You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
OpenAudio_ArduinoLibrary/analyze_rms_f32.h

106 lines
4.4 KiB

/* This is a direct translation of the Teensy Audio Library RMS Analyze
* to use floating point f32. This is intended to be compatible with
* Chip Audette's floating point libraries.
* Bob Larkin 23 April 2020 - AudioAnalyze_RMS_F32
*
* Regard the copyright and licensing:
* Audio Library for Teensy 3.X
* Copyright (c) 2014, Paul Stoffregen, paul@pjrc.com
*
* Development of this audio library was funded by PJRC.COM, LLC by sales of
* Teensy and Audio Adaptor boards. Please support PJRC's efforts to develop
* open source software by purchasing Teensy or other PJRC products.
*
* 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, development funding 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.
*/
/* Input is a block of f32 numbers. Output is the signal RMS amplitude
* calculated over multiple blocks. Useful for audio level response projects,
* and general troubleshooting.
*
* Status: Tested 3.6 and T4.0 No known bugs.
* Functions:
* available(); Returns true if new RMS data is available.
* read(); Read the new RMS value. Return is rms value in float.
* Examples:
* TestPeakRMS.ino
* Similar: File > Examples > Audio > Analysis > PeakAndRMSMeterStereo
* Time: Measured time for the update of F32 RMS is 7 microseconds
* for 128 block size.
*
* The average "power" is found by squaring the sample values, adding them
* together and dividing by the number of samples. The RMS value is a "voltage"
* found by taking the square root of the power. This is in DSP lingo, and
* the units are vague. But, since usually, only relative values are important,
* the units will cancel out!
*
* The two variables, accum and count, keep adding to the power sum until
* a read() takes place. This is fine if the statistics of the input data are
* stationary, i.e., not changing with time. But, if the process is not
* stationary, be aware and do read() at appropriate times.
*/
#ifndef analyze_rms_f32_h_
#define analyze_rms_f32_h_
#include "Arduino.h"
#include "AudioStream_F32.h"
class AudioAnalyzeRMS_F32 : public AudioStream_F32 {
//GUI: inputs:1, outputs:0 //this line used for automatic generation of GUI node
//GUI: shortName: AnalyzeRMS
public:
AudioAnalyzeRMS_F32(void) : AudioStream_F32(1, inputQueueArray_f32) {
// default values from initialization below
}
// Alternate specification of block size. Sample rate does not apply for analyze_rms
AudioAnalyzeRMS_F32(const AudioSettings_F32 &settings) : AudioStream_F32(1, inputQueueArray_f32) {
block_size = settings.audio_block_samples;
}
bool available(void) {
return count > 0;
}
void showError(uint16_t e) { // 0/1 Disables/Enables printing of update() errors
errorPrint = e;
}
float read(void);
virtual void update(void);
private:
audio_block_f32_t *inputQueueArray_f32[1];
uint16_t block_size = AUDIO_BLOCK_SAMPLES;
// double for accum is very safe, but needed? Well, power dynamic Range x 1 sec of data =~ 1E7 x 4E4 = 4E11
// whereas float range for positive numbers is 2^23 =~ 1E7 so double is easily justified for accuracy.
// The timing 7 microseconds per 128, includes using double for accum, so the price is reasonable.
double accum = 0.0;
uint32_t count = 0;
// Control error printing in update(). Should never be enabled
// until all audio objects have been initialized.
// Only used as 0 or 1 now, but 16 bits are available.
uint16_t errorPrint = 0;
};
#endif