资源

因此,我这样设置了QTCaptureSession

    //Setup Camera
    cameraSession = [[QTCaptureSession alloc] init];
    QTCaptureDevice *camera = [QTCaptureDevice deviceWithUniqueID: cameraID];

    BOOL success = [camera open: &error];
    if (!success || error)
    {
        NSLog(@"Could not open device %@.", cameraID);
        NSLog(@"Error: %@", [error localizedDescription]);
        return nil;
    }

    //Setup Input Session
    QTCaptureDeviceInput *cameraInput = [[QTCaptureDeviceInput alloc] initWithDevice: camera];

    success = [cameraSession addInput: cameraInput error: &error];
    if (!success || error)
    {
        NSLog(@"Could not initialize input session.");
        NSLog(@"Error: %@", [error localizedDescription]);
        return nil;
    }

    //Setup Output
    QTCaptureDecompressedVideoOutput *cameraOutput = [[QTCaptureDecompressedVideoOutput alloc] init];
    [cameraOutput setDelegate: self];

    success = [cameraSession addOutput: cameraOutput error: &error];
    if (!success || error)
    {
        NSLog(@"Could not initialize output session.");
        NSLog(@"Error: %@", [error localizedDescription]);
        return nil;
    }


因此,QTCaptureDecompressedVideoOutput代表的captureOutput:didOutputVideoFrame:WithSampleBuffer:fromConnection:

- (void)captureOutput:(QTCaptureOutput *)captureOutput didOutputVideoFrame:(CVImageBufferRef)videoFrame withSampleBuffer:(QTSampleBuffer *)sampleBuffer fromConnection:(QTCaptureConnection *)connection
{
    NSLog(@"starting convert\n");
}


然后,我使用以下命令开始捕获处理:

    [cameraSession startRunning];


所有变量初始化都很好,会话也可以正常启动,但是captureOutput:didOutputVideoFrame:withSampleBuffer:fromConnection:从未被调用。

语境

这是一个由GCC编译的命令行应用程序。它与以下框架链接:


基础
可可
QTKit
石英核心


相关杂项

该帧不太可能丢失,因为captureOutput:didDropVideoFrameWithSampleBuffer:fromConnection:也没有被调用。

最佳答案

因此,在Mike Ash的帮助下,我设法弄清楚我的程序正在立即终止,而不是在等待委托回调(根据Apple的QTKit文档,该回调可能发生在单独的线程上)。

我的解决方案是将BOOL属性添加到名为captureIsFinished的对象,然后将其添加到main()函数:

    //Wait Until Capture is Finished
    while (![snap captureIsFinished])
    {
        [[NSRunLoop currentRunLoop] runUntilDate: [NSDate dateWithTimeIntervalSinceNow: 1]];
    }


它有效地使应用程序的运行循环永续了1秒钟,检查捕获是否完成,然后再运行一秒钟。

关于objective-c - QTCaptureOutput.delegate captureOutput:didOutputVideoFrame:...从未调用,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/9101222/

10-12 02:32