[FFmpeg-user] identifying useable metadata tags

[Dave Rice]

Hi all,
To identify what metadata tags can be written into a given file format I currently skim the corresponding files in libavformat, such as http://git.videolan.org/?p=ffmpeg.git;a=blob;f=libavformat/movenc.c;h=1b851c03dd814e2379a2d63631cd360f19a485e7;hb=HEAD#l2061. Is there another way to determine what metadata tags are available? Is there interest in having something like `ffmpeg -metadata` to output a table of supported tags per file format.
Dave Rice