When I had no (useful) Internet where I was living a few years ago I would save a list of packages to download from Synaptic to a drive and then when I was somewhere I could I would download them, then when I got home I could plug in the drive and update/install them.
More time than trying to shoehorn a defunct package for an abandoned codec in to a random player which even if it works would only be a temporary kludge not a fix?