Android: playing youtube video on Webview

i've a problem to playing youtube video on a WebView. It's all day i reading question and answer on how to do this, but it doesn't work. I've already set the Manifest and this is the code i'm using

mWebview.setWebViewClient(new WebViewClient() {
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            return false;
        }
    });


    mWebview.getSettings().setPluginState(WebSettings.PluginState.ON);
    mWebview.setWebChromeClient(new WebChromeClient());
    mWebview.getSettings().setJavaScriptEnabled(true);
    mWebview.getSettings().setAppCacheEnabled(true);
    mWebview.setInitialScale(1);
    mWebview.getSettings().setLoadWithOverviewMode(true);
    mWebview.getSettings().setUseWideViewPort(true);

    //webSettings.setLoadsImagesAutomatically(true);
    //webSettings.setSupportZoom(false);

    mWebview.loadUrl("https://www.youtube.com/embed/MYVIDEOID");

and what's happen is this i can click the play button the timer start but i can see nothing.

EDIT: The problem seems on the emulator and not on real device, check the comment for the answer.