[FFmpeg-trac] #531(undetermined:new): failure to extract DVB-Teletext track (zero-length file)

[FFmpeg]

#531: failure to extract DVB-Teletext track (zero-length file)
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             Reporter:  BrianEnigma   |                     Type:  defect
               Status:  new           |                 Priority:  normal
            Component:  undetermined  |                  Version:  git
             Keywords:                |               Blocked By:
             Blocking:                |  Reproduced by developer:  0
Analyzed by developer:  0             |
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 So I have two sets of transport stream files, one with a DVB-Sub subtitle
 track and one with a DVB-Teletext track.  In both instances, there's an
 audio track, a video track, and a data track and ffmpeg recognizes all of
 them correctly.  What I'd like to do is extract out just the data track
 (i.e. strip out the audio and video tracks) for analysis and post-
 processing.

 In the DVB-Sub case, I can do something like this (with both ffmpeg 0.8.4
 and the latest git) and everything works as expected:

     ffmpeg -i file1.ts -vn -an -scodec copy -f rawvideo dvbsub.dat

 When I try to do the very same thing for the DVB-Teletext track, I always
 end up with a zero-length file.  I know there should be data in there, as
 I've looked at the data PID in an analyzer and can see the content of the
 teletext payloads.  Ffmpeg sees and recognizes the stream as dvb_teletext,
 but it doesn't seem to want to export it.  Similarly, if I attempt to
 extract just a program (one audio, one video, one teletext subtitle, all
 using the "copy" codec) from a transport stream with multiple programs, I
 get audio and video, but a zero-length subtitle track in the output.

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/531>
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