From d3a81f4f28484b246084a5ec5cac5619adcfa819 Mon Sep 17 00:00:00 2001 From: Raulshc <33253777+Raulshc@users.noreply.github.com> Date: Sun, 20 May 2018 17:23:03 +0200 Subject: EFX: Frequency Shifter implementation Add frequency shifter effect using discrete Hilbert transform. Only mono signal processing by now (LEFT_DIRECTION). --- Alc/effects/fshifter.c | 323 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 323 insertions(+) create mode 100644 Alc/effects/fshifter.c (limited to 'Alc/effects') diff --git a/Alc/effects/fshifter.c b/Alc/effects/fshifter.c new file mode 100644 index 00000000..2d1b64fe --- /dev/null +++ b/Alc/effects/fshifter.c @@ -0,0 +1,323 @@ +/** + * OpenAL cross platform audio library + * Copyright (C) 2018 by Raul Herraiz. + * 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 +#include + +#include "alMain.h" +#include "alAuxEffectSlot.h" +#include "alError.h" +#include "alu.h" +#include "filters/defs.h" + +#include "alcomplex.h" + +#define HIL_SIZE 1024 +#define OVERSAMP (1<<2) + +#define HIL_STEP (HIL_SIZE / OVERSAMP) +#define FIFO_LATENCY (HIL_STEP * (OVERSAMP-1)) + + +typedef struct ALfshifterState { + DERIVE_FROM_TYPE(ALeffectState); + + /* Effect parameters */ + ALsizei count; + ALdouble frac_freq; + ALdouble inc; + ALdouble ld_sign; + + /*Effects buffers*/ + ALfloat InFIFO[HIL_SIZE]; + ALcomplex OutFIFO[HIL_SIZE]; + ALcomplex OutputAccum[2*HIL_SIZE]; + ALcomplex Analytic[HIL_SIZE]; + ALcomplex Outdata[BUFFERSIZE]; + + alignas(16) ALfloat BufferOut[BUFFERSIZE]; + + /* Effect gains for each output channel */ + ALfloat CurrentGains[MAX_OUTPUT_CHANNELS]; + ALfloat TargetGains[MAX_OUTPUT_CHANNELS]; + +} ALfshifterState; + +static ALvoid ALfshifterState_Destruct(ALfshifterState *state); +static ALboolean ALfshifterState_deviceUpdate(ALfshifterState *state, ALCdevice *device); +static ALvoid ALfshifterState_update(ALfshifterState *state, const ALCcontext *context, const ALeffectslot *slot, const ALeffectProps *props); +static ALvoid ALfshifterState_process(ALfshifterState *state, ALsizei SamplesToDo, const ALfloat (*restrict SamplesIn)[BUFFERSIZE], ALfloat (*restrict SamplesOut)[BUFFERSIZE], ALsizei NumChannels); +DECLARE_DEFAULT_ALLOCATORS(ALfshifterState) + +DEFINE_ALEFFECTSTATE_VTABLE(ALfshifterState); + +/* Define a Hann window, used to filter the HIL input and output. */ +alignas(16) static ALdouble HannWindow[HIL_SIZE]; + +static void InitHannWindow(void) +{ + ALsizei i; + + /* Create lookup table of the Hann window for the desired size, i.e. HIL_SIZE */ + for(i = 0;i < HIL_SIZE>>1;i++) + { + ALdouble val = sin(M_PI * (ALdouble)i / (ALdouble)(HIL_SIZE-1)); + HannWindow[i] = HannWindow[HIL_SIZE-1-i] = val * val; + } +} + +static alonce_flag HannInitOnce = AL_ONCE_FLAG_INIT; + +static void ALfshifterState_Construct(ALfshifterState *state) +{ + ALeffectState_Construct(STATIC_CAST(ALeffectState, state)); + SET_VTABLE2(ALfshifterState, ALeffectState, state); + + alcall_once(&HannInitOnce, InitHannWindow); +} + +static ALvoid ALfshifterState_Destruct(ALfshifterState *state) +{ + ALeffectState_Destruct(STATIC_CAST(ALeffectState,state)); +} + +static ALboolean ALfshifterState_deviceUpdate(ALfshifterState *state, ALCdevice *device) +{ + /* (Re-)initializing parameters and clear the buffers. */ + state->count = FIFO_LATENCY; + state->frac_freq = 0.0; + state->inc = 0.0; + state->ld_sign = -1.0; + + memset(state->InFIFO , 0, HIL_SIZE*sizeof(ALfloat)); + memset(state->OutFIFO , 0, HIL_SIZE*sizeof(ALcomplex)); + memset(state->OutputAccum, 0, 2*HIL_SIZE*sizeof(ALcomplex)); + memset(state->Analytic , 0, HIL_SIZE*sizeof(ALcomplex)); + + memset(state->CurrentGains, 0, sizeof(state->CurrentGains)); + memset(state->TargetGains, 0, sizeof(state->TargetGains)); + + return AL_TRUE; +} + +static ALvoid ALfshifterState_update(ALfshifterState *state, const ALCcontext *context, const ALeffectslot *slot, const ALeffectProps *props) +{ + const ALCdevice *device = context->Device; + ALfloat coeffs[MAX_AMBI_COEFFS]; + + state->frac_freq = props->Fshifter.Frequency/device->Frequency; + + switch (props->Fshifter.Left_direction) + { + case AL_FREQUENCY_SHIFTER_DIRECTION_DOWN: + state->ld_sign = -1.0; + break; + + case AL_FREQUENCY_SHIFTER_DIRECTION_UP: + state->ld_sign = 1.0; + break; + + case AL_FREQUENCY_SHIFTER_DIRECTION_OFF: + state->frac_freq = 0.0; + break; + } + + CalcAngleCoeffs(0.0f, 0.0f, 0.0f, coeffs); + ComputeDryPanGains(&device->Dry, coeffs, slot->Params.Gain, state->TargetGains); +} + +static ALvoid ALfshifterState_process(ALfshifterState *state, ALsizei SamplesToDo, const ALfloat (*restrict SamplesIn)[BUFFERSIZE], ALfloat (*restrict SamplesOut)[BUFFERSIZE], ALsizei NumChannels) +{ + ALsizei i,k; + ALfloat *restrict BufferOut = state->BufferOut; + + for (i = 0; i < SamplesToDo; i++){ + + /* Fill FIFO buffer with samples data */ + state->InFIFO[state->count] = SamplesIn[0][i]; + state->Outdata[i] = state->OutFIFO[state->count-FIFO_LATENCY]; + + state->count++; + + /* Check whether FIFO buffer is filled */ + if (state->count >= HIL_SIZE ) + { + state->count = FIFO_LATENCY; + + /* Real signal windowing and store in Analytic buffer */ + for (k = 0; k < HIL_SIZE;k++) + { + state->Analytic[k].Real = state->InFIFO[k] * HannWindow[k]; + state->Analytic[k].Imag = 0.0f; + } + /*Processing signal by Discrete Hilbert Transform (analytical signal)*/ + hilbert(HIL_SIZE, state->Analytic); + + /* Windowing and add to output accumulator */ + for(k=0; k < HIL_SIZE; k++) + { + state->OutputAccum[k].Real += 2.0f*HannWindow[k]*state->Analytic[k].Real / OVERSAMP; + state->OutputAccum[k].Imag += 2.0f*HannWindow[k]*state->Analytic[k].Imag / OVERSAMP; + } + for (k = 0; k < HIL_STEP; k++) + { + state->OutFIFO[k] = state->OutputAccum[k]; + } + + /* shift accumulator */ + memmove(state->OutputAccum, state->OutputAccum + HIL_STEP, HIL_SIZE*sizeof(ALcomplex)); + + /* move input FIFO */ + for (k = 0; k < FIFO_LATENCY; k++) state->InFIFO[k] = state->InFIFO[k + HIL_STEP]; + } + } + /*Process frequency shifter using the analytic signal obtained*/ + for ( k = 0; k < SamplesToDo; k++, state->inc += state->frac_freq ) + { + ALdouble phase; + + if( state->inc >= 1.0 ) state->inc -= 1.0; + + phase = (2.0*M_PI*state->inc); + + BufferOut[k] = (ALfloat)(state->Outdata[k].Real*cos(phase) + + state->ld_sign*state->Outdata[k].Imag*sin(phase)); + } + + /* Now, mix the processed sound data to the output. */ + MixSamples(BufferOut, NumChannels, SamplesOut, state->CurrentGains, state->TargetGains, + maxi(SamplesToDo, 512), 0, SamplesToDo); + +} + +typedef struct FshifterStateFactory { + DERIVE_FROM_TYPE(EffectStateFactory); +} FshifterStateFactory; + +static ALeffectState *FshifterStateFactory_create(FshifterStateFactory *UNUSED(factory)) +{ + ALfshifterState *state; + + NEW_OBJ0(state, ALfshifterState)(); + if(!state) return NULL; + + return STATIC_CAST(ALeffectState, state); +} + +DEFINE_EFFECTSTATEFACTORY_VTABLE(FshifterStateFactory); + +EffectStateFactory *FshifterStateFactory_getFactory(void) +{ + static FshifterStateFactory FshifterFactory = { { GET_VTABLE2(FshifterStateFactory, EffectStateFactory) } }; + + return STATIC_CAST(EffectStateFactory, &FshifterFactory); +} + +void ALfshifter_setParamf(ALeffect *effect, ALCcontext *context, ALenum param, ALfloat val) +{ + ALeffectProps *props = &effect->Props; + switch(param) + { + case AL_FREQUENCY_SHIFTER_FREQUENCY: + if(!(val >= AL_FREQUENCY_SHIFTER_MIN_FREQUENCY && val <= AL_FREQUENCY_SHIFTER_MAX_FREQUENCY)) + SETERR_RETURN(context, AL_INVALID_VALUE,,"Frequency shifter frequency out of range"); + props->Fshifter.Frequency = (ALfloat) val; + break; + + default: + alSetError(context, AL_INVALID_ENUM, "Invalid frequency shifter float property 0x%04x", param); + } +} + +void ALfshifter_setParamfv(ALeffect *effect, ALCcontext *context, ALenum param, const ALfloat *vals) +{ + ALfshifter_setParamf(effect, context, param, vals[0]); +} + +void ALfshifter_setParami(ALeffect *effect, ALCcontext *context, ALenum param, ALint val) +{ + ALeffectProps *props = &effect->Props; + switch(param) + { + case AL_FREQUENCY_SHIFTER_LEFT_DIRECTION: + if(!(val >= AL_FREQUENCY_SHIFTER_MIN_LEFT_DIRECTION && val <= AL_FREQUENCY_SHIFTER_MAX_LEFT_DIRECTION)) + SETERR_RETURN(context, AL_INVALID_VALUE,,"Frequency shifter left direction out of range"); + props->Fshifter.Left_direction = val; + break; + + case AL_FREQUENCY_SHIFTER_RIGHT_DIRECTION: + if(!(val >= AL_FREQUENCY_SHIFTER_MIN_RIGHT_DIRECTION && val <= AL_FREQUENCY_SHIFTER_MAX_RIGHT_DIRECTION)) + SETERR_RETURN(context, AL_INVALID_VALUE,,"Frequency shifter right direction out of range"); + props->Fshifter.Right_direction = val; + break; + + default: + alSetError(context, AL_INVALID_ENUM, "Invalid frequency shifter integer property 0x%04x", param); + } +} +void ALfshifter_setParamiv(ALeffect *effect, ALCcontext *context, ALenum param, const ALint *vals) +{ + ALfshifter_setParami(effect, context, param, vals[0]); +} + +void ALfshifter_getParami(const ALeffect *effect, ALCcontext *context, ALenum param, ALint *val) +{ + const ALeffectProps *props = &effect->Props; + switch(param) + { + case AL_FREQUENCY_SHIFTER_LEFT_DIRECTION: + *val = (ALint)props->Fshifter.Left_direction; + break; + case AL_FREQUENCY_SHIFTER_RIGHT_DIRECTION: + *val = (ALint)props->Fshifter.Right_direction; + break; + default: + alSetError(context, AL_INVALID_ENUM, "Invalid frequency shifter integer property 0x%04x", param); + } +} +void ALfshifter_getParamiv(const ALeffect *effect, ALCcontext *context, ALenum param, ALint *vals) +{ + ALfshifter_getParami(effect, context, param, vals); +} + +void ALfshifter_getParamf(const ALeffect *effect, ALCcontext *context, ALenum param, ALfloat *val) +{ + + const ALeffectProps *props = &effect->Props; + switch(param) + { + case AL_FREQUENCY_SHIFTER_FREQUENCY: + *val = (ALfloat)props->Fshifter.Frequency; + break; + + default: + alSetError(context, AL_INVALID_ENUM, "Invalid frequency shifter float property 0x%04x", param); + } + +} + +void ALfshifter_getParamfv(const ALeffect *effect, ALCcontext *context, ALenum param, ALfloat *vals) +{ + ALfshifter_getParamf(effect, context, param, vals); +} + +DEFINE_ALEFFECT_VTABLE(ALfshifter); -- cgit v1.2.3