title: Why Video plays without sound on MPMoviePlayer in iPhone
body: <p>I am using MPMoviePlayer to play local video files in my app. Files are .mov formated. When I run my app in simulator it works fine. But when I run it in iPhone video runs with no sound. Here is my code,</p>
  
  <pre><code>    self.currUrl = [NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:@"Gun_Shot" ofType:@"mov"]];
      if (self.mpc)
       {
         [self.mpc release];
         self.mpc = nil;
       }
      self.mpc =  [[MPMoviePlayerController alloc]
               initWithContentURL:self.currUrl];   
      [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(moviePlayBackDidFinish:) name:MPMoviePlayerPlaybackDidFinishNotification object:self.mpc];
      [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(moviePlayBackLoadStateDidChange:) name:MPMoviePlayerLoadStateDidChangeNotification object:self.mpc];   
      [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(moviePlayBackDidEnterFullScreen:) name:MPMoviePlayerDidEnterFullscreenNotification object:self.mpc];    
      [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(moviePlayBackDidExitFullScreen:) name:MPMoviePlayerDidExitFullscreenNotification object:self.mpc]; 
      [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(moviePlayBackNowPlayingContinues:) name:MPMoviePlayerNowPlayingMovieDidChangeNotification object:self.mpc];  
      [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(moviePlayBackStateChanged:) name:MPMoviePlayerPlaybackStateDidChangeNotification object:self.mpc];
  
      self.mpc.controlStyle = MPMovieControlStyleNone;
      self.mpc.shouldAutoplay = NO;
      self.mpc.view.frame = CGRectMake(0, 0, self.mpView.frame.size.width, self.mpView.frame.size.height);
      [self.mpView addSubview:self.mpc.view];
      [self.mpView bringSubviewToFront:self.topMainView];
      [self.mpView bringSubviewToFront:self.bottomMainView];
      [self.mpc prepareToPlay];
      self.timeLbl.text = [NSString stringWithFormat:@"%f Sec(s)", self.mpc.duration];
  </code></pre>
  
  <p>I don't understand why the videos gone mute when the app runs on iPhone. Any help will be appreciated..</p>