Iphone 播放电影会停止avcapturesession录制

我有一个iOS应用程序，可以在后台录制来自前置摄像头的视频，并且工作正常。但是现在我尝试同时播放一段短的mp4，使用MPMoviePlayerController播放会停止捕获会话

我尝试了AVPlayer，结果是一样的。 我还设置了[[AVAudioSession sharedInstance]setCategory:AVAudioSessionCategoryPlayAndRecord错误：nil]； 还是不走运。有没有人面对并解决了同样的问题。 谢谢你的建议

使用ios5sdk

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    UIButton *recButton=[[UIButton alloc] initWithFrame:CGRectMake(10,200, 200,40)] ;
    recButton.backgroundColor = [UIColor blackColor];
    [recButton addTarget:self action:@selector(startRecording) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:recButton];
    isRecording=NO;
}

- (void)viewDidUnload
{
    [super viewDidUnload];
    // Release any retained subviews of the main view.
}

-(void) viewWillAppear:(BOOL)animated
{
    self.navigationController.navigationBarHidden = YES;
}

-(void) viewWillDisappear:(BOOL)animated
{
        self.navigationController.navigationBarHidden = NO;
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone) {
        return (interfaceOrientation == UIInterfaceOrientationPortrait);
    } else {
        return YES;
    }
}

#pragma mark video playing
-(void) startRecording
{
    if (isRecording) {
        [self stopVideoRecording];
        isRecording=NO;
    }
    else
    {
        [self initCaptureSession];
        [self startVideoRecording];
        isRecording=YES;
    }


    NSURL *url = [NSURL fileURLWithPath:[[NSBundle mainBundle]
                                         pathForResource:@"new"
                                         ofType:@"mov"]];
    [self playMovieAtURL:url];
}

-(void) playMovieAtURL: (NSURL*) theURL {

    player =
    [[MPMoviePlayerController alloc] initWithContentURL: theURL ];
    [[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayAndRecord error:nil];

    player.scalingMode = MPMovieScalingModeAspectFill;
    player.controlStyle = MPMovieControlStyleNone;
    [player prepareToPlay];
    // Register for the playback finished notification
    [[NSNotificationCenter defaultCenter]
     addObserver: self
     selector: @selector(myMovieFinishedCallback:)
     name: MPMoviePlayerPlaybackDidFinishNotification
     object: player];
    [player.view setFrame: self.view.bounds];
    [self.view addSubview:player.view];
    // Movie playback is asynchronous, so this method returns immediately.
    [player play];
}

// When the movie is done, release the controller.
-(void) myMovieFinishedCallback: (NSNotification*) aNotification
{
    MPMoviePlayerController* theMovie = [aNotification object];

    [[NSNotificationCenter defaultCenter]
     removeObserver: self
     name: MPMoviePlayerPlaybackDidFinishNotification
     object: theMovie];
    [player.view removeFromSuperview];
    [self stopVideoRecording];
}

#pragma mark -

#pragma mark recording

-(void) initCaptureSession
{
    NSLog(@"Setting up capture session");
    captureSession = [[AVCaptureSession alloc] init];
    //----- ADD INPUTS -----
    NSLog(@"Adding video input");

    //ADD VIDEO INPUT
    AVCaptureDevice *VideoDevice =  [self frontFacingCameraIfAvailable ];

    //[AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    if (VideoDevice)
    {
        NSError *error;
        videoInputDevice = [AVCaptureDeviceInput deviceInputWithDevice:VideoDevice error:&error];
        if (!error)
        {
            if ([captureSession canAddInput:videoInputDevice])
                [captureSession addInput:videoInputDevice];
            else
                NSLog(@"Couldn't add video input");
        }
        else
        {
            NSLog(@"Couldn't create video input");
        }
    }
    else
    {
        NSLog(@"Couldn't create video capture device");
    }

    //ADD AUDIO INPUT
    NSLog(@"Adding audio input");
    AVCaptureDevice *audioCaptureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeAudio];
    NSError *error = nil;
    AVCaptureDeviceInput *audioInput = [AVCaptureDeviceInput deviceInputWithDevice:audioCaptureDevice error:&error];
    if (audioInput)
    {

        [captureSession addInput:audioInput];
    }

    //----- ADD OUTPUTS ---
    //ADD MOVIE FILE OUTPUT
    NSLog(@"Adding movie file output");
    movieFileOutput = [[AVCaptureMovieFileOutput alloc] init];

//  Float64 TotalSeconds = 60;          //Total seconds
//  int32_t preferredTimeScale = 30;    //Frames per second
//  CMTime maxDuration = CMTimeMakeWithSeconds(TotalSeconds, preferredTimeScale);   //<<SET MAX DURATION
//  movieFileOutput.maxRecordedDuration = maxDuration;

    movieFileOutput.minFreeDiskSpaceLimit = 1024 * 1024;    //<<SET MIN FREE SPACE IN BYTES FOR RECORDING TO CONTINUE ON A VOLUME

    if ([captureSession canAddOutput:movieFileOutput])
        [captureSession addOutput:movieFileOutput];

    //SET THE CONNECTION PROPERTIES (output properties)
    [self CameraSetOutputProperties];           //(We call a method as it also has to be done after changing camera)

    //----- SET THE IMAGE QUALITY / RESOLUTION -----
    //Options:
    //  AVCaptureSessionPresetHigh - Highest recording quality (varies per device)
    //  AVCaptureSessionPresetMedium - Suitable for WiFi sharing (actual values may change)
    //  AVCaptureSessionPresetLow - Suitable for 3G sharing (actual values may change)
    //  AVCaptureSessionPreset640x480 - 640x480 VGA (check its supported before setting it)
    //  AVCaptureSessionPreset1280x720 - 1280x720 720p HD (check its supported before setting it)
    //  AVCaptureSessionPresetPhoto - Full photo resolution (not supported for video output)
    NSLog(@"Setting image quality");
    [captureSession setSessionPreset:AVCaptureSessionPresetMedium];
    if ([captureSession canSetSessionPreset:AVCaptureSessionPreset640x480])     //Check size based configs are supported before setting them
        [captureSession setSessionPreset:AVCaptureSessionPreset640x480];
    //----- START THE CAPTURE SESSION RUNNING -----
    [captureSession startRunning];
}

//********** CAMERA SET OUTPUT PROPERTIES **********
- (void) CameraSetOutputProperties
{
    AVCaptureConnection *CaptureConnection=nil;
    //SET THE CONNECTION PROPERTIES (output properties)
    NSComparisonResult order = [[UIDevice currentDevice].systemVersion compare: @"5.0.0" options: NSNumericSearch];
    if (order == NSOrderedSame || order == NSOrderedDescending) {
        // OS version >= 5.0.0
        CaptureConnection = [movieFileOutput connectionWithMediaType:AVMediaTypeVideo];
//        if (CaptureConnection.supportsVideoMinFrameDuration)
//            CaptureConnection.videoMinFrameDuration = CMTimeMake(1, CAPTURE_FRAMES_PER_SECOND);
//        if (CaptureConnection.supportsVideoMaxFrameDuration)
//            CaptureConnection.videoMaxFrameDuration = CMTimeMake(1, CAPTURE_FRAMES_PER_SECOND);
//        if (CaptureConnection.supportsVideoMinFrameDuration)
//        {
//           // CMTimeShow(CaptureConnection.videoMinFrameDuration);
//           // CMTimeShow(CaptureConnection.videoMaxFrameDuration);
//        }
    } else {
        // OS version < 5.0.0
        CaptureConnection = [self connectionWithMediaType:AVMediaTypeVideo fromConnections:[movieFileOutput connections]];

    }


    //Set landscape (if required)
    if ([CaptureConnection isVideoOrientationSupported])
    {
        AVCaptureVideoOrientation orientation =  AVCaptureVideoOrientationPortrait;// AVCaptureVideoOrientationLandscapeRight;      //<<<<<SET VIDEO ORIENTATION IF LANDSCAPE
        [CaptureConnection setVideoOrientation:orientation];
    }

    //Set frame rate (if requried)
    //CMTimeShow(CaptureConnection.videoMinFrameDuration);
    //CMTimeShow(CaptureConnection.videoMaxFrameDuration);


}
- (void) startVideoRecording
{
        //Create temporary URL to record to
        NSString *outputPath = [[NSString alloc] initWithFormat:@"%@%@", NSTemporaryDirectory(), @"output.mov"];
        NSURL *outputURL = [[NSURL alloc] initFileURLWithPath:outputPath];
        NSFileManager *fileManager = [NSFileManager defaultManager];
        if ([fileManager fileExistsAtPath:outputPath])
        {
            NSError *error;
            if ([fileManager removeItemAtPath:outputPath error:&error] == NO)
            {
                //Error - handle if requried
                NSLog(@"file remove error");
            }
        }
        //Start recording
        [movieFileOutput startRecordingToOutputFileURL:outputURL recordingDelegate:self];

}

-(void) stopVideoRecording
{
    [movieFileOutput stopRecording];

}
//********** DID FINISH RECORDING TO OUTPUT FILE AT URL **********/
- (void)captureOutput:(AVCaptureFileOutput *)captureOutput
didFinishRecordingToOutputFileAtURL:(NSURL *)outputFileURL
      fromConnections:(NSArray *)connections
                error:(NSError *)error
{

    NSLog(@"didFinishRecordingToOutputFileAtURL - enter");

    BOOL RecordedSuccessfully = YES;
    if ([error code] != noErr)
    {
        // A problem occurred: Find out if the recording was successful.
        id value = [[error userInfo] objectForKey:AVErrorRecordingSuccessfullyFinishedKey];
        if (value)
        {
            RecordedSuccessfully = [value boolValue];
        }
    }
    if (RecordedSuccessfully)
    {
        //----- RECORDED SUCESSFULLY -----
        NSLog(@"didFinishRecordingToOutputFileAtURL - success");
        ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
        if ([library videoAtPathIsCompatibleWithSavedPhotosAlbum:outputFileURL])
        {
            [library writeVideoAtPathToSavedPhotosAlbum:outputFileURL
                                        completionBlock:^(NSURL *assetURL, NSError *error)
             {
                 if (error)
                 {
                     NSLog(@"File save error");
                 }
                 else
                 {
                     recordedVideoURL=assetURL;
                 }
             }];
        }
        else {

            NSString *assetURL=[self copyFileToDocuments:outputFileURL];
            if(assetURL!=nil)
            {
                recordedVideoURL=[NSURL URLWithString:assetURL];
            }
        }
    }
}

- (NSString*) copyFileToDocuments:(NSURL *)fileURL
{
    NSString *documentsDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setDateFormat:@"yyyy-MM-dd_HH-mm-ss"];
    NSString *destinationPath = [documentsDirectory stringByAppendingFormat:@"/output_%@.mov", [dateFormatter stringFromDate:[NSDate date]]];
    NSError *error;
    if (![[NSFileManager defaultManager] copyItemAtURL:fileURL toURL:[NSURL fileURLWithPath:destinationPath] error:&error]) {
        NSLog(@"File save error %@", [error localizedDescription]);
        return nil;

    }
    return destinationPath;
}

- (AVCaptureConnection *)connectionWithMediaType:(NSString *)mediaType fromConnections:(NSArray *)connections
{
    for ( AVCaptureConnection *connection in connections ) {
        for ( AVCaptureInputPort *port in [connection inputPorts] ) {
            if ( [[port mediaType] isEqual:mediaType] ) {
                return connection;
            }
        }
    }
    return nil;
}

- (AVCaptureDevice *)frontFacingCameraIfAvailable
{
    //  look at all the video devices and get the first one that's on the front
    NSArray *videoDevices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
    AVCaptureDevice *captureDevice = nil;
    for (AVCaptureDevice *device in videoDevices)
    {
        if (device.position == AVCaptureDevicePositionFront)
        {
            captureDevice = device;
            break;
        }
    }

    //  couldn't find one on the front, so just get the default video device.
    if ( ! captureDevice)
    {
        captureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    }

    return captureDevice;
}
#pragma mark -

@end

#导入“ViewController.h”
@界面视图控制器（）
@结束
@实现视图控制器
-（无效）viewDidLoad
{
[超级视图下载]；
//加载视图后，通常从nib执行任何其他设置。
UIButton*recButton=[[UIButton alloc]initWithFrame:CGRectMake（10200200,40）]；
recButton.backgroundColor=[UIColor blackColor]；
[recButton addTarget:self action:@selector（startRecording）for ControlEvents:UIControlEventTouchUpInside]；
[self.view addSubview:recButton]；
isRecording=否；
}
-（无效）视图卸载
{
[超级视频下载]；
//释放主视图的所有保留子视图。
}
-（无效）视图将显示：（BOOL）动画
{
self.navigationController.navigationBarHidden=是；
}
-（无效）视图将消失：（BOOL）已设置动画
{
self.navigationController.navigationBarHidden=否；
}
-（布尔）应自动旋转指针面定向：（UIInterfaceOrientation）interfaceOrientation
{
if（[[UIDevice currentDevice]userInterfaceIdiom]==UIUserInterfaceIdiomPhone）{
返回（interfaceOrientation==UIInterfaceOrientationGraphic）；
}否则{
返回YES；
}
}
#布拉格标记视频播放
-（无效）开始记录
{
如果（isRecording）{
[自动停止录像]；
isRecording=否；
}
其他的
{
[自启动捕获会话]；
[自启动视频录制]；
isRecording=是；
}
NSURL*url=[NSURL fileURLWithPath:[[NSBundle mainBundle]
pathForResource:@“新建”
类型：@“mov”]]；
[自拍电影：url]；
}
-（无效）播放电影自然：（NSURL*）URL{
玩家=
[[MPMoviePlayerController alloc]initWithContentURL:theURL]；
[[AVAudioSession sharedInstance]设置类别：AVAudioSessionCategoryPlayAndRecord错误：无]；
player.scalingMode=MPMovieScalingModeAspectFill；
player.controlStyle=MPMovieControlStyleNone；
[玩家准备玩]；
//注册播放完成通知
[[NSNotificationCenter defaultCenter]
addObserver:self
选择器：@selector（myMovieFinishedCallback:）
名称：MPMoviePlayerPlaybackDidFinishNotification
对象：玩家]；
[player.view setFrame:self.view.bounds]；
[self.view addSubview:player.view]；
//电影播放是异步的，因此此方法立即返回。
[玩家游戏]；
}
//电影结束后，释放控制器。
-（作废）myMovieFinishedCallback：（NSNotification*）通知
{
MPMoviePlayerController*theMovie=[aNotification object]；
[[NSNotificationCenter defaultCenter]
移除观察者：自我
名称：MPMoviePlayerPlaybackDidFinishNotification
对象：theMovie]；
[player.view从SuperView移除]；
[自动停止录像]；
}
#布拉格标记-
#杂注标记记录
-（无效）初始捕获会话
{
NSLog（@“设置捕获会话”）；
captureSession=[[AVCaptureSession alloc]init]；
//-----添加输入-----
NSLog（“添加视频输入”）；
//添加视频输入
AVCaptureDevice*VideoDevice=[self-FrontFacingCameraiAvailable]；
//[AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo]；
if（视频设备）
{
n错误*错误；
videoInputDevice=[AVCaptureDeviceInputDeviceInputWithDevice:VideoDevice错误：&错误]；
如果（！错误）
{
if（[captureSession canAddInput:videoInputDevice]）
[captureSession addInput:videoInputDevice]；
其他的
NSLog（@“无法添加视频输入”）；
}
其他的
{
NSLog（@“无法创建视频输入”）；
}
}
其他的
{
NSLog（@“无法创建视频捕获设备”）；
}
//添加音频输入
NSLog（“添加音频输入”）；
AVCaptureDevice*audioCaptureDevice=[AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeAudio]；
n错误*错误=nil；
AVCaptureDeviceInput*audioInput=[AVCaptureDeviceInputDeviceInputWithDevice:AudioCaptureDeviceError:&error]；
中频（音频输入）
{
[捕获会话附加输入：音频输入]；
}
//-----增加产出---
//添加电影文件输出
NSLog（@“添加电影文件输出”）；
movieFileOutput=[[AVCaptureMovieFileOutput alloc]init]；
//Float64 TotalSeconds=60；//总秒数
//int32\u t preferredTimeScale=30；//每秒帧数
//CMTime maxDuration=CMTimeMakeWithSeconds（TotalSeconds，preferredTimeScale）；//我也有这个问题，我不知道如何解决，但我知道问题在这里：

[captureSession addInput:audioInput];

如果你删除这行代码，它将工作良好，我认为这是音频混音或一些音频问题

我仍然在寻找答案

我在这里找到了答案：，它有效

但是你记得添加
AudioToolbox.framework
，可能对你有帮助