Up until now, the writing process for level 1 elements (those elements
for which CRC-32 elements are written by default) was this in case the
output was seekable: Write the EBML ID, write an "unkown length" EBML
number of the desired length, then write the element into a dynamic
buffer, then write the dynamic buffer (after possible calculation and
writing of the CRC-element), then seek back to the size element and
overwrite the unknown-size element with the real size. The seeking and
overwriting part has been eliminated by not writing the size initially.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: James Almer <jamrial@gmail.com>