The logic here was off. If the packet size is exactly two, then
it's a well-formed empty subtitle, used to mark the end of the
duration of the previous subtitle.
Signed-off-by: Philip Langdale <philipl@overt.org>
This change introduces a basic decoder for 3GPP Timed Text subtitles,
also known as TX3G, Quicktime subtitles, or "movtext" in the existing
code.
This initial change doesn't attempt to parse styling information,
and just reads the plain text of the subtitles. I intend to add
support for styles eventually, but it's challenging due to a lack
of existing players that support them.
Signed-off-by: Philip Langdale <philipl@overt.org>