ttml codec: sending a duplicate of the style instead of the original
ttml codec: sending a duplicate of the style instead of the original

The functions which use the styles will merge their
attributes, and to avoid consequences of these merges on the
original styles, we work with duplicates.

Signed-off-by: Hugo Beauzée-Luyssen <3faf7ed52fa83d583fc670a96bcf92da270d0767@beauzee.fr>

xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc