Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.11/site-packages/PIL/MpegImagePlugin.py: 82%

1# 

2# The Python Imaging Library. 

3# $Id$ 

4# 

5# MPEG file handling 

6# 

7# History: 

8# 95-09-09 fl Created 

9# 

10# Copyright (c) Secret Labs AB 1997. 

11# Copyright (c) Fredrik Lundh 1995. 

12# 

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

14# 

15from __future__ import annotations 

16 

17__lazy_modules__ = {"PIL._binary"} 

18 

19from . import Image, ImageFile 

20from ._binary import i8 

21 

22TYPE_CHECKING = False 

23if TYPE_CHECKING: 

24 from ._typing import SupportsRead 

25 

26# 

27# Bitstream parser 

28 

29 

30class BitStream: 

31 def __init__(self, fp: SupportsRead[bytes]) -> None: 

32 self.fp = fp 

33 self.bits = 0 

34 self.bitbuffer = 0 

35 

36 def next(self) -> int: 

37 return i8(self.fp.read(1)) 

38 

39 def peek(self, bits: int) -> int: 

40 while self.bits < bits: 

41 self.bitbuffer = (self.bitbuffer << 8) + self.next() 

42 self.bits += 8 

43 return self.bitbuffer >> (self.bits - bits) & (1 << bits) - 1 

44 

45 def skip(self, bits: int) -> None: 

46 while self.bits < bits: 

47 self.bitbuffer = (self.bitbuffer << 8) + i8(self.fp.read(1)) 

48 self.bits += 8 

49 self.bits = self.bits - bits 

50 

51 def read(self, bits: int) -> int: 

52 v = self.peek(bits) 

53 self.bits = self.bits - bits 

54 return v 

55 

56 

57def _accept(prefix: bytes) -> bool: 

58 return prefix.startswith(b"\x00\x00\x01\xb3") 

59 

60 

61## 

62# Image plugin for MPEG streams. This plugin can identify a stream, 

63# but it cannot read it. 

64 

65 

66class MpegImageFile(ImageFile.ImageFile): 

67 format = "MPEG" 

68 format_description = "MPEG" 

69 

70 def _open(self) -> None: 

71 assert self.fp is not None 

72 

73 s = BitStream(self.fp) 

74 if s.read(32) != 0x1B3: 

75 msg = "not an MPEG file" 

76 raise SyntaxError(msg) 

77 

78 self._mode = "RGB" 

79 self._size = s.read(12), s.read(12) 

80 

81 

82# -------------------------------------------------------------------- 

83# Registry stuff 

84 

85Image.register_open(MpegImageFile.format, MpegImageFile, _accept) 

86 

87Image.register_extensions(MpegImageFile.format, [".mpg", ".mpeg"]) 

88 

89Image.register_mime(MpegImageFile.format, "video/mpeg")