[FFmpeg-user] no such filter

[Moritz Barsnick]

Hi L.,

On Fri, May 22, 2015 at 10:52:10 +0200, lorenzo angeli wrote:

> This doesn't work:
> 
> -filter_complex "[0:v][clip];[1:v][slate];[slate][clip] concat=n=2:v=1,
> scale=1920:1080, fps=25.0[v]"
[...]
> in the first case (the one which doesn't work), shouldn't be sort of
> renaming the input ?

Who says it should? If that syntax is not defined (and documented), it
shouldn't work.

As you noticed, you can help yourself with a filter which does nothing.
For video, "null" comes to mind, for audio "anull":
https://ffmpeg.org/ffmpeg-filters.html#null

Your "scale" may alright, but I would probably choose
"scale=w=iw:h=ih", as not to risk "scale" doing anything. (Scale can
also do other stuff, so I would rather not use it to do "nothing".)

> The streams in and out are (or at least I think are) correctly
> defined.

Sure, but that's not how it's defined. Two [][] next to each other
could be two inputs or two outputs as well.

> here the complete output with debug informations.
> http://pastebin.com/ccHH7Z6L

What was the problem with attaching 11 kB here?

> Hope it does make sense.

Little. You could open a feature request on trac.

Moritz