401
edits
Changes
added SPU
==== Bitmap (closed) captions ====
* sometimes closed captions are represented as a a sequence of transparent bitmaps which are overlayed onto the video at given time offsets to display the closed captions (sometimes used on DVDsalso called SPU subtitles, or [http://www.subtitling.com/downloads/DVB%20subtitling.pdf DVB])
Discussion:
* (-) like open captions, bitmap captions are restrictive because they are just pixels in the video and the actual caption text is not directly accessible other than through OCR
