mirror of
https://github.com/cookiengineer/audacity
synced 2025-04-30 15:49:41 +02:00
93 lines
2.3 KiB
C++
93 lines
2.3 KiB
C++
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#include <fstream>
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#include "allegro.h"
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#include "audioreader.h"
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#include "gen_chroma.h"
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#include "comp_chroma.h"
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using namespace std;
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/* NORM_CHROMA
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*
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* This function normalizes the chroma for each frame of the
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* chrom_energy to mean 0 and std. dev. 1. But if this is a
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* "silent frame", set the 13th element to 1.
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*/
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void norm_chroma( int len, float *chrom_energy ) {
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float avg = 0;
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float dev = 0;
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float sum = 0;
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for( int i = 0; i < len; i++ ) {
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/* Calculate avg for this frame */
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sum = 0;
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for ( int j = 0; j < 12; j++ )
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sum += AREF2(chrom_energy, i, j);
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avg = sum / 12.0;
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/* Silence detection: */
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float silence = 0.0F;
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if (avg < SILENCE_THRESHOLD) { /* assume silent */
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silence = 1.0F;
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}
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AREF2(chrom_energy, i, 12) = silence;
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// printf("avg at %g: %g\n", i * 0.25, avg);
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/* Normalize this frame to avg. 0 */
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for ( int j = 0; j < 12; j++ )
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AREF2(chrom_energy, i, j) -= avg;
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/* Calculate std. dev. for this frame */
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sum = 0;
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for ( int j = 0; j < 12; j++ ) {
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float x = AREF2(chrom_energy, i, j);
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sum += x * x;
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}
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dev = sqrt( sum / 12.0 );
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if (dev == 0.0) dev = 1.0F; /* don't divide by zero */
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/* Normalize this frame to std. dev. 1*/
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for ( int j = 0; j < 12; j++ )
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AREF2(chrom_energy, i, j) /= dev;
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}
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}
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/* Returns the minimum of two values */
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double min2( double x, double y ) {
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return (x < y ? x : y);
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}
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/* GEN_DIST
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*
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* This function generates the Euclidean distance for points i
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* and j in two chroma vectors for use with dynamic time warping of
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* the chroma vectors.
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*/
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float gen_dist( int i, int j, float *chrom_energy1,
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float *chrom_energy2 ) {
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float sum = 0;
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float MAX = 12.0;
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if (AREF2(chrom_energy1, i, CHROMA_BIN_COUNT) !=
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AREF2(chrom_energy2, j, CHROMA_BIN_COUNT)) {
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//printf("gd%g ", SILENCE_DISTANCE); // print result
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return SILENCE_DISTANCE;
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}
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/* Determine the distance between these vectors
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chroma1[i] and chroma2[j] to return */
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for (int k = 0; k < 12; k++) {
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float x = AREF2(chrom_energy1, i, k);
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float y = AREF2(chrom_energy2, j, k);
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float diff = x - y;
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sum += diff*diff ;
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}
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sum = min2( sqrt( sum ), MAX );
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//printf("gd%g ", sum); // print the result
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return sum;
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}
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