How to create .mp3 files in my iPad?

Question

Possible Duplicate:
Recording mp3 instead of caf file

I wonder if any can help me with my issue.

I have found the way to save my voice in the iPad. But so far I have created only .caf files. Can I create .mp3 files??

Thanks in advance. I am attaching my code:

    NSArray *dirPaths;
    NSString *docsDir;

    dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    docsDir = [dirPaths objectAtIndex:0];

    NSString *soundFilePath = [docsDir stringByAppendingPathComponent:@"sound.caf"];
    NSURL *soundFileURL = [NSURL fileURLWithPath:soundFilePath];

    NSDictionary *recordSettings = [NSDictionary dictionaryWithObjectsAndKeys:
    [NSNumber numberWithInt:AVAudioQualityMin], AVEncoderAudioQualityKey, [NSNumber numberWithInt:16], AVEncoderBitRateKey, [NSNumber numberWithInt: 2], AVNumberOfChannelsKey, [NSNumber numberWithFloat:44100.0], AVSampleRateKey, nil];

    NSError *error = nil;
    AVAudioRecorder audioRecorder = [[AVAudioRecorder alloc] initWithURL:soundFileURL settings:recordSettings error:&error];

    if (error){
        NSLog(@"error: %@", [error localizedDescription]);
    } else {
        [audioRecorder prepareToRecord];
        [audioRecorder record];
    }