32 lines
1.9 KiB
C
32 lines
1.9 KiB
C
#ifndef _DFT_H
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#define _DFT_H
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//There are several options here, the last few are selectable by modifying the do_progressive_dft flag.
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//Do a DFT on a live audio ring buffer. It assumes new samples are added on in the + direction, older samples go negative.
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//Frequencies are as a function of the samplerate, for example, a frequency of 22050 is actually 2 Hz @ 44100 SPS
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//bins = number of frequencies to check against.
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void DoDFT( float * outbins, float * frequencies, int bins, float * databuffer, int place_in_data_buffer, int size_of_data_buffer, float q );
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//Skip many of the samples on lower frequencies.
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//Speedup = target number of data points
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void DoDFTQuick( float * outbins, float * frequencies, int bins, const float * databuffer, int place_in_data_buffer, int size_of_data_buffer, float q, float speedup );
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//An unusual tool to do a "progressive" DFT, using data from previous rounds.
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void DoDFTProgressive( float * outbins, float * frequencies, int bins, const float * databuffer, int place_in_data_buffer, int size_of_data_buffer, float q, float speedup );
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//A progressive DFT that's done using only low-bit integer math.
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//This is almost fast enough to work on an AVR, with two AVRs, it's likely that it could be powerful enough.
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//This is fast enough to run on an ESP8266
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void DoDFTProgressiveInteger( float * outbins, float * frequencies, int bins, const float * databuffer, int place_in_data_buffer, int size_of_data_buffer, float q, float speedup );
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//Everything the integer one buys, except it only calculates 2 octaves worth of notes per audio frame.
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//This is sort of working, but still have some quality issues.
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//It would theoretically be fast enough to work on an AVR.
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void DoDFTProgressiveIntegerSkippy( float * outbins, float * frequencies, int bins, const float * databuffer, int place_in_data_buffer, int size_of_data_buffer, float q, float speedup );
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#endif
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