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Pitch Detector: add the possibility to set the reference frequency of A (last part of FS#8768)

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@22753 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Alexander Levin 2009-09-20 16:16:32 +00:00
parent 2474708498
commit 46bb567ec4
1 changed files with 71 additions and 18 deletions
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89
apps/plugins/pitch_detector.c
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@ -178,6 +178,37 @@ const fixed yin_threshold_table[] =
float2fixed(0.50),
};
/* Structure for the reference frequency (frequency of A)
* It's used for scaling the frequency before finding out
* the note. The frequency is scaled in a way that the main
* algorithm can assume the frequency of A to be 440 Hz.
*/
struct freq_A_entry
{
const int frequency; /* Frequency in Hz */
const fixed ratio; /* 440/frequency */
const fixed logratio; /* log2(factor) */
};
const struct freq_A_entry freq_A[] =
{
{435, float2fixed(1.011363636), float2fixed( 0.016301812)},
{436, float2fixed(1.009090909), float2fixed( 0.013056153)},
{437, float2fixed(1.006818182), float2fixed( 0.009803175)},
{438, float2fixed(1.004545455), float2fixed( 0.006542846)},
{439, float2fixed(1.002272727), float2fixed( 0.003275132)},
{440, float2fixed(1.000000000), float2fixed( 0.000000000)},
{441, float2fixed(0.997727273), float2fixed(-0.003282584)},
{442, float2fixed(0.995454545), float2fixed(-0.006572654)},
{443, float2fixed(0.993181818), float2fixed(-0.009870244)},
{444, float2fixed(0.990909091), float2fixed(-0.013175389)},
{445, float2fixed(0.988636364), float2fixed(-0.016488123)},
};
/* Index of the entry for 440 Hz in the table (default frequency for A) */
#define DEFAULT_FREQ_A 5
#define NUM_FREQ_A (sizeof(freq_A)/sizeof(freq_A[0]))
/* How loud the audio has to be to start displaying pitch */
/* Must be between 0 and 100 */
#define VOLUME_THRESHOLD (50)
@ -279,8 +310,9 @@ struct tuner_settings
unsigned sample_size;
unsigned lowest_freq;
unsigned yin_threshold;
bool use_sharps;
bool display_hz;
int freq_A; /* Index of the frequency of A */
bool use_sharps;
bool display_hz;
} tuner_settings;
/*=================================================================*/
@ -325,6 +357,7 @@ void tuner_settings_reset(struct tuner_settings* settings)
settings->sample_size = BUFFER_SIZE;
settings->lowest_freq = period2freq(BUFFER_SIZE / 4);
settings->yin_threshold = DEFAULT_YIN_THRESHOLD;
settings->freq_A = DEFAULT_FREQ_A;
settings->use_sharps = true;
settings->display_hz = false;
}
@ -454,11 +487,12 @@ void set_min_freq(int new_freq)
bool main_menu(void)
{
int selection=0;
int selection = 0;
bool done = false;
bool exit_tuner=false;
bool exit_tuner = false;
int choice;
bool reset = false;
int freq_val;
bool reset;
MENUITEM_STRINGLIST(menu,"Tuner Settings",NULL,
"Return to Tuner",
@ -468,6 +502,7 @@ bool main_menu(void)
"Algorithm Pickiness",
"Accidentals",
"Display Frequency (Hz)",
"Frequency of A (Hz)",
"Reset Settings",
"Quit");
@ -514,21 +549,31 @@ bool main_menu(void)
BOOL, noyes_text, 2, NULL);
break;
case 7:
freq_val = freq_A[tuner_settings.freq_A].frequency;
rb->set_int("Frequency of A (Hz)",
"Hz", UNIT_INT, &freq_val, NULL,
1, freq_A[0].frequency, freq_A[NUM_FREQ_A-1].frequency,
NULL);
tuner_settings.freq_A = freq_val - freq_A[0].frequency;
break;
case 8:
reset = false;
rb->set_option("Reset Tuner Settings?",
&reset,
BOOL, noyes_text, 2, tuner_settings_reset_query);
break;
case 8:
case 9:
exit_tuner = true;
done = true;
break;
case 0:
default:
/* Return to the tuner */
done = true;
break;
}
}
return(exit_tuner);
return exit_tuner;
}
/*=================================================================*/
@ -650,11 +695,11 @@ void draw_bar(fixed wrong_by_cents)
int x;
#ifdef HAVE_LCD_COLOR
rb->lcd_set_foreground(LCD_RGBPACK(255,255,255)); /* Color screens */
rb->lcd_set_foreground(LCD_RGBPACK(255,255,255)); /* Color screens */
#elif LCD_DEPTH > 1
rb->lcd_set_foreground(LCD_BLACK); /* Greyscale screens */
#else
rb->lcd_set_foreground(LCD_BLACK); /* Black and white screens */
rb->lcd_set_foreground(LCD_BLACK); /* Black and white screens */
#endif
rb->lcd_hline(0,LCD_WIDTH-1, BAR_HLINE_Y);
@ -702,14 +747,22 @@ void display_frequency (fixed freq)
{
fixed ldf, mldf;
fixed lfreq, nfreq;
fixed orig_freq;
int i, note = 0;
char str_buf[30];
if (fp_lt(freq, FP_LOW))
freq = FP_LOW;
lfreq = log(freq);
/* We calculate the frequency and its log as if */
/* the reference frequency of A were 440 Hz. */
orig_freq = freq;
lfreq = fp_add(log(freq), freq_A[tuner_settings.freq_A].logratio);
freq = fp_mul(freq, freq_A[tuner_settings.freq_A].ratio);
/* Get the frequency to within the range of our reference table */
/* This calculates a log freq offset for note A */
/* Get the frequency to within the range of our reference table, */
/* i.e. into the right octave. */
while (fp_lt(lfreq, fp_sub(lfreqs[0], fp_shr(LOG_D_NOTE, 1))))
lfreq = fp_add(lfreq, LOG_2);
while (fp_gte(lfreq, fp_sub(fp_add(lfreqs[0], LOG_2),
@ -722,19 +775,19 @@ void display_frequency (fixed freq)
fp_sub(lfreq,lfreqs[i]) : fp_neg(fp_sub(lfreq,lfreqs[i]));
if (fp_lt(ldf, mldf))
{
mldf = ldf;
note = i;
mldf = ldf;
note = i;
}
}
nfreq = freqs[note];
while (fp_gt(fp_div(nfreq, freq), D_NOTE_SQRT))
while (fp_gt(fp_div(nfreq, freq), D_NOTE_SQRT))
nfreq = fp_shr(nfreq, 1);
while (fp_gt(fp_div(freq, nfreq), D_NOTE_SQRT))
{
nfreq = fp_shl(nfreq, 1);
}
ldf=fp_mul(int2fixed(1200), log(fp_div(freq,nfreq)));
ldf = fp_mul(int2fixed(1200), log(fp_div(freq,nfreq)));
rb->lcd_clear_display();
draw_bar(ldf); /* The red bar */
@ -744,8 +797,8 @@ void display_frequency (fixed freq)
if(tuner_settings.display_hz)
{
rb->snprintf(str_buf,30, "%s : %d cents (%d.%02dHz)",
notes[note], fp_round(ldf) ,fixed2int(freq),
fp_round(fp_mul(fp_frac(freq),
notes[note], fp_round(ldf) ,fixed2int(orig_freq),
fp_round(fp_mul(fp_frac(orig_freq),
int2fixed(DISPLAY_HZ_PRECISION))));
print_str(str_buf);
}