[MPlayer-users] å??å¤?ï¼? Re: flv with alpha channel

[Reimar Döffinger]

On Fri, Sep 26, 2008 at 04:02:25AM -0700, RC wrote:
> On Fri, 26 Sep 2008 10:16:16 +0200 (CEST)
> "Oliver Seitz" <info at vtnd.de> wrote:
> 
> > I can tell that it is not very common to have a real apha-channel in
> > video files, so even not knowing internals of mplayer/mencoder I doubt
> > that it would be an easy task to implement a feature like this.
> 
> Easy or not, On2 presumably already did it.  MEncoder is the program
> behind their "Flix Engine" Linux SDK (no doubt the app running behind
> the scenes at YouTube). And to make things even easier, you can download
> a free demo (which thereby gives you the right to request the source
> code, with all modifications they've made). 

Why do you think they support alpha?
Also while MPlayer internally probably should support alpha, I do not
know if it has any encoder that supports alpha and works in flv, e.g.
(m)png encoding should work just fine with alpha (as long as you do no
scaling or similar things).