    afconvert -f caff -d LEI16@44100 -c 1 in.wav out.caf

References:

- Apple&#39;s [Multimedia Programming Guide: Using Audio: Preferred Audio Formats in iOS](https://developer.apple.com/library/ios/documentation/audiovideo/conceptual/multimediapg/usingaudio/usingaudio.html#//apple_ref/doc/uid/TP40009767-CH2-SW28)
- [afconvert(1) man page](https://developer.apple.com/library/mac/documentation/Darwin/Reference/Manpages/man1/afconvert.1.html) (use `afconvert -h` for complete info)

Simple bash script to convert the mp3 files in a folder to caf for iphone

    #!/bin/bash
    for f in *.mp3; do
      echo &quot;Processing $f file...&quot;
      afconvert -f caff -d LEI16@44100 -c 1 &quot;$f&quot; &quot;${f/mp3/caf}&quot;
    done



this is the best for size:

&gt; afconvert -f caff -d ima4 original.wav


thanks for the info.

also, if you&#39;re looking into additional compression with openAL, this might be of interest:

&quot;iPhone, OpenAL, and IMA4/ADPCM&quot;
http://www.wooji-juice.com/blog/iphone-openal-ima4-adpcm.html

It looks like the -c is not working today, I got it with following:
&gt; afconvert -f caff -d LEI16 input.m4a output.caf

My WinForms app uses a number of [BackgroundWorker][1] objects to retrieve information from a database. I&#39;m using BackgroundWorker because it allows the UI to remain unblocked during long-running database queries and it simplifies the threading model for me.

I&#39;m getting occasional DatabaseExceptions in some of these background threads, and I have witnessed at least one of these exceptions in a worker thread while debugging.  I&#39;m fairly confident these exceptions are timeouts which I suppose its reasonable to expect from time to time.

My question is about what happens when an unhandled exception occurs in one of these background worker threads.

I don&#39;t think I can catch an exception in another thread, but can I expect my WorkerCompleted method to be executed?  Is there any property or method of the BackgroundWorker I can interrogate for exceptions?


  [1]: http://msdn.microsoft.com/en-us/library/system.componentmodel.backgroundworker.aspx

Unhandled exceptions in BackgroundWorker

In C++, a function&#39;s signature depends partly on whether or not it&#39;s const.  This means that a class can have two member functions with identical signatures except that one is const and the other is not.  If you have a class like this, then the compiler will decide which function to call based on the object you call it on: if it&#39;s a const instance of the class, the const version of the function will be called; if the object isn&#39;t const, the other version will be called.

In what circumstances might you want to take advantage of this feature?

What is the use of const overloading in C++?

I am using the SoundEngine sample code from Apple in the CrashLanding sample to play back multiple audio files. Using the sample caf files included with CrashLanding everything works fine but when I try and use my own samplesconverted to CAF using afconvert all I get is a stony silence ;)
 
Does anyone have settings for afconvert that will produce a CAF file capable of being played back through OpenAL?

Converting audio to CAF format for playback on iPhone using OpenAL

<p>I am using the SoundEngine sample code from Apple in the CrashLanding sample to play back multiple audio files. Using the sample caf files included with CrashLanding everything works fine but when I try and use my own samplesconverted to CAF using afconvert all I get is a stony silence ;)</p>
<p>Does anyone have settings for afconvert that will produce a CAF file capable of being played back through OpenAL?</p>


__General Description:__

To start with what works, I have a `UITableView` which has been placed onto an Xcode-generated view using Interface Builder.  The view&#39;s File Owner is set to an Xcode-generated subclass of `UIViewController`.  To this subclass I have added working implementations of `numberOfSectionsInTableView: tableView:numberOfRowsInSection:` and `tableView:cellForRowAtIndexPath:` and the Table View&#39;s `dataSource` and `delegate` are connected to this class via the File Owner in Interface Builder.

The above configuration works with no problems.  The issue occurs when I want to move this Table View&#39;s `dataSource` and `delegate`-implementations out to a separate class, most likely because there are other controls on the View besides the Table View and I&#39;d like to move the Table View-related code out to its own class.  To accomplish this, I try the following:

 - Create a new subclass of `UITableViewController` in Xcode&lt;/li&gt;
 - Move the known-good implementations of `numberOfSectionsInTableView:`, `tableView:numberOfRowsInSection:` and `tableView:cellForRowAtIndexPath:` to the new subclass
 - Drag a `UITableViewController` to the top level of the  _existing_ XIB in InterfaceBuilder, delete the `UIView`/`UITableView` that are automatically created for this `UITableViewController`, then set the `UITableViewController`&#39;s class to match the new subclass
 - Remove the previously-working `UITableView`&#39;s existing `dataSource` and `delegate` connections and connect them to the new `UITableViewController`

When complete, I do not have a working `UITableView`.  I end up with one of three outcomes which can seemingly happen at random:

 - When the `UITableView` loads, I get a runtime error indicating I am sending `tableView:cellForRowAtIndexPath:` to an object which does not recognize it
 - When the `UITableView` loads, the project breaks into the debugger without error
 - There is no error, but the `UITableView` does not appear

With some debugging and having created a basic project just to reproduce this issue, I am usually seeing the 3rd option above (no error but no visible table view).  I added some NSLog calls and found that although `numberOfSectionsInTableView:` and `numberOfRowsInSection:` are both getting called, `cellForRowAtIndexPath:` is not.  I am convinced I&#39;m missing something really simple and was hoping the answer may be obvious to someone with more experience than I have.  If this doesn&#39;t turn out to be an easy answer I would be happy to update with some code or a sample project.  Thanks for your time!

__Complete steps to reproduce:__

 - Create a new iPhone OS, View-Based Application in Xcode and call it `TableTest`
 - Open `TableTestViewController.xib` in Interface Builder and drag a `UITableView` onto the provided view surface.
 - Connect the `UITableView`&#39;s `dataSource` and `delegate`-outlets to File&#39;s Owner, which should already represent the `TableTestViewController`-class.  Save your changes
 - Back in Xcode, add the following code to `TableTestViewController.m:`

------

    - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
        NSLog(@&quot;Returning num sections&quot;);
        return 1;
    }
    - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
        NSLog(@&quot;Returning num rows&quot;);
        return 1;
    }
    - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
        NSLog(@&quot;Trying to return cell&quot;);
        static NSString *CellIdentifier = @&quot;Cell&quot;;
    
        UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
        if (cell == nil) {
            cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:CellIdentifier] autorelease];
        }
        cell.text = @&quot;Hello&quot;;
        NSLog(@&quot;Returning cell&quot;);
        return cell;
    }

 - Build and Go, and you should see the word `Hello` appear in the `UITableView`

 - Now to attempt to move this `UITableView`&#39;s logic out to a separate class, first create a new file in Xcode, choosing `UITableViewController` subclass and calling the class `TableTestTableViewController`
 - Remove the above code snippet from `TableTestViewController.m` and place it into `TableTestTableViewController.m`, replacing the default implementation of these three methods with ours.
 - Back in Interface Builder within the same `TableTestViewController.xib`-file, drag a `UITableViewController` into the main IB window and delete the new `UITableView` object that automatically came with it
 - Set the class for this new `UITableViewController` to `TableTestTableViewController`
 - Remove the `dataSource` and `delegate` bindings from the existing, previously-working `UITableView` and reconnect the same two bindings to the new `TableTestTableViewController` we created.
 - Save changes, Build and Go, and if you&#39;re getting the results I&#39;m getting, note the `UITableView` no longer functions properly

__Solution:__
With some more troubleshooting and some assistance from the [iPhone Developer Forums](https://devforums.apple.com/message/5453), I&#39;ve documented a solution!  The main `UIViewController` subclass of the project needs an outlet pointing to the `UITableViewController` instance.  To accomplish this, simply add the following to the primary view&#39;s header (`TableTestViewController.h`):

    #import &quot;TableTestTableViewController.h&quot;

and

    IBOutlet TableTestTableViewController *myTableViewController;

Then, in Interface Builder, connect the new outlet from File&#39;s Owner to `TableTestTableViewController` in the main IB window.  No changes are necessary in the UI part of the XIB.  Simply having this outlet in place, even though no user code directly uses it, resolves the problem completely.  Thanks to those who&#39;ve helped and credit goes to BaldEagle on the iPhone Developer Forums for finding the solution.

UITableView issue when using separate delegate/dataSource

I am trying to load `UIImage` object from `NSData`, and the sample code was to `NSImage`, I guess they should be the same. But just now loading the image, I am wondering what&#39;s the best to troubleshoot the `UIImage` loading `NSData` issue.

NSData and UIImage

I try to get rounded corners on a UIImage, what I read so far, the easiest way is to use a mask images. For this I used code from TheElements iPhone Example and some image resize code I found. My problem is that resizedImage is always nil and I don&#39;t find the error...

    - (UIImage *)imageByScalingProportionallyToSize:(CGSize)targetSize
    {
    	CGSize imageSize = [self size];
    	float width = imageSize.width;
    	float height = imageSize.height;
    	
    	// scaleFactor will be the fraction that we&#39;ll
    	// use to adjust the size. For example, if we shrink
    	// an image by half, scaleFactor will be 0.5. the
    	// scaledWidth and scaledHeight will be the original,
    	// multiplied by the scaleFactor.
    	//
    	// IMPORTANT: the &quot;targetHeight&quot; is the size of the space
    	// we&#39;re drawing into. The &quot;scaledHeight&quot; is the height that
    	// the image actually is drawn at, once we take into
    	// account the ideal of maintaining proportions
    	
    	float scaleFactor = 0.0; 
    	float scaledWidth = targetSize.width;
    	float scaledHeight = targetSize.height;
    	
    	CGPoint thumbnailPoint = CGPointMake(0,0);
    	
    	// since not all images are square, we want to scale
    	// proportionately. To do this, we find the longest
    	// edge and use that as a guide.
    	
    	if ( CGSizeEqualToSize(imageSize, targetSize) == NO )
    	{ 
    		// use the longeset edge as a guide. if the
    		// image is wider than tall, we&#39;ll figure out
    		// the scale factor by dividing it by the
    		// intended width. Otherwise, we&#39;ll use the
    		// height.
    		
    		float widthFactor = targetSize.width / width;
    		float heightFactor = targetSize.height / height;
    		
    		if ( widthFactor &lt; heightFactor )
    			scaleFactor = widthFactor;
    		else
    			scaleFactor = heightFactor;
    		
    		// ex: 500 * 0.5 = 250 (newWidth)
    		
    		scaledWidth = width * scaleFactor;
    		scaledHeight = height * scaleFactor;
    		
    		// center the thumbnail in the frame. if
    		// wider than tall, we need to adjust the
    		// vertical drawing point (y axis)
    		
    		if ( widthFactor &lt; heightFactor )
    			thumbnailPoint.y = (targetSize.height - scaledHeight) * 0.5;
    		
    		else if ( widthFactor &gt; heightFactor )
    			thumbnailPoint.x = (targetSize.width - scaledWidth) * 0.5;
    	}
    	
    	
    	CGContextRef mainViewContentContext;
        CGColorSpaceRef colorSpace;
    	
        colorSpace = CGColorSpaceCreateDeviceRGB();
    	
    	// create a bitmap graphics context the size of the image
        mainViewContentContext = CGBitmapContextCreate (NULL, targetSize.width, targetSize.height, 8, 0, colorSpace, kCGImageAlphaPremultipliedLast);
    	
    	// free the rgb colorspace
        CGColorSpaceRelease(colorSpace);	
    	
    	if (mainViewContentContext==NULL)
    		return NULL;

    	//CGContextSetFillColorWithColor(mainViewContentContext, [[UIColor whiteColor] CGColor]);
    	//CGContextFillRect(mainViewContentContext, CGRectMake(0, 0, targetSize.width, targetSize.height));
    	
    	CGContextDrawImage(mainViewContentContext, CGRectMake(thumbnailPoint.x, thumbnailPoint.y, scaledWidth, scaledHeight), self.CGImage);
    
    	// Create CGImageRef of the main view bitmap content, and then
    	// release that bitmap context
    	CGImageRef mainViewContentBitmapContext = CGBitmapContextCreateImage(mainViewContentContext);
    	CGContextRelease(mainViewContentContext);
    	
    	CGImageRef maskImage = [[UIImage imageNamed:@&quot;Mask.png&quot;] CGImage];
    	
    	CGImageRef resizedImage = CGImageCreateWithMask(mainViewContentBitmapContext, maskImage);
    	CGImageRelease(mainViewContentBitmapContext);
    	
    	// convert the finished resized image to a UIImage 
    	UIImage *theImage = [UIImage imageWithCGImage:resizedImage];

    	// image is retained by the property setting above, so we can 
    	// release the original
    	CGImageRelease(resizedImage);
    	
    	// return the image
    	return theImage;
    }

UIImage rounded corners

The simple HTML below displays differently in Firefox and WebKit-based browsers (I checked in Safari, Chrome and iPhone). 

In Firefox both border and text have the same color (`#880000`), but in Safari the text gets a bit lighter (as if it had some transparency applied to it). 

Can I somehow fix this (remove this transparency in Safari)?

&lt;!-- begin snippet: js hide: false console: true babel: false --&gt;

&lt;!-- language: lang-html --&gt;

    &lt;html xmlns=&quot;http://www.w3.org/1999/xhtml&quot;&gt;
        &lt;head&gt;
            &lt;title&gt;&lt;/title&gt;
            &lt;style type=&quot;text/css&quot;&gt;
            input:disabled{
                border:solid 1px #880000;
                background-color:#ffffff;
                color:#880000;
            }
            &lt;/style&gt;
        &lt;/head&gt;
        &lt;body&gt;
            &lt;form action=&quot;&quot;&gt;
                &lt;input type=&quot;text&quot; value=&quot;disabled input box&quot; disabled=&quot;disabled&quot;/&gt;
            &lt;/form&gt;
        &lt;/body&gt;
    &lt;/html&gt;

&lt;!-- end snippet --&gt;



Disabled input text color on iOS

I&#39;m all for language diversity, but Objective C is insane. So I&#39;m curious: is it possible to code iPhone apps with C++ while using the Cocoa API, etc?

Is it possible to program iPhone in C++

Is there any way we can convert text to speech in an iPhone app?
Is it possible using the SDK?

Text to speech on iPhone

In the documentation I see several Apple frameworks for audio. All of them seem to be targeted at playing and recording audio. So I wonder what the big differences are between these?

 - Audio Toolbox
 - Audio Unit
 - AV Foundation
 - Core Audio

Did I miss a guide that gives a good overview of all these?

What&#39;s the difference between the Apple audio frameworks?

The [documentation for AVPlayer][1] states the following:

&gt; [The] player works equally well with local and remote media files

However, the [documentation for AVAudioPlayer][2] states the following:

&gt; Apple recommends that you use this class for audio playback unless you are playing audio captured from a network stream

For the work I am doing I need some of the capabilities of AVAudioPlayer, but all my audio is being streamed. The main thing I need from AVAudioPlayer that AVPlayer does not have is the &quot;playing&quot; property. It is difficult to build a player UI without that property, among others.

So what is the difference between AVPlayer and AVAudioPlayer that makes the latter unsuitable for network streaming? Is there a way to get some of the info from AVPlayer that AVAudioPlayer provides such as the &quot;playing&quot; property?

  [1]: https://developer.apple.com/reference/avfoundation/avplayer
  [2]: https://developer.apple.com/reference/avfoundation/avaudioplayer

AVPlayer vs. AVAudioPlayer

I reading song from iPod library using assetUrl (in code it named audioUrl)
I can play it many ways, I can cut it, I can make some precessing with this but...
I really don&#39;t understand what I gonna do with this CMSampleBufferRef to get data for drawing waveform! I need info about peak values, how I can get it this (maybe another) way? 


		
		AVAssetTrack * songTrack = [audioUrl.tracks objectAtIndex:0];
		AVAssetReaderTrackOutput * output = [[AVAssetReaderTrackOutput alloc] initWithTrack:songTrack outputSettings:nil];
		[reader addOutput:output];
		[output release];
		
		NSMutableData * fullSongData = [[NSMutableData alloc] init];
		[reader startReading];
		
		while (reader.status == AVAssetReaderStatusReading){
			
			AVAssetReaderTrackOutput * trackOutput = 
			(AVAssetReaderTrackOutput *)[reader.outputs objectAtIndex:0];
			
			CMSampleBufferRef sampleBufferRef = [trackOutput copyNextSampleBuffer];
			
			if (sampleBufferRef){/* what I gonna do with this? */}

Please help me! 


Drawing waveform with AVAssetReader

The situation goes a little something like this:

1. I am programming Xcode whilst concurrently listening to music on my Bluetooth headphones... you know to block out the world.

2. Then, I go to launch my app in the iOS simulator and BOOM all of a sudden my crystal clear music becomes garbled and super low quality like it is playing in a bathtub 2 blocks away... in the 1940s. 

3. Note: the quality deterioration does NOT occur if I am playing music on my laptop or cinema display and I launch the sim. It seems to be exclusively a Sim -&gt; Bluetooth issue. 

The problem is more than just annoying. Because often after stopping the simulator the crappy bathtub quality music continues. To fix it I have to open sound preferences in OSX and briefly toggle back to my laptop sound and then back to my Bluetooth headphones. 

This is a big deal because I launch the simulator 50x a day and have to do this toggle thing every time as well as suffer listening to 40s era mono ham radio quality music. 

For your information, the headphones I am using are Plantronics BackBeat Pro and I am up to date on firmware. I am on OSX 10.11.4 and Xcode 7.3... but this problem has persisted through all versions for 2+ years now. Can you save me from the 1940s?


Content Type	Original Author	Original Content on Stackoverflow
Question	Dave Verwer	View Question on Stackoverflow
Solution 1 - Iphone	Dave Verwer	View Answer on Stackoverflow
Solution 2 - Iphone	tomwilson	View Answer on Stackoverflow
Solution 3 - Iphone	scurioni	View Answer on Stackoverflow
Solution 4 - Iphone	Steph Thirion	View Answer on Stackoverflow
Solution 5 - Iphone	user1528293	View Answer on Stackoverflow

Converting audio to CAF format for playback on iPhone using OpenAL

Iphone Problem Overview

Iphone Solutions

Solution 1 - Iphone

Solution 2 - Iphone

Solution 3 - Iphone

Solution 4 - Iphone

Solution 5 - Iphone

What is the use of const overloading in C++?

Unhandled exceptions in BackgroundWorker

Attributions