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嗨，我想使用 iphone 后置摄像头逐帧获取相框。到目前为止我所做的。

  1. 我以完整模式打开相机。

  • (IBAction) showCameraUI { [self startCameraControllerFromViewController: self usingDelegate: self]; }

  • (BOOL) startCameraControllerFromViewController: (UIViewController*) 控制器 usingDelegate: (id) delegate {

if (([UIImagePickerController isSourceTypeAvailable:
      UIImagePickerControllerSourceTypeCamera] == NO)
    || (delegate == nil)
    || (controller == nil))
    return NO;


UIImagePickerController *cameraUI = [[UIImagePickerController alloc] init];
cameraUI.sourceType = UIImagePickerControllerSourceTypeCamera;

// Displays a control that allows the user to choose picture or
// movie capture, if both are available:
cameraUI.mediaTypes =
[UIImagePickerController availableMediaTypesForSourceType:
 UIImagePickerControllerSourceTypeCamera];

// Hides the controls for moving & scaling pictures, or for
// trimming movies. To instead show the controls, use YES.
cameraUI.allowsEditing = NO;

cameraUI.delegate = delegate;
cameraUI.showsCameraControls=NO;
cameraUI.navigationBarHidden=YES;
cameraUI.toolbarHidden=YES;
cameraUI.wantsFullScreenLayout=YES;
cameraUI.cameraViewTransform = CGAffineTransformScale(cameraUI.cameraViewTransform, CAMERA_SCALAR_SX, CAMERA_SCALAR_SY);
UIButton *btnRecording = [UIButton buttonWithType:UIButtonTypeRoundedRect];
CGRect buttonRect =CGRectMake(190 , 420, 100, 39); // position in the parent view and set the size of the button
btnRecording.frame = buttonRect;
[btnRecording setTitle:@"Recording" forState:UIControlStateNormal];
// add targets and actions
[btnRecording addTarget:self action:@selector(buttonClicked:) forControlEvents:UIControlEventTouchUpInside];
 cameraUI.cameraOverlayView= btnRecording;
[controller presentModalViewController: cameraUI animated: YES];
return YES;

}

  1. 设置 AVCapture 以逐帧获取图片。
  • (void)setupCaptureSession { NSError *error = nil;
// Create the session
AVCaptureSession *session = [[AVCaptureSession alloc] init];

// session.AVCaptureTorchModeOn=YES;

// Configure the session to produce lower resolution video frames, if your
// processing algorithm can cope. We'll specify medium quality for the
// chosen device.
session.sessionPreset = AVCaptureSessionPresetLow;

// Find a suitable AVCaptureDevice
AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
[device lockForConfiguration:nil];
[device setTorchMode:AVCaptureTorchModeOn];  // use AVCaptureTorchModeOff to turn off
[device unlockForConfiguration];
// Create a device input with the device and add it to the session.
AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device
                                                                    error:&error];
if (!input) {
    // Handling the error appropriately.
}
[session addInput:input];

// Create a VideoDataOutput and add it to the session
AVCaptureVideoDataOutput *output = [[AVCaptureVideoDataOutput alloc] init] ;

// output.alwaysDiscardsLateVideoFrames = YES; [会话添加输出：输出]；

dispatch_queue_t queue = dispatch_queue_create("MyQueue", NULL);
[output setSampleBufferDelegate:self queue:queue];
dispatch_release(queue);

// Specify the pixel format
output.videoSettings =
[NSDictionary dictionaryWithObject:
 [NSNumber numberWithInt:kCVPixelFormatType_32BGRA]
                            forKey:(id)kCVPixelBufferPixelFormatTypeKey];


// If you wish to cap the frame rate to a known value, such as 15 fps, set
// minFrameDuration.

// output.minFrameDuration = CMTimeMake(1, 1);

// Start the session running to start the flow of data
  NSLog(@"session is going to start at here");
[session startRunning];

// Assign session to an ivar.
//[self setSession:session];

}

// 从样本缓冲区数据创建 UIImage - (UIImage *) imageFromSampleBuffer:(CMSampleBufferRef) sampleBuffer { NSLog(@"picture is getting"); CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer); // 锁定像素缓冲区的基地址 CVPixelBufferLockBaseAddress(imageBuffer,0);

// Get the number of bytes per row for the pixel buffer
size_t bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer);
// Get the pixel buffer width and height
size_t width = CVPixelBufferGetWidth(imageBuffer);
size_t height = CVPixelBufferGetHeight(imageBuffer);

// Create a device-dependent RGB color space
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
if (!colorSpace)
{
    NSLog(@"CGColorSpaceCreateDeviceRGB failure");
    return nil;
}

// Get the base address of the pixel buffer
void *baseAddress = CVPixelBufferGetBaseAddress(imageBuffer);
// Get the data size for contiguous planes of the pixel buffer.
size_t bufferSize = CVPixelBufferGetDataSize(imageBuffer);

// Create a Quartz direct-access data provider that uses data we supply
CGDataProviderRef provider = CGDataProviderCreateWithData(NULL, baseAddress, bufferSize,
                                                          NULL);
// Create a bitmap image from data supplied by our data provider
CGImageRef cgImage =
CGImageCreate(width,
              height,
              8,
              32,
              bytesPerRow,
              colorSpace,
              kCGImageAlphaNoneSkipFirst | kCGBitmapByteOrder32Little,
              provider,
              NULL,
              true,
              kCGRenderingIntentDefault);
CGDataProviderRelease(provider);
CGColorSpaceRelease(colorSpace);

// Create and return an image object representing the specified Quartz image
UIImage *image = [UIImage imageWithCGImage:cgImage];
CGImageRelease(cgImage);

CVPixelBufferUnlockBaseAddress(imageBuffer, 0);

return image;

}

// 写入样本缓冲区时调用的委托例程 - (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection { // 从样本缓冲区数据创建 UIImage NSLog( @"图片正在获取"); UIImage *image = [self imageFromSampleBuffer:sampleBuffer];

// [self.delegate cameraCaptureGotFrame:image]; }

现在委托“captureOutput”没有接到电话。我不知道我在哪里做错了。这将帮助我。提前致谢。

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