We got defective video when use GCC 4.9.2 instead of GCC 4.9.1 to compile FFMEPG. And further found
that GCC 4.8 and 4.9 need patch to fix the lvsl/lvsr bug on POWER LE, and GCC 5.1 contains
the correct code since its release. The message on gcc-patches requesting approval for lvsl/lvsr
patch is at https://gcc.gnu.org/ml/gcc-patches/2014-10/msg00228.html.

The fixed code avoids using lvsl and will not depends on GCC version, also it uses less instructions on POWER LE.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>