Support Extraction for AKPK / .pck Containers

[Fluke458]

Please add support for extracting AKPK / .pck files.
Newer Wwise versions store audio in .pck instead of .bnk, but internally they still contain WEM entries with IDs similar to .bnk.

Expected behavior:

Detect .pck / AKPK

Parse file index

Extract all WEMs with correct numeric IDs

Output format identical to .bnk extraction

I can provide sample .pck files if needed. Thank you!

[eXpl0it3r]

Do you know if someone has reverse engineered the format already?

[Fluke458]

There is no official documentation from Audiokinetic for AKPK (.pck),
but the format has been partially reverse-engineered by the modding community.
Tools like Wwise-Unpacker, Ravioli, and wwiser can parse parts of the structure
(headers, IDs, and embedded WEM streams).
The format is similar enough to BNK that ID-based extraction is possible,
but there is still no full public specification.
That’s why support in bnkextr would be very useful.

[eXpl0it3r]

Can't say when I get around to it, but sounds interesting enough to have a look.

Can you send me some of those samples? And if possible what it should sound like.
Feel free to use the contact info in my profile, if you don't want to post this publicly.

[isHarryh]

Here's the reversed PCK file structure from the game Arknights Endfield (CBT3). The PCK is just a container of multiple bnk/wem files with a header storing the offset&size of each audio file in the entire file.

But this game uses a custom encryption on the PCK file, so this may not be able to show a general/common PCK structure. For more info, refer to this article about Endfield PCK.