[FFmpeg-devel] Multiple [in] in filtergraph syntax

Stefano Sabatini stefano.sabatini-lala
Sun Dec 19 15:55:02 CET 2010

On date Saturday 2010-12-18 18:37:33 +0100, tajz encoded:
> Hi,
> I am new to ffmpeg. I successfully build from sources (last trunk).
> I read doc, some posts related to multiple inputs and mixing, and a bit
> of source code.
> I see that one can give multiple "-i file" to ffmpeg, but it seems there
> is only one main source "[in]" in a video filter graph ("-vf").
> I would like to mix two videos, using a filtergraph like :
> "[in1] scale=100x50 [vid1]; [vid1] [in2] overlay [out]".
> But it seems that only the first '-i' file is attached to the [in]
> stream of the filtergraph syntax.
> In graphparser.c I found "[in]", and it seems there is no other built-in
> input.
> "overlay"-ing a "color" sourced stream other the first "-i" works. I
> just want to overlay another a second "-i" to the first.
> Am I right ?
> Is there a plan to support this feature (having each '-i' input
> magically mapped to a [in1], [in2], etc stream) ?

Yes, and help is welcome, feel free to create a feature request in

Check also:
FFmpeg = Fabulous Formidable Mere Perennial Entertaining Guru

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