Files
Commonwealth-Online-Public/tools/extract_ba2.py
T
andrew 9c84c9d4bc Add FFDec docs/tools and server-browser fixes
Add comprehensive FFDec walkthrough and short patch docs for safely adding a Multiplayer item to MainMenu.swf, plus helper scripts to extract the vanilla SWF and restore it (tools/extract_ba2.py, tools/restore-vanilla-mainmenu.ps1). Update exported MainMenu.as with a warning comment and remove an outdated exported PATCH markdown. Patch binary Interface/MainMenu.swf (updated).

Hardening fixes in the plugin: include GFx headers, avoid leaving the PrismaUI overlay focused after menu changes, only call OnBrowserHidden when the browser was actually visible, and add IsMainMenuOnMainPanel() so WatchMainMenuState ignores MainMenu when not on the MAIN_STATE. Ensure events are only dispatched when the browser is valid & visible (CanDispatchToBrowser) and make Scaleform UI hide the browser immediately during transitions. These changes prevent the overlay from staying focused during Settings transitions and stop JS events from being sent to a hidden/invalid view.
2026-06-08 22:26:00 +12:00

80 lines
2.5 KiB
Python

#!/usr/bin/env python3
"""Extract a single file from a Fallout 4 BA2 (BTDX) archive."""
from __future__ import annotations
import argparse
import struct
import zlib
from pathlib import Path
def read_name(data: bytes, offset: int) -> tuple[str, int]:
length = struct.unpack_from("<H", data, offset)[0]
start = offset + 2
name = data[start : start + length].decode("utf-8", errors="replace")
return name, start + length
def extract_file(archive: Path, target: str, output: Path) -> None:
data = archive.read_bytes()
if data[:4] != b"BTDX":
raise SystemExit(f"Not a BA2 archive: {archive}")
version = struct.unpack_from("<I", data, 4)[0]
if version not in (1, 7, 8):
raise SystemExit(f"Unsupported BA2 version {version}")
archive_type = data[8:12].decode("ascii", errors="replace")
if archive_type != "GNRL":
raise SystemExit(f"Unsupported archive type {archive_type!r} (only GNRL supported)")
num_files = struct.unpack_from("<I", data, 12)[0]
name_table = struct.unpack_from("<Q", data, 16)[0]
file_table = 24
target_norm = target.replace("/", "\\").lower()
name_cursor = name_table
for i in range(num_files):
name, name_cursor = read_name(data, name_cursor)
entry_offset = file_table + i * 36
(
_name_hash,
_ext,
_dir_hash,
_flags,
file_offset,
packed_size,
unpacked_size,
_unk,
) = struct.unpack_from("<I4sIIQIII", data, entry_offset)
if name.lower() != target_norm:
continue
if packed_size and unpacked_size and packed_size != unpacked_size:
payload = zlib.decompress(data[file_offset : file_offset + packed_size])
else:
size = unpacked_size or packed_size
payload = data[file_offset : file_offset + size]
output.parent.mkdir(parents=True, exist_ok=True)
output.write_bytes(payload)
print(f"Extracted {name} ({len(payload)} bytes) -> {output}")
return
raise SystemExit(f"File not found in archive: {target}")
def main() -> None:
parser = argparse.ArgumentParser(description=__doc__)
parser.add_argument("archive", type=Path)
parser.add_argument("target", help="Archive path, e.g. Interface\\MainMenu.swf")
parser.add_argument("output", type=Path)
args = parser.parse_args()
extract_file(args.archive, args.target, args.output)
if __name__ == "__main__":
main()