rockbox/apps/recorder/peakmeter.c
Linus Nielsen Feltzing a02ffd5afa Some peak meter optimizations
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@2784 a1c6a512-1295-4272-9138-f99709370657
2002-10-30 23:01:27 +00:00

894 lines
26 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2002 by Philipp Pertermann
*
* All files in this archive are subject to the GNU General Public License.
* See the file COPYING in the source tree root for full license agreement.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "mas.h"
#include "thread.h"
#include "kernel.h"
#include "settings.h"
#include "lcd.h"
#include "wps-display.h"
#include "sprintf.h"
#include "button.h"
#include "system.h"
#include "font.h"
#include "icons.h"
#include "lang.h"
#include "peakmeter.h"
/* buffer the read peak value */
static int peak_meter_max_l;
static int peak_meter_max_r;
/* point in time when peak_meter_max_x becomes invalid */
static long peak_meter_timeout_l;
static long peak_meter_timeout_r;
/* when true a clip has occurred */
static bool peak_meter_l_clip = false;
static bool peak_meter_r_clip = false;
/* point in time when peak_meter_x_oveflow becomes invalid */
static long peak_meter_clip_timeout_l;
static long peak_meter_clip_timeout_r;
static int peak_meter_clip_hold;
/* specifies the value range in peak volume values */
unsigned short peak_meter_range_min;
unsigned short peak_meter_range_max;
unsigned short peak_meter_range;
/* if set to true clip timeout is disabled */
static bool peak_meter_clip_eternal = false;
static bool peak_meter_use_dbfs = true;
static unsigned short db_min = 0;
static unsigned short db_max = 9000;
static unsigned short db_range = 9000;
#ifndef SIMULATOR
static int peak_meter_src_l = MAS_REG_DQPEAK_L;
static int peak_meter_src_r = MAS_REG_DQPEAK_R;
#endif
/* temporarily en- / disables peak meter. This is
especially for external applications to detect
if the peak_meter is in use and needs drawing at all */
bool peak_meter_enabled = true;
/*
bool peak_meter_use_thread = false;
static char peak_meter_stack[DEFAULT_STACK_SIZE];
*/
/* used in wps.c to set the display frame rate of the peak meter */
int peak_meter_fps = 20;
static int peak_meter_l;
static int peak_meter_r;
static int peak_meter_hold = 1;
static int peak_meter_release = 8;
/* debug only */
#ifdef PM_DEBUG
static int peek_calls = 0;
#define PEEKS_PER_DRAW_SIZE 40
static unsigned int peeks_per_redraw[PEEKS_PER_DRAW_SIZE];
#define TICKS_PER_DRAW_SIZE 20
static unsigned int ticks_per_redraw[TICKS_PER_DRAW_SIZE];
#endif
/* time out values for max */
static long max_time_out[] = {
0 * HZ, HZ / 5, 30, HZ / 2, HZ, 2 * HZ,
3 * HZ, 4 * HZ, 5 * HZ, 6 * HZ, 7 * HZ, 8 * HZ,
9 * HZ, 10 * HZ, 15 * HZ, 20 * HZ, 30 * HZ, 60 * HZ
};
/* time out values for clip */
static long clip_time_out[] = {
0 * HZ, 1 * HZ, 2 * HZ, 3 * HZ, 4 * HZ, 5 * HZ,
6 * HZ, 7 * HZ, 8 * HZ, 9 * HZ, 10 * HZ, 15 * HZ,
20 * HZ, 25 * HZ, 30 * HZ, 45 * HZ, 60 * HZ, 90 * HZ,
120 * HZ, 180 * HZ, 300 * HZ, 600 * HZ, 1200 * HZ,
2700 * HZ, 5400 * HZ
};
/* precalculated peak values that represent magical
dBfs values. Used to draw the scale */
#define DB_SCALE_SRC_VALUES_SIZE 11
#if 0
const static int db_scale_src_values[DB_SCALE_SRC_VALUES_SIZE] = {
32767, /* 0 db */
23197, /* - 3 db */
16422, /* - 6 db */
11626, /* - 9 db */
8231, /* -12 db */
4125, /* -18 db */
2067, /* -24 db */
1036, /* -30 db */
328, /* -40 db */
104, /* -50 db */
33, /* -60 db */
};
#else
static const int db_scale_src_values[DB_SCALE_SRC_VALUES_SIZE] = {
32752, /* 0 db */
22784, /* - 3 db */
14256, /* - 6 db */
11752, /* - 9 db */
9256, /* -12 db */
4256, /* -18 db */
2186, /* -24 db */
1186, /* -30 db */
373, /* -40 db */
102, /* -50 db */
33, /* -60 db */
};
#endif
static int db_scale_count = DB_SCALE_SRC_VALUES_SIZE;
/* if db_scale_valid is false the content of
db_scale_lcd_coord needs recalculation */
static bool db_scale_valid = false;
/* contains the lcd x coordinates of the magical
scale values in db_scale_src_values */
static int db_scale_lcd_coord[sizeof db_scale_src_values / sizeof (int)];
/**
* Calculates dB Value for the peak meter, uses peak value as input
* @param int sample - The input value
* Make sure that 0 <= value < SAMPLE_RANGE
*
* @return int - The 2 digit fixed comma result of the euation
* 20 * log (sample / SAMPLE_RANGE) + 90
* Output range is 0-8961 (that is 0,0 - 89,6 dB).
* Normally 0dB is full scale, here it is shifted +90dB.
* The calculation is based on the results of a linear
* approximation tool written specifically for this problem
* by Andreas Zwirtes (radhard@gmx.de). The result hat an
* accurracy of better than 2%. It is highly runtime optimized,
* the cascading if-clauses do an successive approximation on
* the input value. This avoids big lookup-tables and
* for-loops.
*/
int calc_db (int isample) {
/* return n+m*(isample-istart)/100 */
int n;
long m;
int istart;
/* Range 1-4 */
if (isample < 119) {
/* Range 1-2 */
if (isample < 5) {
/* Range 1 */
if (isample < 1) {
istart = 0;
n = 0;
m = 5900;
}
/* Range 2 */
else {
istart = 1;
n = 59;
m = 34950;
}
}
/* Range 3-4 */
else {
/* Range 3 */
if (isample < 24) {
istart = 5;
n = 1457;
m = 7168;
}
/* Range 4 */
else {
istart = 24;
n = 2819;
m = 1464;
}
}
}
/* Range 5-8 */
else {
/* Range 5-6 */
if (isample < 2918) {
/* Range 5 */
if (isample < 592) {
istart = 119;
n = 4210;
m = 295;
}
/* Range 6 */
else {
istart = 592;
n = 5605;
m = 60;
}
}
/* Range 7-8 */
else {
/* Range 7 */
if (isample < 15352) {
istart = 2918;
n = 7001;
m = 12;
}
/* Range 8 */
else {
istart = 15352;
n = 8439;
m = 3;
}
}
}
return n + (m * (long)(isample - istart)) / 100L;
}
/**
* A helper function for db_to_sample. Don't call it separately but
* use db_to_sample. If one or both of min and max are outside the
* range 0 <= min (or max) < 8961 the behaviour of this function is
* undefined. It may not return.
* @param int min - The minimum of the value range that is searched.
* @param int max - The maximum of the value range that is searched.
* @param int db - The value in dBfs * (-100) for which the according
* minimal peak sample is searched.
* @return int - A linear volume value with 0 <= value < MAX_PEAK
*/
static int db_to_sample_bin_search(int min, int max, int db){
int test = min + (max - min) / 2;
if (min < max) {
if (calc_db(test) < db) {
test = db_to_sample_bin_search(test, max, db);
} else {
if (calc_db(test-1) > db) {
test = db_to_sample_bin_search(min, test, db);
}
}
}
return test;
}
/**
* Converts a value representing dBfs to a linear
* scaled volume info as it is used by the MAS.
* An incredibly inefficiant function which is
* the vague inverse of calc_db. This really
* should be replaced by something better soon.
*
* @param int db - A dBfs * 100 value with
* -9000 < value <= 0
* @return int - The return value is in the range of
* 0 <= return value < MAX_PEAK
*/
static int db_to_sample(int db) {
int retval = 0;
/* what is the maximum pseudo db value */
int max_peak_db = calc_db(MAX_PEAK - 1);
/* range check: db value to big */
if (max_peak_db + db < 0) {
retval = 0;
}
/* range check: db value too small */
else if (max_peak_db + db >= max_peak_db) {
retval = MAX_PEAK -1;
}
/* value in range: find the matching linear value */
else {
retval = db_to_sample_bin_search(0, MAX_PEAK, max_peak_db + db);
/* as this is a dirty function anyway, we want to adjust the
full scale hit manually to avoid users complaining that when
they adjust maximum for 0 dBfs and display it in percent it
shows 99%. That is due to precision loss and this is the
optical fix */
}
return retval;
}
/**
* Set the min value for restriction of the value range.
* @param int newmin - depending wether dBfs is used
* newmin is a value in dBfs * 100 or in linear percent values.
* for dBfs: -9000 < newmin <= 0
* for linear: 0 <= newmin <= 100
*/
void peak_meter_set_min(int newmin) {
if (peak_meter_use_dbfs) {
peak_meter_range_min = db_to_sample(newmin);
} else {
if (newmin < peak_meter_range_max) {
peak_meter_range_min = newmin * MAX_PEAK / 100;
}
}
peak_meter_range = peak_meter_range_max - peak_meter_range_min;
db_min = calc_db(peak_meter_range_min);
db_range = db_max - db_min;
db_scale_valid = false;
}
/**
* Returns the minimum value of the range the meter
* displays. If the scale is set to dBfs it returns
* dBfs values * 100 or linear percent values.
* @return: using dBfs : -9000 < value <= 0
* using linear scale: 0 <= value <= 100
*/
int peak_meter_get_min(void) {
int retval = 0;
if (peak_meter_use_dbfs) {
retval = calc_db(peak_meter_range_min) - calc_db(MAX_PEAK - 1);
} else {
retval = peak_meter_range_min * 100 / MAX_PEAK;
}
return retval;
}
/**
* Set the max value for restriction of the value range.
* @param int newmax - depending wether dBfs is used
* newmax is a value in dBfs * 100 or in linear percent values.
* for dBfs: -9000 < newmax <= 0
* for linear: 0 <= newmax <= 100
*/
void peak_meter_set_max(int newmax) {
if (peak_meter_use_dbfs) {
peak_meter_range_max = db_to_sample(newmax);
} else {
if (newmax > peak_meter_range_min) {
peak_meter_range_max = newmax * MAX_PEAK / 100;
}
}
peak_meter_range = peak_meter_range_max - peak_meter_range_min;
db_max = calc_db(peak_meter_range_max);
db_range = db_max - db_min;
db_scale_valid = false;
}
/**
* Returns the minimum value of the range the meter
* displays. If the scale is set to dBfs it returns
* dBfs values * 100 or linear percent values
* @return: using dBfs : -9000 < value <= 0
* using linear scale: 0 <= value <= 100
*/
int peak_meter_get_max(void) {
int retval = 0;
if (peak_meter_use_dbfs) {
retval = calc_db(peak_meter_range_max) - calc_db(MAX_PEAK - 1);
} else {
retval = peak_meter_range_max * 100 / MAX_PEAK;
}
return retval;
}
/**
* Returns 1 if the meter currently is
* displaying dBfs values, 0 if the meter
* displays percent values.
* @return int - returns 0 or 1.
*/
int peak_meter_get_use_dbfs(void) {
return peak_meter_use_dbfs ? 1 : 0;
}
/**
* Specifies wether the values displayed are scaled
* as dBfs or as linear percent values.
* @param int - Set to 0 for linear percent scale. Any other value
* switches on dBfs.
*/
void peak_meter_set_use_dbfs(int use){
peak_meter_use_dbfs = ((use & 1) == 1);
db_scale_valid = false;
}
/**
* Initialize the range of the meter. Only values
* that are in the range of [range_min ... range_max]
* are displayed.
* @param bool dbfs - set to true for dBfs,
* set to false for linear scaling in percent
* @param int range_min - Specifies the lower value of the range.
* Pass a value dBfs * 100 when dbfs is set to true.
* Pass a percent value when dbfs is set to false.
* @param int range_max - Specifies the upper value of the range.
* Pass a value dBfs * 100 when dbfs is set to true.
* Pass a percent value when dbfs is set to false.
*/
void peak_meter_init_range( bool dbfs, int range_min, int range_max) {
peak_meter_use_dbfs = dbfs;
peak_meter_set_min(range_min);
peak_meter_set_max(range_max);
}
/**
* Initialize the peak meter with all relevant values concerning times.
* @param int release - Set the maximum amount of pixels the meter is allowed
* to decrease with each redraw
* @param int hold - Select the time preset for the time the peak indicator
* is reset after a peak occurred. The preset values are
* stored in max_time_out.
* @param int clip_hold - Select the time preset for the time the peak
* indicator is reset after a peak occurred. The preset
* values are stored in clip_time_out.
*/
void peak_meter_init_times(int release, int hold, int clip_hold) {
peak_meter_hold = hold;
peak_meter_release = release;
peak_meter_clip_hold = clip_hold;
}
/**
* Set the source of the peak meter to playback or to
* record.
* @param: bool playback - If true playback peak meter is used.
* If false recording peak meter is used.
*/
void peak_meter_playback(bool playback) {
#ifdef SIMULATOR
(void)playback;
#else
if (playback) {
peak_meter_src_l = MAS_REG_DQPEAK_L;
peak_meter_src_r = MAS_REG_DQPEAK_R;
} else {
peak_meter_src_l = MAS_REG_QPEAK_L;
peak_meter_src_r = MAS_REG_QPEAK_R;
}
#endif
}
/**
* Reads peak values from the MAS, and detects clips. The
* values are stored in peak_meter_l peak_meter_r for later
* evauluation. Consecutive calls to peak_meter_peek detect
* that ocurred. This function could be used by a thread for
* busy reading the MAS.
*/
inline void peak_meter_peek(void) {
#ifdef SIMULATOR
int left = 8000;
int right = 9000;
#else
/* read the peak values */
int left = mas_codec_readreg(peak_meter_src_l);
int right = mas_codec_readreg(peak_meter_src_r);
#endif
/* check for clips
An clip is assumed when two consecutive readouts
of the volume are at full scale. This is proven
to be inaccurate in both ways: it may detect clips
when no clip occurred and it may fail to detect
a real clip. */
if ((left == peak_meter_l) &&
(left == MAX_PEAK - 1)) {
peak_meter_l_clip = true;
peak_meter_clip_timeout_l =
current_tick + clip_time_out[peak_meter_clip_hold];
}
if ((right == peak_meter_r) &&
(right == MAX_PEAK - 1)) {
peak_meter_r_clip = true;
peak_meter_clip_timeout_r =
current_tick + clip_time_out[peak_meter_clip_hold];
}
/* peaks are searched -> we have to find the maximum. When
many calls of peak_meter_peek the maximum value will be
stored in peak_meter_x. This maximum is reset by the
functions peak_meter_read_x. */
peak_meter_l = MAX(peak_meter_l, left);
peak_meter_r = MAX(peak_meter_r, right);
#ifdef PM_DEBUG
peek_calls++;
#endif
}
/**
* The thread function for the peak meter calls peak_meter_peek
* to reas out the mas and find maxima, clips, etc. No display
* is performed.
*/
/*
void peak_meter_thread(void) {
sleep(5000);
while (1) {
if (peak_meter_enabled && peak_meter_use_thread){
peak_meter_peek();
}
yield();
}
}
*/
/**
* Creates the peak meter thread
*/
/*
void peak_meter_init(void) {
create_thread(
peak_meter_thread,
peak_meter_stack,
sizeof peak_meter_stack,
"peakmeter");
}
*/
/**
* Reads out the peak volume of the left channel.
* @return int - The maximum value that has been detected
* since the last call of peak_meter_read_l. The value
* is in the range 0 <= value < MAX_PEAK.
*/
static int peak_meter_read_l (void) {
/* peak_meter_l contains the maximum of
all peak values that were read by peak_meter_peek
since the last call of peak_meter_read_r */
int retval = peak_meter_l;
#ifdef PM_DEBUG
peek_calls = 0;
#endif
#ifdef SIMULATOR
peak_meter_l = 8000;
#else
/* reset peak_meter_l so that subsequent calls of
peak_meter_peek doesn't get fooled by an old
maximum value */
peak_meter_l = mas_codec_readreg(peak_meter_src_l);
#endif
return retval;
}
/**
* Reads out the peak volume of the right channel.
* @return int - The maximum value that has been detected
* since the last call of peak_meter_read_l. The value
* is in the range 0 <= value < MAX_PEAK.
*/
static int peak_meter_read_r (void) {
/* peak_meter_r contains the maximum of
all peak values that were read by peak_meter_peek
since the last call of peak_meter_read_r */
int retval = peak_meter_r;
#ifdef PM_DEBUG
peek_calls = 0;
#endif
#ifdef SIMULATOR
peak_meter_l = 8000;
#else
/* reset peak_meter_r so that subsequent calls of
peak_meter_peek doesn't get fooled by an old
maximum value */
peak_meter_r = mas_codec_readreg(peak_meter_src_r);
#endif
return retval;
}
/**
* Reset the detected clips. This method is for
* use by the user interface.
* @param int unused - This parameter was added to
* make the function compatible with set_int
*/
void peak_meter_set_clip_hold(int time) {
peak_meter_clip_eternal = false;
if (time <= 0) {
peak_meter_l_clip = false;
peak_meter_r_clip = false;
peak_meter_clip_eternal = true;
}
}
/**
* Scales a peak value as read from the MAS to the range of meterwidth.
* The scaling is performed according to the scaling method (dBfs / linear)
* and the range (peak_meter_range_min .. peak_meter_range_max).
* @param unsigned short val - The volume value. Range: 0 <= val < MAX_PEAK
* @param int meterwidht - The widht of the meter in pixel
* @return unsigned short - A value 0 <= return value <= meterwidth
*/
unsigned short peak_meter_scale_value(unsigned short val, int meterwidth){
int retval;
if (val <= peak_meter_range_min) {
return 0;
}
if (val >= peak_meter_range_max) {
return meterwidth;
}
retval = val;
/* different scaling is used for dBfs and linear percent */
if (peak_meter_use_dbfs) {
/* scale the samples dBfs */
retval = (calc_db(retval) - db_min) * meterwidth / db_range;
}
/* Scale for linear percent display */
else
{
/* scale the samples */
retval = ((retval - peak_meter_range_min) * meterwidth)
/ peak_meter_range;
}
return retval;
}
/**
* Draws a peak meter in the specified size at the specified position.
* @param int x - The x coordinate.
* Make sure that 0 <= x and x + width < LCD_WIDTH
* @param int y - The y coordinate.
* Make sure that 0 <= y and y + height < LCD_HEIGHT
* @param int width - The width of the peak meter. Note that for display
* of clips a 3 pixel wide area is used ->
* width > 3
* @param int height - The height of the peak meter. height > 3
*/
void peak_meter_draw(int x, int y, int width, int height) {
int left = 0, right = 0;
static int last_left = 0, last_right = 0;
int meterwidth = width - 3;
int i;
#ifdef PM_DEBUG
static long pm_tick = 0;
int tmp = peek_calls;
#endif
/* if disabled only draw the peak meter */
if (peak_meter_enabled) {
/* read the volume info from MAS */
left = peak_meter_read_l();
right = peak_meter_read_r();
/*peak_meter_peek();*/
/* scale the samples dBfs */
left = peak_meter_scale_value(left, meterwidth);
right = peak_meter_scale_value(right, meterwidth);
/* if the scale has changed -> recalculate the scale
(The scale becomes invalid when the range changed.) */
if (!db_scale_valid){
if (peak_meter_use_dbfs) {
db_scale_count = DB_SCALE_SRC_VALUES_SIZE;
for (i = 0; i < db_scale_count; i++){
/* find the real x-coords for predefined interesting
dBfs values. These only are recalculated when the
scaling of the meter changed. */
db_scale_lcd_coord[i] =
peak_meter_scale_value(
db_scale_src_values[i],
meterwidth - 1);
}
}
/* when scaling linear we simly make 10% steps */
else {
db_scale_count = 10;
for (i = 0; i < db_scale_count; i++) {
db_scale_lcd_coord[i] =
(i * (MAX_PEAK / 10) - peak_meter_range_min) *
meterwidth / peak_meter_range;
}
}
/* mark scale valid to avoid recalculating dBfs values
of the scale. */
db_scale_valid = true;
}
/* apply release */
left = MAX(left , last_left - peak_meter_release);
right = MAX(right, last_right - peak_meter_release);
/* reset max values after timeout */
if (TIME_AFTER(current_tick, peak_meter_timeout_l)){
peak_meter_max_l = 0;
}
if (TIME_AFTER(current_tick, peak_meter_timeout_r)){
peak_meter_max_r = 0;
}
if (!peak_meter_clip_eternal) {
if (peak_meter_l_clip &&
TIME_AFTER(current_tick, peak_meter_clip_timeout_l)){
peak_meter_l_clip = false;
}
if (peak_meter_r_clip &&
TIME_AFTER(current_tick, peak_meter_clip_timeout_r)){
peak_meter_r_clip = false;
}
}
/* check for new max values */
if (left > peak_meter_max_l) {
peak_meter_max_l = left - 1;
peak_meter_timeout_l =
current_tick + max_time_out[peak_meter_hold];
}
if (right > peak_meter_max_r) {
peak_meter_max_r = right - 1;
peak_meter_timeout_r =
current_tick + max_time_out[peak_meter_hold];
}
}
/* draw the peak meter */
lcd_clearrect(x, y, width, height);
/* draw left */
lcd_fillrect (x, y, left, height / 2 - 2 );
if (peak_meter_max_l > 0) {
lcd_drawline(x + peak_meter_max_l, y,
x + peak_meter_max_l, y + height / 2 - 2 );
}
if (peak_meter_l_clip) {
lcd_fillrect(x + meterwidth, y, 3, height / 2 - 1);
}
/* draw right */
lcd_fillrect(x, y + height / 2 + 1, right, height / 2 - 2);
if (peak_meter_max_r > 0) {
lcd_drawline( x + peak_meter_max_r, y + height / 2,
x + peak_meter_max_r, y + height - 2);
}
if (peak_meter_r_clip) {
lcd_fillrect(x + meterwidth, y + height / 2, 3, height / 2 - 1);
}
/* draw scale end */
lcd_drawline(x + meterwidth, y,
x + meterwidth, y + height - 2);
/* draw dots for scale marks */
for (i = 0; i < db_scale_count; i++) {
/* The x-coordinates of interesting scale mark points
have been calculated before */
lcd_invertpixel(db_scale_lcd_coord[i], y + height / 2 - 1);
}
#ifdef PM_DEBUG
/* display a bar to show how many calls to peak_meter_peek
have ocurred since the last display */
lcd_invertrect(x, y, tmp, 3);
if (tmp < PEEKS_PER_DRAW_SIZE) {
peeks_per_redraw[tmp]++;
}
tmp = current_tick - pm_tick;
if (tmp < TICKS_PER_DRAW_SIZE ){
ticks_per_redraw[tmp] ++;
}
/* display a bar to show how many ticks have passed since
the last redraw */
lcd_invertrect(x, y + height / 2, current_tick - pm_tick, 2);
pm_tick = current_tick;
#endif
last_left = left;
last_right = right;
}
#ifdef PM_DEBUG
static void peak_meter_clear_histogram(void) {
int i = 0;
for (i = 0; i < TICKS_PER_DRAW_SIZE; i++) {
ticks_per_redraw[i] = (unsigned int)0;
}
for (i = 0; i < PEEKS_PER_DRAW_SIZE; i++) {
peeks_per_redraw[i] = (unsigned int)0;
}
}
bool peak_meter_histogram(void) {
int i;
int btn = BUTTON_NONE;
while ((btn & BUTTON_OFF) != BUTTON_OFF )
{
unsigned int max = 0;
int y = 0;
int x = 0;
lcd_clear_display();
for (i = 0; i < PEEKS_PER_DRAW_SIZE; i++) {
max = MAX(max, peeks_per_redraw[i]);
}
for (i = 0; i < PEEKS_PER_DRAW_SIZE; i++) {
x = peeks_per_redraw[i] * (LCD_WIDTH - 1)/ max;
lcd_drawline(0, y + i, x, y + i);
}
y = PEEKS_PER_DRAW_SIZE + 1;
max = 0;
for (i = 0; i < TICKS_PER_DRAW_SIZE; i++) {
max = MAX(max, ticks_per_redraw[i]);
}
for (i = 0; i < TICKS_PER_DRAW_SIZE; i++) {
x = ticks_per_redraw[i] * (LCD_WIDTH - 1)/ max;
lcd_drawline(0, y + i, x, y + i);
}
lcd_update();
btn = button_get(true);
if (btn == BUTTON_PLAY) {
peak_meter_clear_histogram();
}
}
return false;
}
#endif