If there a way using fmpeg9commandline) to have it do this:

1) If the file is 48000Hz 16 bit stereo, then it will not do anything to the file except write a new file

2) If any of these properties are not above specs are not present then it will apply the apropriate conversion?

what I am getting at is I would like to be able to compress compliant audio streams, without having to check the file for compliancy first and to not waste time processing something that already is right.

Or will it do this automatically? For example, if I tell it to resample audi to 48000, and it already is 48000, will it skip the process and just write a new file unmodified, or wil it waste processing time reprocessing it into what it already is.