[MEncoder-users] Problems with created vobsub IDXs

[Mike Castle]

Recently I noticed something.   When I use -vobsubout, like in the following:
./mencoder -oac copy -ovc copy -vobsubout a.vob -o /dev/null dvd://3


I often get out of order timestamps in the index like this:
id: en, index: 0
timestamp: 00:00:01:401, filepos: 000000000
timestamp: 00:00:03:370, filepos: 000000800
timestamp: 00:00:06:639, filepos: 000001800
timestamp: 00:00:09:376, filepos: 000002000
timestamp: 00:00:00:931, filepos: 000002800
timestamp: 00:00:02:632, filepos: 000003000
timestamp: 00:00:16:466, filepos: 000003800
timestamp: 00:00:19:794, filepos: 000004800


If I use streamripper's subtitle2vobsub on the same DVD, I get correct ordering:
timestamp: 00:00:01:556, filepos: 000000000
timestamp: 00:00:03:357, filepos: 000000800
timestamp: 00:00:06:360, filepos: 000001800
timestamp: 00:00:08:863, filepos: 000002000
timestamp: 00:00:10:883, filepos: 000002800
timestamp: 00:00:12:551, filepos: 000003000
timestamp: 00:00:15:421, filepos: 000003800
timestamp: 00:00:18:457, filepos: 000004800


While the timestamps aren't the same, they do seem to actually work.
This tool has some other issues like not getting the palette right,
but by mixing and matching parts of IDX files generate by
subtitle2vobsub and mencoder, I can get something that works.

Oddly, subtitle2vobsub is derived from mplayer, just from the 0.90pre6 days.

I have not yet written a tool if there has been a regression, or what.
 I've seen some comments about timestamp problems going back to 2003
and even a patch floated in 2005, but never finished up.

Using mplayer, the subtitles on the DVD play correctly, and obviously
some show up at the wrong time when playing.  In tracing through to
compare mplayer and mencoder, and going through mpcommon.c and
mencoder.c, I did get kind of lost.  I have suspicions about
mencoder's use of ``v_muxer_time + d_dvdsub->pts - sh_video->pts'' but
wasn't able to find the equivalent in mpcommon.c for when subtitles
are actually displayed.

Anyone have any suggestions on this matter before I start delving more
deeply into this?

Thanks,
mrc