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# | |
# The Python Imaging Library. | |
# $Id$ | |
# | |
# DCX file handling | |
# | |
# DCX is a container file format defined by Intel, commonly used | |
# for fax applications. Each DCX file consists of a directory | |
# (a list of file offsets) followed by a set of (usually 1-bit) | |
# PCX files. | |
# | |
# History: | |
# 1995-09-09 fl Created | |
# 1996-03-20 fl Properly derived from PcxImageFile. | |
# 1998-07-15 fl Renamed offset attribute to avoid name clash | |
# 2002-07-30 fl Fixed file handling | |
# | |
# Copyright (c) 1997-98 by Secret Labs AB. | |
# Copyright (c) 1995-96 by Fredrik Lundh. | |
# | |
# See the README file for information on usage and redistribution. | |
# | |
from __future__ import annotations | |
from . import Image | |
from ._binary import i32le as i32 | |
from .PcxImagePlugin import PcxImageFile | |
MAGIC = 0x3ADE68B1 # QUIZ: what's this value, then? | |
def _accept(prefix: bytes) -> bool: | |
return len(prefix) >= 4 and i32(prefix) == MAGIC | |
## | |
# Image plugin for the Intel DCX format. | |
class DcxImageFile(PcxImageFile): | |
format = "DCX" | |
format_description = "Intel DCX" | |
_close_exclusive_fp_after_loading = False | |
def _open(self) -> None: | |
# Header | |
s = self.fp.read(4) | |
if not _accept(s): | |
msg = "not a DCX file" | |
raise SyntaxError(msg) | |
# Component directory | |
self._offset = [] | |
for i in range(1024): | |
offset = i32(self.fp.read(4)) | |
if not offset: | |
break | |
self._offset.append(offset) | |
self._fp = self.fp | |
self.frame = -1 | |
self.n_frames = len(self._offset) | |
self.is_animated = self.n_frames > 1 | |
self.seek(0) | |
def seek(self, frame: int) -> None: | |
if not self._seek_check(frame): | |
return | |
self.frame = frame | |
self.fp = self._fp | |
self.fp.seek(self._offset[frame]) | |
PcxImageFile._open(self) | |
def tell(self) -> int: | |
return self.frame | |
Image.register_open(DcxImageFile.format, DcxImageFile, _accept) | |
Image.register_extension(DcxImageFile.format, ".dcx") | |