joshua/spectogram-prototype
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(committing very old stuff) Lots of changes, no clue

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This commit is contained in:
Joshua Moerman 2016-02-28 19:48:29 +00:00
parent 276e840682
commit 61f4cc724b
11 changed files with 132 additions and 20 deletions
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2
SpectogramPrototype/AudioFile.h
View file

@ -16,6 +16,6 @@
+ (AudioFile*) audioFileFromURL:(NSURL*) url;
// Reads nSamples of data (left channel), return actual number of samples read
- (unsigned int) fillLeft:(float*)left andRight:(float*)right withNumberOfSamples:(unsigned int)nSamples;
- (BOOL) fillLeft:(float*)left andRight:(float*)right forRange:(NSRange)range;
@end

83
SpectogramPrototype/AudioFile.m
View file

@ -9,12 +9,29 @@
#import "AudioFile.h"
@import AudioToolbox.ExtendedAudioFile;
static const size_t buffer_size = 1 << 12;
@interface Buffer : NSObject {
@public
float left[buffer_size];
float right[buffer_size];
NSRange range;
}
@end
@implementation Buffer
@end
@interface AudioFile (){
ExtAudioFileRef audioFile;
AudioStreamBasicDescription format;
NSMutableArray * buffers;
}
- (id)initWithExtAudioFileRef:(ExtAudioFileRef) audioFile;
- (void)setupFormat;
- (Buffer*)getBufferForSample:(NSUInteger) sample;
- (Buffer*)appendBuffer;
@end
@implementation AudioFile
@ -25,6 +42,7 @@
- (id)initWithExtAudioFileRef:(ExtAudioFileRef) af{
if(self = [super init]){
audioFile = af;
buffers = [[NSMutableArray alloc] init];
[self setupFormat];
}
return self;
@ -59,22 +77,45 @@
return [[AudioFile alloc] initWithExtAudioFileRef:audioFile];
}
#pragma mark
#pragma mark Usage
- (Buffer *)getBufferForSample:(NSUInteger)sample{
for (Buffer * b in buffers) {
if(NSLocationInRange(sample, b->range)){
return b;
}
}
- (unsigned int)fillLeft:(float *)left andRight:(float *)right withNumberOfSamples:(unsigned int)nSamples {
AudioBufferList bufferList;
while(1){
Buffer * b = [self appendBuffer];
if(!b) return nil;
if(NSLocationInRange(sample, b->range)) return b;
}
}
- (Buffer *)appendBuffer{
Buffer * b = [[Buffer alloc] init];
Buffer * last = [buffers lastObject];
if(last){
b->range.location = last->range.location + last->range.length;
} else {
b->range.location = 0;
}
AudioBufferList bufferList;
bufferList.mNumberBuffers = 1;
bufferList.mBuffers[0].mNumberChannels = 2;
bufferList.mBuffers[0].mDataByteSize = nSamples * format.mBytesPerFrame;
bufferList.mBuffers[0].mDataByteSize = buffer_size * format.mBytesPerFrame;
bufferList.mBuffers[0].mData = calloc(bufferList.mBuffers[0].mDataByteSize, 1);
UInt32 nFrames = nSamples;
UInt32 nFrames = buffer_size;
OSStatus err = ExtAudioFileRead(audioFile, &nFrames, &bufferList);
assert(err == 0);
short * buffer = bufferList.mBuffers[0].mData;
float * leftEnd = left + nSamples;
float * left = b->left;
float * right = b->right;
float * leftEnd = left + buffer_size;
for(unsigned int i = 0; i < nFrames; ++i){
*left++ = *buffer++ / 32768.0f;
*right++ = *buffer++ / 32768.0f;
@ -85,10 +126,34 @@
*left++ = 0;
*right++ = 0;
}
b->range.length = nFrames;
free(bufferList.mBuffers[0].mData);
return nFrames;
if(!nFrames) return nil;
[buffers addObject:b];
return b;
}
#pragma mark
#pragma mark Usage
- (BOOL)fillLeft:(float *)left andRight:(float *)right forRange:(NSRange)range{
NSUInteger n = range.length;
Buffer * b = nil;
while ((b = [self getBufferForSample:range.location])) {
while(range.length && NSLocationInRange(range.location, b->range)){
*left++ = b->left[range.location - b->range.location];
*right++ = b->right[range.location - b->range.location];
range.location++;
range.length--;
}
if(range.length == 0) break;
}
return range.length < n;
}
@end

9
SpectogramPrototype/Base.lproj/Main_iPad.storyboard
View file

@ -1,5 +1,5 @@
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="4514" systemVersion="13B42" targetRuntime="iOS.CocoaTouch.iPad" propertyAccessControl="none" useAutolayout="YES" initialViewController="DUW-zh-mwd">
<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="4514" systemVersion="13C64" targetRuntime="iOS.CocoaTouch.iPad" propertyAccessControl="none" useAutolayout="YES" initialViewController="DUW-zh-mwd">
<dependencies>
<plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="3747"/>
</dependencies>
@ -43,6 +43,13 @@
<action selector="resetView:" destination="DUW-zh-mwd" eventType="touchUpInside" id="xv9-4L-1Ve"/>
</connections>
</button>
<slider opaque="NO" contentMode="scaleToFill" fixedFrame="YES" contentHorizontalAlignment="center" contentVerticalAlignment="center" value="440" minValue="400" maxValue="480" translatesAutoresizingMaskIntoConstraints="NO" id="ywc-Ak-o9S">
<rect key="frame" x="20" y="100" width="200" height="34"/>
<autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMaxY="YES"/>
<connections>
<action selector="tuningChanged:" destination="DUW-zh-mwd" eventType="valueChanged" id="ed0-8G-vOh"/>
</connections>
</slider>
</subviews>
<color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="calibratedWhite"/>
<constraints>

2
SpectogramPrototype/FFTTest.m
View file

@ -17,7 +17,7 @@
@end
const int logN = 12;
const int logN = 13;
const int N = 1 << logN;
const float scaling = 1.0 / N;

1
SpectogramPrototype/RuledScrollView.m
View file

@ -54,6 +54,7 @@
frame3.size.width = rulerWidth;
leftRuler = [[VerticalRuler alloc] initWithFrame:frame3];
leftRuler.layer.opacity = 0.5;
[(VerticalRuler*)leftRuler setTuning: 440.0f];
[self addSubview:leftRuler];
}

1
SpectogramPrototype/Ruler.h
View file

@ -21,4 +21,5 @@ typedef struct Interval {
@end
@interface VerticalRuler : AbstractRuler
@property (nonatomic) float tuning;
@end

20
SpectogramPrototype/Ruler.m
View file

@ -63,6 +63,12 @@
@implementation VerticalRuler
@synthesize tuning;
- (void)setTuning:(float)tuning_{
tuning = tuning_;
[self setNeedsDisplay];
}
- (UIColor*)colorForKey:(int)j{
switch (j) {
@ -90,22 +96,22 @@
const CGFloat d = visibleInterval.end - visibleInterval.begin;
const CGFloat f = 44100;
const CGFloat N = 1 << 12;
const CGFloat height = (1 << 12) >> 3;
const CGFloat N = 1 << 13;
const CGFloat height = (1 << 13) >> 3;
for(int i = 220; i < 44100/8; i *= 2){
for(int i = 110; i < 44100/8; i *= 2){
for(int j = 0; j < 12; ++j){
const CGFloat k = i * pow(2, j/12.0);
const CGFloat k = (tuning/440.0) * i * pow(2, j/12.0);
const CGFloat y = N*k/f;
const CGFloat y2 = (height - y);
const CGFloat gy = 1024 * (y2 - visibleInterval.begin) / d;
const CGFloat gy = self.bounds.size.height * (y2 - visibleInterval.begin) / d;
[[self colorForKey:j] setFill];
if([UIScreen isRetinaDisplay]){
UIRectFill(CGRectMake(0, gy-0.5, self.bounds.size.width, 1.0));
UIRectFill(CGRectMake(0, gy, self.bounds.size.width, 0.5));
} else {
UIRectFill(CGRectMake(0, gy-1, self.bounds.size.width, 2.0));
UIRectFill(CGRectMake(0, gy, self.bounds.size.width, 1.0));
}
}
}

5
SpectogramPrototype/Spectographer.m
View file

@ -19,6 +19,7 @@ uint8_t clamp_to_uint8(float x){
@interface Spectographer (){
FFTTest * FFTHandler;
AudioFile * audioFile;
NSUInteger sample;
float * left;
float * right;
}
@ -31,6 +32,7 @@ uint8_t clamp_to_uint8(float x){
- (id)init{
if(self = [super init]){
FFTHandler = [[FFTTest alloc] init];
sample = 0;
left = calloc(FFTHandler.acceptedSize, sizeof(float));
right = calloc(FFTHandler.acceptedSize, sizeof(float));
}
@ -63,7 +65,7 @@ uint8_t clamp_to_uint8(float x){
unsigned int x = 0;
for(; x < width; ++x){
if(![audioFile fillLeft:left andRight:right withNumberOfSamples:size])
if(![audioFile fillLeft:left andRight:right forRange:NSMakeRange(sample, size)])
break;
[FFTHandler inPlaceFFT:left forSize:size];
[FFTHandler inPlaceFFT:right forSize:size];
@ -74,6 +76,7 @@ uint8_t clamp_to_uint8(float x){
rgba[4*width*yy + 4*x + 2] = clamp_to_uint8(10.0f * (left[y] + right[y]));
rgba[4*width*yy + 4*x + 3] = 0;
}
sample += size / 8;
}
if(!x){
free(rgba);

1
SpectogramPrototype/ViewController.h
View file

@ -17,5 +17,6 @@
- (IBAction)mediaButtonPressed:(UIButton*)sender;
- (IBAction)resetView:(id)sender;
- (IBAction)tuningChanged:(UISlider*)sender;
@end

5
SpectogramPrototype/ViewController.m
View file

@ -11,6 +11,7 @@
#import "ViewController.h"
#import "RuledScrollView.h"
#import "Spectographer.h"
#import "Ruler.h"
typedef enum {
iPad,
@ -175,4 +176,8 @@ device get_device(){
[mediaPicker dismissViewControllerAnimated:YES completion:nil];
}
- (void)tuningChanged:(UISlider*)sender{
[(VerticalRuler*)scrollView.leftRuler setTuning:sender.value];
}
@end

23
Untitled.md Normal file
View file

@ -0,0 +1,23 @@
### Output of FFT:
```
{[DC,NY],C[1],C[2],...,C[n/2]}
```
### On a sample basis
Let ps stand for "per sample"
``` C[1] ``` gives the ```1/N``` ps coefficient
``` C[2] ``` gives the ```2/N``` ps coefficient
``` C[N/2] ``` gives the ```1/2``` ps coefficient ### In seconds Let ```f``` (=44100) be the samplerate. Then:
``` C[1] ``` gives the ```f/N``` hz coefficient
``` C[2] ``` gives the ```2f/N``` hz coefficient
``` C[N/2] ``` gives the ```f/2``` hz coefficient
### From herz to position
Let ```h``` be some frequency. Then from the above we see that for ``` m := Nh/f ``` we get the ```mf/N = h``` hz coefficient in ``` C[m]```.