Playing video in MATLAB

I am trying to play some video files in MATLAB R2012a, but whenever I try to play the video using VideoReader, it shows the following error:

Error using VideoReader/init (line 447)
Failed to initialize internal resources.

Error in VideoReader (line 132)
            obj.init(fileName);

Error in aa (line 15)
VideoReader('face1.mp4');

And whenever I try to play the video using implay function, it plays, but the video doesn't provide the audio.