Conversion of m4a to vorbis with ffmpeg does not work.

[ghost]

This is the command I used. the three ffmpeg binaries are in the same folder.

youtube-dl.exe --restrict-filenames -o %(title)s.%(ext)s -f bestaudio --audio-format vorbis fWyVaX3L77I

I've tried it with multiple videos and they are still in m4a format instead of ogg vorbis.

[yan12125]

What you need is --recode-video. For example:

youtube-dl --restrict-filenames -o "%(title)s.%(ext)s" -f bestaudio --recode-video ogg fWyVaX3L77I

Indeed the option name is somewhat misleading. Anyway it's used for multimedia format conversion.

[jaimeMF]

Or you could add --extract-audio, which tells youtube-dl to run the postprocessor.