Rev to new LMSDenoiseNotch

pull/13/head
boblark 2 years ago
parent 9912cc8e9f
commit a23e900831
  1. 19
      AudioLMSDenoiseNotch_F32.cpp
  2. 39
      AudioLMSDenoiseNotch_F32.h
  3. 121
      examples/LMS1DenoiseNotch/LMS1DenoiseNotch.ino

@ -61,7 +61,15 @@ void AudioLMSDenoiseNotch_F32::update(void)
// Circular delay line to find correlated components
dataD[kNextD] = blockDataIn; // Get a new data point from block
// Rotate to next higher k index
#ifdef LMS_NORMALIZE
powerNorm[i] = blockDataIn*blockDataIn;
pNorm += powerNorm[i];
if(i==127)
pNorm -= powerNorm[0];
else
pNorm -= powerNorm[i+1];
#endif
if(++kNextD >= lengthDataD) // Next spot in delay line
kNextD = 0;
@ -80,10 +88,15 @@ void AudioLMSDenoiseNotch_F32::update(void)
error = blockDataIn - firOut;
// Update the coefficients
#ifdef LMS_NORMALIZE
float32_t kcf = error*beta/pNorm;
#else
float32_t kcf = error*beta;
#endif
for(j=0; j<lengthDataF; j++)
{
k = (j + kOffsetF) & kMask;
coeff[j] = coeff[j] + beta*error*dataF[k];
coeff[j] = coeff[j] + kcf*dataF[k];
}
// Move to next positions in circular data buffer via kOffsetF
@ -94,7 +107,7 @@ void AudioLMSDenoiseNotch_F32::update(void)
if(what == DENOISE)
blockOut->data[i] = firOut;
else
blockOut->data[i] = blockDataIn; // error; // Auto-Notch
blockOut->data[i] = error; // Auto-Notch
}
//transmit the block and be done
AudioStream_F32::transmit(blockOut);

@ -2,7 +2,8 @@
* AudioLMSDenoiseNotch_F32.h
*
* Created: Bob Larkin, January 2022
* Purpose; LMS DeNoise for audio. Assumes floating-point data.
* Purpose; LMS DeNoise and Auto-notch for audio.
* Assumes floating-point data.
*
* 22 January 2022 copyright (c)Robert Larkin 2022
*
@ -33,7 +34,7 @@
* The auto-notch is very effective at removing annoying tones when they are
* reasonably strong. Again for radio systems, this can be quite useful.
* The initialization selects whether DeNoise or AutoNotch is used. It makes
* no sense to use both at once as, in a perfect world, would remove everything.
* no sense to use both at once as, in a perfect world, that would remove everything.
*
* The LMS algorithm for optimization was first proposed by
* Widrow and Hoff in 1960.
@ -44,9 +45,13 @@
* subtracted from the FIR filter output to remove coherent signals,
* producing the so called "auto-notch."
*
* Johan, dsp-10 <<<<<<<<<<<<<<<<<<<<
* This particular write of the denoise and auto-notch traces back to
* Johan Forrer, KC7WW, per September 1994 QEX. From there it was used
* in the DSP-10 project, http://www.janbob.com/electron/dsp10/dsp10.htm
*
* beta and decay
* The normalized version of coefficient update is generally best. If it
* is not desired, it can be removed at compile time by commenting out
* "#define LMS_NORMALIZE" below.
*
* Initialization also sets the size of the FIR buffer used to filter signal
* and noise. Small buffers respond to change quickly. Large buffers can work
@ -62,6 +67,14 @@
*
* This block behaves as a pass-through filter with one input and one output.
*
* There are two parameters that are set in the .ino via the function
* setParameters(float32_t beta, float32_t decay)
* The first, beta determines the rate of convergence of the coefficients.
* This changes the "sound" of the audio and normally is one of a radio's
* front panel adjustments. The second parameter, decay, slowly turns
* the algorithm off when signals are absent. It is normally very
* slightly less than 1.0. This can also change the "sound."
*
* The Teensy 3.6 needs 690 microseconds per 128 block update using a FIR
* buffer size of 32. It needs 1335 microseconds using 64 FIR Buffer.
* Note that the ARM library LMS routines might improve these
@ -74,7 +87,8 @@
* 270 for 64, and 529 microseconds for 128.
*
* All timing was done with a delay buffer of 4, but this size has
* very little effect, anyway.
* very little effect, anyway. Normalization was off, also, but
* again, this has a minor effect.
*/
#ifndef _AudioLMSDenoiseNotch_F32_h
@ -83,6 +97,9 @@
#include <AudioStream_F32.h>
#include "arm_math.h"
// Default is to use the normalized form of coefficient update
#define LMS_NORMALIZE
#define MAX_FIR 256
#define MAX_DELAY 16
#define DENOISE 1
@ -106,6 +123,10 @@ class AudioLMSDenoiseNotch_F32 : public AudioStream_F32
kMask = lengthDataF - 1;
lengthDataD = _lengthDataD;
lengthDataD = (lengthDataD>MAX_DELAY ? MAX_DELAY : lengthDataD); // Limit length
#ifdef LMS_NORMALIZE
for(int i=0; i<128; i++) powerNorm[i] = 0.01f;
pNorm = 0.01f * 128.0f;
#endif
return lengthDataF;
}
@ -138,6 +159,10 @@ class AudioLMSDenoiseNotch_F32 : public AudioStream_F32
uint16_t lengthDataD = 4; // Any value, 2 to MAX_DELAY
float32_t coeff[128];
#ifdef LMS_NORMALIZE
float32_t powerNorm[128];
float32_t pNorm = 0.0f;
#endif
// dataF[] is arranged, by added variables kOffset and
// lengthDataF, to be circular. A power-of-2 mask makes it circular.
@ -147,8 +172,8 @@ class AudioLMSDenoiseNotch_F32 : public AudioStream_F32
uint16_t lengthDataF = 64;
uint16_t kMask = 63;
float32_t beta = 0.001; //0.03f;
float32_t decay = 0.9952f;
float32_t beta = 0.03f;
float32_t decay = 0.995f;
uint16_t numLeak = 0;
};
#endif

@ -0,0 +1,121 @@
/* Test AudioLMSDenoiseNotch_F32 from OpenAudio_ArduinoLibrary
* Just a simpe sine wave plus noise input. Select
* Deoise or AutoNotch Filter functions by #defines below.
* Output is either a sample of the time series or
* the spectrum fro the FFT.
*
* For notes, see: AudioLMSDenoiseNotch_F32.h
*
* Bob Larkin 29 Jan 2022
* Public Domain
*/
#include "AudioStream_F32.h"
#include "Arduino.h"
#include "Audio.h"
#include "OpenAudio_ArduinoLibrary.h"
// ***** UN-COMMENT ONE:
#define DO_DENOISE
//#define DO_AUTONOTCH
// ***** UN-COMMENT ONE:
#define OUTPUT_QUEUE
// #define OUTPUT_FFT
// T3.x supported sample rates: 2000, 8000, 11025, 16000, 22050, 24000, 32000, 44100, 44117, 48000,
// 88200, 88235 (44117*2), 95680, 96000, 176400, 176470, 192000
// T4.x supports any sample rate the codec will handle.
const float sample_rate_Hz = 44117.0f;
const int audio_block_samples = 128;
AudioSettings_F32 audio_settings(sample_rate_Hz, audio_block_samples);
#include "OpenAudio_ArduinoLibrary.h"
#include "AudioStream_F32.h"
#include <Audio.h>
AudioSynthSineCosine_F32 sine1; //xy=60,219
AudioSynthGaussian_F32 GaussianWhiteNoise1; //xy=106,263
AudioMixer4_F32 mixer4_1; //xy=154,334
AudioLMSDenoiseNotch_F32 LMS1; //xy=206,411
AudioOutputI2S_F32 audioOutI2S1; //xy=301,542
AudioAnalyzeFFT1024_F32 FFT1024_1; //xy=362,495
AudioRecordQueue_F32 recordQueue1; //xy=378,446
AudioConnection_F32 patchCord1(sine1, 0, mixer4_1, 0);
AudioConnection_F32 patchCord2(GaussianWhiteNoise1, 0, mixer4_1, 1);
AudioConnection_F32 patchCord3(mixer4_1, LMS1);
AudioConnection_F32 patchCord4(LMS1, recordQueue1);
AudioConnection_F32 patchCord5(LMS1, FFT1024_1);
AudioConnection_F32 patchCord6(LMS1, 0, audioOutI2S1, 0);
AudioConnection_F32 patchCord7(LMS1, 0, audioOutI2S1, 1);
AudioControlSGTL5000 sgtl5000_1; //xy=97,571
float saveDat[512];
void setup() {
Serial.begin(300); // Any value
delay(1000);
Serial.println("OpenAudio_ArduinoLibrary - Test LMS DeNoise & AutoNotch");
// AudioMemory(5);
AudioMemory_F32(50, audio_settings);
sgtl5000_1.enable();
// Change the next 3 to suit your experiment
sine1.frequency(1292.49f);
sine1.amplitude(0.5f);
GaussianWhiteNoise1.amplitude(0.1f); // Standard Deviation
Serial.print("Achieved FIR length = ");
#ifdef DO_DENOISE
// Change the last two parameters for array sizes. See .h file.
Serial.println(LMS1.initializeLMS(DENOISE, 64, 4)); // <== Modify to suit
#endif
#ifdef DO_AUTONOTCH
Serial.println(LMS1.initializeLMS(NOTCH, 32, 4)); // <== Modify to suit
#endif
LMS1.setParameters(0.05f, 0.999f); // (float _beta, float _decay);
LMS1.enable(true);
FFT1024_1.windowFunction(NULL); // (AudioWindowHanning1024);
#ifdef OUTPUT_QUEUE
recordQueue1.begin();
#endif
}
void loop()
{
float *pq;
int nQ;
static uint32_t nTimes = 0;
#ifdef OUTPUT_FFT
if ( FFT1024_1.available() )
{
// When new FFT data is available
// print it all to the Arduino Serial Monitor
float* pin = FFT1024_1.getData();
for (int kk=0; kk<512; kk++)
saveDat[kk]= *(pin + kk);
if(++nTimes>4 && nTimes<6)
{
Serial.println("Freq, Hz Power, dB");
for (int i=0; i<512; i++)
{
Serial.print(43.083f*(float32_t)i, 2);
Serial.print(", ");
Serial.println(20.0f*log10f(0.0078125f*saveDat[i]), 3);
}
Serial.println();
}
}
#endif
#ifdef OUTPUT_QUEUE
if( nQ = recordQueue1.available() )
{// Serial.print("Data Available ");
pq = recordQueue1.readBuffer();
for(int i=0; i<128; i++)
Serial.println(*(pq + i),7);
recordQueue1.freeBuffer();
}
#endif
}
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