[FFmpeg-user] try to change complex filters on runtime

[Stefano Sabatini]

On date Wednesday 2013-07-10 15:43:57 +0200, lucie Lemonnier wrote:
[...]
> For
>  example , I call reinit_filters_complex("[0:0] crop=960:1080:0:0 
> [tin];[2:0] crop=960:1080:0:0 [tmv]);[tin][tmv]overlay=0:0").
> I 
> passed in parameters of ffmpeg -i videoSource.mp4 -i transp.mov -i 
> objets.png -filter_complex "[0:0] crop=960:1080:0:0 [tin];[1:0] 
> crop=960:1080:0:0 [tmv]".
> But It crash on this change.

> I think it's because I free all in filtergraphs.
> But I don't know what is missing for it to work.
> Can you help me, please?
> Thanks.

You could achieve the same by extending libavfilter and using commands
to send interactive commands to filters. For example check my patch on
ffmpeg-devel to change crop parameters, as for what regards changing
overlay you could connect two movie sources and disable/enable the
active overlay (check timeline), or maybe implement a switcher
controlled by a command. Dynamically changing movie input is not
currently supported.