Also allow qmin/qmax to go up to 69 (the current max value for libx264). This will have to increase when we add 9/10-bit support. (cherry picked from commit c7ac200d15e3240972d269df768068f0e3bb9c2f)
Originally committed as revision 23879 to svn://svn.ffmpeg.org/ffmpeg/trunk
Patch by Lou Logan. Originally committed as revision 22714 to svn://svn.ffmpeg.org/ffmpeg/trunk