[FFmpeg-devel] [RFC] Reading from a lavfi source

Stefano Sabatini stefano.sabatini-lala at poste.it
Sat Jun 11 00:53:23 CEST 2011


I want to experiment with lavfi sources so I would like to directly
read from them. Acutally, e.g. if I need to read from the color
source, I use the overlay on top of the input video (same could be
done for audio by implementing a mixer filter).

Now I wonder what could be a more direct way to achieve the same
result. A possibility would be to make ffmpeg/ffplay directly read
from libavfilter sources (by converting each input file to a movie
source), but this requires a major rework so doesn't look very
feasible to me.

So I'm thinking to implement a sort of lavfi virtual input
device/demuxer, which takes in input a filtergraph description with
exactly one output which is passed to the input (we may have two
distinct filtergraphs for audio and video), something like:

ffplay -f lavfi -graph "color=bikeshed [video_out]; notes=AC#E [audio_out]" dummy 

This should also provide a nice example of how to integrate lavfi into
a libav* application.

Do you consider this approach feasible? Better ideas?
FFmpeg = Frenzy and Fundamental Mythic Programmable Ecumenical Gadget

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