spectogram-prototype/SpectogramPrototype/ViewController.m

//
//  ViewController.m
//  SpectogramPrototype
//
//  Created by Joshua Moerman on 21/12/13.
//  Copyright (c) 2013 Joshua Moerman. All rights reserved.
//

#import <MediaPlayer/MPMediaPickerController.h>
#import <AudioToolbox/ExtendedAudioFile.h>

#import "ViewController.h"
#import "RuledScrollView.h"
#import "FFTTest.h"
#import "AudioFile.h"

typedef enum {
	iPad,
	iPod,
	Simulator
} device;

// NOTE: the simulator has no media, so we cant use MPMediaPicker
// and the iPad has to use a popover, while the iPod/iPhone doesn't
// So that's why we check the device
device get_device(){
	device device = iPad;
	
	NSRange range = [[[UIDevice currentDevice] model] rangeOfString:@"Simulator"];
	if(range.location != NSNotFound) {
		device = Simulator;
	}

	if([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone){
		device = iPod;
	}
	
	return device;
}

UInt8 clamp_to_uint8(float x){
	if(x >= 1.0) return 255;
	if(x <= 0.0) return 0;
	return 255.0 * x;
}

@interface ViewController () <MPMediaPickerControllerDelegate> {
	UIPopoverController * pop;
	FFTTest * fft_handler;
	float * data;
}
- (void) openAudioFile:(NSURL*)filePath;
@property (nonatomic, strong) UILabel* header;
@end

@implementation ViewController

@synthesize scrollView, contentView, header;

- (void)viewDidLoad{
	[super viewDidLoad];
	
	if(!contentView){
		[[NSBundle mainBundle] loadNibNamed:@"ContentView" owner:self options:nil];
		[scrollView.content addSubview:contentView];
		contentView.autoresizingMask = UIViewAutoresizingNone;
		scrollView.contentSize = contentView.bounds.size;
	}
}

- (void)didReceiveMemoryWarning{
	[super didReceiveMemoryWarning];
}

- (void)openAudioFile:(NSURL *)filePath{
	AudioFile * audioFile = [AudioFile audioFileFromURL:filePath];
	
	if(!fft_handler)
		fft_handler = [[FFTTest alloc] init];
	
	unsigned int size = fft_handler.acceptedSize;
	unsigned int width = size/4;
	unsigned int height = size/8;
	
	if(!data)
		data = calloc(size, sizeof(float));
	
	char * rgba = calloc(width*height*4, sizeof(char));
	
	for(unsigned int x = 0; x < width; ++x){
		[audioFile fillArray:data withNumberOfSamples:size];
		[fft_handler inPlaceFFT:data forSize:size];
		for(unsigned int y = 0; y < height; ++y){
			unsigned int yy = height - y - 1;
			rgba[4*width*yy + 4*x + 0] = clamp_to_uint8(100.0 * data[y]);
			rgba[4*width*yy + 4*x + 1] = clamp_to_uint8(50.0 * data[y]);
			rgba[4*width*yy + 4*x + 2] = clamp_to_uint8(10.0 * data[y]);
			rgba[4*width*yy + 4*x + 3] = 0;
		}
	}
	
	CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
	assert(colorSpace);
	CGContextRef bitmapContext = CGBitmapContextCreate(rgba, width, height, 8, 4*width, colorSpace, (CGBitmapInfo)kCGImageAlphaNoneSkipLast);
	assert(bitmapContext);
	CGImageRef cgImage = CGBitmapContextCreateImage(bitmapContext);
	assert(cgImage);
	UIImage * newUIImage = [UIImage imageWithCGImage:cgImage];
	assert(newUIImage);
	
	CGColorSpaceRelease(colorSpace);
	CGContextRelease(bitmapContext);
	CGImageRelease(cgImage);
	free(rgba);
	
	UIImageView * view = [[UIImageView alloc] initWithImage:newUIImage];
	view.frame = CGRectMake(0, 0, width, height);
	
	[contentView removeFromSuperview];
	contentView = view;
	
	[scrollView.content addSubview:contentView];
	contentView.autoresizingMask = UIViewAutoresizingNone;
	scrollView.contentSize = contentView.bounds.size;
}

- (void)mediaButtonPressed:(UIButton*)sender{
	MPMediaPickerController * mppc = nil;
	device device = get_device();
	
	switch (device) {
		case iPad:
			mppc = [[MPMediaPickerController alloc] initWithMediaTypes:MPMediaTypeAnyAudio];
			mppc.delegate = self;
			mppc.allowsPickingMultipleItems = NO;
			mppc.showsCloudItems = NO;
			
			if(pop){
				[pop dismissPopoverAnimated:YES];
				pop = nil;
			}
			
			pop = [[UIPopoverController alloc] initWithContentViewController:mppc];
			[pop presentPopoverFromRect:sender.frame inView:self.view permittedArrowDirections:UIPopoverArrowDirectionAny animated:YES];
			break;
		case iPod:
			mppc = [[MPMediaPickerController alloc] initWithMediaTypes:MPMediaTypeAnyAudio];
			mppc.delegate = self;
			mppc.allowsPickingMultipleItems = NO;
			mppc.showsCloudItems = NO;
			
			[self presentViewController:mppc animated:YES completion:nil];
			break;
		case Simulator:
			NSLog(@"WARNING: No MPMediaPicker in Simulator, opening some file");
			[self openAudioFile:[[NSBundle mainBundle] URLForResource:@"testMusic" withExtension:@".mp3"]];
			break;
	}
}

- (void)mediaPicker:(MPMediaPickerController *)mediaPicker didPickMediaItems:(MPMediaItemCollection *)mediaItemCollection {
	for(MPMediaItem * mediaItem in mediaItemCollection.items){
		NSURL * url = [mediaItem valueForProperty:MPMediaItemPropertyAssetURL];
		[self openAudioFile:url];
	}
	[pop dismissPopoverAnimated:YES];
	pop = nil;
}

- (void)mediaPickerDidCancel:(MPMediaPickerController *)mediaPicker {
	[pop dismissPopoverAnimated:YES];
	pop = nil;
}

@end