[vlc-devel] Re: Intergrating libVLC with real-time graphics library

[Sigmund Augdal]

On Fri, Jan 28, 2005 at 12:25:31PM +0000, Robert Osfield wrote:
> Hi Sigmund
> 
> On Friday 28 January 2005 11:26, you wrote:
> > vlc-devel is indeed the right list. Next think I have to say is that,
> > unfortunatly, the libvlc api is not really suitable for this kind of task.
> > As you say it mostly provide a modular way to create vlc-like applications.
> > I know several other apis are available that might suit your needs better.
> > This includes (but are probably not limited to) gstreamer, libxine and
> > ffmpeg.
> 
> Thanks for the pointers, I've looked at ffmpeg a bit, but haven't come across 
> gstreamer and libxine before.  I presume by libxine you mean xine-lib, as I 
> couldn't find a project website for libxine just from a google search.

Probably, just a glip of memory. As far as I know there is allready quite a
few video players using xine-lib and/or gstreamer. This makes me belive that
these libraries allow for the user to have better control over the video
output. Though I didn't actually confirm this. It might very well be that
both user the same way of doing stuff that vlc do.

> 
> > I think indeed the libvlc api could be updated to support this kind of
> > setup without too much work, but as far as I know there is no plan for
> > doing so any time soon. Off course any contribution is welcome (and we
> > might even give you some starting pointers).
> >
> > I'm glad to hear your interrest in vlc, and libvlc and hope my answer was
> > helpful.
> 
> My interest in libvlc in particular is it being a one stop shop for handling 
> the codecs and the streaming in and out of videos.  I've began thinking about 
> how one would integrate it as a plugin, but don't yet have a clear plan of 
> acition.  
> 
> My first step would probably be creating a SDL video out option that uses the 
> OpenSceneGraph to do OpenGL rendering, this would allow sdl to spawn an 3D 
> window with a video running it.  After this I'll have to work out how to 
> subvert the process such that its the OpenSceneGraph plugin that sets up 
> libVLC such that it can be used in any OpenSceneGraph based application - 
> where the application will have already created windows and be handling its 
> own events - with libVLC taking a background role.

I would rather have made api-calls in libvlc that allow the libvlc user to
register a kindof vout system using function pointers or something similar.
Then libvlc would call a function of the users choice each time a new output
frame is available. This would allow you to easily use that frame of video
as a OpenGL texture or anything else of your choice.

> However, I'll look into the other 3rd party options right now to see how much 
> they might provide.  It might be the case that I'll develop several plugins 
> which link to different 3rdParty video libraries.  I would prefer to be able 
> to develop just one library though which could do it all, which is why I've 
> been considering libVLC.
> 
> I'll post more info how I get on.
> 
> I may well be developing a YUV to RGB fragment program as part of this work, 
> this will help offload some of the processing work on to the GPU, this may 
> well be useful to libVLC even if I don't go ahead and implement a libVLC 
> plugin.

Vlc allready have yuv to rgb conversion both in software and hardware on
most platforms. I think it might even be usable as a command line app for
converting files from yuv to rgb, provided you can come up with the correct
incarnation to do that. But I might have misunderstood what you are talking
about here.

Sigmund

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