PIL.FliImagePlugin 源代码

#
# The Python Imaging Library.
# $Id$
#
# FLI/FLC file handling.
#
# History:
#       95-09-01 fl     Created
#       97-01-03 fl     Fixed parser, setup decoder tile
#       98-07-15 fl     Renamed offset attribute to avoid name clash
#
# Copyright (c) Secret Labs AB 1997-98.
# Copyright (c) Fredrik Lundh 1995-97.
#
# See the README file for information on usage and redistribution.
#

import os

from . import Image, ImageFile, ImagePalette
from ._binary import i16le as i16
from ._binary import i32le as i32
from ._binary import o8

#
# decoder


def _accept(prefix):
    return (
        len(prefix) >= 6
        and i16(prefix, 4) in [0xAF11, 0xAF12]
        and i16(prefix, 14) in [0, 3]  # flags
    )


##
# Image plugin for the FLI/FLC animation format.  Use the <b>seek</b>
# method to load individual frames.


[文档] class FliImageFile(ImageFile.ImageFile): format = "FLI" format_description = "Autodesk FLI/FLC Animation" _close_exclusive_fp_after_loading = False def _open(self): # HEAD s = self.fp.read(128) if not (_accept(s) and s[20:22] == b"\x00\x00"): msg = "not an FLI/FLC file" raise SyntaxError(msg) # frames self.n_frames = i16(s, 6) self.is_animated = self.n_frames > 1 # image characteristics self.mode = "P" self._size = i16(s, 8), i16(s, 10) # animation speed duration = i32(s, 16) magic = i16(s, 4) if magic == 0xAF11: duration = (duration * 1000) // 70 self.info["duration"] = duration # look for palette palette = [(a, a, a) for a in range(256)] s = self.fp.read(16) self.__offset = 128 if i16(s, 4) == 0xF100: # prefix chunk; ignore it self.__offset = self.__offset + i32(s) s = self.fp.read(16) if i16(s, 4) == 0xF1FA: # look for palette chunk number_of_subchunks = i16(s, 6) chunk_size = None for _ in range(number_of_subchunks): if chunk_size is not None: self.fp.seek(chunk_size - 6, os.SEEK_CUR) s = self.fp.read(6) chunk_type = i16(s, 4) if chunk_type in (4, 11): self._palette(palette, 2 if chunk_type == 11 else 0) break chunk_size = i32(s) if not chunk_size: break palette = [o8(r) + o8(g) + o8(b) for (r, g, b) in palette] self.palette = ImagePalette.raw("RGB", b"".join(palette)) # set things up to decode first frame self.__frame = -1 self._fp = self.fp self.__rewind = self.fp.tell() self.seek(0) def _palette(self, palette, shift): # load palette i = 0 for e in range(i16(self.fp.read(2))): s = self.fp.read(2) i = i + s[0] n = s[1] if n == 0: n = 256 s = self.fp.read(n * 3) for n in range(0, len(s), 3): r = s[n] << shift g = s[n + 1] << shift b = s[n + 2] << shift palette[i] = (r, g, b) i += 1
[文档] def seek(self, frame): if not self._seek_check(frame): return if frame < self.__frame: self._seek(0) for f in range(self.__frame + 1, frame + 1): self._seek(f)
def _seek(self, frame): if frame == 0: self.__frame = -1 self._fp.seek(self.__rewind) self.__offset = 128 else: # ensure that the previous frame was loaded self.load() if frame != self.__frame + 1: msg = f"cannot seek to frame {frame}" raise ValueError(msg) self.__frame = frame # move to next frame self.fp = self._fp self.fp.seek(self.__offset) s = self.fp.read(4) if not s: raise EOFError framesize = i32(s) self.decodermaxblock = framesize self.tile = [("fli", (0, 0) + self.size, self.__offset, None)] self.__offset += framesize
[文档] def tell(self): return self.__frame
# # registry Image.register_open(FliImageFile.format, FliImageFile, _accept) Image.register_extensions(FliImageFile.format, [".fli", ".flc"])