Well, part of that is it predates Composer by a few years (and especially popular adoption of Composer). PEAR never really had the adoption that Composer did. The popularity of frameworks didn't soar until Composer was adopted by the community, either. And the overall application is actually fairly simple, assuming that getid3 folder is a third party library as it appears to be.

That said, I'm not discounting anything done here. I've had to do deep dives on streaming video before. Even built my own h264 streaming protocol prior to HLS and DASH being introduced more than a decade ago now. Figuring out the format, finding obscure documentation on the file headers, figuring out how request and send it in pieces, hell just finding documentation that long ago... it's not easy. And at least when I did it, I was working on PHP 5.4 which had namespaces. This was likely built on 5.2 if I had a guess, which lacked that luxury