This api is in linux kernel since version 2.6.39,
and present in all version 3.
The commit that adds the API in master branch of the
linux kernel source is:
f8f3914cf9
v4l2 doc: "Some devices require data for each input
or output video frame to be placed in discontiguous
memory buffers"
There are newer structures 'struct v4l2_pix_format_mplane'
and 'struct v4l2_plane'.
So the pixel format is not setup with the same API when using
multi-planar.
Also for gst-v4l2, one of the difference is that in GstV4l2Meta
there are now one mem pointer for each maped plane.
When not using multi-planar, this commit takes care of keeping
the same code path than previously. So that the 2 cases are
in two different blocks triggered from V4L2_TYPE_IS_MULTIPLANAR.
Fixes bug https://bugzilla.gnome.org/show_bug.cgi?id=712754