[FFmpeg-user] Metadata muxer/demuxer documentation?

[Tristan Trutna]

The metadata documentation for ffmetadata (
http://www.ffmpeg.org/ffmpeg.html#TOC130 ) clearly explains the fileformat,
but I am unable to find documentation regarding input or output of these
files.

Specifically, I would like to create an ffmetadata file from an input mp3
file, edit that file, and then transcode the mp3 file into an AAC file using
the edited ffmetadata file to provide metadata to the new AAC file rather
than using the -map_meta_data argument.  What is the argument I should be
using to output or input ffmetadata files?

Thank you,
Tristan