[Flac] Copying ID3 metadata when encoding with flac command-line tool

[Seb Francis]

Hi,

I want to convert music purchased as AIFF to FLAC.  The AIFF files are 
coming with full metadata & artwork in an ID3v2.4 tag and I would like 
this transferred into a FLAC tag in the destination file.

I had assumed the flac command-line tool would automatically copy the 
ID3 metadata but it doesn't.  I have tried the --keep-foreign-metadata 
option, and while this does then include the ID3 tag within the FLAC 
file, it's not useable since most software expects the data in a FLAC tag.

ffmpeg seems to copy the metadata (apart from converting jpeg covers to 
png at 10x the size), but I feel more comfortable using the reference 
libFLAC rather than Lavf, so would prefer to use the flac command-line 
tool if possible.

Is there a way to achieve metadata data transfer with this?

Thanks,
Seb