[vlc-devel] snapshot, i_pts_delay, date...

kpetiot at free.fr kpetiot at free.fr
Thu Apr 27 18:48:52 CEST 2006

Hey everyone!

I'm still trying find a way to be able to get position from snapshot, witch come
from all_snapshots in Media_control_API.

In fact, what I want to do is to be able to get a date that make the user can
make marker in and marker out ( to select the desired video part only), from the
frame he's would like. And then, extract the part of the video.

As I know it's the "date" is not exact, but I'm trying to understand why, and
how I could find a better way to get it (if you have any idea, its welcome )?

The date is determinate from date = (val.i_time - p_imput->i_pts_delay)/1000

But, I can't figure out where p_imput->i_pts_delay is determinat.  it's seems to
depend if vlc is reading a stream or a file. But in case of a file, it should
be always the same, isn't it?
Is there a way, to make i_pts_ delay calculate more often ?

Or the second possibility is, that the error come from val.i_time.

I know that, the best way, would be timestamp packet/image along the whole
process, but I'm trying to find a way to get more accurate without doing it,
because, it's a heavy modification.

My other point, is that  VLC can synchronised to video output, that can able to
play exactly the same frame at the same time. Is there a way, to use it
to get the date more accuracy ? Can you explain me how vlc is doing this synchro
What I was thinking (because vlc doesn't know what is a frame), it's to get the
snapshots, and make the user choose a image. Then the application is getting the
and send it to a video editing server, that would built the new video.

Now I want your advise in:
1) what is the best way to get he accurate date?
2) How VLC is doing the synchro between different video outputs on different
3) How and where to the VLC calculates the "p_imput->i_pts_delay" and
val.i_time? (snapchot.c snapshot_GetMovietime function)
4) Do you have some suggestions for the markin and markout application



This is the vlc-devel mailing-list, see http://www.videolan.org/vlc/
To unsubscribe, please read http://developers.videolan.org/lists.html

More information about the vlc-devel mailing list