i have a bunch of .m4a files in one folder, 1000s. can i automate their conversion somehow?
No as both are lossy codecs you will always lose quality doing so. You can do it with ffmpeg.
parallel ffmpeg -i {} {.}.opus ::: *.m4aYou may want to tweak parameters for bitrate, etc. But this is not needed at all, as AAC had patents that are now expired.
If you get .flac, .wav or similar lossless music, you should encode that with opus. But lossy to lossy makes nearly no sense (apart from specific players not supporting them)
If you get .flac, .wav or similar lossless music, you
shouldcould encode that with opus.Fixed.
Unless you have a strong stance against people storing lossless files of their music? But I don't think that's quite what you meant :)
"If you get .flac, .wav or similar lossless music, you should encode that with opus."
I am looking forward to similarly useful discussions XD