1200 Minute Conversion Error

[Bigmack3000 96]

Every now and then when I convert a file, Emby makes the final file 1200 minutes long.  I can cut off the excess and the file is then fine, but it's an odd problem to run into.

[Luke 40065]

Hi there, what is the length of the source? What kind of source file?

[Bigmack3000 96]

Various lengths. from 20 minute shorts to 3 hour films.  They are mkv rips of blurays and/or dvds.  It seems to be random too.  I could convert a season of a show, and two thirds of the episodes are fine but then the other 3rd have this problem. 

 

But it's also seems to just be the timecode that's incorrect.  There's nothing actually playable after the end of the film's normal runtime.  

[Luke 40065]

How are you determining that its' 1200 minutes?

[Bigmack3000 96]

 

It shows up with that length when opened in VLC.  But if I scroll past the normal runtime, the file closes.  Which makes me think there's no actual data added, just the wrong length being put in the file conversion.  But every time it happens, it's the same wrong length.

 

Also, I don't know why the screenshot uploaded like that, but the actual video looks fine after the conversion.  It's just the length.

Edited December 1, 2019 by Bigmack3000

[Luke 40065]

What length does the new file show in Emby?

[Bigmack3000 96]

 

Same length.  

 

The uploaded looks odd, but again that part looks fine on my computer.

[Bigmack3000 96]

I'm not positive, but as I go through all the ones that have this happen, It seems to be far more common in files that had subtitles auto burned in during conversion.

[Luke 40065]

Can you provide a source file for testing? Thanks.

[Bigmack3000 96]

Sure, but how would I do this?

[Luke 40065]

dropbox or google drive would be great. before you do that, can you provide an ffmpeg conversion log in case we might be able to spot something there? thanks.

[Bigmack3000 96]

Ok, I attempted the file again and got the same error.  Attached is the log for that conversion.

Emby Transcode Log.txt

[Luke 40065]

So just to confirm, you haven't yet seen this when not burning in subtitles, right?

[Bigmack3000 96]

I don't believe so, but I have about 5 converting tonight that shouldn't have subtitles burned in.  I'll check them when they're done.

[Luke 40065]

Ok thanks. I was actually just able to reproduce this on an input file with pgs subtitles.

[Bigmack3000 96]

You think the type of subtitle is the problem?  

 

Also, none of the conversions last night or today had burned in subtitles and none had the error either.

[Luke 40065]

We're looking into it. Thanks.

[Bigmack3000 96]

Would it be possible to just make burning in subtitles optional?

[Luke 40065]

Yes more subtitle conversion options are planned for the future. Thanks.

[softworkz 4566]

You think the type of subtitle is the problem?  

 

Also, none of the conversions last night or today had burned in subtitles and none had the error either.

 

So, here's what's happening:

 

 

 

Sometimes (or maybe even always in case of PGS subs), the subtitle frames not have valid values for start_display_time and end_display_time. 

 

Like above:  4294967295 is just the maximum for 32 bit uint, but ffmpeg seems to interpret that value.

 

That is no problem as long as there's another subtitle frame following which indicates the end of the previous one (that next one might even be empty just to invalidate the previous one).

 

But when it comes to the very last subtitle graphic the end_display time is considered to be a frame event. Ffmpeg considers the 4294967295 to be valid and "waits" for that to happen. Meanwhile. the video main has ended as well, but by default configuration, the overlay filter repeats a stream's image when it has reached its end.

 

And that causes one additional frame to be added to the output file with an insanely high timestamp value:

 

 

 

That one additional frame is in turn causing the high and incorrect container duration.

 

This is fixed in the upcoming beta (4.4.0.1)

Edited December 6, 2019 by softworkz

[pwhodges 1855]

What's the program generating those windows?

[softworkz 4566]

It's an internal tool.

[Bigmack3000 96]

That's interesting.  Thank you for the in-depth explanation!

[Bigmack3000 96]

Also, how would I get in on the beta?

[Bigmack3000 96]

I'm not sure if the update was supposed to fix the problem.  But just incase, it's still happening for me.