Single video source -> multiple windows/monitors

[Klaus Roy]

I have an application where I want to render a single video source on several windows/monitors simultaneously .
The video source can be a harddisk file, a DVD or some other video input.
The output device(s) is one or more windows typically on different monitors. The windows may be of different sizes. On top of the video windows some additional information is written/painted, different for each window.

I have made a Visual Studio C++ Windows Forms application which basically does this. It opens a VLC mediaplayer for each of the windows, each with the same input specification. The information on top of the video is made using some transparent window panels onto which the information is drawn.

This system works OK when the video source is a hard disk file, but ( maybe not so surprisingly ) fails when e.g. a DVD is the input source.

What I'm looking for is for away to open the input source just once, then render it on all the different windows.

Does anyone know whether this is possible with libVLC off the shelf and if so how?
If it is not possible as it is now, how much tweaking of libVLC would be necessary to implement such features?

I can figure out that much of the functionality are available already, e.g filters to output on "walls" more or less do this, but can this be readily modified to output on different sized windows or does it require major recoding?

Regards,
Klaus Roy-Poulsen

[Jean-Baptiste Kempf]

Why not using VLC/libVLC and the clone filter?

[Klaus Roy]

Why not using VLC/libVLC and the clone filter?

This may very well be possible, but even though I have spent many days browsing the documentation and vlc source code, I haven't figured out how to get the output from the clone filter directed into specific Windows handles. Sending the output to individual monitors seems easy enough, but I need to control position and size of each of each of the outputs as it has to line up with other information/windows on the monitors and that still eludes me.
If you have any hints/directions where to look, I will appreciate it very much.

Regards,
Klaus Roy-Poulsen

[Jean-Baptiste Kempf]

I don't think this is supported indeed.

[Rémi Denis-Courmont]

I have not checked, but the video callbacks should support this. You will need to create the windows and do the rendering (from bitmap) yourself however.

[Klaus Roy]

My current idea goes in the direction of creating a slightly modified version of the clone filter with added options to set the position and sizes of the individual windows. As far as I can understand from e.g. the wall filter which calculates these data for each window, this should be possible. Currently the clone filter just sets the position to 0,0.
As far as I can see, it should be a reasonable simple thing to implement.

It will not be outputting data to my Windows Forms controls/windows, but as long as it ends up the right place on the screen it should be ok.

One of the drawbacks I can see is that I end up with a nonstandard version of libvlc, unless of course the code ends up in the official library.

Does this sound crazy or would you agree it is doable?

Regards,
Klaus Roy-Poulsen

[yarospo]

Hey Klaus Roy,

Were you able to solve this? I'm currently facing the same challenge, absolutely stumped for over a week now.