Add support for parsing and muxing smpte 2094-50 metadata. It will
be stored as an ITUT-T35 message in the BlockAdditional element with
an AddId type of 4 (which is reserved for ITUT-T35 in the matroska
spec).
https://www.matroska.org/technical/codec_specs.html#itu-t35-metadata
Signed-off-by: Vignesh Venkatasubramanian <vigneshv@google.com>
And rename it to ff_encode_add_stats_side_data() and move its
declaration to encode.h. Also constify the error pointee.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>