Capturing the visualization output

[hansschmucker]

This may be fairly obvious to many people here, but I'm a VLC scripting newbie and sadly, the documentation is pretty confusing.

I'm trying to write out the visualization output for an audio-only file to a video/audio container. After some experimenting (apparently, the syntax for calling the visualizer changed a bunch of times, I finally got the normal, to-display output working with:

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vlc -I rc land.m4a --audio-visual=visual --effect-list=spectrum --effect-width=480 --effect-height=80 --visual-nbbands=16 --visual-separ=0 --no-visual-peaks vlc://quit

So far so good, the audio plays and I get a visualization. However if I try to combine this with a simple transcode, like so:

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vlc -I rc --audio-visual=visual --effect-list=spectrum --effect-width=480 --effect-height=80 --visual-nbbands=16 --visual-separ=0 --no-visual-peaks --sout=#transcode{vcodec=mp2v,acodec=mp2a}:standard{access=file,mux=ps,dst=out.mpg} land.m4a vlc://quit

I still end up with an audio-online file, which is understandable, seeing as I failed to actually include the visualizer in the filter chain.
Problem is, how do I do that? Some threads in here suggest afilter=visual may do the trick, but that filter can't be initialised, according to "-vvv"

I'd really be grateful for ANY pointers

Hans Schmucker

[andreyvit]

Hey, bumping this topic because I want this too, and I've spent a couple of hours trying to get it to work without any success. (The use case is publishing an audio podcast on YouTube.)

Can someone please please give a pointer, or at least tell us that it's impossible?

[Rémi Denis-Courmont]

Most visualization use OpenGL, which in practice means the video is created by the graphics card for display purpose. It cannot be encoded, at least not in any straight forward manner.

[andreyvit]

Thank you, Rémi. That explains it. (I'm using the spectrum visualizer. I'll try the other ones to see if any of them can be rendered.)