= About =

This Python script is able to extract all music tracks from a Runescape cache. It is not necessary to have the game installed. Only the cache files need to be present in a directory. Specifically the files main_file_cache.dat2, main_file_cache.idx17 and main_file_cache.idx40 are needed.

= Usage =

If you have Runescape installed, you can find the cache in your user directory in jagexcache/runescape/LIVE/. If you run Runescape under Wine, then they will be located in $WINEPREFIX/drive_c/windows/profiles/josch/jagexcache/runescape/LIVE/.

Then run the script like this:

./rsmusicextract.py path/to/cache path/for/extracted/files

You can omit the path to extract the music files to, in which case the program will only list which music tracks are available.

You can also add the --incomplete option in which case also incomplete music tracks will be extracted (or displayed in case you omitted the directory to extract to).

= Combining the music =

If an output directory is given, then the script will create it if necessary and extract the individual music chunks into subdirectories which are named after the music track they belong to. The chunks are mostly either 3.918 s or 7.836 s long.

Each individual chunk is an ogg vorbis file which, when concatenated, make the full music track. They are numbered sequentially to concatenate them in the right order.

The vorbis container format allows to concatenate multiple vorbis files by simply running (on unix-like operating systems):

cat file1.ogg file2.ogg file3.ogg > combined.ogg

The problem is, that there are some players which either do not support ogg files of that kind and will only play the very first chunk or which add split-second pauses between the individual parts. Even using the ffmpeg concat demuxer will leave audible gaps between the individual chunks. I posted the following questions to find a solution to this problem:

• http://superuser.com/questions/864911/lossless-concatenation-of-ogg-vorbis-files
• http://stackoverflow.com/questions/27980960/how-to-lossless-concatenate-ogg-vorbis-files

Until that problem is solved, you can concatenate the individual tracks in a single file by re-encoding the output stream. To not loose any quality, flac can be used as the codex. The following snippet will combine the individual ogg chunks in every directory into a single file of the same name:

$ mkdir combined
$ for dir in */; do \
	dir=${dir%*/}; \
	sox --combine concatenate "$dir"/* -C 8 "combined/$dir.flac"; \
done

= Origin =

This code is inspired by RSCacheTool by Villermen:

https://github.com/Villermen/RSCacheTool

It especially benefits from the reverse engineering that was done to create that tool.

This script was written because of certain fundamental design shortcomings of RSCacheTool which made it suboptimal for my use case. For example, to just list all music tracks, RSCacheTool first has to extract all files from archive 40 which can take up a couple of gigabytes of disk space.

While RSCacheTool aims to be a swiss army knife for Runescape cache files, this script only wants to provide the means to display and extract the Runescape music from Runescape cache files.

RSCacheTool also has to be run in two stages to extract and name the music track. This script does both actions in one go.

This script works "the other way round" compared to RSCacheTool. While RSCacheTool first extracts all files and allows to rename them later, this script will first extract the list of all available music and then extract the necessary files from the archive. This allows to list all available music tracks without having to extract them first.

Finally, because of its simplicity, this script is only 20% of the length of RSCacheTool. For example it does not attempt to join the extract music as this can be done by a small shell invocation as demonstrated above.