The Matroska Projection master element has such a small maximum length
that it can always be written with a length field of length one.
So it is unnecessary to first write the element into a dynamic buffer to
get the accurate length in order not to waste bytes on the length field.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: James Almer <jamrial@gmail.com>