[MPlayer-users] capturing and seeking

[keithcsl at ihug.co.nz]

Hi rcooley

Thank you for your response. This is the mencoder command I
am using:

mencoder tv:// -tv
driver=v4l:device=/dev/video0:norm=pal:input=0:noaudio -ovc
lavc -lavcopts vcodec=msmpeg4v2 -o capture.mpg

For playback I am using:
mplayer capture.mpg

Now, with:
mplayer -ss 30 capture.mpg

it does not seek to 30 secs accurately. As a workaround, I
am temporarily converting to MJPEG:

mencoder -oav copy -ovc lavc -lavcopts vcodec=mjpeg -o
capture-temp.mpg capture.mpg

mplayer -ss 30 capture-temp.mpg

I want to keep the msmpeg4v2 (alternative is mpeg), but also
want seeking.

Regards
Keith



> On Sun, 31 Jul 2005 01:23:42 +1200
> keithcsl at ihug.co.nz wrote:
>
> > I am capturing video from a camera using mencoder in
> > mpeg4 format.
>
> You seem confused on the subject.  The video codec you are
> using is NOT the file-format.  With mencoder, unless you
> use the "-of" option, it is outputting AVI files.
>
> mp4 is a container format which a CVS snapshot of mencoder
> can output to.  However, it's not an MPEG format, it's
> actually a modified .mov format.
>
> mpg files can be made with MPEG-4 video, using mencoder,
> but it's definately not normal, and I doubt many players
> can handle it.
>
> > However, having read from previous posts, the -ss is
> > inaccurate for mpeg files.
>
> -ss is innacurate for some MPEG files, because mpeg is
> rather flexible in how it allows you to write the
> timestamps (pos), and some encoders use that to make very
> screwy files.  Since mencoder has a pretty
> straight-forward mpeg muxer, it should not be a problem to
> seek in the mpeg files it creates (no special options
> needed).
>