The SMIL Tutorial - Layout - Make your medium scroll within its area

Make your medium scroll within its area

And to conclude with the fit attribute, the last case is when the media is bigger than its region. You would like to scroll this area, as explain below.

Set the fit attribute to "scroll" in your <region> tag.

<smil>
 <head>
  <layout>
   <root-layout width="147" height="116" background-color="yellow" />
   <region id="region_1" left="8" top="10" width="116" height="81"
           background-color="white" fit="scroll"/>
  </layout>
 </head>
 <body>
  <!-- this image is BIGGER than its region -->
  <img src="eurotango.gif" region="region_1" />
 </body>
</smil>

Source (vim HTML version)