在Webview中显示视频

Question

如何在网页浏览中在iframe中显示视频？ 现在我只听到音频，但视频是黑色的，为什么？

WebView wb = (WebView) dialog.findViewById(R.id.webView);
            wb.setWebChromeClient(new WebChromeClient());
            wb.getSettings().setJavaScriptEnabled(true);
            wb.loadDataWithBaseURL("not_needed",
                    "<iframe src=\"**********\" frameborder=\"0\" \"webkitallowfullscreen=\"true\" mozallowfullscreen=\"true\" allowfullscreen=\"true\"></iframe>",
                    "text/html",
                    "utf-8",
                    "not_needed");