AVAudioPlayer throws breakpoint in debug mode

Question

Every time I load the app it stops as if I had set a breakpoint on this line:

self.audioPlayer = 
 [[[AVAudioPlayer alloc] initWithData:[dataPersister loadData:self.fileName] 
                                error:&outError] autorelease];

There's no breakpoint above or any place near this line. It only happens when I run the app in debug mode and nothing crashes after the breakpoint. The app works as nothing happened when I click "Continue program execution".

This is the loadData method, which is called with initWithData:

-(NSData*)loadData:(NSString*)fileName
{
    NSString *dataPath = [self.path stringByAppendingPathComponent:fileName];
    dataPath = [dataPath stringByStandardizingPath];
    NSData *data = [[[NSData alloc] initWithContentsOfFile:dataPath]autorelease ];
    return data;
}

The loadData function seems to be working fine. The requested mp3 file is loaded and played without any problems after the breakpoint.

Do you have any idea what I'm doing wrong?

EDIT: I ran a backtrace when it stops at the breakpoint. This was the output:

(lldb) bt
* thread #1: tid = 0x1c03, 0x30df1724 libc++abi.dylib`__cxa_throw, stop reason = breakpoint 1.2
    frame #0: 0x30df1724 libc++abi.dylib`__cxa_throw
    frame #1: 0x36403a24 AudioToolbox`ID3ParserHandle::ID3ParserHandle(void*, long (*)(void*, unsigned long, unsigned long, unsigned long, void**, unsigned long*)) + 452
    frame #2: 0x36403b0e AudioToolbox`ID3ParserOpen + 142
    frame #3: 0x3635bd16 AudioToolbox`MPEGAudioFile::ParseID3Tags() + 58
    frame #4: 0x3635b9aa AudioToolbox`MPEGAudioFile::ParseAudioFile() + 26
    frame #5: 0x3631723e AudioToolbox`AudioFileObject::DoOpenWithCallbacks(void*, long (*)(void*, long long, unsigned long, void*, unsigned long*), long (*)(void*, long long, unsigned long, void const*, unsigned long*), long long (*)(void*), long (*)(void*, long long)) + 166
    frame #6: 0x36316480 AudioToolbox`AudioFileOpenWithCallbacks + 612
    frame #7: 0x31f4c1ec AVFoundation`-[AVAudioPlayer initWithData:error:] + 120

"SOLUTION": It turns out, if I disable exception breakpoint for all exceptions and only use breakpoint for Objective-C exceptions the problem disappears. But it doesn't solve the problem that the allocation of AVAudioPlayer throws a C++ exception.

Answer 1

Add your exception breakpoint and edit the exception type from "All" to "Objective-C exceptions"

Some classes in AudioToolbox throw regular C++ exceptions. You can filter them off this way.

Answer 2

AVAudioPlayer and AVAudioRecorder both will throw exceptions, several of them. These are handled internally by the players but if you have a breakpoint for "All Breakpoints" (i.e. Exception: All, Break: On Throw) you will catch these exceptions. If you continue execution on these, the app will continue to run normally and not crash at all.

The only solution I've come up with so far is to click on the breakpoint bar in the Breakpoint Navigator, disabling this particular breakpoint, and running with it disabled.

When/if the app ever crashes with a thrown exception, I cmd-6, enable that breakpoint, and rerun and do whatever I did when it crashed.

Edit: setting to "Objective-C exceptions" is obviously how to do it. See above answer!

Answer 3

Here's a screenshot showing how I fixed this error. I'm not sure if this is the same way that the answers above are talking about, but I assume its similar.

1. Go to the Breakpoint navigator in Xcode.
2. Control-click on the 'All Exceptions' line.
3. Select the 'Edit Breakpoint...' option.
4. Change the Exception from All to Objective-C.

Answer 4

The backtrace helped a lot, thanks!. We'd started running into the same issue recently. It turns out the mp3 files it was throwing on did not have a valid ID3 tag and running them through an app such as Tagr fixed them right up!