps[64];
  76         ALuint td = minu(SamplesToDo-base, 64);
  77
  78         if(state->Enabled)
  79         {
  80             ALfloat output, smp, amplitude;
  81             ALfloat gain = state->GainCtrl;
  82
  83             for(it = 0;it < td;it++)
  84             {
  85                 smp = SamplesIn[it+base];
  86
  87                 amplitude = fabsf(smp);
  88                 if(amplitude > gain)
  89                     gain = minf(gain+state->AttackRate, amplitude);
  90                 else if(amplitude < gain)
  91                     gain = maxf(gain-state->ReleaseRate, amplitude);
  92                 output = 1.0f / clampf(gain, 0.5f, 2.0f);
  93
  94                 temps[it] = smp * output;
  95             }
  96
  97             state->GainCtrl = gain;
  98         }
  99         else
 100         {
 101             ALfloat output, smp, amplitude;
 102             ALfloat gain = state->GainCtrl;
 103
 104             for(it = 0;it < td;it++)
 105             {
 106                 smp = SamplesIn[it+base];
 107
 108                 amplitude = 1.0f;
 109                 if(amplitude > gain)
 110                     gain = minf(gain+state->AttackRate, amplitude);
 111                 else if(amplitude < gain)
 112                     gain = maxf(gain-state->ReleaseRate, amplitude);
 113                 output = 1.0f / clampf(gain, 0.5f, 2.0f);
 114
 115                 temps[it] = smp * output;
 116             }
 117
 118             state->GainCtrl = gain;
 119         }
 120
 121
 122         for(kt = 0;kt < MaxChannels;kt++)
 123         {
 124             ALfloat gain = state->Gain[kt];
 125             if(!(gain > GAIN_SILENCE_THRESHOLD))
 126                 continue;
 127
 128             for(it = 0;it < td;it++)
 129                 SamplesOut[kt][base+it] += gain * temps[it];
 130         }
 131
 132         base += td;
 133     }
 134 }
 135
 136 DECLARE_DEFAULT_ALLOCATORS(ALcompressorState)
 137
 138 DEFINE_ALEFFECTSTATE_VTABLE(ALcompressorState);
 139
 140
 141 typedef struct ALcompressorStateFactory {
 142     DERIVE_FROM_TYPE(ALeffectStateFactory);
 143 } ALcompressorStateFactory;
 144
 145 static ALeffectState *ALcompressorStateFactory_create(ALcompressorStateFactory *UNUSED(factory))
 146 {
 147     ALcompressorState *state;
 148
 149     state = ALcompressorState_New(sizeof(*state));
 150     if(!state) return NULL;
 151     SET_VTABLE2(ALcompressorState, ALeffectState, state);
 152
 153     state->Enabled = AL_TRUE;
 154     state->AttackRate = 0.0f;
 155     state->ReleaseRate = 0.0f;
 156     state->GainCtrl = 1.0f;
 157
 158     return STATIC_CAST(ALeffectState, state);
 159 }
 160
 161 DEFINE_ALEFFECTSTATEFACTORY_VTABLE(ALcompressorStateFactory);
 162
 163 ALeffectStateFactory *ALcompressorStateFactory_getFactory(void)
 164 {
 165     static ALcompressorStateFactory CompressorFactory = { { GET_VTABLE2(ALcompressorStateFactory, ALeffectStateFactory) } };
 166
 167     return STATIC_CAST(ALeffectStateFactory, &CompressorFactory);
 168 }
 169
 170
 171 void ALcompressor_setParami(ALeffect *effect, ALCcontext *context, ALenum param, ALint val)
 172 {
 173     ALeffectProps *props = &effect->Props;
 174     switch(param)
 175     {
 176         case AL_COMPRESSOR_ONOFF:
 177             if(!(val >= AL_COMPRESSOR_MIN_ONOFF && val <= AL_COMPRESSOR_MAX_ONOFF))
 178                 SET_ERROR_AND_RETURN(context, AL_INVALID_VALUE);
 179             props->Compressor.OnOff = val;
 180             break;
 181
 182     default:
 183         SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM);
 184     }
 185 }
 186 void ALcompressor_setParamiv(ALeffect *effect, ALCcontext *context, ALenum param, const ALint *vals)
 187 {
 188     ALcompressor_setParami(effect, context, param, vals[0]);
 189 }
 190 void ALcompressor_setParamf(ALeffect *UNUSED(effect), ALCcontext *context, ALenum UNUSED(param), ALfloat UNUSED(val))
 191 { SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM); }
 192 void ALcompressor_setParamfv(ALeffect *effect, ALCcontext *context, ALenum param, const ALfloat *vals)
 193 {
 194     ALcompressor_setParamf(effect, context, param, vals[0]);
 195 }
 196
 197 void ALcompressor_getParami(const ALeffect *effect, ALCcontext *context, ALenum param, ALint *val)
 198 {
 199     const ALeffectProps *props = &effect->Props;
 200     switch(param)
 201     {
 202         case AL_COMPRESSOR_ONOFF:
 203             *val = props->Compressor.OnOff;
 204             break;
 205         default:
 206             SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM);
 207     }
 208 }
 209 void ALcompressor_getParamiv(const ALeffect *effect, ALCcontext *context, ALenum param, ALint *vals)
 210 {
 211     ALcompressor_getParami(effect, context, param, vals);
 212 }
 213 void ALcompressor_getParamf(const ALeffect *UNUSED(effect), ALCcontext *context, ALenum UNUSED(param), ALfloat *UNUSED(val))
 214 { SET_ERROR_AND_RETURN(context, AL_INVALID_ENUM); }
 215 void ALcompressor_getParamfv(const ALeffect *effect, ALCcontext *context, ALenum param, ALfloat *vals)
 216 {
 217     ALcompressor_getParamf(effect, context, param, vals);
 218 }
 219
 220 DEFINE_ALEFFECT_VTABLE(ALcompressor);