Strange m4a

[bop251]

My friend and i are using rockbox with ihp140
we are both using macs. on and of we trade music. some "m4a" files seem to work while others don't.
is there any explanation for that, i thought that rockbox does not support m4a codecs.
Maybe there is another name for this codec while macintosh names it m4a.
if someone could clear this mystery.
Thanks a lot

[Llorean]

Support for it has been worked on some. It's unsupported because not all of them work yet, as you've noticed, only some do.