[MEncoder-users] Subtitle extraction

[Stefan]

Hello,

I am experimenting with the extraction of subtitle streams in vobsub
format and are confused because of different results and warning
messages by mkvmerge.

The command I use with MPlayer 1.0rc2:

> mencoder -dvd-device $DEVICE dvd://$TITLE -nosound -ovc copy -o /dev/null -sid $SID -vobsubout $FILENAME

The extraction itself wents fine but with some streams when I add them
with mkvmerge it says

> Warning: The current timestamp (xyz) is smaller than the last one (abc).

and sometimes also

> Warning: spu_extract_duration: Encountered broken SPU packet (next_off < start_off) at timecode ...

For the first warning I recognize, that there are in deed entries in the
idx file like:

> ...
> timestamp: 00:06:32:480, filepos: 000054000
> timestamp: 00:06:32:479, filepos: 000054800
> ...


Now I tried extracting the vobsub stream with subtitleripper which says
it is based on the mplayer source. In the idx header the version
mentioned is MPlayer 0.90pre6-2.95.3

The idx file I get with this is smaller and has less timestamps. There
are no warnings shown when merging them, but it is more work to use this
tool. The .sub files are different, too.


Now the big question is, why the difference between those files?
Assuming newer MPlayer/MEncoder versions lead to better results and the
extraction is easier I would like to use the above mentioned command,
but should I be worried about those warnings?
I found nothing helpful about those messages though.


Thanks in advance,
Stefan