valve-parsers 1.2.2

Python library for parsing Valve game files (VPK, PCF, MDL)

Valve Parsers

A Python library for parsing Valve game files, extracted from my casual-preloader project. This library provides support for:

• VPK (Valve Package) files - Valve's archive format used in Source engine games
• PCF (Particle) files - Valve's particle system files - See constants.py for supported versions
• MDL (Model) files - read materials[] / materialDirectories[]

Features

• Support for single-file and multi-file VPK archives (creation and modification)
• Full VPK directory parsing and file extraction
• In-place VPK file patching with size checking
• PCF parsing and encoding
• Support for all PCF attribute types (see constants.py for these as well)

Installation

pip install valve-parsers

Quick Start (Parsing + Modification)

Creating VPK Archives

from valve_parsers import VPKFile

# Create a single-file VPK
success = VPKFile.create("source_directory", "output/archive.vpk")

# Create a multi-file VPK with size limit (100MB per archive split)
success = VPKFile.create("source_directory", "output/archive", split_size=100*1024*1024)

Working with VPK Archives

from valve_parsers import VPKFile

# Open a VPK file
vpk = VPKFile("path/to/archive.vpk")

# List all files
files = vpk.list_files()
print(f"Found {len(files)} files")

# Find files matching a pattern
texture_files = vpk.list_files(extension="vtf")
material_files = vpk.find_files("materials/*.vmt")

# Extract all files matching a pattern
count = vpk.extract_all("output_dir", pattern="materials/*.vmt")
print(f"Extracted {count} material files")

# Extract a file
vpk.extract_file("materials/models/player/scout.vmt", "output/scout.vmt")

# Or load it directly into memory
file_data = vpk.get_file_data("materials/models/player/scout.vmt")
if file_data:
    content = file_data.decode('utf-8')
    
# Patch a file
# Read a new material file from disk
new_texture_path = "custom_scout_red.vmt"
with open(new_texture_path, 'rb') as f:
    new_texture_data = f.read()

# Target file path inside the VPK
target_file = "materials/models/player/scout_red.vmt"

# Check if a file exists
if vpk.file_exists(target_file):
    print("File found!")
    # Get file info
    info = vpk.get_file_info(target_file)
    if info:
        print(f"Size: {info['size']} bytes, CRC: 0x{info['crc']:08X}")
        # IMPORTANT: Patched files must match original size exactly!
        original_size = info['size']
        if len(new_texture_data) != original_size:
            if len(new_texture_data) < original_size:
                # Pad with spaces to match original size
                padding_needed = original_size - len(new_texture_data)
                print(f"Adding {padding_needed} bytes of padding")
                new_texture_data = new_texture_data + b' ' * padding_needed
            else:
                print(f"ERROR: New file is {len(new_texture_data) - original_size} bytes larger!")
                print("File cannot be patched - size must match exactly")
    
        # Now patch the file
        vpk.patch_file(target_file, new_texture_data, create_backup=False)

MDL Files

from valve_parsers import MDLFile

# Open and parse a MDL file
mdl = MDLFile("path/to/model.mdl")

print(f"version: {mdl.version}")
print(f"checksum: 0x{mdl.checksum:08X}")
print(f"name: {mdl.name}")
print(f"materials: {mdl.materials}")
print(f"material_dirs: {mdl.material_dirs}")

# Rewrite materialDirectories[] in place. New strings are appended at EOF.
new_dirs = [d.replace("models\\", "console\\models\\") for d in mdl.material_dirs]
mdl.rewrite_material_dirs(new_dirs)

PCF Files

from valve_parsers import PCFFile

# Open and decode a PCF file
pcf = PCFFile("path/to/particles.pcf").decode()

print(f"PCF Version: {pcf.version}")
print(f"String dictionary: {len(pcf.string_dictionary)} entries")
print(f"Elements: {len(pcf.elements)} particle systems")

# Print particle system data
for element in pcf.elements:
    print(f"Element: {element.element_name}")
    for attr_name, (attr_type, attr_value) in element.attributes.items():
        print(f"  {attr_name.decode()}: {attr_value}")
        
# Rename all operators to ''
for i, element in enumerate(pcf.elements):
    type_name = pcf.string_dictionary[element.type_name_index].decode('ascii')
    if type_name == 'DmeParticleOperator':
        element.element_name = str('').encode('ascii')

# Encode back to file
pcf.encode("output/modified_particles.pcf")

# Find a specific element by name
element = pcf.find_element_by_name("my_explosion_effect")
if element:
    print(f"Found element with {len(element.attributes)} attributes")

# Get all elements of a specific type
operators = pcf.get_elements_by_type('DmeParticleOperator')
print(f"Found {len(operators)} operators")

# Get and set attribute values with helper methods
from valve_parsers import AttributeType

element = pcf.find_element_by_name("my_effect")
if element:
    # Get attribute value
    radius = pcf.get_attribute_value(element, "radius", default=5.0)
    print(f"Current radius: {radius}")

    # Set attribute value
    pcf.set_attribute_value(element, "radius", 10.0, AttributeType.FLOAT)
    pcf.set_attribute_value(element, "color", (255, 0, 0, 255), AttributeType.COLOR)

pcf.encode("output/modified_particles.pcf")

API Reference

VPKFile

The main class for working with VPK archives.

Constructor

• VPKFile(vpk_path: Union[str, Path], auto_parse: bool = True) - Initialize with path to VPK file
  • vpk_path: Path to the VPK file
  • auto_parse: Automatically parse directory on init (default: True)

Methods

• parse_directory() -> VPKFile - Parse the VPK directory structure (called automatically unless auto_parse=False)
• list_files(extension: str = None, path: str = None) -> List[str] - List files with optional filtering
• find_files(pattern: str) -> List[str] - Find files matching a glob pattern
• find_file_path(filename: str) -> Optional[str] - Find the full path of a filename
• extract_file(filepath: str, output_path: str) -> bool - Extract a file from the archive
• extract_all(output_dir: str, pattern: str = None) -> int - Extract multiple files to a directory
• patch_file(filepath: str, new_data: bytes, create_backup: bool = False) -> bool - Modify a file in the archive
• get_file_data(filepath: str) -> Optional[bytes] - Read a file's contents directly into memory
• file_exists(filepath: str) -> bool - Check if a file exists in the archive
• get_file_info(filepath: str) -> Optional[Dict] - Get comprehensive information about a file
• create(source_dir: str, output_base_path: str, split_size: int = None) -> bool - Create new VPK archive (class method)

Properties

• directory - Parsed directory structure
• is_dir_vpk - Whether this is a directory VPK file
• vpk_path - Path to the VPK file

VPKDirectoryEntry

Represents an entry in the VPK directory.

Properties

• crc: int - CRC32 checksum
• preload_bytes: int - Number of preload bytes
• archive_index: int - Archive file index
• entry_offset: int - Offset within archive
• entry_length: int - Length of file data
• preload_data: Optional[bytes] - Preloaded data

PCFFile

The main class for working with PCF particle files.

Constructor

• PCFFile(input_file: Union[Path, str], version: str = "DMX_BINARY2_PCF1") - Initialize with file path, default version is "DMX_BINARY2_PCF1"

Methods

• decode() -> PCFFile - Parse the PCF file
• encode(output_path: Union[Path, str]) -> PCFFile - Write PCF file to disk
• find_element_by_name(name: str) -> Optional[PCFElement] - Find a particle element by its name
• get_elements_by_type(type_name: str) -> List[PCFElement] - Get all elements of a specific type
• get_attribute_value(element: PCFElement, attr_name: str, default=None) - Get an attribute value from an element (static method)
• set_attribute_value(element: PCFElement, attr_name: str, value, attr_type: AttributeType) - Set an attribute value on an element

Properties

• version - PCF version string
• string_dictionary - List of strings used in the file
• elements - List of particle system elements

PCFElement

Represents a particle system element.

Properties

• type_name_index: int - Index into string dictionary for type name
• element_name: bytes - Name of the element
• data_signature: bytes - 16-byte signature
• attributes: Dict[bytes, Tuple[AttributeType, Any]] - Element attributes

MDLFile

The main class for reading and rewriting Source MDL model files.

Constructor

• MDLFile(mdl_path: Union[str, Path], auto_parse: bool = True) - Initialize with path to MDL file
  • mdl_path: Path to the MDL file
  • auto_parse: Automatically parse on init (default: True)

Methods

• parse() -> MDLFile - Parse the MDL header (called automatically unless auto_parse=False)
• rewrite_material_dirs(new_dirs: List[str], *, update_data_length: bool = True) -> None - Replace materialDirectories[] in place

Properties

• version: int - MDL format version
• checksum: int - MDL checksum
• name: str - Internal model name
• data_length: int - Header dataLength field
• file_size: int - Current size of the file on disk
• materials: List[str] - Material names referenced by the model
• material_dirs: List[str] - Search directories the engine looks in for those materials

Constants

• PCFVersion - Enum of supported PCF versions
• AttributeType - Enum of PCF attribute types

Supported Games

This library works with files from Orange Box titles. Mostly intended for TF2, YMMV with other games.

See:

https://developer.valvesoftware.com/wiki/PCF

https://developer.valvesoftware.com/wiki/VPK_(file_format)

https://developer.valvesoftware.com/wiki/MDL_(Source)

Contributing

This library was yoinked from my casual-pre-loader project. Contributions are welcome!

Changelog

1.2.2

• Added support for path lists to grow in size

1.2.1

• Added support for empty paths in model strings

1.2.0

• Start of MDL parser (MDLFile)

1.0.7

• Performance: Replaced rglob with os.walk for VPK creation
• Performance: Replaced Path.match with fnmatch in find_files()
• Bug fix: find_files() now uses correct glob matching behavior

1.0.6

• Updated README with corrected examples
• Added documentation for all VPK methods: extract_all(), get_file_data(), file_exists(), get_file_info()
• Added file patching size-checking examples
• Made get_file_entry() private
• Cleaned up internal method documentation

1.0.5

• Auto-parse support
• Reading and writing is now 2-3x faster

1.0.2

• Single file VPK no longer has _dir name

1.0.1

• Nothing

1.0.0

• Initial release
• VPK parsing and creation support
• PCF parsing and encoding support