Simple to use compressor effect

This commit is contained in:
Juan Linietsky 2017-01-22 18:18:56 -03:00
parent 2d8e765aab
commit 4d944b4996
3 changed files with 254 additions and 0 deletions

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@ -0,0 +1,188 @@
#include "audio_effect_compressor.h"
#include "servers/audio_server.h"
void AudioEffectCompressorInstance::process(const AudioFrame *p_src_frames,AudioFrame *p_dst_frames,int p_frame_count) {
float treshold = Math::db2linear(base->treshold);
float sample_rate=AudioServer::get_singleton()->get_mix_rate();
float ratatcoef = exp(-1 / (0.00001f * sample_rate));
float ratrelcoef = exp(-1 / (0.5f * sample_rate));
float attime = base->attack_us / 1000000.0;
float reltime = base->release_ms / 1000.0;
float atcoef = exp(-1 / (attime * sample_rate));
float relcoef = exp(-1 / (reltime * sample_rate));
float makeup = Math::db2linear(base->gain);
float mix = base->mix;
float gr_meter_decay = exp(1 / (1 * sample_rate));
for(int i=0;i<p_frame_count;i++) {
AudioFrame s = p_src_frames[i];
//convert to positive
s.l = Math::abs(s.l);
s.r = Math::abs(s.r);
float peak = MAX(s.l,s.r);
float overdb = 2.08136898f * Math::linear2db(peak/treshold);
if (overdb<0.0) //we only care about what goes over to compress
overdb=0.0;
if(overdb-rundb>5) // diffeence is too large
averatio = 4;
if(overdb > rundb) {
rundb = overdb + atcoef * (rundb - overdb);
runratio = averatio + ratatcoef * (runratio - averatio);
} else {
rundb = overdb + relcoef * (rundb - overdb);
runratio = averatio + ratrelcoef * (runratio - averatio);
}
overdb = rundb;
averatio = runratio;
float cratio;
if(false) { //rato all-in
cratio = 12 + averatio;
} else {
cratio = base->ratio;
}
float gr = -overdb * (cratio-1)/cratio;
float grv = Math::db2linear(gr);
runmax = maxover + relcoef * (runmax - maxover); // highest peak for setting att/rel decays in reltime
maxover = runmax;
if (grv < gr_meter) {
gr_meter=grv;
} else {
gr_meter*=gr_meter_decay;
if(gr_meter>1)
gr_meter=1;
}
p_dst_frames[i] = p_src_frames[i] * grv * makeup * mix + p_src_frames[i] * (1.0-mix);
}
}
Ref<AudioEffectInstance> AudioEffectCompressor::instance() {
Ref<AudioEffectCompressorInstance> ins;
ins.instance();
ins->base=Ref<AudioEffectCompressor>(this);
ins->rundb=0;
ins->runratio=0;
ins->averatio=0;
ins->runmax=0;
ins->maxover=0;
ins->gr_meter=1.0;
return ins;
}
void AudioEffectCompressor::set_treshold(float p_treshold) {
treshold=p_treshold;
}
float AudioEffectCompressor::get_treshold() const {
return treshold;
}
void AudioEffectCompressor::set_ratio(float p_ratio) {
ratio=p_ratio;
}
float AudioEffectCompressor::get_ratio() const {
return ratio;
}
void AudioEffectCompressor::set_gain(float p_gain) {
gain=p_gain;
}
float AudioEffectCompressor::get_gain() const {
return gain;
}
void AudioEffectCompressor::set_attack_us(float p_attack_us) {
attack_us=p_attack_us;
}
float AudioEffectCompressor::get_attack_us() const {
return attack_us;
}
void AudioEffectCompressor::set_release_ms(float p_release_ms) {
release_ms=p_release_ms;
}
float AudioEffectCompressor::get_release_ms() const {
return release_ms;
}
void AudioEffectCompressor::set_mix(float p_mix) {
mix=p_mix;
}
float AudioEffectCompressor::get_mix() const {
return mix;
}
void AudioEffectCompressor::_bind_methods() {
ClassDB::bind_method(_MD("set_treshold","treshold"),&AudioEffectCompressor::set_treshold);
ClassDB::bind_method(_MD("get_treshold"),&AudioEffectCompressor::get_treshold);
ClassDB::bind_method(_MD("set_ratio","ratio"),&AudioEffectCompressor::set_ratio);
ClassDB::bind_method(_MD("get_ratio"),&AudioEffectCompressor::get_ratio);
ClassDB::bind_method(_MD("set_gain","gain"),&AudioEffectCompressor::set_gain);
ClassDB::bind_method(_MD("get_gain"),&AudioEffectCompressor::get_gain);
ClassDB::bind_method(_MD("set_attack_us","attack_us"),&AudioEffectCompressor::set_attack_us);
ClassDB::bind_method(_MD("get_attack_us"),&AudioEffectCompressor::get_attack_us);
ClassDB::bind_method(_MD("set_release_ms","release_ms"),&AudioEffectCompressor::set_release_ms);
ClassDB::bind_method(_MD("get_release_ms"),&AudioEffectCompressor::get_release_ms);
ClassDB::bind_method(_MD("set_mix","mix"),&AudioEffectCompressor::set_mix);
ClassDB::bind_method(_MD("get_mix"),&AudioEffectCompressor::get_mix);
ADD_PROPERTY(PropertyInfo(Variant::REAL,"treshold",PROPERTY_HINT_RANGE,"-60,0,0.1"),_SCS("set_treshold"),_SCS("get_treshold"));
ADD_PROPERTY(PropertyInfo(Variant::REAL,"ratio",PROPERTY_HINT_RANGE,"1,48,0.1"),_SCS("set_ratio"),_SCS("get_ratio"));
ADD_PROPERTY(PropertyInfo(Variant::REAL,"gain",PROPERTY_HINT_RANGE,"-20,20,0.1"),_SCS("set_gain"),_SCS("get_gain"));
ADD_PROPERTY(PropertyInfo(Variant::REAL,"attack_us",PROPERTY_HINT_RANGE,"20,2000,1"),_SCS("set_attack_us"),_SCS("get_attack_us"));
ADD_PROPERTY(PropertyInfo(Variant::REAL,"release_ms",PROPERTY_HINT_RANGE,"20,2000,1"),_SCS("set_release_ms"),_SCS("get_release_ms"));
ADD_PROPERTY(PropertyInfo(Variant::REAL,"mix",PROPERTY_HINT_RANGE,"0,1,0.01"),_SCS("set_mix"),_SCS("get_mix"));
}
AudioEffectCompressor::AudioEffectCompressor()
{
treshold=0;
ratio=4;
gain=0;
attack_us=20;
release_ms=250;
mix=1;
}

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@ -0,0 +1,64 @@
#ifndef AUDIOEFFECTCOMPRESSOR_H
#define AUDIOEFFECTCOMPRESSOR_H
#include "servers/audio/audio_effect.h"
class AudioEffectCompressor;
class AudioEffectCompressorInstance : public AudioEffectInstance {
GDCLASS(AudioEffectCompressorInstance,AudioEffectInstance)
friend class AudioEffectCompressor;
Ref<AudioEffectCompressor> base;
float rundb,averatio,runratio,runmax,maxover,gr_meter;
public:
virtual void process(const AudioFrame *p_src_frames,AudioFrame *p_dst_frames,int p_frame_count);
};
class AudioEffectCompressor : public AudioEffect {
GDCLASS(AudioEffectCompressor,AudioEffect)
friend class AudioEffectCompressorInstance;
float treshold;
float ratio;
float gain;
float attack_us;
float release_ms;
float mix;
protected:
static void _bind_methods();
public:
Ref<AudioEffectInstance> instance();
void set_treshold(float p_treshold);
float get_treshold() const;
void set_ratio(float p_ratio);
float get_ratio() const;
void set_gain(float p_gain);
float get_gain() const;
void set_attack_us(float p_attack_us);
float get_attack_us() const;
void set_release_ms(float p_release_ms);
float get_release_ms() const;
void set_mix(float p_mix);
float get_mix() const;
AudioEffectCompressor();
};
#endif // AUDIOEFFECTCOMPRESSOR_H

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@ -46,6 +46,7 @@
#include "audio/effects/audio_effect_panner.h"
#include "audio/effects/audio_effect_chorus.h"
#include "audio/effects/audio_effect_delay.h"
#include "audio/effects/audio_effect_compressor.h"
static void _debugger_get_resource_usage(List<ScriptDebuggerRemote::ResourceUsage>* r_usage) {
@ -107,6 +108,7 @@ void register_server_types() {
ClassDB::register_class<AudioEffectPanner>();
ClassDB::register_class<AudioEffectChorus>();
ClassDB::register_class<AudioEffectDelay>();
ClassDB::register_class<AudioEffectCompressor>();
}