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I have made 2 iPhone apps which can record audio and save it to a file and play it back again.

One of them uses AVAudiorecorder and AVAudioplayer. The second one is Apple's SpeakHere example with Audio Queues.

Both run on Simulater as well as the Device.

BUT when I restart either app the recorded file is not found!!! I've tried all possible suggestions found on stackoverflow but it still doesnt work!

This is what I use to save the file:

NSArray *dirPaths; 
NSString *docsDir; 

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

NSString *soundFilePath = [docsDir stringByAppendingPathComponent:@"sound1.caf"]; 
NSURL *soundFileURL = [NSURL fileURLWithPath:soundFilePath];
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1 回答 1

16

好的，我终于解决了。问题是我正在设置 AVAudioRecorder 并在我的 ViewController.m 的 viewLoad 中归档路径，覆盖现有的同名文件。

  1. 录制音频并将其保存到文件并停止应用程序后，我可以在 Finder 中找到该文件。（/Users/xxxxx/Library/Application Support/iPhone Simulator/6.0/Applications/0F107E80-27E3-4F7C-AB07-9465B575EDAB/Documents/sound1.caf）

  2. 当我重新启动应用程序时，记录器的设置代码（来自 viewLoad）将覆盖我的旧文件，称为：

    sound1.caf

  3. 一个新的。同名但没有内容。

  4. 回放只会播放一个空的新文件。--> 显然没有声音。

所以这就是我所做的：

我使用 NSUserdefaults 来保存录制文件名的路径，以便稍后在我的 playBack 方法中检索。

在 ViewController.m 中清理了 viewLoad：

- (void)viewDidLoad
{

     AVAudioSession *audioSession = [AVAudioSession sharedInstance];

     [audioSession setCategory:AVAudioSessionCategoryPlayAndRecord error:nil];

     [audioSession setActive:YES error:nil];

     [recorder setDelegate:self];

     [super viewDidLoad];
}

在 ViewController.m 中编辑记录：

- (IBAction) record
{

    NSError *error;

    // Recording settings
    NSMutableDictionary *settings = [NSMutableDictionary dictionary];

    [settings setValue: [NSNumber numberWithInt:kAudioFormatLinearPCM] forKey:AVFormatIDKey];
    [settings setValue: [NSNumber numberWithFloat:8000.0] forKey:AVSampleRateKey];
    [settings setValue: [NSNumber numberWithInt: 1] forKey:AVNumberOfChannelsKey];
    [settings setValue: [NSNumber numberWithInt:16] forKey:AVLinearPCMBitDepthKey];
    [settings setValue: [NSNumber numberWithBool:NO] forKey:AVLinearPCMIsBigEndianKey];
    [settings setValue: [NSNumber numberWithBool:NO] forKey:AVLinearPCMIsFloatKey];
    [settings setValue:  [NSNumber numberWithInt: AVAudioQualityMax] forKey:AVEncoderAudioQualityKey];

    NSArray *searchPaths =NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentPath_ = [searchPaths objectAtIndex: 0];

    NSString *pathToSave = [documentPath_ stringByAppendingPathComponent:[self dateString]];

    // File URL
    NSURL *url = [NSURL fileURLWithPath:pathToSave];//FILEPATH];


    //Save recording path to preferences
    NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];


    [prefs setURL:url forKey:@"Test1"];
    [prefs synchronize];


    // Create recorder
    recorder = [[AVAudioRecorder alloc] initWithURL:url settings:settings error:&error];

    [recorder prepareToRecord];

    [recorder record];
}

在 ViewController.m 中编辑播放：

-(IBAction)playBack
{

AVAudioSession *audioSession = [AVAudioSession sharedInstance];

[audioSession setCategory:AVAudioSessionCategoryPlayback error:nil];

[audioSession setActive:YES error:nil];


//Load recording path from preferences
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];


temporaryRecFile = [prefs URLForKey:@"Test1"];



player = [[AVAudioPlayer alloc] initWithContentsOfURL:temporaryRecFile error:nil];



player.delegate = self;


[player setNumberOfLoops:0];
player.volume = 1;


[player prepareToPlay];

[player play];


}

并向 ViewController.m 添加了一个新的 dateString 方法：

- (NSString *) dateString
{
    // return a formatted string for a file name
    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
    formatter.dateFormat = @"ddMMMYY_hhmmssa";
    return [[formatter stringFromDate:[NSDate date]] stringByAppendingString:@".aif"];
}

现在它可以通过 NSUserdefaults 加载最后记录的文件：

    //Load recording path from preferences
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];


temporaryRecFile = [prefs URLForKey:@"Test1"];



player = [[AVAudioPlayer alloc] initWithContentsOfURL:temporaryRecFile error:nil];

在（IBAction）播放中。temporaryRecFile 是我的 ViewController 类中的 NSURL 变量。

声明如下 ViewController.h ：

@interface SoundRecViewController : UIViewController <AVAudioSessionDelegate,AVAudioRecorderDelegate, AVAudioPlayerDelegate>
{
......
......
    NSURL *temporaryRecFile;

    AVAudioRecorder *recorder;
    AVAudioPlayer *player;

}
......
......
@end
于 2013-02-25T23:49:33.813 回答