[vlc-devel] Private substream for closed captioning data from video capture cards

RATH, CHRISTOPHER A (CHRISTOPHER A) car at research.att.com
Fri Sep 11 14:38:44 CEST 2009

>> There is already a special case in the ps demuxer for handling VCD and SVCD
>> data tracks that causes VLC to ignore the timestamp in the PES header for
>> that packet.  I believe we need to add another case to detect the closed
>> captioning data in substream 0x69.  I have already tested a fix in my local
>> branch of 1.0-bugfixes to do this and now the video is playable.  The fix
>> would have no other affect as VLC does not have a way to process the 0x69
>> substream and thus ignores the data in those packets anyway.
> Can you put a sample somewhere? I will have a look at it.


First, apologies for the previous post with all of the goofy html in it.  I
only get the vlc-devel digest messages and haven't figured out a good way to
reply to a single message in the digest.

In answer to your request for a sample, unfortunately the content is
proprietary, so I can't share it.  However, we do have an application that
we use to pull and index the closed-captioning data.  The debugging output
from this application shows the packet contents.  I may be able to send you
enough of the debugging output that you can see the pattern of good vs. bad
timestamps in the packet headers.

Let me know if that would be good enough, and where I can send it to you.

Chris Rath

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