Avoid memcpy when passing buffers

[Nicolas Dufresne]

Le vendredi 12 décembre 2014 à 09:42 +0100, Sebastian Dröge a écrit :
> And also take a look at the v4l2src element, which is a source element
> providing custom memory to downstream elements without copying.

A final note while at it, when skipping the copies, it's often needed to
make sure downstream can handle custom stride (unless your stride
matches GStreamer default). Downstream will support any stride if it
support the VIDEO_META API.

Nicolas