Running Mp4 or Flash Video

Hi I am trying to run video.For that I have embedded mp4 and flash file inside video tag using below Tag:
<video controls="controls" poster="http://sandbox.thewikies.com/vfe-generator/images/big-buck-bunny_poster.jpg" width="640" height="360">
      <source src="http://clips.vorwaerts-gmbh.de/big_buck_bunny.mp4" type="video/mp4" />
            <object type="application/x-shockwave-flash" data="http://releases.flowplayer.org/swf/flowplayer-3.2.1.swf" width="640" height="360">
            <param name="movie" value="http://releases.flowplayer.org/swf/flowplayer-3.2.1.swf" />
            <param name="allowFullScreen" value="true" />
            <param name="wmode" value="transparent" />      
      </object>
</video>


 So if mp4 fails then it run .swf file(Flash) What i noticed is that flash video quality is not same when it play  as it is for orginal.Can u plz help me like how I can make flash video looks great,Is there any property for showing higher resolution while playing. Please help.