I have a delegate method but it doesn't help me . Please refer to the method below
-(BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType
What page are you trying to open? UIWebView will NOT auto play any video by default. So if your video dose auto played, it should be some javascript in your HTML let it start to play.
Maybe you should check your HTML first.