Convert MP3 to MP4 Black Screen

[nicksteel]

I need to a simple (free) method of creating long duration black screen mp4's from mp3's for sleep aids.
Not online conversions.

[jagabo]

ffmpeg can do this quickly and easily:

ffmpeg -f lavfi -i color=c=black:s=640x480:r=24 -i "input.mp3" -preset ultrafast -c:a copy -shortest "output.mp4"

That creates a 640x480 24 fps black video for the audio and puts them in an mp4 file.

You can do it with a drag/drop onto a batch file:

ffmpeg -f lavfi -i color=c=black:s=640x480:r=24 -i "%~dpnx1" -preset ultrafast -c:a copy -shortest "%~dpn1.mp4"

That will create an mp4 with the same base name as the mp3 file.

It's also possible to do the same for all files in a folder, or even an entire folder tree. I can give you a batch file for that if you want...

[nicksteel]

Perfect! Exactly what I needed and the batch file works great.
Many thanks.