Eloi Bail authored Nov 05, 2015 and Guillaume Roguez committed Nov 06, 2015

AVPacket are not freed after use. The solution deals with
allocating AVPacket on the stack and ensuring to free it
calling av_packet_unref.
This fix has also widly deployed on Video for having a unique
method other the code.

Change-Id: I049b29effb4e6748ee2dd12b4c52536c99fef498
Tuleap: #91