git.sesse.net Git - pitch/blob - pitch.cpp

   1 #include <stdio.h>
   2 #include <string.h>
   3 #include <stdlib.h>
   4 #include <unistd.h>
   5
   6 #include "linux_audio.h"
   7 #include "pitchdetector.h"
   8
   9 #define BASE_PITCH      440.0
  10 #define SAMPLE_RATE     22050
  11 #define FFT_LENGTH      4096     /* in samples */
  12 #define PAD_FACTOR      2        /* 1/pf of the FFT samples are real samples, the rest are padding */
  13 #define OVERLAP         4        /* 1/ol samples will be replaced in the buffer every frame. Should be
  14                                   * a multiple of 2 for the Hamming window (see
  15                                   * http://www-ccrma.stanford.edu/~jos/parshl/Choice_Hop_Size.html).
  16                                   */
  17
  18 #define EQUAL_TEMPERAMENT     0
  19 #define WELL_TEMPERED_GUITAR  1
  20
  21 #define TUNING WELL_TEMPERED_GUITAR
  22
  23 void print_spectrogram(double freq, double amp);
  24 void write_sine(int dsp_fd, double freq, unsigned num_samples);
  25
  26 int main()
  27 {
  28         PitchDetector pd(SAMPLE_RATE, FFT_LENGTH, PAD_FACTOR, OVERLAP);
  29         int fd = get_dsp_fd(SAMPLE_RATE, FFT_LENGTH, OVERLAP);
  30         for ( ;; ) {
  31                 short buf[FFT_LENGTH / PAD_FACTOR / OVERLAP];
  32
  33                 read_chunk(fd, buf, FFT_LENGTH / PAD_FACTOR / OVERLAP);
  34                 std::pair<double, double> peak = pd.detect_pitch(buf);
  35
  36                 if (peak.first < 50.0 || peak.second - log10(FFT_LENGTH) < 0.0) {
  37 #if TUNING == WELL_TEMPERED_GUITAR
  38                         printf("......\n");
  39 #else
  40                         printf("............\n");
  41 #endif
  42                 } else {
  43                         print_spectrogram(peak.first, peak.second - log10(FFT_LENGTH));
  44                 }
  45         }
  46 }
  47
  48 std::string freq_to_tonename(double freq)
  49 {
  50         std::string notenames[] = { "C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B" };
  51         double half_notes_away = 12.0 * log2(freq / BASE_PITCH) - 3.0;
  52         int hnai = int(floor(half_notes_away + 0.5));
  53         int octave = (hnai + 48) / 12;
  54
  55         char buf[256];
  56         sprintf(buf, "%s%d + %.2f [%d]", notenames[((hnai % 12) + 12) % 12].c_str(), octave, half_notes_away - hnai, hnai);
  57         return buf;
  58 }
  59
  60 #if TUNING == EQUAL_TEMPERAMENT
  61 void print_spectrogram(double freq, double amp)
  62 {
  63         std::string notenames[] = { "C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B" };
  64         double half_notes_away = 12.0 * log2(freq / BASE_PITCH) - 3.0;
  65         int hnai = int(floor(half_notes_away + 0.5));
  66         int octave = (hnai + 48) / 12;
  67
  68         for (int i = 0; i < 12; ++i)
  69                 if (i == ((hnai % 12) + 12) % 12)
  70                         printf("#");
  71                 else
  72                         printf(".");
  73
  74         printf(" (%-2s%d %+.2f, %5.2fHz) [%5.2fdB]  [", notenames[((hnai % 12) + 12) % 12].c_str(), octave, half_notes_away - hnai,
  75                 freq, amp);
  76
  77         double off = half_notes_away - hnai;
  78         for (int i = -10; i <= 10; ++i) {
  79                 if (off >= (i-0.5) * 0.05 && off < (i+0.5) * 0.05) {
  80                         printf("#");
  81                 } else {
  82                         if (i == 0) {
  83                                 printf("|");
  84                         } else {
  85                                 printf("-");
  86                         }
  87                 }
  88         }
  89         printf("]\n");
  90
  91 }
  92 #else
  93 struct note {
  94         char notename[16];
  95         double freq;
  96 };
  97 static note notes[] = {
  98         { "E-3", BASE_PITCH/4.0 * (3.0/4.0) },
  99         { "A-3", BASE_PITCH/4.0 },
 100         { "D-4", BASE_PITCH/4.0 * (4.0/3.0) },
 101         { "G-4", BASE_PITCH/4.0 * (4.0/3.0)*(4.0/3.0) },
 102         { "B-4", BASE_PITCH * (3.0/4.0)*(3.0/4.0) },
 103         { "E-5", BASE_PITCH * (3.0/4.0) }
 104 };
 105
 106 void print_spectrogram(double freq, double amp)
 107 {
 108         double best_away = 999999999.9;
 109         unsigned best_away_ind = 0;
 110
 111         for (unsigned i = 0; i < sizeof(notes)/sizeof(note); ++i) {
 112                 double half_notes_away = 12.0 * log2(freq / notes[i].freq);
 113                 if (fabs(half_notes_away) < fabs(best_away)) {
 114                         best_away = half_notes_away;
 115                         best_away_ind = i;
 116                 }
 117         }
 118
 119         for (unsigned i = 0; i < sizeof(notes)/sizeof(note); ++i)
 120                 if (i == best_away_ind)
 121                         printf("#");
 122                 else
 123                         printf(".");
 124
 125         printf(" (%s %+.2f, %5.2fHz) [%5.2fdB]  [", notes[best_away_ind].notename, best_away, freq, amp);
 126
 127         // coarse tuning
 128         for (int i = -10; i <= 10; ++i) {
 129                 if (best_away >= (i-0.5) * 0.05 && best_away < (i+0.5) * 0.05) {
 130                         printf("#");
 131                 } else {
 132                         if (i == 0) {
 133                                 printf("|");
 134                         } else {
 135                                 printf("-");
 136                         }
 137                 }
 138         }
 139         printf("]  [");
 140
 141         // fine tuning
 142         for (int i = -10; i <= 10; ++i) {
 143                 if (best_away >= (i-0.5) * 0.01 && best_away < (i+0.5) * 0.01) {
 144                         printf("#");
 145                 } else {
 146                         if (i == 0) {
 147                                 printf("|");
 148                         } else {
 149                                 printf("-");
 150                         }
 151                 }
 152         }
 153         printf("]\n");
 154 }
 155 #endif