gst-ffmpeg: fix for Security Advisory CVE-2013-0849

gst-ffmpeg: fix for Security Advisory CVE-2013-0849

The roq_decode_init function in libavcodec/roqvideodec.c in FFmpeg
before 1.1 allows remote attackers to have an unspecified impact via a
crafted (1) width or (2) height dimension that is not a multiple of
sixteen in id RoQ video data.

http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2013-0849

Signed-off-by: Yue Tao <Yue.Tao@windriver.com>
Signed-off-by: Roy Li <rongqing.li@windriver.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>