停止视频在WinJS捕捉编程

Question

我有一个winJS我在哪里录制的视频。虽然我可以做它的工作，我想在15秒后自动停止摄像机录制。目前，凸轮记录超过15秒，然后修剪出从视频15秒。我想自动15secs后关闭相机/停止录制。我有以下代码：

function captureVideo() {
    WinJS.log && WinJS.log("", "sample", "status");

    // Using Windows.Media.Capture.CameraCaptureUI API to capture a video
    var dialog = new Windows.Media.Capture.CameraCaptureUI();

    dialog.videoSettings.allowTrimming = true;
    dialog.videoSettings.format = Windows.Media.Capture.CameraCaptureUIVideoFormat.mp4;
    dialog.videoSettings.maxDurationInSeconds = document.getElementById("txtDuration").value;
    dialog.captureFileAsync(Windows.Media.Capture.CameraCaptureUIMode.video).done(function (file) {

        if (file) {

            var videoBlobUrl = URL.createObjectURL(file, {oneTimeOnly: true});
            document.getElementById("capturedVideo").src = videoBlobUrl;
            localSettings.values[videoKey] = file.path;

        } else {
            WinJS.log && WinJS.log("No video captured.", "sample", "status");
        }
    }, function (err) {
        WinJS.log && WinJS.log(err, "sample", "error");
    });
}