0 terminated ASS/SSA compatible event line. The presentation of this is unaffected by the other values in this struct.
< height of pict, undefined when pict is not set
< number of colors in pict, undefined when pict is not set
data+linesize for the bitmap of this subtitle. can be set for text/ass as well once they where rendered
< 0 terminated plain UTF-8 text
< width of pict, undefined when pict is not set
< top left corner of pict, undefined when pict is not set
< top left corner of pict, undefined when pict is not set