Combine multiple UHJ encoder all-pass loops
This commit is contained in:
Chris Robinson
parent
7ed37a8282
commit
0cfb8fee44
@ -19,27 +19,56 @@ namespace {
|
||||
#define MAX_UPDATE_SAMPLES 128
|
||||
|
||||
|
||||
constexpr float Filter1CoeffSqr[4] = {
|
||||
constexpr float Filter1CoeffSqr[4]{
|
||||
0.479400865589f, 0.876218493539f, 0.976597589508f, 0.997499255936f
|
||||
};
|
||||
constexpr float Filter2CoeffSqr[4] = {
|
||||
constexpr float Filter2CoeffSqr[4]{
|
||||
0.161758498368f, 0.733028932341f, 0.945349700329f, 0.990599156685f
|
||||
};
|
||||
|
||||
void allpass_process(AllPassState *state, float *dst, const float *src, const float aa,
|
||||
void allpass_process(AllPassState *state, float *dst, const float *src, const float *coeffs,
|
||||
const size_t todo)
|
||||
{
|
||||
float z1{state->z[0]};
|
||||
float z2{state->z[1]};
|
||||
auto proc_sample = [aa,&z1,&z2](const float input) noexcept -> float
|
||||
const float aa0{coeffs[0]};
|
||||
const float aa1{coeffs[1]};
|
||||
const float aa2{coeffs[2]};
|
||||
const float aa3{coeffs[3]};
|
||||
float z01{state[0].z[0]};
|
||||
float z02{state[0].z[1]};
|
||||
float z11{state[1].z[0]};
|
||||
float z12{state[1].z[1]};
|
||||
float z21{state[2].z[0]};
|
||||
float z22{state[2].z[1]};
|
||||
float z31{state[3].z[0]};
|
||||
float z32{state[3].z[1]};
|
||||
auto proc_sample = [aa0,aa1,aa2,aa3,&z01,&z02,&z11,&z12,&z21,&z22,&z31,&z32](
|
||||
float input) noexcept -> float
|
||||
{
|
||||
const float output{input*aa + z1};
|
||||
z1 = z2; z2 = output*aa - input;
|
||||
float output{input*aa0 + z01};
|
||||
z01 = z02; z02 = output*aa0 - input;
|
||||
input = output;
|
||||
|
||||
output = input*aa1 + z11;
|
||||
z11 = z12; z12 = output*aa1 - input;
|
||||
input = output;
|
||||
|
||||
output = input*aa2 + z21;
|
||||
z21 = z22; z22 = output*aa2 - input;
|
||||
input = output;
|
||||
|
||||
output = input*aa3 + z31;
|
||||
z31 = z32; z32 = output*aa3 - input;
|
||||
return output;
|
||||
};
|
||||
std::transform(src, src+todo, dst, proc_sample);
|
||||
state->z[0] = z1;
|
||||
state->z[1] = z2;
|
||||
state[0].z[0] = z01;
|
||||
state[0].z[1] = z02;
|
||||
state[1].z[0] = z11;
|
||||
state[1].z[1] = z12;
|
||||
state[2].z[0] = z21;
|
||||
state[2].z[1] = z22;
|
||||
state[3].z[0] = z31;
|
||||
state[3].z[1] = z32;
|
||||
}
|
||||
|
||||
} // namespace
|
||||
@ -68,71 +97,45 @@ void allpass_process(AllPassState *state, float *dst, const float *src, const fl
|
||||
void Uhj2Encoder::encode(FloatBufferLine &LeftOut, FloatBufferLine &RightOut,
|
||||
FloatBufferLine *InSamples, const size_t SamplesToDo)
|
||||
{
|
||||
alignas(16) float D[MAX_UPDATE_SAMPLES], S[MAX_UPDATE_SAMPLES];
|
||||
alignas(16) float temp[MAX_UPDATE_SAMPLES];
|
||||
|
||||
ASSUME(SamplesToDo > 0);
|
||||
|
||||
auto winput = InSamples[0].cbegin();
|
||||
auto xinput = InSamples[1].cbegin();
|
||||
auto yinput = InSamples[2].cbegin();
|
||||
for(size_t base{0};base < SamplesToDo;)
|
||||
{
|
||||
const size_t todo{minz(SamplesToDo - base, MAX_UPDATE_SAMPLES)};
|
||||
ASSUME(todo > 0);
|
||||
const auto winput = al::assume_aligned<16>(InSamples[0].cbegin());
|
||||
const auto xinput = al::assume_aligned<16>(InSamples[1].cbegin());
|
||||
const auto yinput = al::assume_aligned<16>(InSamples[2].cbegin());
|
||||
|
||||
/* D = 0.6554516*Y */
|
||||
std::transform(yinput, yinput+todo, std::begin(temp),
|
||||
[](const float y) noexcept -> float { return 0.6554516f*y; });
|
||||
allpass_process(&mFilter1_Y[0], temp, temp, Filter1CoeffSqr[0], todo);
|
||||
allpass_process(&mFilter1_Y[1], temp, temp, Filter1CoeffSqr[1], todo);
|
||||
allpass_process(&mFilter1_Y[2], temp, temp, Filter1CoeffSqr[2], todo);
|
||||
allpass_process(&mFilter1_Y[3], temp, temp, Filter1CoeffSqr[3], todo);
|
||||
/* NOTE: Filter1 requires a 1 sample delay for the final output, so
|
||||
* take the last processed sample from the previous run as the first
|
||||
* output sample.
|
||||
*/
|
||||
D[0] = mLastY;
|
||||
for(size_t i{1};i < todo;i++)
|
||||
D[i] = temp[i-1];
|
||||
mLastY = temp[todo-1];
|
||||
/* D = 0.6554516*Y */
|
||||
std::transform(yinput, yinput+SamplesToDo, mTemp.begin(),
|
||||
[](const float y) noexcept -> float { return 0.6554516f*y; });
|
||||
/* NOTE: Filter1 requires a 1 sample delay for the final output, so take
|
||||
* the last processed sample from the previous run as the first output
|
||||
* sample.
|
||||
*/
|
||||
mSide[0] = mLastY;
|
||||
allpass_process(mFilter1_Y, mSide.data()+1, mTemp.data(), Filter1CoeffSqr, SamplesToDo);
|
||||
mLastY = mSide[SamplesToDo];
|
||||
|
||||
/* D += j(-0.3420201*W + 0.5098604*X) */
|
||||
std::transform(winput, winput+todo, xinput, std::begin(temp),
|
||||
[](const float w, const float x) noexcept -> float
|
||||
{ return -0.3420201f*w + 0.5098604f*x; });
|
||||
allpass_process(&mFilter2_WX[0], temp, temp, Filter2CoeffSqr[0], todo);
|
||||
allpass_process(&mFilter2_WX[1], temp, temp, Filter2CoeffSqr[1], todo);
|
||||
allpass_process(&mFilter2_WX[2], temp, temp, Filter2CoeffSqr[2], todo);
|
||||
allpass_process(&mFilter2_WX[3], temp, temp, Filter2CoeffSqr[3], todo);
|
||||
for(size_t i{0};i < todo;i++)
|
||||
D[i] += temp[i];
|
||||
/* D += j(-0.3420201*W + 0.5098604*X) */
|
||||
std::transform(winput, winput+SamplesToDo, xinput, mTemp.begin(),
|
||||
[](const float w, const float x) noexcept -> float
|
||||
{ return -0.3420201f*w + 0.5098604f*x; });
|
||||
allpass_process(mFilter2_WX, mTemp.data(), mTemp.data(), Filter2CoeffSqr, SamplesToDo);
|
||||
for(size_t i{0};i < SamplesToDo;++i)
|
||||
mSide[i] += mTemp[i];
|
||||
|
||||
/* S = 0.9396926*W + 0.1855740*X */
|
||||
std::transform(winput, winput+todo, xinput, std::begin(temp),
|
||||
[](const float w, const float x) noexcept -> float
|
||||
{ return 0.9396926f*w + 0.1855740f*x; });
|
||||
allpass_process(&mFilter1_WX[0], temp, temp, Filter1CoeffSqr[0], todo);
|
||||
allpass_process(&mFilter1_WX[1], temp, temp, Filter1CoeffSqr[1], todo);
|
||||
allpass_process(&mFilter1_WX[2], temp, temp, Filter1CoeffSqr[2], todo);
|
||||
allpass_process(&mFilter1_WX[3], temp, temp, Filter1CoeffSqr[3], todo);
|
||||
S[0] = mLastWX;
|
||||
for(size_t i{1};i < todo;i++)
|
||||
S[i] = temp[i-1];
|
||||
mLastWX = temp[todo-1];
|
||||
/* S = 0.9396926*W + 0.1855740*X */
|
||||
std::transform(winput, winput+SamplesToDo, xinput, mTemp.begin(),
|
||||
[](const float w, const float x) noexcept -> float
|
||||
{ return 0.9396926f*w + 0.1855740f*x; });
|
||||
mMid[0] = mLastWX;
|
||||
allpass_process(mFilter1_WX, mMid.data()+1, mTemp.data(), Filter1CoeffSqr, SamplesToDo);
|
||||
mLastWX = mMid[SamplesToDo];
|
||||
|
||||
/* Left = (S + D)/2.0 */
|
||||
float *RESTRICT left{al::assume_aligned<16>(LeftOut.data()+base)};
|
||||
for(size_t i{0};i < todo;i++)
|
||||
left[i] += (S[i] + D[i]) * 0.5f;
|
||||
/* Right = (S - D)/2.0 */
|
||||
float *RESTRICT right{al::assume_aligned<16>(RightOut.data()+base)};
|
||||
for(size_t i{0};i < todo;i++)
|
||||
right[i] += (S[i] - D[i]) * 0.5f;
|
||||
|
||||
winput += todo;
|
||||
xinput += todo;
|
||||
yinput += todo;
|
||||
base += todo;
|
||||
}
|
||||
/* Left = (S + D)/2.0 */
|
||||
float *RESTRICT left{al::assume_aligned<16>(LeftOut.data())};
|
||||
for(size_t i{0};i < SamplesToDo;i++)
|
||||
left[i] += (mMid[i] + mSide[i]) * 0.5f;
|
||||
/* Right = (S - D)/2.0 */
|
||||
float *RESTRICT right{al::assume_aligned<16>(RightOut.data())};
|
||||
for(size_t i{0};i < SamplesToDo;i++)
|
||||
right[i] += (mMid[i] - mSide[i]) * 0.5f;
|
||||
}
|
||||
|
||||
@ -1,8 +1,6 @@
|
||||
#ifndef UHJFILTER_H
|
||||
#define UHJFILTER_H
|
||||
|
||||
#include "AL/al.h"
|
||||
|
||||
#include "alcmain.h"
|
||||
#include "almalloc.h"
|
||||
|
||||
@ -37,6 +35,10 @@ struct AllPassState {
|
||||
*/
|
||||
|
||||
struct Uhj2Encoder {
|
||||
alignas(16) std::array<float,BUFFERSIZE> mTemp;
|
||||
alignas(16) std::array<float,BUFFERSIZE+1> mMid;
|
||||
alignas(16) std::array<float,BUFFERSIZE+1> mSide;
|
||||
|
||||
AllPassState mFilter1_Y[4];
|
||||
AllPassState mFilter2_WX[4];
|
||||
AllPassState mFilter1_WX[4];
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user