[FFmpeg-user] Metadata: map key-to-key for different (container) formats?

[Peter B.]

Hello everyone!

Metadata-related questions again :D

**Is there a way to map metadata values by their key?**

For example, I've got a bunch of MKVs with RIFF tag keys that are lost 
when I convert into an MP4 container:

   INAM (Title)
   ICRD (Creation Date)
   IARL (Archival location)
   ITCH (Technician)

I'm aware of "-map_metadata", but it seems to only be able to copy 
metadata as-is (same key).
Any way I could tell ffmpeg that "INAM=title" and "ICRD=date", etc 
during encoding?


Thank you very much for any suggestions! :)
Peter