Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.11/site-packages/PIL/DcxImagePlugin.py: 88%

1# 

2# The Python Imaging Library. 

3# $Id$ 

4# 

5# DCX file handling 

6# 

7# DCX is a container file format defined by Intel, commonly used 

8# for fax applications. Each DCX file consists of a directory 

9# (a list of file offsets) followed by a set of (usually 1-bit) 

10# PCX files. 

11# 

12# History: 

13# 1995-09-09 fl Created 

14# 1996-03-20 fl Properly derived from PcxImageFile. 

15# 1998-07-15 fl Renamed offset attribute to avoid name clash 

16# 2002-07-30 fl Fixed file handling 

17# 

18# Copyright (c) 1997-98 by Secret Labs AB. 

19# Copyright (c) 1995-96 by Fredrik Lundh. 

20# 

21# See the README file for information on usage and redistribution. 

22# 

23from __future__ import annotations 

24 

25from . import Image 

26from ._binary import i32le as i32 

27from ._util import DeferredError 

28from .PcxImagePlugin import PcxImageFile 

29 

30MAGIC = 0x3ADE68B1 # QUIZ: what's this value, then? 

31 

32 

33def _accept(prefix: bytes) -> bool: 

34 return len(prefix) >= 4 and i32(prefix) == MAGIC 

35 

36 

37## 

38# Image plugin for the Intel DCX format. 

39 

40 

41class DcxImageFile(PcxImageFile): 

42 format = "DCX" 

43 format_description = "Intel DCX" 

44 _close_exclusive_fp_after_loading = False 

45 

46 def _open(self) -> None: 

47 # Header 

48 assert self.fp is not None 

49 s = self.fp.read(4) 

50 if not _accept(s): 

51 msg = "not a DCX file" 

52 raise SyntaxError(msg) 

53 

54 # Component directory 

55 self._offset = [] 

56 for i in range(1024): 

57 offset = i32(self.fp.read(4)) 

58 if not offset: 

59 break 

60 self._offset.append(offset) 

61 

62 self._fp = self.fp 

63 self.frame = -1 

64 self.n_frames = len(self._offset) 

65 self.is_animated = self.n_frames > 1 

66 self.seek(0) 

67 

68 def seek(self, frame: int) -> None: 

69 if not self._seek_check(frame): 

70 return 

71 if isinstance(self._fp, DeferredError): 

72 raise self._fp.ex 

73 self.frame = frame 

74 self.fp = self._fp 

75 self.fp.seek(self._offset[frame]) 

76 PcxImageFile._open(self) 

77 

78 def tell(self) -> int: 

79 return self.frame 

80 

81 

82Image.register_open(DcxImageFile.format, DcxImageFile, _accept) 

83 

84Image.register_extension(DcxImageFile.format, ".dcx")