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-rw-r--r--Alc/filters/biquad.cpp127
-rw-r--r--Alc/filters/biquad.h113
-rw-r--r--Alc/filters/nfc.cpp391
-rw-r--r--Alc/filters/nfc.h58
-rw-r--r--Alc/filters/splitter.cpp115
-rw-r--r--Alc/filters/splitter.h50
6 files changed, 0 insertions, 854 deletions
diff --git a/Alc/filters/biquad.cpp b/Alc/filters/biquad.cpp
deleted file mode 100644
index 6a3cef64..00000000
--- a/Alc/filters/biquad.cpp
+++ /dev/null
@@ -1,127 +0,0 @@
-
-#include "config.h"
-
-#include "biquad.h"
-
-#include <algorithm>
-#include <cassert>
-#include <cmath>
-
-#include "opthelpers.h"
-
-
-template<typename Real>
-void BiquadFilterR<Real>::setParams(BiquadType type, Real gain, Real f0norm, Real rcpQ)
-{
- // Limit gain to -100dB
- assert(gain > 0.00001f);
-
- const Real w0{al::MathDefs<Real>::Tau() * f0norm};
- const Real sin_w0{std::sin(w0)};
- const Real cos_w0{std::cos(w0)};
- const Real alpha{sin_w0/2.0f * rcpQ};
-
- Real sqrtgain_alpha_2;
- Real a[3]{ 1.0f, 0.0f, 0.0f };
- Real b[3]{ 1.0f, 0.0f, 0.0f };
-
- /* Calculate filter coefficients depending on filter type */
- switch(type)
- {
- case BiquadType::HighShelf:
- sqrtgain_alpha_2 = 2.0f * std::sqrt(gain) * alpha;
- b[0] = gain*((gain+1.0f) + (gain-1.0f)*cos_w0 + sqrtgain_alpha_2);
- b[1] = -2.0f*gain*((gain-1.0f) + (gain+1.0f)*cos_w0 );
- b[2] = gain*((gain+1.0f) + (gain-1.0f)*cos_w0 - sqrtgain_alpha_2);
- a[0] = (gain+1.0f) - (gain-1.0f)*cos_w0 + sqrtgain_alpha_2;
- a[1] = 2.0f* ((gain-1.0f) - (gain+1.0f)*cos_w0 );
- a[2] = (gain+1.0f) - (gain-1.0f)*cos_w0 - sqrtgain_alpha_2;
- break;
- case BiquadType::LowShelf:
- sqrtgain_alpha_2 = 2.0f * std::sqrt(gain) * alpha;
- b[0] = gain*((gain+1.0f) - (gain-1.0f)*cos_w0 + sqrtgain_alpha_2);
- b[1] = 2.0f*gain*((gain-1.0f) - (gain+1.0f)*cos_w0 );
- b[2] = gain*((gain+1.0f) - (gain-1.0f)*cos_w0 - sqrtgain_alpha_2);
- a[0] = (gain+1.0f) + (gain-1.0f)*cos_w0 + sqrtgain_alpha_2;
- a[1] = -2.0f* ((gain-1.0f) + (gain+1.0f)*cos_w0 );
- a[2] = (gain+1.0f) + (gain-1.0f)*cos_w0 - sqrtgain_alpha_2;
- break;
- case BiquadType::Peaking:
- gain = std::sqrt(gain);
- b[0] = 1.0f + alpha * gain;
- b[1] = -2.0f * cos_w0;
- b[2] = 1.0f - alpha * gain;
- a[0] = 1.0f + alpha / gain;
- a[1] = -2.0f * cos_w0;
- a[2] = 1.0f - alpha / gain;
- break;
-
- case BiquadType::LowPass:
- b[0] = (1.0f - cos_w0) / 2.0f;
- b[1] = 1.0f - cos_w0;
- b[2] = (1.0f - cos_w0) / 2.0f;
- a[0] = 1.0f + alpha;
- a[1] = -2.0f * cos_w0;
- a[2] = 1.0f - alpha;
- break;
- case BiquadType::HighPass:
- b[0] = (1.0f + cos_w0) / 2.0f;
- b[1] = -(1.0f + cos_w0);
- b[2] = (1.0f + cos_w0) / 2.0f;
- a[0] = 1.0f + alpha;
- a[1] = -2.0f * cos_w0;
- a[2] = 1.0f - alpha;
- break;
- case BiquadType::BandPass:
- b[0] = alpha;
- b[1] = 0.0f;
- b[2] = -alpha;
- a[0] = 1.0f + alpha;
- a[1] = -2.0f * cos_w0;
- a[2] = 1.0f - alpha;
- break;
- }
-
- a1 = a[1] / a[0];
- a2 = a[2] / a[0];
- b0 = b[0] / a[0];
- b1 = b[1] / a[0];
- b2 = b[2] / a[0];
-}
-
-template<typename Real>
-void BiquadFilterR<Real>::process(Real *dst, const Real *src, int numsamples)
-{
- ASSUME(numsamples > 0);
-
- const Real b0{this->b0};
- const Real b1{this->b1};
- const Real b2{this->b2};
- const Real a1{this->a1};
- const Real a2{this->a2};
- Real z1{this->z1};
- Real z2{this->z2};
-
- /* Processing loop is Transposed Direct Form II. This requires less storage
- * compared to Direct Form I (only two delay components, instead of a four-
- * sample history; the last two inputs and outputs), and works better for
- * floating-point which favors summing similarly-sized values while being
- * less bothered by overflow.
- *
- * See: http://www.earlevel.com/main/2003/02/28/biquads/
- */
- auto proc_sample = [b0,b1,b2,a1,a2,&z1,&z2](Real input) noexcept -> Real
- {
- Real output = input*b0 + z1;
- z1 = input*b1 - output*a1 + z2;
- z2 = input*b2 - output*a2;
- return output;
- };
- std::transform(src, src+numsamples, dst, proc_sample);
-
- this->z1 = z1;
- this->z2 = z2;
-}
-
-template class BiquadFilterR<float>;
-template class BiquadFilterR<double>;
diff --git a/Alc/filters/biquad.h b/Alc/filters/biquad.h
deleted file mode 100644
index 893a69a9..00000000
--- a/Alc/filters/biquad.h
+++ /dev/null
@@ -1,113 +0,0 @@
-#ifndef FILTERS_BIQUAD_H
-#define FILTERS_BIQUAD_H
-
-#include <cmath>
-#include <utility>
-
-#include "math_defs.h"
-
-
-/* Filters 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
- */
-/* Implementation note: For the shelf filters, the specified gain is for the
- * reference frequency, which is the centerpoint of the transition band. This
- * better matches EFX filter design. To set the gain for the shelf itself, use
- * the square root of the desired linear gain (or halve the dB gain).
- */
-
-enum class BiquadType {
- /** EFX-style low-pass filter, specifying a gain and reference frequency. */
- HighShelf,
- /** EFX-style high-pass filter, specifying a gain and reference frequency. */
- LowShelf,
- /** Peaking filter, specifying a gain and reference frequency. */
- Peaking,
-
- /** Low-pass cut-off filter, specifying a cut-off frequency. */
- LowPass,
- /** High-pass cut-off filter, specifying a cut-off frequency. */
- HighPass,
- /** Band-pass filter, specifying a center frequency. */
- BandPass,
-};
-
-template<typename Real>
-class BiquadFilterR {
- /* Last two delayed components for direct form II. */
- Real z1{0.0f}, z2{0.0f};
- /* Transfer function coefficients "b" (numerator) */
- Real b0{1.0f}, b1{0.0f}, b2{0.0f};
- /* Transfer function coefficients "a" (denominator; a0 is pre-applied). */
- Real a1{0.0f}, a2{0.0f};
-
-public:
- void clear() noexcept { z1 = z2 = 0.0f; }
-
- /**
- * Sets the filter state for the specified filter type and its parameters.
- *
- * \param type The type of filter to apply.
- * \param gain The gain for the reference frequency response. Only used by
- * the Shelf and Peaking filter types.
- * \param f0norm The reference frequency normal (ref_freq / sample_rate).
- * This is the center point for the Shelf, Peaking, and
- * BandPass filter types, or the cutoff frequency for the
- * LowPass and HighPass filter types.
- * \param rcpQ The reciprocal of the Q coefficient for the filter's
- * transition band. Can be generated from rcpQFromSlope or
- * rcpQFromBandwidth as needed.
- */
- void setParams(BiquadType type, Real gain, Real f0norm, Real rcpQ);
-
- void copyParamsFrom(const BiquadFilterR &other)
- {
- b0 = other.b0;
- b1 = other.b1;
- b2 = other.b2;
- a1 = other.a1;
- a2 = other.a2;
- }
-
-
- void process(Real *dst, const Real *src, int numsamples);
-
- /* Rather hacky. It's just here to support "manual" processing. */
- std::pair<Real,Real> getComponents() const noexcept
- { return {z1, z2}; }
- void setComponents(Real z1_, Real z2_) noexcept
- { z1 = z1_; z2 = z2_; }
- Real processOne(const Real in, Real &z1_, Real &z2_) const noexcept
- {
- Real out{in*b0 + z1_};
- z1_ = in*b1 - out*a1 + z2_;
- z2_ = in*b2 - out*a2;
- return out;
- }
-
- /**
- * Calculates the rcpQ (i.e. 1/Q) coefficient for shelving filters, using
- * the reference gain and shelf slope parameter.
- * \param gain 0 < gain
- * \param slope 0 < slope <= 1
- */
- static Real rcpQFromSlope(Real gain, Real slope)
- { return std::sqrt((gain + 1.0f/gain)*(1.0f/slope - 1.0f) + 2.0f); }
-
- /**
- * Calculates the rcpQ (i.e. 1/Q) coefficient for filters, using the
- * normalized reference frequency and bandwidth.
- * \param f0norm 0 < f0norm < 0.5.
- * \param bandwidth 0 < bandwidth
- */
- static Real rcpQFromBandwidth(Real f0norm, Real bandwidth)
- {
- const Real w0{al::MathDefs<Real>::Tau() * f0norm};
- return 2.0f*std::sinh(std::log(Real{2.0f})/2.0f*bandwidth*w0/std::sin(w0));
- }
-};
-
-using BiquadFilter = BiquadFilterR<float>;
-
-#endif /* FILTERS_BIQUAD_H */
diff --git a/Alc/filters/nfc.cpp b/Alc/filters/nfc.cpp
deleted file mode 100644
index 1a567f2c..00000000
--- a/Alc/filters/nfc.cpp
+++ /dev/null
@@ -1,391 +0,0 @@
-
-#include "config.h"
-
-#include "nfc.h"
-
-#include <algorithm>
-
-#include "alcmain.h"
-
-
-/* Near-field control filters are the basis for handling the near-field effect.
- * The near-field effect is a bass-boost present in the directional components
- * of a recorded signal, created as a result of the wavefront curvature (itself
- * a function of sound distance). Proper reproduction dictates this be
- * compensated for using a bass-cut given the playback speaker distance, to
- * avoid excessive bass in the playback.
- *
- * For real-time rendered audio, emulating the near-field effect based on the
- * sound source's distance, and subsequently compensating for it at output
- * based on the speaker distances, can create a more realistic perception of
- * sound distance beyond a simple 1/r attenuation.
- *
- * These filters do just that. Each one applies a low-shelf filter, created as
- * the combination of a bass-boost for a given sound source distance (near-
- * field emulation) along with a bass-cut for a given control/speaker distance
- * (near-field compensation).
- *
- * Note that it is necessary to apply a cut along with the boost, since the
- * boost alone is unstable in higher-order ambisonics as it causes an infinite
- * DC gain (even first-order ambisonics requires there to be no DC offset for
- * the boost to work). Consequently, ambisonics requires a control parameter to
- * be used to avoid an unstable boost-only filter. NFC-HOA defines this control
- * as a reference delay, calculated with:
- *
- * reference_delay = control_distance / speed_of_sound
- *
- * This means w0 (for input) or w1 (for output) should be set to:
- *
- * wN = 1 / (reference_delay * sample_rate)
- *
- * when dealing with NFC-HOA content. For FOA input content, which does not
- * specify a reference_delay variable, w0 should be set to 0 to apply only
- * near-field compensation for output. It's important that w1 be a finite,
- * positive, non-0 value or else the bass-boost will become unstable again.
- * Also, w0 should not be too large compared to w1, to avoid excessively loud
- * low frequencies.
- */
-
-namespace {
-
-constexpr float B[5][4] = {
- { 0.0f },
- { 1.0f },
- { 3.0f, 3.0f },
- { 3.6778f, 6.4595f, 2.3222f },
- { 4.2076f, 11.4877f, 5.7924f, 9.1401f }
-};
-
-NfcFilter1 NfcFilterCreate1(const float w0, const float w1) noexcept
-{
- NfcFilter1 nfc{};
- float b_00, g_0;
- float r;
-
- nfc.base_gain = 1.0f;
- nfc.gain = 1.0f;
-
- /* Calculate bass-boost coefficients. */
- r = 0.5f * w0;
- b_00 = B[1][0] * r;
- g_0 = 1.0f + b_00;
-
- nfc.gain *= g_0;
- nfc.b1 = 2.0f * b_00 / g_0;
-
- /* Calculate bass-cut coefficients. */
- r = 0.5f * w1;
- b_00 = B[1][0] * r;
- g_0 = 1.0f + b_00;
-
- nfc.base_gain /= g_0;
- nfc.gain /= g_0;
- nfc.a1 = 2.0f * b_00 / g_0;
-
- return nfc;
-}
-
-void NfcFilterAdjust1(NfcFilter1 *nfc, const float w0) noexcept
-{
- const float r{0.5f * w0};
- const float b_00{B[1][0] * r};
- const float g_0{1.0f + b_00};
-
- nfc->gain = nfc->base_gain * g_0;
- nfc->b1 = 2.0f * b_00 / g_0;
-}
-
-
-NfcFilter2 NfcFilterCreate2(const float w0, const float w1) noexcept
-{
- NfcFilter2 nfc{};
- float b_10, b_11, g_1;
- float r;
-
- nfc.base_gain = 1.0f;
- nfc.gain = 1.0f;
-
- /* Calculate bass-boost coefficients. */
- r = 0.5f * w0;
- b_10 = B[2][0] * r;
- b_11 = B[2][1] * r * r;
- g_1 = 1.0f + b_10 + b_11;
-
- nfc.gain *= g_1;
- nfc.b1 = (2.0f*b_10 + 4.0f*b_11) / g_1;
- nfc.b2 = 4.0f * b_11 / g_1;
-
- /* Calculate bass-cut coefficients. */
- r = 0.5f * w1;
- b_10 = B[2][0] * r;
- b_11 = B[2][1] * r * r;
- g_1 = 1.0f + b_10 + b_11;
-
- nfc.base_gain /= g_1;
- nfc.gain /= g_1;
- nfc.a1 = (2.0f*b_10 + 4.0f*b_11) / g_1;
- nfc.a2 = 4.0f * b_11 / g_1;
-
- return nfc;
-}
-
-void NfcFilterAdjust2(NfcFilter2 *nfc, const float w0) noexcept
-{
- const float r{0.5f * w0};
- const float b_10{B[2][0] * r};
- const float b_11{B[2][1] * r * r};
- const float g_1{1.0f + b_10 + b_11};
-
- nfc->gain = nfc->base_gain * g_1;
- nfc->b1 = (2.0f*b_10 + 4.0f*b_11) / g_1;
- nfc->b2 = 4.0f * b_11 / g_1;
-}
-
-
-NfcFilter3 NfcFilterCreate3(const float w0, const float w1) noexcept
-{
- NfcFilter3 nfc{};
- float b_10, b_11, g_1;
- float b_00, g_0;
- float r;
-
- nfc.base_gain = 1.0f;
- nfc.gain = 1.0f;
-
- /* Calculate bass-boost coefficients. */
- r = 0.5f * w0;
- b_10 = B[3][0] * r;
- b_11 = B[3][1] * r * r;
- b_00 = B[3][2] * r;
- g_1 = 1.0f + b_10 + b_11;
- g_0 = 1.0f + b_00;
-
- nfc.gain *= g_1 * g_0;
- nfc.b1 = (2.0f*b_10 + 4.0f*b_11) / g_1;
- nfc.b2 = 4.0f * b_11 / g_1;
- nfc.b3 = 2.0f * b_00 / g_0;
-
- /* Calculate bass-cut coefficients. */
- r = 0.5f * w1;
- b_10 = B[3][0] * r;
- b_11 = B[3][1] * r * r;
- b_00 = B[3][2] * r;
- g_1 = 1.0f + b_10 + b_11;
- g_0 = 1.0f + b_00;
-
- nfc.base_gain /= g_1 * g_0;
- nfc.gain /= g_1 * g_0;
- nfc.a1 = (2.0f*b_10 + 4.0f*b_11) / g_1;
- nfc.a2 = 4.0f * b_11 / g_1;
- nfc.a3 = 2.0f * b_00 / g_0;
-
- return nfc;
-}
-
-void NfcFilterAdjust3(NfcFilter3 *nfc, const float w0) noexcept
-{
- const float r{0.5f * w0};
- const float b_10{B[3][0] * r};
- const float b_11{B[3][1] * r * r};
- const float b_00{B[3][2] * r};
- const float g_1{1.0f + b_10 + b_11};
- const float g_0{1.0f + b_00};
-
- nfc->gain = nfc->base_gain * g_1 * g_0;
- nfc->b1 = (2.0f*b_10 + 4.0f*b_11) / g_1;
- nfc->b2 = 4.0f * b_11 / g_1;
- nfc->b3 = 2.0f * b_00 / g_0;
-}
-
-
-NfcFilter4 NfcFilterCreate4(const float w0, const float w1) noexcept
-{
- NfcFilter4 nfc{};
- float b_10, b_11, g_1;
- float b_00, b_01, g_0;
- float r;
-
- nfc.base_gain = 1.0f;
- nfc.gain = 1.0f;
-
- /* Calculate bass-boost coefficients. */
- r = 0.5f * w0;
- b_10 = B[4][0] * r;
- b_11 = B[4][1] * r * r;
- b_00 = B[4][2] * r;
- b_01 = B[4][3] * r * r;
- g_1 = 1.0f + b_10 + b_11;
- g_0 = 1.0f + b_00 + b_01;
-
- nfc.gain *= g_1 * g_0;
- nfc.b1 = (2.0f*b_10 + 4.0f*b_11) / g_1;
- nfc.b2 = 4.0f * b_11 / g_1;
- nfc.b3 = (2.0f*b_00 + 4.0f*b_01) / g_0;
- nfc.b4 = 4.0f * b_01 / g_0;
-
- /* Calculate bass-cut coefficients. */
- r = 0.5f * w1;
- b_10 = B[4][0] * r;
- b_11 = B[4][1] * r * r;
- b_00 = B[4][2] * r;
- b_01 = B[4][3] * r * r;
- g_1 = 1.0f + b_10 + b_11;
- g_0 = 1.0f + b_00 + b_01;
-
- nfc.base_gain /= g_1 * g_0;
- nfc.gain /= g_1 * g_0;
- nfc.a1 = (2.0f*b_10 + 4.0f*b_11) / g_1;
- nfc.a2 = 4.0f * b_11 / g_1;
- nfc.a3 = (2.0f*b_00 + 4.0f*b_01) / g_0;
- nfc.a4 = 4.0f * b_01 / g_0;
-
- return nfc;
-}
-
-void NfcFilterAdjust4(NfcFilter4 *nfc, const float w0) noexcept
-{
- const float r{0.5f * w0};
- const float b_10{B[4][0] * r};
- const float b_11{B[4][1] * r * r};
- const float b_00{B[4][2] * r};
- const float b_01{B[4][3] * r * r};
- const float g_1{1.0f + b_10 + b_11};
- const float g_0{1.0f + b_00 + b_01};
-
- nfc->gain = nfc->base_gain * g_1 * g_0;
- nfc->b1 = (2.0f*b_10 + 4.0f*b_11) / g_1;
- nfc->b2 = 4.0f * b_11 / g_1;
- nfc->b3 = (2.0f*b_00 + 4.0f*b_01) / g_0;
- nfc->b4 = 4.0f * b_01 / g_0;
-}
-
-} // namespace
-
-void NfcFilter::init(const float w1) noexcept
-{
- first = NfcFilterCreate1(0.0f, w1);
- second = NfcFilterCreate2(0.0f, w1);
- third = NfcFilterCreate3(0.0f, w1);
- fourth = NfcFilterCreate4(0.0f, w1);
-}
-
-void NfcFilter::adjust(const float w0) noexcept
-{
- NfcFilterAdjust1(&first, w0);
- NfcFilterAdjust2(&second, w0);
- NfcFilterAdjust3(&third, w0);
- NfcFilterAdjust4(&fourth, w0);
-}
-
-
-void NfcFilter::process1(float *RESTRICT dst, const float *RESTRICT src, const int count)
-{
- ASSUME(count > 0);
-
- const float gain{first.gain};
- const float b1{first.b1};
- const float a1{first.a1};
- float z1{first.z[0]};
- auto proc_sample = [gain,b1,a1,&z1](const float in) noexcept -> float
- {
- const float y{in*gain - a1*z1};
- const float out{y + b1*z1};
- z1 += y;
- return out;
- };
- std::transform(src, src+count, dst, proc_sample);
- first.z[0] = z1;
-}
-
-void NfcFilter::process2(float *RESTRICT dst, const float *RESTRICT src, const int count)
-{
- ASSUME(count > 0);
-
- const float gain{second.gain};
- const float b1{second.b1};
- const float b2{second.b2};
- const float a1{second.a1};
- const float a2{second.a2};
- float z1{second.z[0]};
- float z2{second.z[1]};
- auto proc_sample = [gain,b1,b2,a1,a2,&z1,&z2](const float in) noexcept -> float
- {
- const float y{in*gain - a1*z1 - a2*z2};
- const float out{y + b1*z1 + b2*z2};
- z2 += z1;
- z1 += y;
- return out;
- };
- std::transform(src, src+count, dst, proc_sample);
- second.z[0] = z1;
- second.z[1] = z2;
-}
-
-void NfcFilter::process3(float *RESTRICT dst, const float *RESTRICT src, const int count)
-{
- ASSUME(count > 0);
-
- const float gain{third.gain};
- const float b1{third.b1};
- const float b2{third.b2};
- const float b3{third.b3};
- const float a1{third.a1};
- const float a2{third.a2};
- const float a3{third.a3};
- float z1{third.z[0]};
- float z2{third.z[1]};
- float z3{third.z[2]};
- auto proc_sample = [gain,b1,b2,b3,a1,a2,a3,&z1,&z2,&z3](const float in) noexcept -> float
- {
- float y{in*gain - a1*z1 - a2*z2};
- float out{y + b1*z1 + b2*z2};
- z2 += z1;
- z1 += y;
-
- y = out - a3*z3;
- out = y + b3*z3;
- z3 += y;
- return out;
- };
- std::transform(src, src+count, dst, proc_sample);
- third.z[0] = z1;
- third.z[1] = z2;
- third.z[2] = z3;
-}
-
-void NfcFilter::process4(float *RESTRICT dst, const float *RESTRICT src, const int count)
-{
- ASSUME(count > 0);
-
- const float gain{fourth.gain};
- const float b1{fourth.b1};
- const float b2{fourth.b2};
- const float b3{fourth.b3};
- const float b4{fourth.b4};
- const float a1{fourth.a1};
- const float a2{fourth.a2};
- const float a3{fourth.a3};
- const float a4{fourth.a4};
- float z1{fourth.z[0]};
- float z2{fourth.z[1]};
- float z3{fourth.z[2]};
- float z4{fourth.z[3]};
- auto proc_sample = [gain,b1,b2,b3,b4,a1,a2,a3,a4,&z1,&z2,&z3,&z4](const float in) noexcept -> float
- {
- float y{in*gain - a1*z1 - a2*z2};
- float out{y + b1*z1 + b2*z2};
- z2 += z1;
- z1 += y;
-
- y = out - a3*z3 - a4*z4;
- out = y + b3*z3 + b4*z4;
- z4 += z3;
- z3 += y;
- return out;
- };
- std::transform(src, src+count, dst, proc_sample);
- fourth.z[0] = z1;
- fourth.z[1] = z2;
- fourth.z[2] = z3;
- fourth.z[3] = z4;
-}
diff --git a/Alc/filters/nfc.h b/Alc/filters/nfc.h
deleted file mode 100644
index b656850a..00000000
--- a/Alc/filters/nfc.h
+++ /dev/null
@@ -1,58 +0,0 @@
-#ifndef FILTER_NFC_H
-#define FILTER_NFC_H
-
-struct NfcFilter1 {
- float base_gain, gain;
- float b1, a1;
- float z[1];
-};
-struct NfcFilter2 {
- float base_gain, gain;
- float b1, b2, a1, a2;
- float z[2];
-};
-struct NfcFilter3 {
- float base_gain, gain;
- float b1, b2, b3, a1, a2, a3;
- float z[3];
-};
-struct NfcFilter4 {
- float base_gain, gain;
- float b1, b2, b3, b4, a1, a2, a3, a4;
- float z[4];
-};
-
-class NfcFilter {
- NfcFilter1 first;
- NfcFilter2 second;
- NfcFilter3 third;
- NfcFilter4 fourth;
-
-public:
- /* NOTE:
- * w0 = speed_of_sound / (source_distance * sample_rate);
- * w1 = speed_of_sound / (control_distance * sample_rate);
- *
- * Generally speaking, the control distance should be approximately the
- * average speaker distance, or based on the reference delay if outputing
- * NFC-HOA. It must not be negative, 0, or infinite. The source distance
- * should not be too small relative to the control distance.
- */
-
- void init(const float w1) noexcept;
- void adjust(const float w0) noexcept;
-
- /* Near-field control filter for first-order ambisonic channels (1-3). */
- void process1(float *RESTRICT dst, const float *RESTRICT src, const int count);
-
- /* Near-field control filter for second-order ambisonic channels (4-8). */
- void process2(float *RESTRICT dst, const float *RESTRICT src, const int count);
-
- /* Near-field control filter for third-order ambisonic channels (9-15). */
- void process3(float *RESTRICT dst, const float *RESTRICT src, const int count);
-
- /* Near-field control filter for fourth-order ambisonic channels (16-24). */
- void process4(float *RESTRICT dst, const float *RESTRICT src, const int count);
-};
-
-#endif /* FILTER_NFC_H */
diff --git a/Alc/filters/splitter.cpp b/Alc/filters/splitter.cpp
deleted file mode 100644
index 09e7bfe8..00000000
--- a/Alc/filters/splitter.cpp
+++ /dev/null
@@ -1,115 +0,0 @@
-
-#include "config.h"
-
-#include "splitter.h"
-
-#include <cmath>
-#include <limits>
-#include <algorithm>
-
-#include "math_defs.h"
-
-template<typename Real>
-void BandSplitterR<Real>::init(Real f0norm)
-{
- const Real w{f0norm * al::MathDefs<Real>::Tau()};
- const Real cw{std::cos(w)};
- if(cw > std::numeric_limits<float>::epsilon())
- coeff = (std::sin(w) - 1.0f) / cw;
- else
- coeff = cw * -0.5f;
-
- lp_z1 = 0.0f;
- lp_z2 = 0.0f;
- ap_z1 = 0.0f;
-}
-
-template<typename Real>
-void BandSplitterR<Real>::process(Real *hpout, Real *lpout, const Real *input, const int count)
-{
- ASSUME(count > 0);
-
- const Real ap_coeff{this->coeff};
- const Real lp_coeff{this->coeff*0.5f + 0.5f};
- Real lp_z1{this->lp_z1};
- Real lp_z2{this->lp_z2};
- Real ap_z1{this->ap_z1};
- auto proc_sample = [ap_coeff,lp_coeff,&lp_z1,&lp_z2,&ap_z1,&lpout](const Real in) noexcept -> Real
- {
- /* Low-pass sample processing. */
- Real d{(in - lp_z1) * lp_coeff};
- Real lp_y{lp_z1 + d};
- lp_z1 = lp_y + d;
-
- d = (lp_y - lp_z2) * lp_coeff;
- lp_y = lp_z2 + d;
- lp_z2 = lp_y + d;
-
- *(lpout++) = lp_y;
-
- /* All-pass sample processing. */
- Real ap_y{in*ap_coeff + ap_z1};
- ap_z1 = in - ap_y*ap_coeff;
-
- /* High-pass generated from removing low-passed output. */
- return ap_y - lp_y;
- };
- std::transform(input, input+count, hpout, proc_sample);
- this->lp_z1 = lp_z1;
- this->lp_z2 = lp_z2;
- this->ap_z1 = ap_z1;
-}
-
-template<typename Real>
-void BandSplitterR<Real>::applyHfScale(Real *samples, const Real hfscale, const int count)
-{
- ASSUME(count > 0);
-
- const Real ap_coeff{this->coeff};
- const Real lp_coeff{this->coeff*0.5f + 0.5f};
- Real lp_z1{this->lp_z1};
- Real lp_z2{this->lp_z2};
- Real ap_z1{this->ap_z1};
- auto proc_sample = [hfscale,ap_coeff,lp_coeff,&lp_z1,&lp_z2,&ap_z1](const Real in) noexcept -> Real
- {
- /* Low-pass sample processing. */
- Real d{(in - lp_z1) * lp_coeff};
- Real lp_y{lp_z1 + d};
- lp_z1 = lp_y + d;
-
- d = (lp_y - lp_z2) * lp_coeff;
- lp_y = lp_z2 + d;
- lp_z2 = lp_y + d;
-
- /* All-pass sample processing. */
- Real ap_y{in*ap_coeff + ap_z1};
- ap_z1 = in - ap_y*ap_coeff;
-
- /* High-pass generated from removing low-passed output. */
- return (ap_y-lp_y)*hfscale + lp_y;
- };
- std::transform(samples, samples+count, samples, proc_sample);
- this->lp_z1 = lp_z1;
- this->lp_z2 = lp_z2;
- this->ap_z1 = ap_z1;
-}
-
-template<typename Real>
-void BandSplitterR<Real>::applyAllpass(Real *samples, const int count) const
-{
- ASSUME(count > 0);
-
- const Real coeff{this->coeff};
- Real z1{0.0f};
- auto proc_sample = [coeff,&z1](const Real in) noexcept -> Real
- {
- const Real out{in*coeff + z1};
- z1 = in - out*coeff;
- return out;
- };
- std::transform(samples, samples+count, samples, proc_sample);
-}
-
-
-template class BandSplitterR<float>;
-template class BandSplitterR<double>;
diff --git a/Alc/filters/splitter.h b/Alc/filters/splitter.h
deleted file mode 100644
index 927c4d17..00000000
--- a/Alc/filters/splitter.h
+++ /dev/null
@@ -1,50 +0,0 @@
-#ifndef FILTER_SPLITTER_H
-#define FILTER_SPLITTER_H
-
-#include "alcmain.h"
-#include "almalloc.h"
-
-
-/* Band splitter. Splits a signal into two phase-matching frequency bands. */
-template<typename Real>
-class BandSplitterR {
- Real coeff{0.0f};
- Real lp_z1{0.0f};
- Real lp_z2{0.0f};
- Real ap_z1{0.0f};
-
-public:
- BandSplitterR() = default;
- BandSplitterR(const BandSplitterR&) = default;
- BandSplitterR(Real f0norm) { init(f0norm); }
-
- void init(Real f0norm);
- void clear() noexcept { lp_z1 = lp_z2 = ap_z1 = 0.0f; }
- void process(Real *hpout, Real *lpout, const Real *input, const int count);
-
- void applyHfScale(Real *samples, const Real hfscale, const int count);
-
- /* The all-pass portion of the band splitter. Applies the same phase shift
- * without splitting the signal. Note that each use of this method is
- * indepedent, it does not track history between calls.
- */
- void applyAllpass(Real *samples, const int count) const;
-};
-using BandSplitter = BandSplitterR<float>;
-
-
-struct FrontStablizer {
- static constexpr size_t DelayLength{256u};
-
- alignas(16) float DelayBuf[MAX_OUTPUT_CHANNELS][DelayLength];
-
- BandSplitter LFilter, RFilter;
- alignas(16) float LSplit[2][BUFFERSIZE];
- alignas(16) float RSplit[2][BUFFERSIZE];
-
- alignas(16) float TempBuf[BUFFERSIZE + DelayLength];
-
- DEF_NEWDEL(FrontStablizer)
-};
-
-#endif /* FILTER_SPLITTER_H */
generated by cgit v1.2.3 (git 2.39.1) at 2025-04-19 04:02:24 +0000