On Tuesday, July 26, 2016 9:41:26 PM CEST, Harald Albrecht wrote: > I can't get my head around really understanding why MLT, taken > the following example, uses video frames from track #1 (middle > track) instead of from track #0 with track #2 composed onto it. > Besides the overall documentation, I've also tried to read the > core sources for tractor, multitrack, and transition, but I > sadly notice I still lack a lot of understanding of the inner > workings of the MLT framework... > > Let's assume a simple MLT setup, along the lines of this XML; > hopefully this shows the gist: > > <mlt> > ... <!-- some producers here --> > <tractor> > <multitrack> > <track producer="playlist1"/> > <track producer="playlist2"/> > <track producer="playlist3"/> > </multitrack> > <transition id="transition1"> > <property name="a_track">0</property> > <property name="b_track">2</property> > <property name="mlt_service">composite</property> > </transition> > </tractor> > </mlt> > > Now let's also assume that all three playlists have video clips > starting with the same in and out points. That is, all three > clips overlap each other in my imaginary timeline. > > Without any transition, if I'm correct, I understand the > tractor to work such that it takes always the "topmost" video > frame from track #2, that is, from "playlist3". > > But with "transition1" in place, the tractor takes the frames > from track #1, aka "playlist2". Can someone please explain to me > simpleton why the tractor now "produces" video frames from track > #1 instead of from the composition of track #2 onto track #0?
Quick answer: a transition merges the b_track onto the a_track. So the track containing "playlist3" is merged into the track containing "playlist1". The first visible track will now be "playlist2". regards jb ------------------------------------------------------------------------------ What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic patterns at an interface-level. Reveals which users, apps, and protocols are consuming the most bandwidth. Provides multi-vendor support for NetFlow, J-Flow, sFlow and other flows. Make informed decisions using capacity planning reports.http://sdm.link/zohodev2dev _______________________________________________ Mlt-devel mailing list Mlt-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mlt-devel
