change while loops to do-while as the condition is true the first time and the check just wastes cpu cycles

Originally committed as revision 7576 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 7575 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 7574 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 7573 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 7572 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 7571 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 7570 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 7569 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 7568 to svn://svn.ffmpeg.org/ffmpeg/trunk

and fix GPL/LGPL version mismatches.

Originally committed as revision 6577 to svn://svn.ffmpeg.org/ffmpeg/trunk

     libavformat/utils.c into libavutil

Originally committed as revision 6310 to svn://svn.ffmpeg.org/ffmpeg/trunk