iOS 5 - AVAPlayer 不再工作

Question

我有一些在 iOS 4.3 上运行良好的代码。我上网查了一下，发现其他人也有同样的问题，但没有答案，这对我有用。我认为我可以录制一些东西，但无法播放它。这是我的代码：

DetailViewController.h

#import <UIKit/UIKit.h>
#import <AVFoundation/AVFoundation.h>
#import <CoreAudio/CoreAudioTypes.h>
#import <AudioToolbox/AudioServices.h>

@interface DetailViewController : UIViewController <UISplitViewControllerDelegate, AVAudioRecorderDelegate> {

id detailItem;
UILabel *detailDescriptionLabel;

IBOutlet UIButton *btnStart;
IBOutlet UIButton *btnPlay;

//Variables setup for access in the class:
NSURL * recordedTmpFile;
AVAudioRecorder * recorder;
BOOL toggle;
}

// Needed properties
@property (nonatomic, retain) IBOutlet UIButton *btnStart;
@property (nonatomic, retain) IBOutlet UIButton *btnPlay;
@property (strong, nonatomic) id detailItem;
@property (strong, nonatomic) IBOutlet UILabel *detailDescriptionLabel;

-(IBAction) start_button_pressed;
-(IBAction) play_button_pressed;
@end

DetailViewController.m

- (void)viewDidLoad {
[super viewDidLoad];
toggle = YES;
btnPlay.hidden = YES;
NSError *error;

// Create the Audio Session
AVAudioSession *audioSession = [AVAudioSession sharedInstance];

// Set up the type of session
[audioSession setCategory:AVAudioSessionCategoryPlayAndRecord error:&error];

// Activate the session.
[audioSession setActive:YES error:&error];

[self configureView];    
}

-(IBAction) start_button_pressed{
if (toggle) {
    toggle = NO;
    [btnStart setTitle:@"Press to stop recording" forState:UIControlStateNormal];
    btnPlay.enabled = toggle;
    btnPlay.hidden = !toggle;
            NSError *error;

    NSMutableDictionary *recordSettings = [[NSMutableDictionary alloc] init];

    [recordSettings setValue:[NSNumber numberWithInt:kAudioFormatAppleIMA4] forKey:AVFormatIDKey];

    [recordSettings setValue:[NSNumber numberWithFloat:44100.0] forKey:AVSampleRateKey];

    [recordSettings setValue:[NSNumber numberWithInt:2] forKey:AVNumberOfChannelsKey];

    // Create a temporary files to save the recording. 
    recordedTmpFile = [NSURL fileURLWithPath:[NSTemporaryDirectory() stringByAppendingPathComponent:[NSString stringWithFormat: @"%.0f.%@", [NSDate timeIntervalSinceReferenceDate] * 1000.0, @"caf"]]];

    NSLog(@"The temporary file used is: %@", recordedTmpFile);

    recorder = [[AVAudioRecorder alloc] initWithURL:recordedTmpFile settings:recordSettings error:&error];

    [recorder setDelegate:self];

    [recorder prepareToRecord];
    [recorder record];
}
else {
    toggle = YES;
    [btnStart setTitle:@"Start recording" forState:UIControlStateNormal];
    btnPlay.hidden = !toggle;
    btnPlay.enabled = toggle;

    NSLog(@"Recording stopped and saved in file: %@", recordedTmpFile);
    [recorder stop];
}
}

-(IBAction) play_button_pressed{

NSError *error;
AVAudioPlayer * avPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:recordedTmpFile error:&error];

   if (!error)
   {
       [avPlayer prepareToPlay];
       [avPlayer play];

       NSLog(@"File is playing");
   }

}

- (void) audioPlayerDidFinishPlaying: (AVAudioPlayer *) player
                    successfully: (BOOL) flag {
     NSLog (@"audioPlayerDidFinishPlaying:successfully:");
}

- (void)audioRecorderDidFinishRecording:(AVAudioRecorder *) aRecorder successfully: (BOOL)flag
{
    NSLog (@"audioRecorderDidFinishRecording:successfully:");
}

这是我的程序运行的代码：

2011-11-25 11:58:02.005 Bluetooth1[897:707] 使用的临时文件是：文件://localhost/private/var/mobile/Applications/D81023F8-C53D-4AC4-B1F7-14D66EB4844A/tmp/343915082005.caf 2011-11-25 11:58:05.956 Bluetooth1[897:707] 录制停止并保存在文件中： file://localhost/private/var/mobile/Applications/D81023F8-C53D-4AC4-B1F7-14D66EB4844A/tmp/343915082005 .caf 2011-11-25 11:58:05.998 蓝牙1[897:707]audioRecorderDidFinishRecording：成功： 2011-11-25 11:58:11.785 Bluetooth1[897:707] 文件正在播放

由于某种原因，函数audioPlayerDidFinishPlaying 从未被调用。不过，似乎有些事情已经被记录下来了。现在我不知道哪个部分不起作用，但我想这与 AVAudioPlayer 有关。

[编辑] 事情变得越来越奇怪了。我想确保记录了某些内容，因此我寻找记录的持续时间。这是新的播放功能：

-(IBAction) play_button_pressed{

    NSError *error;
AVAudioPlayer * avPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL: recordedTmpFile error:&error];

    if (!error)
    {
        AVURLAsset* audioAsset = [AVURLAsset URLAssetWithURL:recordedTmpFile options:nil];
        CMTime audioDuration = audioAsset.duration;
        float audioDurationSeconds = CMTimeGetSeconds(audioDuration);

        [avPlayer prepareToPlay];
        [avPlayer play];

        NSString *something = [NSString stringWithFormat:@"%f",audioDurationSeconds]; 
        NSLog(@"File is playing: %@", something);
    }
    else
    {
         NSLog(@"Error playing.");
    }   
}

现在，记录的长度被记录下来并且有意义（如果我记录 10 秒，它会显示大约 10 秒的内容）。然而，当我第一次输入这些代码行时，我忘记了将 float 转换为 NSString。所以它崩溃了...并且应用程序播放了声音...经过不同的测试，我可以得出结论，我的应用程序可以录制和播放声音，但会崩溃以播放录制的声音。我不知道会出现什么问题。我发现 AVPlayer 是异步的，这与他们有什么关系吗？我完全迷失了...

Answer 1

将 urlpath 替换为以下代码：

NSString *documentsDirectory = [NSSearchPathForDirectoriesInDomains(
         NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString *filepath = [documentsDirectory stringByAppendingPathComponent:@"urfile.xxx"];

NSURL *url = [NSURL fileURLWithPath:filepath];

Answer 2

尝试此处的解决方案：

录音和播放

Answer 3

好吧，回答你自己的问题并不是很酷。此外，当答案不干净但它正在工作时......为了播放我录制的内容，我使用了以下代码块：

    AVURLAsset* audioAsset = [AVURLAsset URLAssetWithURL:recordedTmpFile options:nil];
    CMTime audioDuration = audioAsset.duration;
    float audioDurationSeconds = CMTimeGetSeconds(audioDuration);

    [avPlayer prepareToPlay];
    [avPlayer play];

    // Block for audioDurationSeconds seconds
    [NSThread sleepForTimeInterval:audioDurationSeconds];

我正在计算录制文件的长度，并且我正在等待这段时间。 ..它很脏，但它正在发挥作用。另外，如果它在另一个线程中启动，它不会阻塞应用程序。

我任何人都有东西我很乐意接受！