Fix build errors for older versions of the api where
VIDIOC_ENUM_DV_TIMINGS was defined but V4L2_IN_CAP_DV_TIMINGS was not.
I was under the impression that they were added at the same time, but
apparently i was wrong there.
Thanks to kmoore@FreeBSD.org for spotting this on FreeBSD.
Add compatibility with older versions of the api by not failing to
build when the VIDIOC_ENUM_DV_TIMINGS is missing. In older versions
of the api there was a different system to get dv-timing presets, which
was replaced by the current enumeration system with Linux 3.4.
This will allow for the plugin to be built against older versions of the
api by disabling the enumeration support, thus reducing the
functionality for some devices.
Since the helper function also needs to pack/unpack the resolution, the
pack/unpack functions were moved to the helper library and prefixed with
v4l2_ in order to avoid possible collisions.
This moves some functions that are generic to a separate source
file. While doing so the api to those functions was improved to
be more generic and not depend on knowledge about the internal
structure of the plugin.
fryshorts