If training requires making a copy in memory, then that may be copyright infringement.
Or viewing it on my television requires multiple copies as the data moves through wires and tuners and memory and storage. Obviously a video just be copied into RAM to process and display for normal viewing. Why would making a copy in memory to run through a training algorithm be different than an algorithm to encode or decode for display on a screen?
I don’t think transmission should count as making copies.
It’s different to store material vs stream and process.
“Copies” are material objects, other than phonorecords, in which a work is fixed by any method now known or later developed, and from which the work can be perceived, reproduced, or otherwise communicated, either directly or with the aid of a machine or device.
There’s no way to look at your brain to perceive, reproduce, or communicate a work that you looked at, so under US law, your neurons are not a copy.
As for decoding a video to display it on a television, yes, that process requires making copies. That is why if you don’t have a license to a work, then decoding and displaying it is copyright infringement.