General Discussion/Off-topic - Page 366

On February 17 2011 17:15 tec27 wrote:
So as I mentioned a few days ago, I've been playing around with developing my own replay system and such. Well, while I was playing around with LoL in a debugger the other day, I happened upon a function that built a table of names for what appears to be each packet type in the game. (I think this table is built for use by the scripting engine that the developers use to do a lot of stuff).

This is fairly interesting/useful, since each name is indexed to a number, and these numbers are all the same size (a byte each), meaning they're likely the same numbers used inside the packets themselves. I was figuring that this table in itself would not be all that useful, cause the packets were likely encrypted/compressed; however, after playing around with a hex editor for a few hours and some of the packet dumps so graciously ouput by LOLReplay, it seems apparent to me that either the packets are not encrypted/compressed at all, or the encryption is only done *after* the packet type identifier.

Sorry if that was too technical, but I guess what I'm trying to say is that much more functional replays from a 3rd party program are not all that far-fetched, especially if the content format of the packets can be deduced. The current replay program is content-agnostic, that is, it has no clue what each individual packet is doing in the game, it merely records the time it was sent and the data it contained, then tries to repeat the sending as close to that time as possible for replaying. If we instead know what the packet does, there's a high likelihood that we can do much cooler things, like:

• Combine replays of the same game to form a complete view
  
• Skip past the loading screen and straight into the game after the replay viewer has loaded (without any of this messy "skipping around" that actually just speeds up how fast the packets are being sent)
  
• Remove useless packets to further decrease the size of replays
  
• Automatically track stats/item builds/whatever in a game (either after the fact or during)
  

There's a lot more possibilities, but thats just a few off the top of my head. Here's a link to the list of packet types and their byte values in case anyone wants it: http://pastebin.com/V03NUsVU Hopefully I'll have some time soon to setup a better environment for comparing packets of the same type, so that maybe I can get an understanding of how they are formatted past their type specifier.