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OpenAudio_ArduinoLibrary/AudioAnalyzePhase_F32.cpp

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5.9 KiB

/*
* AudioAnalyzePhase_F32.cpp
*
* 31 March 2020 Rev 8 April 2020
* Bob Larkin, in support of the library:
* Chip Audette, OpenAudio, Apr 2017
*
* * Copyright (c) 2020 Bob Larkin
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
/* There are two inputs, I and Q (Left and Right or 0 and 1)
* There is one output, the phase angle between the two inputs expressed in
* radians (180 degrees is Pi radians). See AudioAnalyzePhase_F32.h
* for details.
*/
#include "AudioAnalyzePhase_F32.h"
#include <math.h>
#include "mathDSP_F32.h"
void AudioAnalyzePhase_F32::update(void) {
audio_block_f32_t *block0, *block1;
uint16_t i;
float32_t mult0, mult1, min0, max0, minmax0, min1, max1, minmax1;
float32_t min_max = 1.0f; // Filled in correctly, later
mathDSP_F32 mathDSP1;
#if TEST_TIME
if (iitt++ >1000000) iitt = -10;
uint32_t t1, t2;
t1 = tElapse;
#endif
// Get first input, 0
block0 = AudioStream_F32::receiveWritable_f32(0);
if (!block0) {
if(errorPrint) Serial.println("AN_PHASE ERR: No input memory");
return;
}
// Get second input, 1
block1 = AudioStream_F32::receiveWritable_f32(1);
if (!block1){
if(errorPrint) Serial.println("AN_PHASE ERR: No input memory");
AudioStream_F32::release(block0);
return;
}
// Limiter on both inputs; can be used with narrow IIR filter
if (pdConfig & LIMITER_MASK) {
for (uint16_t j = 0; j<block0->length; j++) {
if (block0->data[j]>=0.0f)
block0->data[j] = 1.0f;
else
block0->data[j] = -1.0f;
if (block1->data[j]>=0.0f)
block1->data[j] = 1.0f;
else
block1->data[j] = -1.0f;
}
}
// If needed, find a scaling factor for the multiplier type phase det
// This would not normally be used with a limiter---they are
// both trying to solve the same problem.
if(pdConfig & SCALE_MASK) {
min0 = 1.0E6f; max0 = -1.0E6f;
min1 = 1.0E6f; max1 = -1.0E6f;
for (i=0; i < block0->length; i++){
if(block0->data[i] < min0) min0 = block0->data[i];
if(block0->data[i] > max0) max0 = block0->data[i];
if(block1->data[i] < min1) min1 = block1->data[i];
if(block1->data[i] > max1) max1 = block1->data[i];
}
minmax0 = max0 - min0; // 0 to 2
minmax1 = max1 - min1; // 0 to 2
min_max = minmax0 * minmax1; // 0 to 4
}
// multiply the two inputs to get phase plus second harmonic. Low pass
// filter and then apply ArcCos of the result to return the phase difference
// in radians. Multiply and leave result in 1
arm_mult_f32(block0->data, block1->data, block1->data, block0->length);
if (LPType == NO_LP_FILTER) {
for (i=0; i < block0->length; i++)
block0->data[i] = block1->data[i]; // Move back to block0
}
else if(LPType == IIR_LP_FILTER) {
// Now filter 1, leaving result in 0. This is 4 BiQuads
arm_biquad_cascade_df1_f32(&iir_inst, block1->data, block0->data, block0->length);
}
else { // Alternate FIR filter for FIR_LP_FILTER
arm_fir_f32(&fir_inst, block1->data, block0->data, block0->length);
}
AudioStream_F32::release(block1); // Not needed further
/* For variable, pdConfig:
* LIMITER_MASK: 0=No Limiter 1=Use limiter
* ACOS_MASK: 00=Use no acos linearizer 01=undefined
* 10=Fast, math-continuous acos() (default) 11=Accurate acos()
* SCALE_MASK: 0=No scale of multiplier 1=scale to min-max (default)
* UNITS_MASK: 0=Output in degrees 1=Output in radians (default)
*/
if(pdConfig & SCALE_MASK)
mult0 = 8.0f / min_max;
else
mult0 = 2.0f;
if(pdConfig & UNITS_MASK)
mult1 = 1.0;
else
mult1 = 57.295779f;
// Optionally, apply ArcCos() to linearize block0 output in radians * units to scale to degrees
if (pdConfig & ACOS_MASK) {
if((pdConfig & ACOS_MASK) == 0b00110) { // Accurate acosf from C-library
for (uint i = 0; i<block_size; i++) {
block0->data[i] = mult1 * acosf(mult0 * block0->data[i]);
}
}
else if ((pdConfig & ACOS_MASK) == 0b00100) { // Fast acos from polynomial
for (uint i = 0; i<block_size; i++) {
block0->data[i] = mult1 * mathDSP1.acos_f32(mult0 * block0->data[i]);
}
}
}
// Not applying linearization or scaling, at all. Works for multiplier outputs near 0 (90 deg difference)
else {
float32_t mult = 8.0f * mult0 * mult1;
for (uint i = 0; i<block_size; i++) {
block0->data[i] = mult * block0->data[i];
}
}
AudioStream_F32::transmit(block0, 0);
AudioStream_F32::release(block0);
#if TEST_TIME
t2 = tElapse;
if(iitt++ < 0) {Serial.print("At AnalyzePhase end, microseconds = "); Serial.println (t2 - t1); }
t1 = tElapse;
#endif
} // End update()