#nipa

Nitro+ — http://www.nitroplus.co.jp/
Nitro+ CHiRAL — http://www.nitrochiral.com/

Description (from comments)

This is a tool made for Nitro+'s NPA archives which is used by the N2System engine. The engine is used in 6 games total between Nitro+ and Nitro+ CHiRAL. It supports unpacking and repacking even if the format is archived and/or encrypted. There are 3 versions of the NPA archive that is currently known. See npadoc.html (also archived here) for documentation on the NPA format.

Usage

For the uninitiated, this is a non-interactive command-line program so this is best run from the command line.

• General
  • -h — Displays help information and lists Game IDs.
• Extraction
  • -x (file) — Extract NPA archive
  • -g (id) — Game ID for encryption (if applicable). Defaults to ChaosHead if no encryption is entered
• Creation
  • -c (folder) (output file) — Create archive
  • -z — Compress files
  • -cg (folder) (output file) (id) — Create encrypted archive using game id.

DO NOT compress a CG folder. There is little change in size by doing so and it messes up the engine. This is a problem with the engine and Nitro+ doesn't compress their CG files because of it.

Examples

-x nss.npa — Extract nss.npa into the folder "nss"
-xg nss.npa MuramasaTr — Extract nss.npa into the folder "nss" using the Muramasa Trial encryption
-c nss nss.npa — Create an archive out of the folder "nss"
-cz nss nss.npa — Create a compressed archive out of the folder "nss"
-czg nss nss.npa Lamento — Create a compressed archive of the folder "nss" then use Lamento encryption.

Supported Games

Game IDs in code formatting.

• Nitro+
  • Chaos;Head ChaosHead
  • Chaos;Head Trial 1 ChaosHeadTr1
  • Chaos;Head Trial 2 ChaosHeadTr2
  • FullMetalDaemon MURAMASA Muramasa
  • FullMetalDaemon MURAMASA Janen Hen MuramasaAD
  • FullMetalDaemon MURAMASA Trial MuramasaTr
  • FullMetalDaemon MURAMASA Shokuzai hen MuramasaSS
  • Guilty Crown Lost Xmas Trailer LostXTrailer
  • Guilty Crown Lost Xmas LostX
  • Kikokugai Kikokugai
  • Kimi to Kajono to Kanojo no Koi Totono
  • Sumaga Sumaga
  • Sumaga 3% Sumaga3P
  • Sumaga Special SumagaSP
  • Demonbane The Best Demonbane
  • Axanael/Axanael Trial Axanael
  • Sonicomi Sonicomi
  • Sonicomi Trial 2 SonicomiTr2
  • Zoku Satsuriku no Django Django
• Nitro+ CHiRAL
  • Lamento -Beyond the Void- Lamento
  • sweet pool sweetpool
  • DRAMAtical Murder DramaticalMurder
  • DRAMAtical Murder re:connect DramaticalMurderRC

Credits

Minagi from the NovelNews.net forum for reverse-engineering the npa format and writing the original code.