Gran Turismo File System (GTFS): Python parsing library

File extension

vol

KS implementation details

License: CC0-1.0

References

This page hosts a formal specification of Gran Turismo File System (GTFS) using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.

Usage

Runtime library

All parsing code for Python generated by Kaitai Struct depends on the Python runtime library. You have to install it before you can parse data.

The Python runtime library can be installed from PyPI:

python3 -m pip install kaitaistruct

Code

Parse a local file and get structure in memory:

data = GranTurismoVol.from_file("path/to/local/file.vol")

Or parse structure from a bytes:

from kaitaistruct import KaitaiStream, BytesIO

raw = b"\x00\x01\x02..."
data = GranTurismoVol(KaitaiStream(BytesIO(raw)))

After that, one can get various attributes from the structure by invoking getter methods like:

data.magic # => get magic

Python source code to parse Gran Turismo File System (GTFS)

gran_turismo_vol.py

# This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild

from pkg_resources import parse_version
import kaitaistruct
from kaitaistruct import KaitaiStruct, KaitaiStream, BytesIO


if parse_version(kaitaistruct.__version__) < parse_version('0.9'):
    raise Exception("Incompatible Kaitai Struct Python API: 0.9 or later is required, but you have %s" % (kaitaistruct.__version__))

class GranTurismoVol(KaitaiStruct):
    def __init__(self, _io, _parent=None, _root=None):
        self._io = _io
        self._parent = _parent
        self._root = _root if _root else self
        self._read()

    def _read(self):
        self.magic = self._io.read_bytes(8)
        if not self.magic == b"\x47\x54\x46\x53\x00\x00\x00\x00":
            raise kaitaistruct.ValidationNotEqualError(b"\x47\x54\x46\x53\x00\x00\x00\x00", self.magic, self._io, u"/seq/0")
        self.num_files = self._io.read_u2le()
        self.num_entries = self._io.read_u2le()
        self.reserved = self._io.read_bytes(4)
        if not self.reserved == b"\x00\x00\x00\x00":
            raise kaitaistruct.ValidationNotEqualError(b"\x00\x00\x00\x00", self.reserved, self._io, u"/seq/3")
        self.offsets = [None] * (self.num_files)
        for i in range(self.num_files):
            self.offsets[i] = self._io.read_u4le()


    class FileInfo(KaitaiStruct):
        def __init__(self, _io, _parent=None, _root=None):
            self._io = _io
            self._parent = _parent
            self._root = _root if _root else self
            self._read()

        def _read(self):
            self.timestamp = self._io.read_u4le()
            self.offset_idx = self._io.read_u2le()
            self.flags = self._io.read_u1()
            self.name = (KaitaiStream.bytes_terminate(KaitaiStream.bytes_strip_right(self._io.read_bytes(25), 0), 0, False)).decode(u"ASCII")

        @property
        def size(self):
            if hasattr(self, '_m_size'):
                return self._m_size if hasattr(self, '_m_size') else None

            self._m_size = ((self._root.offsets[(self.offset_idx + 1)] & 4294965248) - self._root.offsets[self.offset_idx])
            return self._m_size if hasattr(self, '_m_size') else None

        @property
        def body(self):
            if hasattr(self, '_m_body'):
                return self._m_body if hasattr(self, '_m_body') else None

            if not (self.is_dir):
                _pos = self._io.pos()
                self._io.seek((self._root.offsets[self.offset_idx] & 4294965248))
                self._m_body = self._io.read_bytes(self.size)
                self._io.seek(_pos)

            return self._m_body if hasattr(self, '_m_body') else None

        @property
        def is_dir(self):
            if hasattr(self, '_m_is_dir'):
                return self._m_is_dir if hasattr(self, '_m_is_dir') else None

            self._m_is_dir = (self.flags & 1) != 0
            return self._m_is_dir if hasattr(self, '_m_is_dir') else None

        @property
        def is_last_entry(self):
            if hasattr(self, '_m_is_last_entry'):
                return self._m_is_last_entry if hasattr(self, '_m_is_last_entry') else None

            self._m_is_last_entry = (self.flags & 128) != 0
            return self._m_is_last_entry if hasattr(self, '_m_is_last_entry') else None


    @property
    def ofs_dir(self):
        if hasattr(self, '_m_ofs_dir'):
            return self._m_ofs_dir if hasattr(self, '_m_ofs_dir') else None

        self._m_ofs_dir = self.offsets[1]
        return self._m_ofs_dir if hasattr(self, '_m_ofs_dir') else None

    @property
    def files(self):
        if hasattr(self, '_m_files'):
            return self._m_files if hasattr(self, '_m_files') else None

        _pos = self._io.pos()
        self._io.seek((self.ofs_dir & 4294965248))
        self._m_files = [None] * (self._root.num_entries)
        for i in range(self._root.num_entries):
            self._m_files[i] = GranTurismoVol.FileInfo(self._io, self, self._root)

        self._io.seek(_pos)
        return self._m_files if hasattr(self, '_m_files') else None