Errors when playing mpg2 files that contain CC in VBI

[marc.aronson]

Note: I am running VLC on Windows XP/SP2 and running VLC version 0.85.

I am a mythtv user and recently upgraded to mythtv version 0.19, which enables one to capture the Closed Caption data in the VBI. My capture card in a Hauppauge PVR-250 and I am in the United States so my format is NTSC. I use VLC to do playback of recorded files on my laptop. What I have found is that files recorded without CC data playback fine, but files that contain the CC data in the VBI do not play back well. Starting 18-seconds into the playback the video becomes very "jerky" and a large number of warnings start to show up in the messages window, as shown below.

I understand from other posts that there aren't any near-term plans to support display of the CC text, but is there a way to fix the problem that causes the video display to go bad when the mpeg2 stream contains CC data in the VBI? If not, is there a simple way to filter out the CC data from the VBI before it is fed to VLC?

Thank you.

Marc

main warning: computed PTS is out of range (27848), clearing out
main warning: PTS is out of range (27886), dropping buffer
main warning: output PTS is out of range (51914), clearing out
main warning: PTS is out of range (3957), dropping buffer
main warning: PTS is out of range (-18721), dropping buffer
main warning: late picture skipped (68161)
main warning: late picture skipped (150194)
main warning: late picture skipped (232224)
main warning: computed PTS is out of range (656125), clearing out
main warning: PTS is out of range (656169), dropping buffer
main warning: output PTS is out of range (668196), clearing out
main warning: late picture skipped (314259)
main warning: late picture skipped (396290)
main warning: late picture skipped (478324)
main warning: PTS is out of range (853032), dropping buffer
main warning: PTS is out of range (829120), dropping buffer
main warning: late picture skipped (455688)
main warning: PTS is out of range (859437), dropping buffer
main warning: PTS is out of range (835529), dropping buffer
main warning: PTS is out of range (812164), dropping buffer
main warning: PTS is out of range (788218), dropping buffer
main warning: late picture skipped (417115)
main warning: PTS is out of range (779019), dropping buffer
main warning: PTS is out of range (782932), dropping buffer
main warning: PTS is out of range (758995), dropping buffer
main warning: PTS is out of range (735871), dropping buffer
main warning: PTS is out of range (711926), dropping buffer
main warning: PTS is out of range (688813), dropping buffer
main warning: PTS is out of range (664869), dropping buffer
main warning: PTS is out of range (641480), dropping buffer
main warning: PTS is out of range (618137), dropping buffer
main warning: PTS is out of range (594192), dropping buffer
main warning: PTS is out of range (585168), dropping buffer
main warning: PTS is out of range (561226), dropping buffer
main warning: PTS is out of range (537587), dropping buffer
main warning: PTS is out of range (513641), dropping buffer
main warning: PTS is out of range (508066), dropping buffer
main warning: PTS is out of range (529152), dropping buffer
main warning: PTS is out of range (505212), dropping buffer
main warning: PTS is out of range (493302), dropping buffer
main warning: PTS is out of range (469366), dropping buffer
main warning: PTS is out of range (449857), dropping buffer
main warning: PTS is out of range (425918), dropping buffer
main warning: PTS is out of range (403813), dropping buffer
main warning: late picture skipped (61223)
main warning: PTS is out of range (450437), dropping buffer
main warning: PTS is out of range (426502), dropping buffer
main warning: PTS is out of range (403258), dropping buffer
main warning: PTS is out of range (379314), dropping buffer
main warning: PTS is out of range (356078), dropping buffer
main warning: PTS is out of range (332162), dropping buffer
main warning: PTS is out of range (308672), dropping buffer
main warning: PTS is out of range (285140), dropping buffer
main warning: PTS is out of range (261194), dropping buffer
main warning: PTS is out of range (267438), dropping buffer
main warning: PTS is out of range (243505), dropping buffer
main warning: PTS is out of range (219895), dropping buffer
main warning: PTS is out of range (195949), dropping buffer
main warning: PTS is out of range (172665), dropping buffer
main debug: decoded 85/105 pictures
main warning: PTS is out of range (170328), dropping buffer

[The DJ]

Ehm, this has notthing to do with the CC. The timeline of this mpeg is simply incorrect/inconsistent, and therefore the video is an invalid MPEG file.

(ergo, it was written incorrectly)

[marc.aronson]

Thank you for the quick response. Here is some additional information that may be relevant:

1. All files captured with CC enabled have this problem when I try to play them with VLC.

2. All of those sames files play properly when played with the embedded myth player and Nero show time.

3. If I turn off capturing of the CC data then VLC is able to playback the files, as are the other two players I mentioned.

That is why I suspect it is an issue with VLC. Does this additional information have any impact on your thinking?

Marc

[The DJ]

The timeline of the CC data is not synchronized with the timeline of the other data in the mpeg. It should be. That other players don't care about the timeline says more about the other players, then about the quality of this mpeg.

BTW: this issue is quite common. Try pulling your file trough a validater/corrector like ProjectX for instance. It should be able to fix your files.

[marc.aronson]

DJ, thanks for the additional information and the pointer to projectx. What you've said makes a lot of sense. I am starting to suspect that the reason the video goes "choppy" is because of all the cycles spent logging the various error messages. It would be very helpful if I could avoid running a pre-processor like projectx. Is there a way I can tell VLC to not generate any messages when it encounters this problem in the mpeg stream? I already have the "verbose" level set to 0 -- is there a setting that will supress these error messages? Thanks!

Marc