[MPlayer-users] MPlayer Total Length in Slave Mode

[Reimar Döffinger]

On Tue, Dec 15, 2009 at 07:48:03AM +1300, Dominic Driver wrote:
> I'm launching MPlayer with:
> 
> mplayer -slave -quiet -nocache -input file=ControlFile dvdnav:// -dvd-device <location>
> 
> where <location> is either /dev/scd0 or the HDD directory containing the authored files.
> 
> If I use identify, I have to specify the actual file VTS_01_1.VOB instead of the directory. In this case, I get the following:
> 
> ID_LENGTH=29.91

That's what I feared. The VOB does not really have to have much to do with the DVD titles,
if you play the VOB directly you won't get any useful information and sometimes not even
a working file at all.

> I don't have a value for ID_DVD_TITLE_1_LENGTH, it doesn't appear in any mplayer output.

mplayer dvdnav:// -identify
[...]
ID_DVD_TITLE_1_LENGTH=8832.000

> When I then launch MPlayer using the line above, the responses to the following commands are:
> 
> get_time_length : ANS_LENGTH=27.08
> get_property time_pos : ANS_time_pos=<position in time within the original mpeg file>
> 
> When playback transitions from the original mpeg 1 to the second mpeg 2, the total time length doesn't change.
> 
> However, responses to time_pos are relative to the start of the original second mpeg file.
> i.e. if I were to continually poll using the time_pos command, I'd see values:
> 
> 
>      Original MPEG 1               | Original MPEG 2
> Play ... 0.0 ... 10.0 ... 22.7 ... 0.0 .... 1.0 ... 2.0 ... Stop
> 
> I expected output to be from 0.0 -> <total title length> in an uninterrupted way. Is my assumption correct?

The output is whatever the creator of the file put there.

> What am I missing here?

For better or worse, MPlayer uses the time values stored in the file, it doesn't make up its own.
If you don't like that you have to remux the file, which usually will give it continuous time stamps.
Or in the case if DVD, using dvdnav:// or dvd:// can/should help, since it makes use of the more
enduser-friendly info that is stored someplace else on the DVD.
In this particular case I'd say if you play the VOB directly, behaviour above is what you asked for...