我有以下适用于 iOS 6 和 7.x 的代码。

在 iOS 8.1 中，我有一个奇怪的问题，如果您捕获一个 session 大约 13 秒或更长时间，生成的 AVAsset 只有 1 个轨道(视频)，音频轨道不存​​在。

如果您录制的时间较短，则 AVAsset 具有预期的 2 个轨道(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

最佳答案

这将帮助您修复它。

[movieOutput setMovieFragmentInterval:kCMTimeInvalid];

我认为这是一个错误。文档说，如果记录没有成功完成，则不会写入示例表。因此，如果它确实成功完成，它将自动写入。但是现在好像没有。

有什么想法吗？

关于iOS 8 iPad AVCaptureMovieFileOutput 在录制 13 - 14 秒后丢失/丢失/从未获得音轨，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/26735627/