Tuesday 21 January 2003

Pic of the day: I suppose I could have many more if I increased my screen resolution. It certainly doesn't slow down the machine much.

BitTorrent?

Well, "Torrent" may be an exaggeration. But here's the story so far.

An online friend (Skyknyt, the young man who helped me buy Shrouded Isles from the USA) had a link to AnimeSuki.com. This is a site that distributes fansubbed anime. That is to say, Japanese cartoons (anime) that are not available in western languages and thus not sellable in our parts of the world, but which have been video edited by fans who know both Japanese and English, so as to include subtexts in English. Thus, fan-subbed.

Since these cartoons are not marketed in our countries, there is no loss of income from the companies that own the digital rights. Well, that is not exactly true. They could choose to translate these at a later time. Or people may watch these instead of buying other anime. None of these is very common, but the first has actually happened. The policy of fan sites is to immediately stop distributing the video in such a case, and to exhort the fans who have it already to buy the commercial release. Remember, we are talking fans here. And this is one of the ways in which people become fans in the first place: By downloading reduced quality video over the Internet.

***

Anyway, this is largely beside the point of today, which is BitTorrent. You see, these people are fans. They don't have large budgets. As more and more people get interested in anime, it becomes problematic to publish all this. Internet Service Providers are less than happy with customers with heavy traffic and low pay. So if you want to serve hundreds of customers, you have to fork up cash, lots of cash. Alternatively you can stick with a small, low bandwidth account and just let people queue up. This was the solution when last I left the scene, around February 2001.

There are fans, and there are fans. Most are not quite that fanatical, and most don't have much computer competence. Setting up a file server would be beyond most of us technically, even could we afford it. This is where file sharing software comes in. It was made famous by Napster, which was used mainly for illegal piracy of music. Other more general file sharing programs emerged, allowing users to swap pictures and movies too. By and large, people won't pay for things they can get for free, that's just the way humans are made. (Some will if it is simple, or at least simple and cheap.)

***

BitTorrent is a new file sharing program, but with a twist. It is designed and marketed for tasks that stand the light of day at least somewhat. It is partly centralized and partly decentralized. Here is how it works:

The common user downloads a small program, the BitTorrent client. It installs itself and registers a file type, with file names ending in .torrent. (It may possibly integrate itself in browsers too, but it didn't do so in my Opera 7 Beta.) The company that wants to distribute a product over the Net then posts a small pointer file from their web page. You click and download it like any other small file. Then you, the common user, open that file. Since it is registered to BitTorrent, it will invoke this program. The program asks you where to download the actual file. This can be in the same folder as the pointer file, or anywhere else. It then starts downloading.

The distributor runs a program called a tracker. It keeps track on who is downloading at any one time. The file is broken down in small chunks (ca 1MB, I believe) which are sent independently of one another. When a new user logs on, another has probably already downloaded at least a part of the file. The request is redirected to that other user, whose program passes on the chunk of file he has himself downloaded. The more users that are downloading the same file, the faster it will be. If none of the current downloaders have the chunk, it will be fetched from a "seed", that is a fully downloaded file. Once you have completely downloaded your file, you are politely asked to let the download window stay open for an hour or more if you can. Your complete file is now a seed, a source, an uploader of last resort. The original distributor is of course supposed to provide a seed along with the tracker; otherwise the thing would never start in the first instance.

As long as there are external seeds, or even several almost-finished downloads, the distributor won't need to use bandwidth for anything except the tracker. The burden of distributing is passed on to the "leeches". To further enforce this, the program works on a tit-for-tat basis: The higher your upload, the more priority is given to your own downloads. I believe this is separate for each single download. (It is still called a download even if you upload too .. there is no separate upload window for finished files, you just let the download window stay open (minimized is OK too, just don't close it or log off the Net).)

You can resume a download at any time, by opening the pointer file and "saving" to the same location. Only missing parts will be downloaded. If the file is complete, you have opened a seed, an upload source, instead. Not intuitive perhaps, but very simple. The need for user interface is very limited.

***

Now to my own experience so far. The information on how to use the program is rudimentary and fragmented at best. Evidently this is made by and for geeks. On the anime site I found a link to download the client. This took little time on my broadband connection, it was rather a small program. I opened the installer program, and it told me immediately that the program was installed. No InstallShield and full-screen graphics and stuff. Just like that, the program is installed. I had no idea how to use it now that it was installed. I double clicked, I right-clicked, I looked in the Start menu for a new program, nothing. Then I went back to the web site of BitTorrent and it told me that for a demo I should download the CodeCon archive. (You probably don't want to do that, because it is an MP3 encoded version of geeks presenting their inventions. I did not know that. I thought it was the rest of the program, since it could not be so small.) So I clicked the link.

Opera downloaded a small file, which I supposed was the complete CodeCon archive, and put it on the desktop. That sure was fast! It was a zip file, but when I tried to open it, it did not show contents. Instead it showed a list of the content of the folder where this file was. Huh? And it also asked me to save it somewhere. I exited and tried right-clicking. One alternative was open in BitTorrent, so I did. I got the same content list. It dawned on me that the file was not a zip file but a pointer file. Right, properties showed that its actual name ended in .torrent. This is where I got the revelation about how the thing worked. I opened it again, and chose to save the file to the same location. Now it saved an actual zip file. Now I understood what they meant by saying that it created an empty file. I now had a full size file on my desktop but with no content. This is where the legendary Download Window popped up. After a little bit it started downloading. Almost at once, it also started uploading.

Now that I understood how it worked, I also started to download an anime episode. Later I added another, with no ill effect on the download speed. This may be because the speed is very low. It's typically in the range 5-10 KB/second now. This may however be due to the fact that my ISP had problems with their connection out of the country, as a mail from them informed me earlier today. I've later got a mail that the connection is restored, but the speed remains sluggish. So you may want to try this out for yourself. I tried with and without the firewall in Windows XP, and it seems to make no difference to the speed (contrary to what a FAQ says).

Another likely explanation is the low number of downloaders and seeds for the files I am downloading ... The scant documentation does indeed claim that the program works better the more people use it. Anime is not exactly a standardized market where lots of people download the same thing at the same time. It is pretty narrow. If some large entertainment company had released a famous movie, I bet there would be thousands of leeches. Then we could truly have put it to the test! (Tests so far show that on the same server, download is several times faster when there are many downloaders. I'd still not call it a torrent, though.)

Anyway, I don't mind. I pay per month, so if it uses a day to download an episode, that's fine by me. Especially since I can download tons of them at the same time if I am so inclined. The more I download, the better for all my fellow leeches out there! In fact, I take a certain pleasure in opening the download window and look at the upload. For instance, on my Jungle download the upload is now well above the download, and I've only finished about 1/6th of the file. I like that. Then again, I am possibly unusual for a leech.

I'm certainly feeling morally justified in what I do here. But the legality is more uncertain. I guess this could hurt my chances at running for president when Norway eventually becomes a republic. I doubt it qualifies for the police confiscating my computer, though, especially since it's somewhat unclear whether a fansubbed anime is a separate work or a copy. I'd definitely not use this to get ripped stuff. (Tell that to the judge, pardner...)