Teletext subtitles out of sync

[Delphi]

The problem (they come up too early) occurs when paying back a recorded ts file in DVBViewer. Here a snippet (~73 MB):

 

http://www.a123.dk/temp/antonsen.ts

 

The teletext subtitles are on page 398.

When watching live TV there is no problem.

 

The support.zip:

 

http://www.a123.dk/temp/support.zip

 

It has been so for quite some time (more than a year?). Maybe it has something to do with Denmark switching to h.264/MPEG4 for all channels (even SD)?

 

I have tried a lot of settings and tried on different computers, the problem persists.

 

It might not look that bad, but is actually quite annoying and when teletext subtitles are mixed with DVB subtitles the teletext subtitles come on top of the DVB ones making both unreadable.

 

I would realy appreciate a solution to this.

 

TIA

[Griga]

In DVBViewer Pro teletext subtitles are not synchronized with audio / video. They are more or less displayed on arrival. I guess they come too early on file playback, which means there is a (relative) delay in audio / video playback, that depends on the used video/audio decoders and renderers. When I play your file in DVBViewer Pro, the sync is quite ok.

 

For comparison you may want to play the file with DVBViewer GE (see customer area, read the ReadMe!). It provides synchronized teletext subs when they are selected from the settings menu. Internally DVBViewer GE uses the broadcasted teletext presentation time stamps (PTS) for this purpose. The implementation has not found its way into DVBViewer Pro yet, but it's on the todo list, and I hope next year we will find time for it.

 

when teletext subtitles are mixed with DVB subtitles the teletext subtitles come on top of the DVB ones making both unreadable.

 

How does this happen? Steps to reproduce the issue?

[Delphi]

Thanks for the answers!

 

depends on the used video/audio decoders and renderers

I have tried to play the file with several combinations of decoders and renderers: no difference here.

 

When I play your file in DVBViewer Pro, the sync is quite ok

Here they are 2-4 seconds ahead, which is quite annoying. Consider a quiz show where you get the right answer 4 seconds before the question is actually answered.

 

For comparison you may want to play the file with DVBViewer GE

In DVBViewer GE the syncronisation is perfect!!!!!

A few seconds make a big difference in viewing experience!

 

Internally DVBViewer GE uses the broadcasted teletext presentation time stamps (PTS) for this purpose. The implementation has not found its way into DVBViewer Pro yet, but it's on the todo list, and I hope next year we will find time for it.

Great! Just knowing there might be a solution on the way makes me feel better

 

How does this happen? Steps to reproduce the issue?

Here a snippet (DVB subtitles Danish, teletext subtitles page 398):

 

http://www.a123.dk/temp/broen.ts

 

DVBViewer Pro settings:

 

Settings>Options>Subtitles>DVB Subtitles>Language 1>Danish(dan) and check "Enable if available"

 

Now select teletext subtitles page 398 and you will se both types.

[Delphi]

Just a correction:

 

The claimed DVB subtitles in file broen.ts are NOT DVB subtitles, they are hardcoded into the video, so you don't need

 

Settings>Options>Subtitles>DVB Subtitles>Language 1>Danish(dan) and check "Enable if available"

 

(It IS possible to display both types at the same time that way in DVBViewer Pro)

 

 

Luckily it means, that I can play this file in DVBViewer GE watching both types of subtitles. Again: The syncronisation is perfect in DVBViewer GE!!!