Source code for PIL.MpegImagePlugin

#
# The Python Imaging Library.
# $Id$
#
# MPEG file handling
#
# History:
#       95-09-09 fl     Created
#
# Copyright (c) Secret Labs AB 1997.
# Copyright (c) Fredrik Lundh 1995.
#
# See the README file for information on usage and redistribution.
#


from . import Image, ImageFile
from ._binary import i8

#
# Bitstream parser


[docs]class BitStream: def __init__(self, fp): self.fp = fp self.bits = 0 self.bitbuffer = 0
[docs] def next(self): return i8(self.fp.read(1))
[docs] def peek(self, bits): while self.bits < bits: c = self.next() if c < 0: self.bits = 0 continue self.bitbuffer = (self.bitbuffer << 8) + c self.bits += 8 return self.bitbuffer >> (self.bits - bits) & (1 << bits) - 1
[docs] def skip(self, bits): while self.bits < bits: self.bitbuffer = (self.bitbuffer << 8) + i8(self.fp.read(1)) self.bits += 8 self.bits = self.bits - bits
[docs] def read(self, bits): v = self.peek(bits) self.bits = self.bits - bits return v
## # Image plugin for MPEG streams. This plugin can identify a stream, # but it cannot read it.
[docs]class MpegImageFile(ImageFile.ImageFile): format = "MPEG" format_description = "MPEG" def _open(self): s = BitStream(self.fp) if s.read(32) != 0x1B3: msg = "not an MPEG file" raise SyntaxError(msg) self.mode = "RGB" self._size = s.read(12), s.read(12)
# -------------------------------------------------------------------- # Registry stuff Image.register_open(MpegImageFile.format, MpegImageFile) Image.register_extensions(MpegImageFile.format, [".mpg", ".mpeg"]) Image.register_mime(MpegImageFile.format, "video/mpeg")