播放暂停的AVAudioRecorder文件 [英] Play a paused AVAudioRecorder file

问题描述

在我的程序中，我希望用户能够:

in my program I want the user to be able to:

• 记录他的声音，
• 暂停录音过程，
• 听他记录的内容
• 然后继续记录.

我设法达到了可以使用AVAudioRecorder和AVAudioPlayer录制和播放录音的地步.但是，每当我尝试录制，暂停录制然后再播放时，播放的部分都会毫无错误地失败.

I have managed to get to the point where I can record and play the recordings with AVAudioRecorder and AVAudioPlayer. But whenever I try to record, pause recording and then play, the playing part fails with no error.

我可以猜到它没有播放的原因是因为音频文件尚未保存并且仍在内存中.

I can guess that the reason it's not playing is because the audio file hasn't been saved yet and is still in memory or something.

有没有办法播放暂停的录音? 如果有的话请告诉我如何

Is there a way I can play paused recordings? If there is please tell me how

我正在使用xcode 4.3.2

I'm using xcode 4.3.2

推荐答案

RecordAudioViewController.h

RecordAudioViewController.h

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

   @interface record_audio_testViewController : UIViewController <AVAudioRecorderDelegate> {

IBOutlet UIButton * btnStart;
IBOutlet UIButton * btnPlay;
IBOutlet UIActivityIndicatorView * actSpinner;
BOOL toggle;

//Variables setup for access in the class:
NSURL * recordedTmpFile;
AVAudioRecorder * recorder;
NSError * error;

 }

 @property (nonatomic,retain)IBOutlet UIActivityIndicatorView * actSpinner;
 @property (nonatomic,retain)IBOutlet UIButton * btnStart;
 @property (nonatomic,retain)IBOutlet UIButton * btnPlay;

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

RecordAudioViewController.m

RecordAudioViewController.m

  @synthesize actSpinner, btnStart, btnPlay;
   - (void)viewDidLoad {
    [super viewDidLoad];

//Start the toggle in true mode.
toggle = YES;
btnPlay.hidden = YES;

//Instanciate an instance of the AVAudioSession object.
AVAudioSession * audioSession = [AVAudioSession sharedInstance];
//Setup the audioSession for playback and record. 
//We could just use record and then switch it to playback leter, but
//since we are going to do both lets set it up once.
[audioSession setCategory:AVAudioSessionCategoryPlayAndRecord error: &error];
//Activate the session
[audioSession setActive:YES error: &error];

  }


 - (IBAction)  start_button_pressed{

if(toggle)
{
    toggle = NO;
    [actSpinner startAnimating];
    [btnStart setTitle:@"Stop Recording" forState: UIControlStateNormal ];  
    btnPlay.enabled = toggle;
    btnPlay.hidden = !toggle;

    //Begin the recording session.
    //Error handling removed.  Please add to your own code.

    //Setup the dictionary object with all the recording settings that this 
    //Recording sessoin will use
    //Its not clear to me which of these are required and which are the bare minimum.
    //This is a good resource: http://www.totodotnet.net/tag/avaudiorecorder/
    NSMutableDictionary* recordSetting = [[NSMutableDictionary alloc] init];
    [recordSetting setValue :[NSNumber numberWithInt:kAudioFormatAppleIMA4] forKey:AVFormatIDKey];
    [recordSetting setValue:[NSNumber numberWithFloat:44100.0] forKey:AVSampleRateKey]; 
    [recordSetting setValue:[NSNumber numberWithInt: 2] forKey:AVNumberOfChannelsKey];

    //Now that we have our settings we are going to instanciate an instance of our recorder instance.
    //Generate a temp file for use by the recording.
    //This sample was one I found online and seems to be a good choice for making a tmp file that
    //will not overwrite an existing one.
    //I know this is a mess of collapsed things into 1 call.  I can break it out if need be.
    recordedTmpFile = [NSURL fileURLWithPath:[NSTemporaryDirectory() stringByAppendingPathComponent: [NSString stringWithFormat: @"%.0f.%@", [NSDate timeIntervalSinceReferenceDate] * 1000.0, @"caf"]]];
    NSLog(@"Using File called: %@",recordedTmpFile);
    //Setup the recorder to use this file and record to it.
    recorder = [[ AVAudioRecorder alloc] initWithURL:recordedTmpFile settings:recordSetting error:&error];
    //Use the recorder to start the recording.
    //Im not sure why we set the delegate to self yet.  
    //Found this in antother example, but Im fuzzy on this still.
    [recorder setDelegate:self];
    //We call this to start the recording process and initialize 
    //the subsstems so that when we actually say "record" it starts right away.
    [recorder prepareToRecord];
    //Start the actual Recording
    [recorder record];
    //There is an optional method for doing the recording for a limited time see 
    //[recorder recordForDuration:(NSTimeInterval) 10]

}
else
{
    toggle = YES;
    [actSpinner stopAnimating];
    [btnStart setTitle:@"Start Recording" forState:UIControlStateNormal ];
    btnPlay.enabled = toggle;
    btnPlay.hidden = !toggle;

    NSLog(@"Using File called: %@",recordedTmpFile);
    //Stop the recorder.
    [recorder stop];
}
  }

  - (void)didReceiveMemoryWarning {
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];

// Release any cached data, images, etc that aren't in use.
  }

  -(IBAction) play_button_pressed{

//The play button was pressed... 
//Setup the AVAudioPlayer to play the file that we just recorded.
AVAudioPlayer * avPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:recordedTmpFile error:&error];
[avPlayer prepareToPlay];
[avPlayer play];

  }

   - (void)viewDidUnload {
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
//Clean up the temp file.
NSFileManager * fm = [NSFileManager defaultManager];
[fm removeItemAtPath:[recordedTmpFile path] error:&error];
//Call the dealloc on the remaining objects.
[recorder dealloc];
recorder = nil;
recordedTmpFile = nil;
  }


  - (void)dealloc {
[super dealloc];
  }

 @end

RecordAudioViewController.xib

RecordAudioViewController.xib

按2个按钮. 1个用于开始录制，另一个用于Play录制

take 2 Buttons. 1 for begin recording and another for Play recording

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