Welcome to the official home of ReScene!

ReScene is a mechanism for backing up and restoring the metadata from "scene" released RAR files. It was created to support the x264 community, but we have found that it works for many of the other "scenes" out there too.

How it works

Most of the various scene groups out there distribute their releases packed in RAR files. These RAR files, while useful for distribution, must be unpacked before the goodies inside can be used. Traditionally, this left us with a quandry. Do we unpack the files so we can use the goodies? Or do we keep the RAR files intact so we can trade them on one of those popular file sharing sites/services the kids are using nowadays? Or do we do both?

Well, with ReScene, you don't have to choose!

What's that you say? If you unpack and delete the RARs, there's no way to get back to the originals? Not true, my friends! You see, a RAR file is made up of two things: the data that we want to get out of them, and metadata that describes that data (file names, dates, and attributes) or that supports some of RAR's many other features (comments, authenticity verification, recovery records, etc.) While it is true that if you were to unpack a RAR archive and then try to re-create it exactly by just re-RARing it, you'd have VERY little chance of succeeding, if you back up all that metadata, you CAN re-create those rars EXACTLY as they were.

A typical RAR file looks something like this:

hvfDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDrt

In this representation, the D's represent the data that is stored in the RAR file. The other characters represent blocks of metadata. If we were to unpack that RAR, this is what we'd have:

DDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD

That's nice, because it's the data we're most interested in, but what about all that other stuff? We have no way of getting it back if we delete that RAR file. Even if we duplicate the settings originally used to create the RAR *exactly*, there's still a good chance the new RAR will be different than the old one. Did you know, for example, that RAR files include a byte that indicates what platform they were created on? So, if a RAR set was originally created on Linux, there would be no way to create that same RAR in Windows (without some hacking, anyway...). But what if we made a backup of the metadata before we delete those RARs? Something like this:

hvfXrt

The X here represents the data that we extracted, and the rest of the blocks are copied exactly as they were in the original file. Now if we want to re-create that RAR, all we have to do is replace the X with the file data (D's), and we have the exact same file we started with.

How to use it

In its current version ReScene is pretty simple to use. The first thing you'll need is one of the scene releases I've been talking about. They will typically come with one or more RAR files and an SFV file that contains CRC values for those RAR files.

If you run the ReScene command-line utility (srr.exe) and pass the SFV file in as a parameter, it will read the SFV and locate all the RAR files from the release. The utility then creates a .srr file. The SRR file contains a copy of the SFV you specified as well as a backup of all those metadata blocks I mentioned earlier. It's typically a very small file (maybe 10-20KB depending on the number of RARs), and it is created very quickly (typically <1 second). Once you have that .srr file, you can extract the archive and delete the RAR and SFV files.

To re-create the original release files, all you need is the .srr and the files you extracted from the archive. Pass the .srr file in to the utility to start the reconstruction. The SFV file will be restored from the SRR file, and then each orginal RAR will be painstakingly (but quickly) reconstructed from the data files and the backed-up blocks in the SRR file. As a final step, you can validate the files against the SFV to make sure they came through the process unscathed.

The catch

You knew there had to be a catch, right? Ok, there is one, but it's small. This process only works on RAR files created with "Store" mode (otherwise known as -m0 or No Compression). That's not too much of a restriction, though, as most scene releases use this mode anyway. Also, I think it goes without saying that ReScene doesn't support encrypted RARs.