[vlc] closed caption

[Rick Davis]

I am working on a project that requires closed captioning. I have modified
the MPEG2 decoder and libmpeg2 to detect the CC data. I store the data in
p_pic when libmpeg2 detects STATE_END or STATE_SLICE and is returning a
non-null p_pic. This all seems to be working fine. I then modified
video_output.c of libvlc to remove the CC data from p_picture and store it
in a queue just before calling pf_display. I the have a timer running every
16msec or so that removes the CC data and writes it to a chip on my H/W that
puts the CC data on line 21 of NTSC. The problem I am having is the
character order appears to be swapped sometimes. i.e.

This is what it should be

Thiss  iwhatt  ishou bld

I thought that by the time VLC decided to draw the picture the data would be
in the same order even if things came in out of order. The above example
isn't exact but you should be able to get the jist of my problem.

If I set my encoder source to do frames IP only, it works fine. If I set the
encoder to do IBBP frames, it gets out of order.

	Regards,
	Rick


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