May allow for more flexible distribution terms for your code 
           when it uses videoIO (ffmpeg may be compiled with either 
           the LGPL or GPL license).

     'ffmpegDirect': low-overhead method on Linux
       - same as ffmpegPopen2, but the ffmpeg libraries are loaded
         directly by the MEX file.
         - May not work if MathWorks' and your version of GCC are
           incompatible. 
         - Slightly faster than ffmpegPopen2 since there is no
           interprocess co