410 lines
10 KiB
C
410 lines
10 KiB
C
#include "embeddednf.h"
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#include <stdio.h>
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uint16_t folded_bins[FIXBPERO];
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uint16_t fuzzed_bins[FIXBINS];
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uint8_t note_peak_freqs[MAXNOTES];
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uint16_t note_peak_amps[MAXNOTES];
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uint16_t note_peak_amps2[MAXNOTES];
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uint8_t note_jumped_to[MAXNOTES];
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static const float bf_table[24] = {
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1.000000, 1.029302, 1.059463, 1.090508, 1.122462, 1.155353,
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1.189207, 1.224054, 1.259921, 1.296840, 1.334840, 1.373954,
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1.414214, 1.455653, 1.498307, 1.542211, 1.587401, 1.633915,
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1.681793, 1.731073, 1.781797, 1.834008, 1.887749, 1.943064 };
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/* The above table was generated using the following code:
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#include <stdio.h>
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#include <math.h>
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int main()
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{
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int i;
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#define FIXBPERO 24
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printf( "const float bf_table[%d] = {", FIXBPERO );
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for( i = 0; i < FIXBPERO; i++ )
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{
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if( ( i % 6 ) == 0 )
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printf( "\n\t" );
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printf( "%f, ", pow( 2, (float)i / (float)FIXBPERO ) );
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}
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printf( "};\n" );
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return 0;
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}
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*/
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#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
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void UpdateFreqs()
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{
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uint16_t fbins[FIXBPERO];
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int i;
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BUILD_BUG_ON( sizeof(bf_table) != FIXBPERO*4 );
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//Warning: This does floating point. Avoid doing this frequently. If you
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//absolutely cannot have floating point on your system, you may precompute
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//this and store it as a table. It does preclude you from changing
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//BASE_FREQ in runtime.
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for( i = 0; i < FIXBPERO; i++ )
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{
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float frq = ( bf_table[i] * BASE_FREQ );
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fbins[i] = ( 65536.0 ) / ( DFREQ ) * frq * 16;
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}
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#ifdef USE_32DFT
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UpdateBins32( fbins );
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#else
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UpdateBinsForProgressiveIntegerSkippyInt( fbins );
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#endif
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}
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void Init()
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{
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int i;
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//Set up and initialize arrays.
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for( i = 0; i < MAXNOTES; i++ )
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{
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note_peak_freqs[i] = 255;
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note_peak_amps[i] = 0;
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note_peak_amps2[i] = 0;
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}
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for( i = 0; i < FIXBPERO; i++ )
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{
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folded_bins[i] = 0;
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}
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for( i = 0; i < FIXBINS; i++ )
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{
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fuzzed_bins[i] = 0;
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}
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//Step 1: Initialize the Integer DFT.
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#ifdef USE_32DFT
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SetupDFTProgressive32();
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#else
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SetupDFTProgressiveIntegerSkippy();
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#endif
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//Step 2: Set up the frequency list. You could do this multiple times
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//if you want to change the loadout of the frequencies.
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UpdateFreqs();
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}
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void HandleFrameInfo()
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{
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int i, j, k;
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uint8_t hitnotes[MAXNOTES];
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for( i = 0; i < MAXNOTES; i++ )
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{
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hitnotes[i] = 0;
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}
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#ifdef USE_32DFT
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uint16_t * strens;
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UpdateOutputBins32();
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strens = embeddedbins32;
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#else
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uint16_t * strens = embeddedbins;
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#endif
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//Copy out the bins from the DFT to our fuzzed bins.
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for( i = 0; i < FIXBINS; i++ )
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{
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fuzzed_bins[i] = (fuzzed_bins[i] + (strens[i]>>FUZZ_IIR_BITS) -
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(fuzzed_bins[i]>>FUZZ_IIR_BITS));
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}
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//Taper first octave
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for( i = 0; i < FIXBPERO; i++ )
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{
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uint32_t taperamt = (65536 / FIXBPERO) * i;
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fuzzed_bins[i] = (taperamt * fuzzed_bins[i]) >> 16;
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}
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//Taper last octave
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for( i = 0; i < FIXBPERO; i++ )
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{
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int newi = FIXBINS - i - 1;
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uint32_t taperamt = (65536 / FIXBPERO) * i;
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fuzzed_bins[newi] = (taperamt * fuzzed_bins[newi]) >> 16;
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}
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//Fold the bins from fuzzedbins into one octave.
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for( i = 0; i < FIXBPERO; i++ )
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folded_bins[i] = 0;
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k = 0;
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for( j = 0; j < OCTAVES; j++ )
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{
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for( i = 0; i < FIXBPERO; i++ )
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{
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folded_bins[i] += fuzzed_bins[k++];
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}
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}
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//Now, we must blur the folded bins to get a good result.
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//Sometimes you may notice every other bin being out-of
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//line, and this fixes that. We may consider running this
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//more than once, but in my experience, once is enough.
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for( j = 0; j < FILTER_BLUR_PASSES; j++ )
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{
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//Extra scoping because this is a large on-stack buffer.
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uint16_t folded_out[FIXBPERO];
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uint8_t adjLeft = FIXBPERO-1;
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uint8_t adjRight = 1;
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for( i = 0; i < FIXBPERO; i++ )
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{
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uint16_t lbin = folded_bins[adjLeft]>>2;
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uint16_t rbin = folded_bins[adjRight]>>2;
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uint16_t tbin = folded_bins[i]>>1;
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folded_out[i] = lbin + rbin + tbin;
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//We do this funny dance to avoid a modulus operation. On some
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//processors, a modulus operation is slow. This is cheap.
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adjLeft++; if( adjLeft == FIXBPERO ) adjLeft = 0;
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adjRight++; if( adjRight == FIXBPERO ) adjRight = 0;
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}
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for( i = 0; i < FIXBPERO; i++ )
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{
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folded_bins[i] = folded_out[i];
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}
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}
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//Next, we have to find the peaks, this is what "decompose" does in our
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//normal tool. As a warning, it expects that the values in foolded_bins
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//do NOT exceed 32767.
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{
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uint8_t adjLeft = FIXBPERO-1;
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uint8_t adjRight = 1;
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for( i = 0; i < FIXBPERO; i++ )
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{
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int16_t prev = folded_bins[adjLeft];
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int16_t next = folded_bins[adjRight];
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int16_t this = folded_bins[i];
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uint8_t thisfreq = i<<SEMIBITSPERBIN;
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int16_t offset;
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adjLeft++; if( adjLeft == FIXBPERO ) adjLeft = 0;
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adjRight++; if( adjRight == FIXBPERO ) adjRight = 0;
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if( this < MIN_AMP_FOR_NOTE ) continue;
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if( prev > this || next > this ) continue;
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if( prev == this && next == this ) continue;
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//i is at a peak...
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int32_t totaldiff = (( this - prev ) + ( this - next ));
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int32_t porpdiffP = ((this-prev)<<16) / totaldiff; //close to 0 =
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//closer to this side, 32768 = in the middle, 65535 away.
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int32_t porpdiffN = ((this-next)<<16) / totaldiff;
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if( porpdiffP < porpdiffN )
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{
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//Closer to prev.
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offset = -(32768 - porpdiffP);
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}
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else
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{
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//Closer to next
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offset = (32768 - porpdiffN);
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}
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//Need to round. That's what that extra +(15.. is in the center.
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thisfreq += (offset+(1<<(15-SEMIBITSPERBIN)))>>(16-SEMIBITSPERBIN);
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//In the event we went 'below zero' need to wrap to the top.
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if( thisfreq > 255-(1<<SEMIBITSPERBIN) )
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thisfreq = (1<<SEMIBITSPERBIN)*FIXBPERO - (256-thisfreq);
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//Okay, we have a peak, and a frequency. Now, we need to search
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//through the existing notes to see if we have any matches.
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//If we have a note that's close enough, we will try to pull it
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//closer to us and boost it.
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int8_t lowest_found_free_note = -1;
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int8_t closest_note_id = -1;
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int16_t closest_note_distance = 32767;
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for( j = 0; j < MAXNOTES; j++ )
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{
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uint8_t nf = note_peak_freqs[j];
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if( nf == 255 )
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{
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if( lowest_found_free_note == -1 )
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lowest_found_free_note = j;
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continue;
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}
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int16_t distance = thisfreq - nf;
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if( distance < 0 ) distance = -distance;
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//Make sure that if we've wrapped around the right side of the
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//array, we can detect it and loop it back.
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if( distance > ((1<<(SEMIBITSPERBIN-1))*FIXBPERO) )
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{
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distance = ((1<<(SEMIBITSPERBIN))*FIXBPERO) - distance;
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}
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//If we find a note closer to where we are than any of the
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//others, we can mark it as our desired note.
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if( distance < closest_note_distance )
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{
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closest_note_id = j;
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closest_note_distance = distance;
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}
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}
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int8_t marked_note = -1;
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if( closest_note_distance <= MAX_JUMP_DISTANCE )
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{
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//We found the note we need to augment.
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note_peak_freqs[closest_note_id] = thisfreq;
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marked_note = closest_note_id;
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}
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//The note was not found.
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else if( lowest_found_free_note != -1 )
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{
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note_peak_freqs[lowest_found_free_note] = thisfreq;
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marked_note = lowest_found_free_note;
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}
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//If we found a note to attach to, we have to use the IIR to
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//increase the strength of the note, but we can't exactly snap
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//it to the new strength.
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if( marked_note != -1 )
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{
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hitnotes[marked_note] = 1;
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note_peak_amps[marked_note] =
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note_peak_amps[marked_note] -
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(note_peak_amps[marked_note]>>AMP_1_IIR_BITS) +
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(this>>(AMP_1_IIR_BITS-3));
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note_peak_amps2[marked_note] =
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note_peak_amps2[marked_note] -
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(note_peak_amps2[marked_note]>>AMP_2_IIR_BITS) +
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((this<<3)>>(AMP_2_IIR_BITS));
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}
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}
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}
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#if 0
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for( i = 0; i < MAXNOTES; i++ )
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{
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if( note_peak_freqs[i] == 255 ) continue;
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printf( "%d / ", note_peak_amps[i] );
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}
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printf( "\n" );
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#endif
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//Now we need to handle combining notes.
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for( i = 0; i < MAXNOTES; i++ )
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for( j = 0; j < i; j++ )
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{
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//We'd be combining nf2 (j) into nf1 (i) if they're close enough.
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uint8_t nf1 = note_peak_freqs[i];
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uint8_t nf2 = note_peak_freqs[j];
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int16_t distance = nf1 - nf2;
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if( nf1 == 255 || nf2 == 255 ) continue;
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if( distance < 0 ) distance = -distance;
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//If it wraps around above the halfway point, then we're closer to it
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//on the other side.
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if( distance > ((1<<(SEMIBITSPERBIN-1))*FIXBPERO) )
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{
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distance = ((1<<(SEMIBITSPERBIN))*FIXBPERO) - distance;
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}
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if( distance > MAX_COMBINE_DISTANCE )
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{
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continue;
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}
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int into;
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int from;
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if( note_peak_amps[i] > note_peak_amps[j] )
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{
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into = i;
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from = j;
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}
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else
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{
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into = j;
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from = i;
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}
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//We need to combine the notes. We need to move the new note freq
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//towards the stronger of the two notes.
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int16_t amp1 = note_peak_amps[into];
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int16_t amp2 = note_peak_amps[from];
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//0 to 32768 porportional to how much of amp1 we want.
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uint32_t porp = (amp1<<15) / (amp1+amp2);
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uint16_t newnote = (nf1 * porp + nf2 * (32768-porp))>>15;
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//When combining notes, we have to use the stronger amplitude note.
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//trying to average or combine the power of the notes looks awful.
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note_peak_freqs[into] = newnote;
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note_peak_amps[into] = (note_peak_amps[into]>note_peak_amps[from])?
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note_peak_amps[into]:note_peak_amps[j];
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note_peak_amps2[into] = (note_peak_amps2[into]>note_peak_amps2[from])?
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note_peak_amps2[into]:note_peak_amps2[j];
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note_peak_freqs[from] = 255;
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note_peak_amps[from] = 0;
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note_jumped_to[from] = i;
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}
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//For al lof the notes that have not been hit, we have to allow them to
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//to decay. We only do this for notes that have not found a peak.
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for( i = 0; i < MAXNOTES; i++ )
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{
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if( note_peak_freqs[i] == 255 || hitnotes[i] ) continue;
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note_peak_amps[i] -= note_peak_amps[i]>>AMP_1_IIR_BITS;
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note_peak_amps2[i] -= note_peak_amps2[i]>>AMP_2_IIR_BITS;
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//In the event a note is not strong enough anymore, it is to be
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//returned back into the great pool of unused notes.
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if( note_peak_amps[i] < MINIMUM_AMP_FOR_NOTE_TO_DISAPPEAR )
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{
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note_peak_freqs[i] = 255;
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note_peak_amps[i] = 0;
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note_peak_amps2[i] = 0;
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}
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}
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//We now have notes!!!
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#if 0
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for( i = 0; i < MAXNOTES; i++ )
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{
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if( note_peak_freqs[i] == 255 ) continue;
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printf( "(%3d %4d %4d) ", note_peak_freqs[i], note_peak_amps[i], note_peak_amps2[i] );
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}
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printf( "\n") ;
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#endif
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#if 0
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for( i = 0; i < FIXBPERO; i++ )
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{
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printf( "%4d ", folded_bins[i] );
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}
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printf( "\n" );
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#endif
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}
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