[Kdenlive-devel] Re: mlt, kdenlive

Jason Wood jasonwood at blueyonder.co.uk
Sun Oct 16 13:03:14 UTC 2005

So far in the past week, I have spoken to  Lúcio Flávio Corrêa, Rob Hare, and  
Marco, mostly on irc.

So you have a low down, our approach to porting Kdenlive to MLT is as 
follows :

I have disabled the workspace monitor and the capture monitor for the time 
being to concentrate on the simplest case, the clip monitor.

All of the following involves only the files krender.cpp and krender.h

Our first step has been to initialise MLT and create a video window when 
kdenlive requests one. This happens in the createVideoXWindow method.
The first step was to produce some kind of picture, embedded in the kdenlive 
monitor, for which we used the 'noise' producer.

The second step was to load clips into the project window. This creates a 
temporary producer with which to grab the relevant details out of. I am 
unsure as to if this is enough to get the correct details. This happens in 

The third step was to be able to select a file in the project window, and then 
play it in the clip monitor. There is some code in the KRender::play() 
methods in order to stop and start the consumer. I am not sure if this is the 
best way to do this.

I also made a start at porting the old Kdenlive SceneList format over to 
westley. My first plan is to pass a westley document to mlt and play it. At 
the moment, there is enough in there to get a single clip into the clip 

Marco is looking at miracle and valerie, my current focus is on porting the 
scenelist format to westley.

If you want to start by monitoring activity, the greatest thing that you could 
do is to look over the mlt related code in krender and tell us if it looks 
like it is going in the right direction.


On Sunday 16 October 2005 04:52, Dan Dennedy wrote:
> Is Ruslan Popov working with you on this? He has been working a bit with
> Kino and I see some of his messages in the kdenlive mailing list archives.
> Ruslan, I just responded to Jason indicating that I am very interested in
> kdenlive for MLT. Maybe you are interested in joining this effort.
> I just checked the kdenlive CVS and see some other developers including
> kfilm author. I think it would be great for us all to collaborate.
> Personally, since I can not contribute at the level that I used to with
> Kino, it would be nice to be working with a larger team.
> On Saturday 15 October 2005 04:29 pm, Jason Wood wrote:
> > Hi Dan,
> >
> > I spoke to you a couple of years ago about kdenlive and mlt.
> >
> > Kdenlive has been in hibernation for well over a year now, but I have
> > revived it since there is a very enthusiastic bunch of developers who
> > wanted to work on it that just needed a little bit of guidance to get
> > started.
> >
> > You might be interested to know that we are porting it to use mlt as a
> > first step. I'm impressed with what I have seen so far, a nice api to
> > work with!
> >
> > Cheers,
> > Jason

Jason Wood
Homepage : www.uchian.pwp.blueyonder.co.uk

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