Extract KF2 Audio: BNK to WEM to OGG Scripts

Killing Floor 2 stores its sound effects and music in Wwise containers: .bnk banks that hold .wem streams. This article rewrites a community guide that bundles the community's known extraction tools into a set of scripts, so you can right-click a bank and get playable .ogg files. It is about extracting only, not replacing; for replacement see custom music with Wwise and WEM and swapping music with Wwise and Audacity.

An easier option first

The author added a note that Ravioli Tools is easier: it has a full user interface, can convert to other formats including WAV and lets you choose the export location. If the script kit feels too long, try that first.

What the kit uses

• bnk extractor (bnkextr) to unpack .bnk files.
• ww2ogg (v0.24) to convert Wwise .wem files to .ogg.
• revorb to fix the generated .ogg files so players handle them correctly.

The method is built on a well-known "how to extract game audio files" guide and simplified into scripts. The author also supplies a documentation page and a long video (the video is outdated as of 2021; the documentation is the better source).

Installation

1. From the download archive, extract the kf2_sdk folder anywhere, or to C:\.
2. If it is not at C:\kf2_sdk, run _set_location_for_context_menu_reg_files.cmd.
3. Open the context_menu_entries folder and run the .reg files to add Explorer context-menu entries.
4. Run _generate_sendto_shortcuts.cmd to create shortcuts in the Send To menu, which can be used for batch conversion via right-click, Send To.

You can also drag and drop input files straight onto the scripts.

Uninstallation

• Run the *_remove.reg files in the remove folder.
• Run _delete_sendto_shortcuts.cmd (or delete the shortcuts manually).
• Delete the files.

What the scripts do

bnk_to_ogg.cmd for .bnk input:

1. Copies the file into a new subfolder of the same name.
2. Extracts the .wem files (bnkextr.exe).
3. Deletes the duplicate .bnk copy.
4. Converts the .wem files to .ogg (ww2ogg.exe).
5. Runs revorb on the .ogg files.
6. Deletes the intermediate .wem files.

wem_to_ogg.cmd converts .wem input to .ogg and revorbs it. If the input is a folder, it converts every .wem in it. It does not delete the original .wem files unless the del_wem variable is set to true.

Screenshots

Send To entries for batch conversion.

The folder context-menu entry.

The .bnk file context-menu entry.

Notes

• Explorer may behave sluggishly after a large extraction, probably due to heavy file writes and indexing.
• The author likes Resonic Player for browsing sound files and music.