I've got some OPUS files I've created with FFMPEG on Linux (from MP3 originals I've deleted to save storage space). I'd like to make them playable on a Mac and, if possible, on an iPhone via iTunes. As far as I know Apple hardware and software (not the web browsers though) support OPUS but don't support its native OGG container format and need it to be contained in Core Audio files instead. How do I perform this conversion on Linux and/or on MacOS?
I know I can just convert back to MP3 or AAC and know how to do this but I'm curious about creating Core Audio files without re-encoding the actual audio data.