小编Hap*_*per的帖子

我能够录制视频并将电影正确输出到文件中.但是,在尝试使用AVAudioPlayer播放某些音频时,我遇到了视频录制(没有视频输出)的问题.这是否意味着我不能同时使用AVCaptureSession和AVAudioPlayer？这是我创建捕获会话和播放音频的代码.首先启动视频捕获,然后在捕获期间,我想播放一些音频.非常感谢您的帮助.

用于创建捕获会话以记录视频(带音频)的代码 - 输出到.mov文件:

- (void)addVideoInput
    AVCaptureDevice *audioDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeAudio];
    //... also some code for setting up videoDevice/frontCamera
    NSError *error;
    AVCaptureDeviceInput *videoIn = [AVCaptureDeviceInput 
    deviceInputWithDevice:frontCamera error:&error];
    AVCaptureDeviceInput *audioIn = [AVCaptureDeviceInput 
    deviceInputWithDevice:audioDevice error:&error];
    if (!error) {
         if ([captureSession canAddInput:audioIn])
              [captureSession addInput:audioIn];
         else
              NSLog(@"Couldn't add audio input.");  
         if ([captureSession canAddInput:videoIn])
              [captureSession addInput:videoIn];
         else
              NSLog(@"Couldn't add video input.");
}
- (void)addVideoOutput
{
     AVCaptureMovieFileOutput *m_captureFileOutput = [[AVCaptureMovieFileOutput alloc] init];
     [captureSession addOutput:m_captureFileOutput];

     [captureSession startRunning];

     NSString *docDir = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
     NSMutableString *filePath = …

是否可以检测到每个被触摸的像素？更具体地,当用户触摸屏幕时,是否可以跟踪用户触摸的点群集的所有xy坐标？如何区分用户使用拇指绘图以及何时使用手指绘图？我想根据用户触摸屏幕的方式反映画笔差异,并且还想跟踪随时间触摸的所有像素的xy坐标.非常感谢您的帮助.

我正在尝试为我的视图实现UIPanGestureRecognizer.如何添加多点触控？下面是我视图中的代码(UIView的子类).我希望能够同时知道所有触摸的位置和速度.当前代码仅打印一次触摸的位置和速度.更改属性minimumNumberOfTouches和maximumNumberOfTouches不起作用.非常感谢您的帮助.

UIPanGestureRecognizer *panGestureRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(handlePanGesture:)];
panGestureRecognizer.cancelsTouchesInView = NO;
[self addGestureRecognizer:panGestureRecognizer];


- (void)handlePanGesture:(UIPanGestureRecognizer *)panGestureRecognizer
{
    CGPoint location = [panGestureRecognizer locationInView:panGestureRecognizer.view];
    CGPoint velocity = [panGestureRecognizer velocityInView:panGestureRecognizer.view];

    NSLog(@"Location: %@",  NSStringFromCGPoint(location));
    NSLog(@"Velocity: %@",  NSStringFromCGPoint(velocity));

}