[FFmpeg-devel] lavfi: expected behavior for multiple filter definitions

Mina Nagy Zaki mnzaki at gmail.com
Thu Mar 31 15:21:19 CEST 2011

On Wednesday 30 March 2011 13:09:24 Michael Niedermayer wrote:
> On Wed, Mar 30, 2011 at 07:30:32AM +0200, Mina Nagy Zaki wrote:
> > What is the expected behavior of:
> > ffmpeg -i in.mp3 -af aresample=8000 out1.mp3 -af earwax out2.mp3
> it should behave the same as with video filters.
> [...]

They are both equally broken (IMHO) in that only the last -vf/-af is ever 
evaluated and the rest are discarded. Actually each -af could simply add on to 
the filter graph definition, inserting new links/filters, and then when an output 
file is specified a new aout/vout is created and linked to the last available 
open output. This way multiple output files can be inserted easily at different 
parts of the graph, or even multiple independent chains (and hence independent 
outputs) can all be connected to a single src.


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