Camera API (Tizen Extension): Using the Camera

This tutorial demonstrates how you can control the camera on a wearable device.

This feature is supported in wearable applications only.

Warm-up

Become familiar with the Camera API (Tizen Extension) API basics by learning about:

• Accessing the Camera Device

  Access the media stream from the camera.

• Managing the Camera

  Record videos and capture images with the camera, and set the camera settings.

• Deallocating the Camera Preview Stream

  Deallocate the camera preview stream resources when the application is invisible.

Task

In the Camera task, we will walk through launching and controlling the camera on the Tizen wearable device.

Accessing the Camera Device

To take advantage of the camera features, you must learn to access the camera device:

1. Access the camera with the stream that you can receive from the getUserMedia() method. The second parameter for that method is an event handler that is triggered when the stream is successfully retrieved.

   var stream;
   navigator.webkitGetUserMedia({video: true, audio: false}, gotStreamCallback, 
                                noStreamCallback);
   function gotStream(rStream) 
   {
      stream = rStream;
   }
   

2. Use the received stream as the first parameter for the createCameraControl() method, which returns the cameraControl object. The createCameraControl() method is a member object of tizCamera from the navigator.

   navigator.tizCamera.createCameraControl(stream, gotCameraCallback, noCameraCallback); 
   

3. You can use the cameraControl in the success event handler of the createCameraControl() method, where it is provided as a parameter:

   function gotCameraCallback(cameraControl)
   

Managing the Camera

To take advantage of the camera features, you must learn to manage the camera:

• You can record videos with the cameraControl object.

  Use the start() to start the recording, and the stop() method to stop the recording:

  cameraControl.recorder.start(recordingStartSuccess, recordingStartError);
  cameraControl.recorder.stop(recordingStopSuccess, recordingStopError);    
  

• Use the takePicture() method to capture an image and write it in a file:

  cameraControl.image.takePicture(takePictureSuccess, takePictureError);    
  

• Use the applySettings() method to modify the camera settings (to set the file name of the recorded video or captured image):

  var recordingSetting = 
  {
     fileName: "sample.3gp";
  }   
  cameraControl.recorder.applySettings(recordingSetting, 
                                       recorderSettingSuccessCallback, 
                                       recorderSettingErrorCallback);
  

  Note
  If a setting cannot be set, the error callback is called to resolve the issue.

Deallocating the Camera Preview Stream

To take advantage of the camera features, you must learn to deallocate the camera preview stream resources when the application is invisible, so that the preview stream can be assigned to another application:

1. Access the camera preview stream using the getUserMedia() method:

   function initCameraPreview() 
   {
      navigator.webkitGetUserMedia({video: true, audio: false},
                                   onPreviewStream,
                                   onPreviewStreamError);
   }
   
   function onPreviewStream(stream) 
   {
      cameraStream = stream;
   }

2. Use the onVisibilityChange() event listener to detect changes in the visibility state of the application. When the application becomes invisible, the cameraStream.stop() method is called to release the preview stream. When the application becomes visible again, the preview stream is re-initialized.

   function onVisibilityChange() 
   {
      if (document.visibilityState !== 'visible') 
      {
         cameraStream.stop();
      } 
      else 
      {
         initCameraPreview();
      }
   }