[FFmpeg-user] lbavfilter. watermark. time interval.

[demimurych]

В сообщении от Понедельник, 12-дек-2011 15:32:30 автор Mark Himsley написал:
> On 11/12/11 22:15, demimurych wrote:
> > В сообщении от Суббота, 10-дек-2011 21:42:42 автор Mark Himsley написал:>
> >  On 09/12/2011 23:18, Clément Bœsch wrote:>  >  On Fri, Dec 09, 2011 at
> > 11:48:05PM +0200, demimurych wrote:>  >>  Hello.>  >>  >  >>  I'm
> > currently working with libavfilter and have a question relating>  >> 
> > watermarks.>  >>  >  >>  What I already know is how to put a watermark
> > on a whole video clip.>  >>  ffmpeg  -i inputfile   -vf
> > "movie=650_360_net.png [logo]; [in][logo]>  >>  overlay=W- w-20:H-h-20
> > [out]"  outpufile>  >>  >  >>  What I'm trying to achieve is to place a
> > watermark that would only be>  >>  visible from some certain point and
> > to some point - for example, only>  >>  the first 10 seconds of the
> > video clip.>  >>  >  >>  If there's a workaround that can make it
> > possible please let me know.>  >>  I'm stuck on this issue right now so
> > I would be glad to receive an>  >>  answer.>  >>  >  >>  Thanks in
> > advance.>  >  >  >  Maybe you could generate a 10 second
> 
> s video with your source image, and>  >  use it as overlay?
> 
> > Hello again,thank you very much for a fast answer. Using of fade effect
> > is a smart solution indeed. However it's still not really obvious for
> > me, how can I fade just the watermark and not the whole frame. I would
> > appreciate if you could explain the workaround further and tell more
> > details.Thanks in advance,Max
> 
> Hum, don't know what's happening with line wrapping... Probably my mail
> server doing something wrong with base64 to 8bit conversion.
> 
> Generically (assuming your logo has an alpha):
> 
> ffmpeg -i background.movie -vf
> "movie=watermark.movie,fade=in:25:25:alpha=1,fade=out:300:25:alpha=1[logo];
> [in][logo] overlay=0:0 [out]" <encoding options> output.movie


Hello again,
thank you for the example and explanation, it's really working if i put 
another video fragment over my clip and fade it as you meant. The problem is, 
when I try to place a watermark in the same way, the displayed result is a 
black rectangle instead of the watermark.
I tried it several times using a direct copy-paste of your code with fade:0:0 
and fade:0:1 etc, unfortunately still without success. Maybe this behavior is 
already known and you could tell me what I'm doing wrong?
Thanks in advance,
Max