iOS 8 iPad AVCaptureMovieFileOutput在录制13 - 14秒后丢失/丢失/永远不会获得音轨

Question

我有以下代码适用于iOS 6和7.x.

在iOS 8.1中,我有一个奇怪的问题,如果你捕获会话大约13秒或更长时间,结果AVAsset只有1个轨道(视频),音频轨道就不存在.

如果您录制的时间较短,则AVAsset会有预期的2个音轨(视频和音频).我有足够的磁盘空间,该应用程序有权使用相机和麦克风.

我用最少的代码创建了一个新项目,它重现了这个问题.

任何想法将不胜感激.

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController
{
    enum RecordingState { Recording, Stopped };
    enum RecordingState recordingState;

    AVCaptureSession *session;
    AVCaptureMovieFileOutput *output;
    AVPlayer *player;
    AVPlayerLayer *playerLayer;
    bool audioGranted;
}

- (void)viewDidLoad {
    [super viewDidLoad];

    [self setupAV];
    recordingState = Stopped;
}

-(void)setupAV
{
    session = [[AVCaptureSession alloc] init];
    [session beginConfiguration];
    AVCaptureDevice *videoDevice = nil;

    for ( AVCaptureDevice *device in [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo] ) {
        if ( device.position == AVCaptureDevicePositionBack ) {
            videoDevice = device;
            break;
        }
    }
    AVCaptureDevice *audioDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeAudio];
    if (videoDevice && audioDevice)
    {
        AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:videoDevice error:nil];
        [session addInput:input];

        AVCaptureDeviceInput *audioInput = [AVCaptureDeviceInput deviceInputWithDevice:audioDevice error:nil];
        [session addInput:audioInput];

        NSURL *recordURL = [self tempUrlForRecording];
        [[NSFileManager defaultManager] removeItemAtURL:recordURL error:nil];

        output= [[AVCaptureMovieFileOutput alloc] init];
        output.maxRecordedDuration = CMTimeMake(45, 1);
        output.maxRecordedFileSize = 1028 * 1028 * 1000;
        [session addOutput:output];
    }
    [session commitConfiguration];
}

- (IBAction)recordingButtonClicked:(id)sender {
    if(recordingState == Stopped)
    {
        [self startRecording];
    }
    else
    {
        [self stopRecording];
    }
}

-(void)startRecording
{
    recordingState = Recording;
    [session startRunning];
    [output startRecordingToOutputFileURL:[self tempUrlForRecording] recordingDelegate:self];

}

-(void)stopRecording
{
    recordingState = Stopped;
    [output stopRecording];
    [session stopRunning];
}

- (void)captureOutput:(AVCaptureFileOutput *)captureOutput didFinishRecordingToOutputFileAtURL:(NSURL *)outputFileURL fromConnections:(NSArray *)connections error:(NSError *)error
{
    AVAsset *cameraInput = [AVAsset assetWithURL:[self tempUrlForRecording]];
    //DEPENDING ON HOW LONG RECORDED THIS DIFFERS (<14 SECS - 2 Tracks, >14 SECS - 1 Track)
    NSLog(@"Number of tracks: %i", cameraInput.tracks.count);
}

-(id)tempUrlForRecording
{
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectoryPath = [paths objectAtIndex:0];

    NSString *path = @"camerabuffer.mp4";
    NSString *pathCameraInput =[documentsDirectoryPath stringByAppendingPathComponent: path];
    NSURL *urlCameraInput = [NSURL fileURLWithPath:pathCameraInput];

    return urlCameraInput;
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end

Answer 1

这将帮助您解决它.

[movieOutput setMovieFragmentInterval:kCMTimeInvalid];

我认为这是一个错误.文档说如果录制没有成功完成,则不会写入示例表.因此,如果它成功完成,它将自动写入.但现在看起来似乎没有.

有任何想法吗？