89 lines
2.1 KiB
Python
89 lines
2.1 KiB
Python
#
|
|
# 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 __future__ import annotations
|
|
|
|
from . import Image, ImageFile
|
|
from ._binary import i8
|
|
from ._typing import SupportsRead
|
|
|
|
#
|
|
# Bitstream parser
|
|
|
|
|
|
class BitStream:
|
|
def __init__(self, fp: SupportsRead[bytes]) -> None:
|
|
self.fp = fp
|
|
self.bits = 0
|
|
self.bitbuffer = 0
|
|
|
|
def next(self) -> int:
|
|
return i8(self.fp.read(1))
|
|
|
|
def peek(self, bits: int) -> int:
|
|
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
|
|
|
|
def skip(self, bits: int) -> None:
|
|
while self.bits < bits:
|
|
self.bitbuffer = (self.bitbuffer << 8) + i8(self.fp.read(1))
|
|
self.bits += 8
|
|
self.bits = self.bits - bits
|
|
|
|
def read(self, bits: int) -> int:
|
|
v = self.peek(bits)
|
|
self.bits = self.bits - bits
|
|
return v
|
|
|
|
|
|
def _accept(prefix: bytes) -> bool:
|
|
return prefix[:4] == b"\x00\x00\x01\xb3"
|
|
|
|
|
|
##
|
|
# Image plugin for MPEG streams. This plugin can identify a stream,
|
|
# but it cannot read it.
|
|
|
|
|
|
class MpegImageFile(ImageFile.ImageFile):
|
|
format = "MPEG"
|
|
format_description = "MPEG"
|
|
|
|
def _open(self) -> None:
|
|
assert self.fp is not None
|
|
|
|
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, _accept)
|
|
|
|
Image.register_extensions(MpegImageFile.format, [".mpg", ".mpeg"])
|
|
|
|
Image.register_mime(MpegImageFile.format, "video/mpeg")
|