analyze_fft256iq.h

/* 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.
 */

#ifndef analyze_fft256iq_h_
#define analyze_fft256iq_h_

#include "AudioStream.h"
#include "arm_math.h"

// windows.c
extern "C" {
extern const int16_t AudioWindowHanning256[];
extern const int16_t AudioWindowBartlett256[];
extern const int16_t AudioWindowBlackman256[];
extern const int16_t AudioWindowFlattop256[];
extern const int16_t AudioWindowBlackmanHarris256[];
extern const int16_t AudioWindowNuttall256[];
extern const int16_t AudioWindowBlackmanNuttall256[];
extern const int16_t AudioWindowWelch256[];
extern const int16_t AudioWindowHamming256[];
extern const int16_t AudioWindowCosine256[];
extern const int16_t AudioWindowTukey256[];
}

class AudioAnalyzeFFT256IQ : public AudioStream
{
public:
  AudioAnalyzeFFT256IQ() : AudioStream(2, inputQueueArray),
    window(AudioWindowBlackmanNuttall256), prevblock_i(NULL), prevblock_q(NULL),count(0),
    naverage(8), outputflag(false) {
    arm_cfft_radix4_init_q15(&fft_inst, 256, 0, 1);
  }

  bool available() {
    if (outputflag == true) {
      outputflag = false;
      return true;
    }
    return false;
  }

  float read(unsigned int binNumber) {
    if (binNumber > 255) return 0.0;
    return (float)(output[binNumber]) * (1.0 / 16384.0);
  }

  float read(unsigned int binFirst, unsigned int binLast) {
    if (binFirst > binLast) {
      unsigned int tmp = binLast;
      binLast = binFirst;
      binFirst = tmp;
    }
    if (binFirst > 255) return 0.0;
    if (binLast > 255) binLast = 255;
    uint32_t sum = 0;
    do {
      sum += output[binFirst++];
    } while (binFirst < binLast);
    return (float)sum * (1.0 / 16384.0);
  }

  void averageTogether(uint8_t n) {
    if (n == 0) n = 1;
    naverage = n;
  }

  void windowFunction(const int16_t *w) {
    window = w;
  }

  virtual void update(void);
  uint16_t output[256] __attribute__ ((aligned (4)));
private:
  const int16_t *window;
  audio_block_t *prevblock_i,*prevblock_q;
  int16_t buffer[512] __attribute__ ((aligned (4)));
  uint32_t sum[256];
  uint8_t count;
  uint8_t naverage;
  volatile bool outputflag;
  audio_block_t *inputQueueArray[2];
  arm_cfft_radix4_instance_q15 fft_inst;
};

#endif