Add VideoSource.video

docs/api/camera-source.md

 # CameraSource
 
-A [source of data](source.md) linked to a webcam.
+A [source of data](source.md) linked to a webcam. This class extends [VideoSource](video-source.md).
 
 ## Instantiation
 

docs/api/video-source.md

 
 **Returns**
 
-A new source of data.
+A new source of data.
+
+## Properties
+
+### video
+
+`source.video: HTMLVideoElement, read-only`
+
+The underlying `<video>` element.
+
+*Since:* 0.4.1

src/sources/camera-source.ts

  */
 export class CameraSource extends VideoSource
 {
-    /** Video element */
-    private _cameraVideo: HTMLVideoElement;
-
     /** Options of the constructor */
     private _options: Required<CameraSourceOptions>;
 
         const video = document.createElement('video');
 
         super(video);
-        this._cameraVideo = video;
         this._options = Object.assign({}, DEFAULT_CAMERA_OPTIONS, options);
     }
 
             video: {
                 width: size.width,
                 height: size.height,
+                aspectRatio: options.aspectRatio,
                 ...options.constraints,
             }
         };
         // load camera stream
         return new Speedy.Promise<HTMLVideoElement>((resolve, reject) => {
             navigator.mediaDevices.getUserMedia(constraints).then(stream => {
-                const video = this._cameraVideo;
+                const video = this.video;
                 video.onloadedmetadata = () => {
                     const promise = video.play();
                     const success = 'Access to the webcam has been granted.';
                     error
                 ));
             });
-        }).then(_ => super._init()); // this will call VideoSource._handleBrowserQuirks()
+        }).then(_ => super._init()); // this will handle browser quirks
     }
 
     /**
      */
     _release(): SpeedyPromise<void>
     {
-        const stream = this._cameraVideo.srcObject as MediaStream;
+        const video = this.video;
+        const stream = video.srcObject as MediaStream;
         const tracks = stream.getTracks();
 
         // stop camera feed
         tracks.forEach(track => track.stop());
-        this._cameraVideo.onloadedmetadata = null;
-        this._cameraVideo.srcObject = null;
+        video.onloadedmetadata = null;
+        video.srcObject = null;
 
         // release the media
         return super._release();

src/sources/video-source.ts

     }
 
     /**
+     * The underlying <video> element
+     */
+    get video(): HTMLVideoElement
+    {
+        return this._video;
+    }
+
+    /**
      * A type-identifier of the source of data
      * @internal
      */