The Armchair Politician

This is something that drives me batty when downloading torrents: compressing videos into .rar format.

What’s the point? First off, splitting it into multiple files was a reasonable idea, back when people had terribly slow connections, which were mostly unreliable. Nowadays, people have resumable downloads and always-on broadband. Not to mention, this is all in a torrent anyway — so what’s the point?

I hope it’s not to save space, because in most cases, adding another layer of compression actually increases the size of the file. Why? Because it’s already compressed. That’s all a video codec is: some way of compressing a raw stream of video into something more manageable.  The difference is, video codecs are explicitly written to take advantage of the specific types of redundant information in video, where generic compressors like WinRAR, gzip, and WinZip try and compress all types of files.

Composing the two together, though, doesn’t work. Once the codec is done, the video is already pretty damn near maximally compressed; there’s nothing redundant left to pack away. So all another layer of compression does is increase the size of the resulting file, because it has to tack on information about how to decompress it. Net result? Most videos end up being 10-15MiB larger, which means another few minutes downloading. It’s not much, but when you consider 10,000 people downloading it, it adds up to a lot of bandwidth and a lot of time.

So please, don’t be a donk. Just torrent the fucking video.