I have taken a stab at adding support for UTF-8 ID3v2.4 tag and posted my patch here: https://sourceforge.net/p/lame/patches/99/#aad8
I have taken a stab at adding support for UTF-8 ID3v2.4 tag - see the ID3v2.4_UTF8_support.patch file attached. Some details below. Background as I understand it The ID3v2.4 is the first ID3 tag version to explicitly support UTF-8 encoding - it is done by specifying 0x03 value for the encoding byte. The encoding byte of 0x00 indicates ISO-8859-1 (latin-1) encoding. For context, there are 3 versions of ID3 metadata tags at play here: ID3v1 - doesn't explicitly support UTF-8. Seems like you can use...
Apologies, meant to post this as a feature request. Did so here: https://sourceforge.net/p/lame/feature-requests/84/
support for ID3v2.4 (UTF-8)
support for ID3v2.4 (UTF-8)