224 lines
7.6 KiB
C++
224 lines
7.6 KiB
C++
/**
|
|
* OpenAL cross platform audio library
|
|
* Copyright (C) 2013 by Anis A. Hireche
|
|
* 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 <cstdlib>
|
|
|
|
#include "al/auxeffectslot.h"
|
|
#include "alcmain.h"
|
|
#include "alcontext.h"
|
|
#include "alu.h"
|
|
#include "vecmat.h"
|
|
|
|
|
|
namespace {
|
|
|
|
#define AMP_ENVELOPE_MIN 0.5f
|
|
#define AMP_ENVELOPE_MAX 2.0f
|
|
|
|
#define ATTACK_TIME 0.1f /* 100ms to rise from min to max */
|
|
#define RELEASE_TIME 0.2f /* 200ms to drop from max to min */
|
|
|
|
|
|
struct CompressorState final : public EffectState {
|
|
/* Effect gains for each channel */
|
|
float mGain[MAX_AMBI_CHANNELS][MAX_OUTPUT_CHANNELS]{};
|
|
|
|
/* Effect parameters */
|
|
bool mEnabled{true};
|
|
float mAttackMult{1.0f};
|
|
float mReleaseMult{1.0f};
|
|
float mEnvFollower{1.0f};
|
|
|
|
|
|
void deviceUpdate(const ALCdevice *device) override;
|
|
void update(const ALCcontext *context, const ALeffectslot *slot, const EffectProps *props, const EffectTarget target) override;
|
|
void process(const size_t samplesToDo, const al::span<const FloatBufferLine> samplesIn, const al::span<FloatBufferLine> samplesOut) override;
|
|
|
|
DEF_NEWDEL(CompressorState)
|
|
};
|
|
|
|
void CompressorState::deviceUpdate(const ALCdevice *device)
|
|
{
|
|
/* Number of samples to do a full attack and release (non-integer sample
|
|
* counts are okay).
|
|
*/
|
|
const float attackCount{static_cast<float>(device->Frequency) * ATTACK_TIME};
|
|
const float releaseCount{static_cast<float>(device->Frequency) * RELEASE_TIME};
|
|
|
|
/* Calculate per-sample multipliers to attack and release at the desired
|
|
* rates.
|
|
*/
|
|
mAttackMult = std::pow(AMP_ENVELOPE_MAX/AMP_ENVELOPE_MIN, 1.0f/attackCount);
|
|
mReleaseMult = std::pow(AMP_ENVELOPE_MIN/AMP_ENVELOPE_MAX, 1.0f/releaseCount);
|
|
}
|
|
|
|
void CompressorState::update(const ALCcontext*, const ALeffectslot *slot, const EffectProps *props, const EffectTarget target)
|
|
{
|
|
mEnabled = props->Compressor.OnOff;
|
|
|
|
mOutTarget = target.Main->Buffer;
|
|
auto set_gains = [slot,target](auto &gains, al::span<const float,MAX_AMBI_CHANNELS> coeffs)
|
|
{ ComputePanGains(target.Main, coeffs.data(), slot->Params.Gain, gains); };
|
|
SetAmbiPanIdentity(std::begin(mGain), slot->Wet.Buffer.size(), set_gains);
|
|
}
|
|
|
|
void CompressorState::process(const size_t samplesToDo, const al::span<const FloatBufferLine> samplesIn, const al::span<FloatBufferLine> samplesOut)
|
|
{
|
|
for(size_t base{0u};base < samplesToDo;)
|
|
{
|
|
float gains[256];
|
|
const size_t td{minz(256, samplesToDo-base)};
|
|
|
|
/* Generate the per-sample gains from the signal envelope. */
|
|
float env{mEnvFollower};
|
|
if(mEnabled)
|
|
{
|
|
for(size_t i{0u};i < td;++i)
|
|
{
|
|
/* Clamp the absolute amplitude to the defined envelope limits,
|
|
* then attack or release the envelope to reach it.
|
|
*/
|
|
const float amplitude{clampf(std::fabs(samplesIn[0][base+i]), AMP_ENVELOPE_MIN,
|
|
AMP_ENVELOPE_MAX)};
|
|
if(amplitude > env)
|
|
env = minf(env*mAttackMult, amplitude);
|
|
else if(amplitude < env)
|
|
env = maxf(env*mReleaseMult, amplitude);
|
|
|
|
/* Apply the reciprocal of the envelope to normalize the volume
|
|
* (compress the dynamic range).
|
|
*/
|
|
gains[i] = 1.0f / env;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* Same as above, except the amplitude is forced to 1. This helps
|
|
* ensure smooth gain changes when the compressor is turned on and
|
|
* off.
|
|
*/
|
|
for(size_t i{0u};i < td;++i)
|
|
{
|
|
const float amplitude{1.0f};
|
|
if(amplitude > env)
|
|
env = minf(env*mAttackMult, amplitude);
|
|
else if(amplitude < env)
|
|
env = maxf(env*mReleaseMult, amplitude);
|
|
|
|
gains[i] = 1.0f / env;
|
|
}
|
|
}
|
|
mEnvFollower = env;
|
|
|
|
/* Now compress the signal amplitude to output. */
|
|
auto changains = std::addressof(mGain[0]);
|
|
for(const auto &input : samplesIn)
|
|
{
|
|
const float *outgains{*(changains++)};
|
|
for(FloatBufferLine &output : samplesOut)
|
|
{
|
|
const float gain{*(outgains++)};
|
|
if(!(std::fabs(gain) > GAIN_SILENCE_THRESHOLD))
|
|
continue;
|
|
|
|
for(size_t i{0u};i < td;i++)
|
|
output[base+i] += input[base+i] * gains[i] * gain;
|
|
}
|
|
}
|
|
|
|
base += td;
|
|
}
|
|
}
|
|
|
|
|
|
void Compressor_setParami(EffectProps *props, ALenum param, int val)
|
|
{
|
|
switch(param)
|
|
{
|
|
case AL_COMPRESSOR_ONOFF:
|
|
if(!(val >= AL_COMPRESSOR_MIN_ONOFF && val <= AL_COMPRESSOR_MAX_ONOFF))
|
|
throw effect_exception{AL_INVALID_VALUE, "Compressor state out of range"};
|
|
props->Compressor.OnOff = (val != AL_FALSE);
|
|
break;
|
|
|
|
default:
|
|
throw effect_exception{AL_INVALID_ENUM, "Invalid compressor integer property 0x%04x",
|
|
param};
|
|
}
|
|
}
|
|
void Compressor_setParamiv(EffectProps *props, ALenum param, const int *vals)
|
|
{ Compressor_setParami(props, param, vals[0]); }
|
|
void Compressor_setParamf(EffectProps*, ALenum param, float)
|
|
{ throw effect_exception{AL_INVALID_ENUM, "Invalid compressor float property 0x%04x", param}; }
|
|
void Compressor_setParamfv(EffectProps*, ALenum param, const float*)
|
|
{
|
|
throw effect_exception{AL_INVALID_ENUM, "Invalid compressor float-vector property 0x%04x",
|
|
param};
|
|
}
|
|
|
|
void Compressor_getParami(const EffectProps *props, ALenum param, int *val)
|
|
{
|
|
switch(param)
|
|
{
|
|
case AL_COMPRESSOR_ONOFF:
|
|
*val = props->Compressor.OnOff;
|
|
break;
|
|
|
|
default:
|
|
throw effect_exception{AL_INVALID_ENUM, "Invalid compressor integer property 0x%04x",
|
|
param};
|
|
}
|
|
}
|
|
void Compressor_getParamiv(const EffectProps *props, ALenum param, int *vals)
|
|
{ Compressor_getParami(props, param, vals); }
|
|
void Compressor_getParamf(const EffectProps*, ALenum param, float*)
|
|
{ throw effect_exception{AL_INVALID_ENUM, "Invalid compressor float property 0x%04x", param}; }
|
|
void Compressor_getParamfv(const EffectProps*, ALenum param, float*)
|
|
{
|
|
throw effect_exception{AL_INVALID_ENUM, "Invalid compressor float-vector property 0x%04x",
|
|
param};
|
|
}
|
|
|
|
DEFINE_ALEFFECT_VTABLE(Compressor);
|
|
|
|
|
|
struct CompressorStateFactory final : public EffectStateFactory {
|
|
EffectState *create() override { return new CompressorState{}; }
|
|
EffectProps getDefaultProps() const noexcept override;
|
|
const EffectVtable *getEffectVtable() const noexcept override { return &Compressor_vtable; }
|
|
};
|
|
|
|
EffectProps CompressorStateFactory::getDefaultProps() const noexcept
|
|
{
|
|
EffectProps props{};
|
|
props.Compressor.OnOff = AL_COMPRESSOR_DEFAULT_ONOFF;
|
|
return props;
|
|
}
|
|
|
|
} // namespace
|
|
|
|
EffectStateFactory *CompressorStateFactory_getFactory()
|
|
{
|
|
static CompressorStateFactory CompressorFactory{};
|
|
return &CompressorFactory;
|
|
}
|