id	summary	reporter	owner	description	type	status	priority	component	version	resolution	keywords	cc	blockedby	blocking	reproduced	analyzed
531	failure to extract DVB-Teletext track (zero-length file)	BrianEnigma		"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.
"	defect	closed	normal	undetermined	git-master	fixed	dvbsub				1	0