CEA608_IN_CEA708_RAW is the same format as CEA708_RAW. It's only
difference is that it must contain only CEA608 and a format like this
does not exist in practice. In practice every element that handles raw
cc_data triplets must check each triplet for their actual content and
handle them accordingly.
For CC-only streams a parser could signal the existence of CEA608 and/or
CEA708 inside the caps but for metas this can only potentially be
signalled via the ALLOCATION query for negotiation purposes.
A separate format for this is not very useful and instead it should be a
format qualifier.
CEA608_S334_1A is the format defined by SMPTE S334-1 Annex A and which
is used for transferring CEA608 over SDI instead of CEA708 CDP packets.
This commits add common elements for Ancillary Data and Closed
Caption support in GStreamer:
* A VBI (Video Blanking Interval) parser that supports detection
and extraction of Ancillary data according to the SMPTE S291M
specification. Currently supports the v210 and UYVY video
formats.
* A new GstMeta for Closed Caption : GstVideoCaptionMeta. This
supports the two types of CC : CEA-608 and CEA-708, along with
the 4 different ways they can be transported (other systems
are super-set of those).
https://bugzilla.gnome.org/show_bug.cgi?id=794901
