Fixes issue 694. patch by Anuradha Suraparaju, anuradha rd.bbc.co uk Originally committed as revision 16261 to svn://svn.ffmpeg.org/ffmpeg/trunk
submitted by Anuradha Suraparaju, anuradha rd.bbc.co uk Originally committed as revision 13041 to svn://svn.ffmpeg.org/ffmpeg/trunk