Metadata on aac files (ID3v2 TXXX or APEv2 or something else?) 2018-05-31 14:53:16 Hey,I'm currently trying to add metadata to my .aac-music files. I used the linux tool id3v2 to add the standard metadata (title, artist ...) but I also want to add replaygain_track_gain and replaygain_track_peak to my files. The question is: What is a working and good way to store this information? I want to do this programmatically so I look for a simple commandline tool or nodejs library.I have tried multiple things to accomplish that. Using id3v2 directly on the aac-files for the TXXX field results in the TXXX field overwritten by the last value I tried to add. When I use id3v2 on the same file, but renamed to .mp3 I can add multiple key-value-pairs to the TXXX-field and the data is correctly read when renaming back to .aac. This behaviour makes no sense to me and I couldn't find a clue to that behaviour in the source (https://github.com/myers/id3v2). I also tried some other tools to set those values to the TXXX field. They work perfectly with .mp3 but they struggle to do the same thing when the file is .aac. Why is that?Is there a better mediadata standard for aac, which I can write in a simple way from the terminal? I hope someone else also came across this problem and solved it. I'm happy to hear you ideas.