Proprietary tags (ITUNSMPB etc) questions - inlcl., "did they get destroyed"? 2020-12-10 13:19:06 I have accumulated a lot of junk tags over the years, some destroyed by me or others. I nowadays use fb2k and Mp3tag and occasionally Picard, and they differ a bit at what they remap and what they show at all. This looks like I'm requesting the remapping wiki to be enhanced with applications-specifics, but ... what the heck. I'm curious.A couple of fb2k/Mp3tag-specific questions first:* Why fb2k hides the tags that Mp3tag calls <DESCRIPTION> (in .m4a) and <POPULARIMETER> (in .mp3) beats me. Anything special? * What is what Mp3tag calls <LENGTH>? Is it just another metadata field one can do without, or asked the other way: is there anything strange about it missing? * .wma is quite some thing. I have what Mp3tag calls <PERFORMER> and what Mp3tag calls <FOOBAR2000/PERFORMER>; fb2k refuses to read the former and Picard refuses to read any. I conjecture that Peter and Florian have just each done their thing and not seen a point in coordinating? Nothing to do about it but retag using the application of choice?Then iTunes tags. * Sometimes iTunes-tags that fb2k would normally hide, show up. Are they then "destroyed" in the sense that behind the scenes they are at the wrong field? Or maybe a copy-all-tags have put a tag scheme from MP4 into an MP3 or something like that? Like when fb2k shows me <COMMENT ITUNSMPB>? * Is there any application that "converts" iTunes gapless tags to e.g. Lame/Xing headers?* Oh, and is there any interesting information in <COMMENT ITUNES_CDDB_IDS>? Apple even had a <COMMENT ITUNES_CDDB_TRACKNUMBER>, * Is <COMMENT SOUNDJAM CDDB_1> the same as <ITUNES_CDDB_1>?They look the same and Apple bought Soundjam and ... And a couple more: * <CT_GAPLESS_DATA>, I can only guess what - but is there anything useful for it* <FILETYPE> ... who made that? OK, "video/x-flv" probably tells me that this "demo tape rip" is really a transcode from one of a few services.