[MPlayer-users] DVD ID_LENGHT (lenght in seconds) is uncorrect

[Dominik 'Rathann' Mierzejewski]

On Wednesday, 22 September 2004 at 23:44, Alessandro Di Rubbo wrote:
[...]
> > It won't be fixed in MPlayer in reasonable time, most probably. AFAIR OSD
> > displays current PTS, which is read from MPEG headers. So if they're
> > wrong, it'll be incorrect, too. Feel free to correct me if I'm wrong.
> 
> The greatest problem is not that I can see the correct total time
> directly from mplayer, but that I cannot see or encode a  DVD starting
> from the nth second (using -ss function). Example. I want encode
> separately, at a constant bitrate, movie credits that don't start at last
> chapter beginning: OSD/GUI value before "/" isn't in relation with total
> time value after "/" so I can't use it, but I can't use the corret credits
> start time displayed by another player, too, because the total displayed
> by mplayer is uncorrect (and there isn't a linear correlation between the
> true lenght and the lenght diplayed by mplayer)...

It's true and it's a well known issue. Doing proper seeking in MPEG files
is impossible to achieve without reading the _whole_ movie. MPlayer tries
to do approximate seeking based on the video bitrate stored in MPEG
headers (which is usually not an average bitrate anyway), hence the
inaccuracies you (and everyone else) are experiencing.

I think this qualifies for a FAQ entry. I'll try to send a patch.

R.

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