colorchord/DFT32.h

#ifndef _DFT32_H
#define _DFT32_H

#include <stdint.h>

//A 32-bit version of the DFT used for ColorChord.
//This header makes it convenient to use for an embedded system.
//The 32-bit DFT avoids some bit shifts, however it uses slightly
//more RAM and it uses a lot of 32-bit arithmatic. 
//
//This is basically a clone of "ProgressiveIntegerSkippy" and changes
//made here should be backported there as well.

//You can # define these to be other things elsewhere.
#ifndef OCTAVES
#define OCTAVES  5
#endif

#ifndef FIXBPERO
#define FIXBPERO 24
#endif

#ifndef FIXBINS
#define FIXBINS  (FIXBPERO*OCTAVES)
#endif

#ifndef BINCYCLE
#define BINCYCLE (1<<OCTAVES)
#endif

//You may increase this past 5 but if you do, the amplitude of your incoming signal
//must decrease.  Increasing this value makes responses slower.  Lower values are
//more responsive.
#ifndef DFTIIR
#define DFTIIR 6
#endif

//Everything the integer one buys, except it only calculates 2 octaves worth of notes per audio frame.
//This is sort of working, but still have some quality issues.
//It would theoretically be fast enough to work on an AVR.
//NOTE: This is the only DFT available to the embedded port of ColorChord
#ifndef CCEMBEDDED
void DoDFTProgressive32( float * outbins, float * frequencies, int bins, const float * databuffer, int place_in_data_buffer, int size_of_data_buffer, float q, float speedup );
#endif

//It's actually split into a few functions, which you can call on your own:
int SetupDFTProgressive32();  //Call at start. Returns nonzero if error.
void UpdateBins32( const uint16_t * frequencies );

//Call this to push on new frames of sound. 
//Though it accepts an int16, it actually only takes -4095 to +4095. (13-bit)
//Any more and you will exceed the accumulators and it will cause an overflow.
void PushSample32( int16_t dat );

#ifndef CCEMBEDDED
void UpdateBinsForDFT32( const float * frequencies ); //Update the frequencies
#endif

void UpdateOutputBins32();

//Whenever you need to read the bins, you can do it from here.
//These outputs are limited to 0..~2047, this makes it possible
//for you to process with uint16_t's more easily.
//This is updated every time the DFT hits the octavecount, or 1/32 updates.
extern uint16_t embeddedbins32[];  //[FIXBINS]


#endif