Hacking libyaz0 - A library for compressing and decompressing Yaz0/1 compression formats.

AboodXD · Nov 22, 2017

libyaz0 is a library in Python for decompressing and compressing Yaz0/1 compression formats.
Written in Python 3.

Yaz0 is a compression format used in several games from the N64, GC, Wii, 3DS, Wii U, and now the Switch.

A few of those games:

The Legend of Zelda: Ocarina of Time.
Super Mario Sunshine.
Mario Kart Wii.
Super Mario 3D Land.
New Super Mario Bros. U.
Mario Kart 8.
Breath of the Wild.
ARMS.
Splatoon 2.

I'd say it's a Nintendo-favorite. :>

--------------------------------------------------------------------------------------------

Example of how Yaz0 compressed data can be decompressed:

Code:

from libyaz0 import decompress

# Yaz0 compressed data
data = b"Yaz0\x00\x00\x00\x10\x00\x00\x00\x00\x00" \
          b"\x00\x00\x00\xfbThis \x10\x02a \xf8test!"

# Decompress it
decompressed_data = decompress(data)

Code:

>>> decompressed_data.decode('utf-8')
'This is a test!'

--------------------------------------------------------------------------------------------

Example of how decompressed data can be Yaz0 compressed:

Code:

from libyaz0 import compress

# Decompressed data
data = 'This is a test!'.encode('utf-8')

# Compress it
## unk: the 4-bytes value that will be located at 0x8-0xC of the Yaz0 header
### default is 0x00000000
unk = 0

## level: compression level.
### 0: No compression (Fastest)
### 9: Best compression (Slowest)
#### default is 1
level = 9

compressed_data = compress(data, unk, level)

Code:

>>> compressed_data
b'Yaz0\x00\x00\x00\x10\x00\x00\x00\x00\x00\x00\x00\x00\xfbThis \x10\x02a \xf8test!'

--------------------------------------------------------------------------------------------

libyaz0 can also be used to guess the file extension from the decompressed data.

File formats libyaz0 can detect:

BNTX (.bntx)
BNSH (.bnsh)
BFLAN (.bflan)
BFLYT (.bflyt)
BFLIM (.bflim)
GTX (.gtx)
SARC (.sarc)
Yaz0/SZS (.yaz0)

Code:

from libyaz0 import guessFileExt

# Guess the file extension from the decompressed data
file_extension = guessFileExt(decompressed_data)

--------------------------------------------------------------------------------------------

libyaz0 can also be used as a standalone program. (Download below)

Usage:

libyaz0 [option...] input

Options:

-o <output>: Output file, if not specified, the output file will have the same name as the intput file
-c: Compress (Will try to decompress if not specified)

Compression options:

-level <level>: compression level (1-9) (1 is the default)
0: No compression (Fastest)
9: Best compression (Slowest)
-unk <unk>: the unknown value that will be located at 0x8-0xC (0x00000000 is the default)

--------------------------------------------------------------------------------------------

Download:

You can get libyaz0 using pip:

Code:

pip install libyaz0==0.4

Or you could get the source code from GitHub.
Github.
Standalone program (Windows).

--------------------------------------------------------------------------------------------

Credits:
Written by AboodXD.
Decompression algorithm based on wszst's.
Special thanks to RoadrunnerWMC for helping with looking up matches for the compression algorithm.

DSpider · Nov 22, 2017

Cool. But the game files are still encrypted after decompressing them, right?

tunip3 · Nov 23, 2017

AboodXD said:
libyaz0 is a library in Python for decompressing and compressing Yaz0/1 compression formats.
Written in Python 3.

Yaz0 is a compression format used in several games from GC, Wii, 3DS, Wii U, and now the Switch.

A few of those games:

Super Mario Sunshine.

Mario Kart Wii.

Super Mario 3D Land.

Mario Kart 8.

Breath of the Wild.

Splatoon 2.

I'd say it's a Nintendo-favorite. :>

--------------------------------------------------------------------------------------------

Example of how Yaz0 compressed data can be decompressed:

Code:

from libyaz0 import decompress # Yaz0 compressed data data = b"Yaz0\x00\x00\x00\x10\x00\x00\x00\x00\x00" \ b"\x00\x00\x00\xfbThis \x10\x02a \xf8test!" # Decompress it decompressed_data = decompress(data)

Code:

>>> decompressed_data.decode('utf-8') 'This is a test!'

--------------------------------------------------------------------------------------------

Example of how decompressed data can be Yaz0 compressed:

Code:

from libyaz0 import compress # Decompressed data data = 'This is a test!'.encode('utf-8') # Compress it ## unk: the 4-bytes value that will be located at 0x8-0xC of the Yaz0 header ### default is 0x00000000 unk = 0 ## level: compression level. ### 0: No compression (Fastest) ### 9: Best compression (Slowest) #### default is 1 level = 9 compressed_data = compress(data, unk, level)

Code:

>>> compressed_data b'Yaz0\x00\x00\x00\x10\x00\x00\x00\x00\x00\x00\x00\x00\xfbThis \x10\x02a \xf8test!'

--------------------------------------------------------------------------------------------

libyaz0 can also be used to guess the file extension from the decompressed data.

File formats libyaz0 can detect:

BNTX (.bntx)

BNSH (.bnsh)

BFLAN (.bflan)

BFLYT (.bflyt)

BFLIM (.bflim)

GTX (.gtx)

SARC (.sarc)

Yaz0/SZS (.yaz0)

Code:

from libyaz0 import guessFileExt # Guess the file extension from the decompressed data file_extension = guessFileExt(decompressed_data)

--------------------------------------------------------------------------------------------

libyaz0 can also be used as a standalone program. (Download below)

Usage:

libyaz0 [option...] input

Options:

-o <output>: Output file, if not specified, the output file will have the same name as the intput file

-c: Compress (Will try to decompress if not specified)

Compression options:

-level <level>: compression level (1-9) (1 is the default)
0: No compression (Fastest)
9: Best compression (Slowest)

-unk <unk>: the unknown value that will be located at 0x8-0xC (0x00000000 is the default)

--------------------------------------------------------------------------------------------

Download:

You can get libyaz0 using pip:

Code:

pip install libyaz0

Getting libyaz0 from GitHub is rather recommended because it includes a Cython version of the algorithms, which is much faster.

Github.
Standalone program (Windows).

--------------------------------------------------------------------------------------------

Credits:
Written by AboodXD.
Decompression algorithm based on wszst's.
Special thanks to RoadrunnerWMC for helping with looking up matches for the compression algorithm.

and how would you dump it

AboodXD · Nov 24, 2017

DSpider said:
Cool. But the game files are still encrypted after decompressing them, right?

Not as far as I know.

tunip3 said:
and how would you dump it

Yaz0 files? From the game files. They usually end with .szs.

tunip3 · Nov 24, 2017

AboodXD said:
Not as far as I know.

Yaz0 files? From the game files. They usually end with .szs.

but how do you dump the games

AboodXD · Nov 25, 2017

tunip3 said:
but how do you dump the games

You can find dumps online.

AboodXD · Nov 25, 2017

Just released v0.3 which fixes a major bug where the uncompressed data size is not saved correctly when compressing.

You can get it using pip:

Code:

pip install libyaz0==0.3.1

Or you could get the source code from Github.

Updated the standalone program (Windows) as well.

AboodXD · Dec 31, 2017

Just released v0.4 which allows for faster compressing and decompressing.

You can get it using pip:

Code:

pip install libyaz0==0.4

Or you could get the source code from Github.

Updated the standalone program (Windows) as well.

Alzter · Jul 2, 2018

I try to open the .exe and then it closes. Help? (I'm trying to decrypt a .szs file I found in the rom of Photo Dojo that I believe contains all the graphics...)

AceTartarSquad · Jul 2, 2018

Alzter said:
I try to open the .exe and then it closes. Help? (I'm trying to decrypt a .szs file I found in the rom of Photo Dojo that I believe contains all the graphics...)

You need to double click the python library, and if that doesn't work, try double clicking it twice.

Alzter · Jul 3, 2018

I opened a command line at the install location, entered the command and it worked perfectly! Thank you so much!

AboodXD · Jul 3, 2018

Alzter said:
I opened a command line at the install location, entered the command and it worked perfectly! Thank you so much!

You're welcome; but I recommend you to use SARC Tool instead.

Alzter · Jul 4, 2018

I did a sprite rip

Manurocker95 · Aug 21, 2019

does decompressing BNSH files see the shader code?

AboodXD · Aug 25, 2019

It depends on whether BNSH can in fact include code or not.

Hacking libyaz0 - A library for compressing and decompressing Yaz0/1 compression formats.

I hack NSMB games, and other shiz.

Well-Known Member

[debugger active]

I hack NSMB games, and other shiz.

[debugger active]

I hack NSMB games, and other shiz.

I hack NSMB games, and other shiz.

I hack NSMB games, and other shiz.

Member

Member

Member

I hack NSMB games, and other shiz.

Member

Game Developer & Pokémon Master

I hack NSMB games, and other shiz.

Popular threads in this forum