[Libav-user] right syntax for ffmpeg Libavfilter filter

[Stefano Sabatini]

On date Wednesday 2011-07-06 08:02:34 -0700, bdfy encoded:
> I want to add watermark to movie and after scale movie. This string don't
> work:
>  ffmpeg -y -i "$infile" -an -pass 1 -threads 2 -vf 'movie=test.png [logo];

> [in][logo] overlay=0:0 [out]' -fv 'scale=100x100 ' $options "$tmpfile"
                                ^^^           ^

-fv is wrong

scale=100x100 is wrong, the accepted syntax is scale=100:100. Also why
two distinct -vf commands? Only the second one is considered, what you
want is:

-vf "movie=test.png[logo]; [in][logo] overlay=0:0, scale=100:100"
 
> Why ?

Also always post complete command and output, and learn the art of
reading/interpreting computer program error messages, they are useful
at times.