#
# THIS IS WORK IN PROGRESS
#
# The Python Imaging Library.
# $Id: ArgImagePlugin.py 2309 2005-03-02 15:06:34Z fredrik $
#
# ARG animation support code
#
# history:
# 1996-12-30 fl Created
# 1996-01-06 fl Added safe scripting environment
# 1996-01-10 fl Added JHDR, UHDR and sYNC support
# 2005-03-02 fl Removed AAPP and ARUN support
#
# Copyright (c) Secret Labs AB 1997.
# Copyright (c) Fredrik Lundh 1996-97.
#
# See the README file for information on usage and redistribution.
#
__version__ = "0.4"
import marshal, string
import Image, ImageFile, ImagePalette
from PngImagePlugin import i16, i32, ChunkStream, _MODES
MAGIC = "\212ARG\r\n\032\n"
# --------------------------------------------------------------------
# ARG parser
class ArgStream(ChunkStream):
"Parser callbacks for ARG data"
def __init__(self, fp):
ChunkStream.__init__(self, fp)
self.eof = 0
self.im = None
self.palette = None
self.__reset()
def __reset(self):
# reset decoder state (called on init and sync)
self.count = 0
self.id = None
self.action = ("NONE",)
self.images = {}
self.names = {}
def chunk_AHDR(self, offset, bytes):
"AHDR -- animation header"
# assertions
if self.count != 0:
raise SyntaxError, "misplaced AHDR chunk"
s = self.fp.read(bytes)
self.size = i32(s), i32(s[4:])
try:
self.mode, self.rawmode = _MODES[(ord(s[8]), ord(s[9]))]
except:
raise SyntaxError, "unknown ARG mode"
if Image.DEBUG:
print "AHDR size", self.size
print "AHDR mode", self.mode, self.rawmode
return s
def chunk_AFRM(self, offset, bytes):
"AFRM -- next frame follows"
# assertions
if self.count != 0:
raise SyntaxError, "misplaced AFRM chunk"
self.show = 1
self.id = 0
self.count = 1
self.repair = None
s = self.fp.read(bytes)
if len(s) >= 2:
self.id = i16(s)
if len(s) >= 4:
self.count = i16(s[2:4])
if len(s) >= 6:
self.repair = i16(s[4:6])
else:
self.repair = None
if Image.DEBUG:
print "AFRM", self.id, self.count
return s
def chunk_ADEF(self, offset, bytes):
"ADEF -- store image"
# assertions
if self.count != 0:
raise SyntaxError, "misplaced ADEF chunk"
self.show = 0
self.id = 0
self.count = 1
self.repair = None
s = self.fp.read(bytes)
if len(s) >= 2:
self.id = i16(s)
if len(s) >= 4:
self.count = i16(s[2:4])
if Image.DEBUG:
print "ADEF", self.id, self.count
return s
def chunk_NAME(self, offset, bytes):
"NAME -- name the current image"
# assertions
if self.count == 0:
raise SyntaxError, "misplaced NAME chunk"
name = self.fp.read(bytes)
self.names[self.id] = name
return name
def chunk_AEND(self, offset, bytes):
"AEND -- end of animation"
if Image.DEBUG:
print "AEND"
self.eof = 1
raise EOFError, "end of ARG file"
def __getmodesize(self, s, full=1):
size = i32(s), i32(s[4:])
try:
mode, rawmode = _MODES[(ord(s[8]), ord(s[9]))]
except:
raise SyntaxError, "unknown image mode"
if full:
if ord(s[12]):
pass # interlace not yet supported
if ord(s[11]):
raise SyntaxError, "unknown filter category"
return size, mode, rawmode
def chunk_PAST(self, offset, bytes):
"PAST -- paste one image into another"
# assertions
if self.count == 0:
raise SyntaxError, "misplaced PAST chunk"
if self.repair is not None:
# we must repair the target image before we
# start pasting
# brute force; a better solution would be to
# update only the dirty rectangles in images[id].
# note that if images[id] doesn't exist, it must
# be created
self.images[self.id] = self.images[self.repair].copy()
self.repair = None
s = self.fp.read(bytes)
im = self.images[i16(s)]
x, y = i32(s[2:6]), i32(s[6:10])
bbox = x, y, im.size[0]+x, im.size[1]+y
if im.mode in ["RGBA"]:
# paste with transparency
# FIXME: should handle P+transparency as well
self.images[self.id].paste(im, bbox, im)
else:
# paste without transparency
self.images[self.id].paste(im, bbox)
self.action = ("PAST",)
self.__store()
return s
def chunk_BLNK(self, offset, bytes):
"BLNK -- create blank image"
# assertions
if self.count == 0:
raise SyntaxError, "misplaced BLNK chunk"
s = self.fp.read(bytes)
size, mode, rawmode = self.__getmodesize(s, 0)
# store image (FIXME: handle colour)
self.action = ("BLNK",)
self.im = Image.core.fill(mode, size, 0)
self.__store()
return s
def chunk_IHDR(self, offset, bytes):
"IHDR -- full image follows"
# assertions
if self.count == 0:
raise SyntaxError, "misplaced IHDR chunk"
# image header
s = self.fp.read(bytes)
size, mode, rawmode = self.__getmodesize(s)
# decode and store image
self.action = ("IHDR",)
self.im = Image.core.new(mode, size)
self.decoder = Image.core.zip_decoder(rawmode)
self.decoder.setimage(self.im, (0,0) + size)
self.data = ""
return s
def chunk_DHDR(self, offset, bytes):
"DHDR -- delta image follows"
# assertions
if self.count == 0:
raise SyntaxError, "misplaced DHDR chunk"
s = self.fp.read(bytes)
size, mode, rawmode = self.__getmodesize(s)
# delta header
diff = ord(s[13])
offs = i32(s[14:18]), i32(s[18:22])
bbox = offs + (offs[0]+size[0], offs[1]+size[1])
if Image.DEBUG:
print "DHDR", diff, bbox
# FIXME: decode and apply image
self.action = ("DHDR", diff, bbox)
# setup decoder
self.im = Image.core.new(mode, size)
self.decoder = Image.core.zip_decoder(rawmode)
self.decoder.setimage(self.im, (0,0) + size)
self.data = ""
return s
def chunk_JHDR(self, offset, bytes):
"JHDR -- JPEG image follows"
# assertions
if self.count == 0:
raise SyntaxError, "misplaced JHDR chunk"
# image header
s = self.fp.read(bytes)
size, mode, rawmode = self.__getmodesize(s, 0)
# decode and store image
self.action = ("JHDR",)
self.im = Image.core.new(mode, size)
self.decoder = Image.core.jpeg_decoder(rawmode)
self.decoder.setimage(self.im, (0,0) + size)
self.data = ""
return s
def chunk_UHDR(self, offset, bytes):
"UHDR -- uncompressed image data follows (EXPERIMENTAL)"
# assertions
if self.count == 0:
raise SyntaxError, "misplaced UHDR chunk"
# image header
s = self.fp.read(bytes)
size, mode, rawmode = self.__getmodesize(s, 0)
# decode and store image
self.action = ("UHDR",)
self.im = Image.core.new(mode, size)
self.decoder = Image.core.raw_decoder(rawmode)
self.decoder.setimage(self.im, (0,0) + size)
self.data = ""
return s
def chunk_IDAT(self, offset, bytes):
"IDAT -- image data block"
# pass compressed chunks through the decoder
s = self.fp.read(bytes)
self.data = self.data + s
n, e = self.decoder.decode(self.data)
if n < 0:
# end of image
if e < 0:
raise IOError, "decoder error %d" % e
else:
self.data = self.data[n:]
return s
def chunk_DEND(self, offset, bytes):
return self.chunk_IEND(offset, bytes)
def chunk_JEND(self, offset, bytes):
return self.chunk_IEND(offset, bytes)
def chunk_UEND(self, offset, bytes):
return self.chunk_IEND(offset, bytes)
def chunk_IEND(self, offset, bytes):
"IEND -- end of image"
# we now have a new image. carry out the operation
# defined by the image header.
# won't need these anymore
del self.decoder
del self.data
self.__store()
return self.fp.read(bytes)
def __store(self):
# apply operation
cid = self.action[0]
if cid in ["BLNK", "IHDR", "JHDR", "UHDR"]:
# store
self.images[self.id] = self.im
elif cid == "DHDR":
# paste
cid, mode, bbox = self.action
im0 = self.images[self.id]
im1 = self.im
if mode == 0:
im1 = im1.chop_add_modulo(im0.crop(bbox))
im0.paste(im1, bbox)
self.count = self.count - 1
if self.count == 0 and self.show:
self.im = self.images[self.id]
raise EOFError # end of this frame
def chunk_PLTE(self, offset, bytes):
"PLTE -- palette data"
s = self.fp.read(bytes)
if self.mode == "P":
self.palette = ImagePalette.raw("RGB", s)
return s
def chunk_sYNC(self, offset, bytes):
"SYNC -- reset decoder"
if self.count != 0:
raise SyntaxError, "misplaced sYNC chunk"
s = self.fp.read(bytes)
self.__reset()
return s
# --------------------------------------------------------------------
# ARG reader
def _accept(prefix):
return prefix[:8] == MAGIC
##
# Image plugin for the experimental Animated Raster Graphics format.
class ArgImageFile(ImageFile.ImageFile):
format = "ARG"
format_description = "Animated raster graphics"
def _open(self):
if self.fp.read(8) != MAGIC:
raise SyntaxError, "not an ARG file"
self.arg = ArgStream(self.fp)
# read and process the first chunk (AHDR)
cid, offset, bytes = self.arg.read()
if cid != "AHDR":
raise SyntaxError, "expected an AHDR chunk"
s = self.arg.call(cid, offset, bytes)
self.arg.crc(cid, s)
# image characteristics
self.mode = self.arg.mode
self.size = self.arg.size
def load(self):
if self.arg.im is None:
self.seek(0)
# image data
self.im = self.arg.im
self.palette = self.arg.palette
# set things up for further processing
Image.Image.load(self)
def seek(self, frame):
if self.arg.eof:
raise EOFError, "end of animation"
self.fp = self.arg.fp
while 1:
#
# process chunks
cid, offset, bytes = self.arg.read()
if self.arg.eof:
raise EOFError, "end of animation"
try:
s = self.arg.call(cid, offset, bytes)
except EOFError:
break
except "glurk": # AttributeError
if Image.DEBUG:
print cid, bytes, "(unknown)"
s = self.fp.read(bytes)
self.arg.crc(cid, s)
self.fp.read(4) # ship extra CRC
def tell(self):
return 0
def verify(self):
"Verify ARG file"
# back up to first chunk
self.fp.seek(8)
self.arg.verify(self)
self.arg.close()
self.fp = None
#
# --------------------------------------------------------------------
Image.register_open("ARG", ArgImageFile, _accept)
Image.register_extension("ARG", ".arg")
Image.register_mime("ARG", "video/x-arg")
@KyuuKazami