wrapper/gstreamer plugin based on xcore

sample launch line:

gst-launch-1.0 xcamsrc sensor=0 capturemode=0x4000 memtype=4 \
  buffercount=8 fpsn=25 fpsd=1 width=1920 height=1080        \
  pixelformat=0 field=0 bytesperline=3840                    \
  ! video/x-raw, format=NV12, width=1920, height=1080,       \
    framerate=30/1 ! queue ! vaapiencode_h264 ! fakesink
17 files changed