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- from . import Image, ImageFile
- try:
- from . import _webp
- SUPPORTED = True
- except ImportError as e:
- SUPPORTED = False
- from io import BytesIO
-
-
- _VALID_WEBP_MODES = {
- "RGBX": True,
- "RGBA": True,
- "RGB": True,
- }
-
- _VALID_WEBP_LEGACY_MODES = {
- "RGB": True,
- "RGBA": True,
- }
-
- _VP8_MODES_BY_IDENTIFIER = {
- b"VP8 ": "RGB",
- b"VP8X": "RGBA",
- b"VP8L": "RGBA", # lossless
- }
-
-
- def _accept(prefix):
- is_riff_file_format = prefix[:4] == b"RIFF"
- is_webp_file = prefix[8:12] == b"WEBP"
- is_valid_vp8_mode = prefix[12:16] in _VP8_MODES_BY_IDENTIFIER
-
- if is_riff_file_format and is_webp_file and is_valid_vp8_mode:
- if not SUPPORTED:
- return "image file could not be identified because WEBP support not installed"
- return True
-
-
- class WebPImageFile(ImageFile.ImageFile):
-
- format = "WEBP"
- format_description = "WebP image"
-
- def _open(self):
- if not _webp.HAVE_WEBPANIM:
- # Legacy mode
- data, width, height, self.mode, icc_profile, exif = \
- _webp.WebPDecode(self.fp.read())
- if icc_profile:
- self.info["icc_profile"] = icc_profile
- if exif:
- self.info["exif"] = exif
- self._size = width, height
- self.fp = BytesIO(data)
- self.tile = [("raw", (0, 0) + self.size, 0, self.mode)]
- self._n_frames = 1
- return
-
- # Use the newer AnimDecoder API to parse the (possibly) animated file,
- # and access muxed chunks like ICC/EXIF/XMP.
- self._decoder = _webp.WebPAnimDecoder(self.fp.read())
-
- # Get info from decoder
- width, height, loop_count, bgcolor, frame_count, mode = \
- self._decoder.get_info()
- self._size = width, height
- self.info["loop"] = loop_count
- bg_a, bg_r, bg_g, bg_b = \
- (bgcolor >> 24) & 0xFF, \
- (bgcolor >> 16) & 0xFF, \
- (bgcolor >> 8) & 0xFF, \
- bgcolor & 0xFF
- self.info["background"] = (bg_r, bg_g, bg_b, bg_a)
- self._n_frames = frame_count
- self.mode = 'RGB' if mode == 'RGBX' else mode
- self.rawmode = mode
- self.tile = []
-
- # Attempt to read ICC / EXIF / XMP chunks from file
- icc_profile = self._decoder.get_chunk("ICCP")
- exif = self._decoder.get_chunk("EXIF")
- xmp = self._decoder.get_chunk("XMP ")
- if icc_profile:
- self.info["icc_profile"] = icc_profile
- if exif:
- self.info["exif"] = exif
- if xmp:
- self.info["xmp"] = xmp
-
- # Initialize seek state
- self._reset(reset=False)
- self.seek(0)
-
- def _getexif(self):
- from .JpegImagePlugin import _getexif
- return _getexif(self)
-
- @property
- def n_frames(self):
- return self._n_frames
-
- @property
- def is_animated(self):
- return self._n_frames > 1
-
- def seek(self, frame):
- if not _webp.HAVE_WEBPANIM:
- return super(WebPImageFile, self).seek(frame)
-
- # Perform some simple checks first
- if frame >= self._n_frames:
- raise EOFError("attempted to seek beyond end of sequence")
- if frame < 0:
- raise EOFError("negative frame index is not valid")
-
- # Set logical frame to requested position
- self.__logical_frame = frame
-
- def _reset(self, reset=True):
- if reset:
- self._decoder.reset()
- self.__physical_frame = 0
- self.__loaded = -1
- self.__timestamp = 0
-
- def _get_next(self):
- # Get next frame
- ret = self._decoder.get_next()
- self.__physical_frame += 1
-
- # Check if an error occurred
- if ret is None:
- self._reset() # Reset just to be safe
- self.seek(0)
- raise EOFError("failed to decode next frame in WebP file")
-
- # Compute duration
- data, timestamp = ret
- duration = timestamp - self.__timestamp
- self.__timestamp = timestamp
-
- # libwebp gives frame end, adjust to start of frame
- timestamp -= duration
- return data, timestamp, duration
-
- def _seek(self, frame):
- if self.__physical_frame == frame:
- return # Nothing to do
- if frame < self.__physical_frame:
- self._reset() # Rewind to beginning
- while self.__physical_frame < frame:
- self._get_next() # Advance to the requested frame
-
- def load(self):
- if _webp.HAVE_WEBPANIM:
- if self.__loaded != self.__logical_frame:
- self._seek(self.__logical_frame)
-
- # We need to load the image data for this frame
- data, timestamp, duration = self._get_next()
- self.info["timestamp"] = timestamp
- self.info["duration"] = duration
- self.__loaded = self.__logical_frame
-
- # Set tile
- if self.fp:
- self.fp.close()
- self.fp = BytesIO(data)
- self.tile = [("raw", (0, 0) + self.size, 0, self.rawmode)]
-
- return super(WebPImageFile, self).load()
-
- def tell(self):
- if not _webp.HAVE_WEBPANIM:
- return super(WebPImageFile, self).tell()
-
- return self.__logical_frame
-
-
- def _save_all(im, fp, filename):
- encoderinfo = im.encoderinfo.copy()
- append_images = list(encoderinfo.get("append_images", []))
-
- # If total frame count is 1, then save using the legacy API, which
- # will preserve non-alpha modes
- total = 0
- for ims in [im]+append_images:
- total += 1 if not hasattr(ims, "n_frames") else ims.n_frames
- if total == 1:
- _save(im, fp, filename)
- return
-
- background = encoderinfo.get("background", (0, 0, 0, 0))
- duration = im.encoderinfo.get("duration", 0)
- loop = im.encoderinfo.get("loop", 0)
- minimize_size = im.encoderinfo.get("minimize_size", False)
- kmin = im.encoderinfo.get("kmin", None)
- kmax = im.encoderinfo.get("kmax", None)
- allow_mixed = im.encoderinfo.get("allow_mixed", False)
- verbose = False
- lossless = im.encoderinfo.get("lossless", False)
- quality = im.encoderinfo.get("quality", 80)
- method = im.encoderinfo.get("method", 0)
- icc_profile = im.encoderinfo.get("icc_profile", "")
- exif = im.encoderinfo.get("exif", "")
- xmp = im.encoderinfo.get("xmp", "")
- if allow_mixed:
- lossless = False
-
- # Sensible keyframe defaults are from gif2webp.c script
- if kmin is None:
- kmin = 9 if lossless else 3
- if kmax is None:
- kmax = 17 if lossless else 5
-
- # Validate background color
- if (not isinstance(background, (list, tuple)) or len(background) != 4 or
- not all(v >= 0 and v < 256 for v in background)):
- raise IOError("Background color is not an RGBA tuple clamped "
- "to (0-255): %s" % str(background))
-
- # Convert to packed uint
- bg_r, bg_g, bg_b, bg_a = background
- background = (bg_a << 24) | (bg_r << 16) | (bg_g << 8) | (bg_b << 0)
-
- # Setup the WebP animation encoder
- enc = _webp.WebPAnimEncoder(
- im.size[0], im.size[1],
- background,
- loop,
- minimize_size,
- kmin, kmax,
- allow_mixed,
- verbose
- )
-
- # Add each frame
- frame_idx = 0
- timestamp = 0
- cur_idx = im.tell()
- try:
- for ims in [im]+append_images:
- # Get # of frames in this image
- if not hasattr(ims, "n_frames"):
- nfr = 1
- else:
- nfr = ims.n_frames
-
- for idx in range(nfr):
- ims.seek(idx)
- ims.load()
-
- # Make sure image mode is supported
- frame = ims
- rawmode = ims.mode
- if ims.mode not in _VALID_WEBP_MODES:
- alpha = 'A' in ims.mode or 'a' in ims.mode \
- or (ims.mode == 'P' and 'A' in ims.im.getpalettemode())
- rawmode = 'RGBA' if alpha else 'RGB'
- frame = ims.convert(rawmode)
-
- if rawmode == 'RGB':
- # For faster conversion, use RGBX
- rawmode = 'RGBX'
-
- # Append the frame to the animation encoder
- enc.add(
- frame.tobytes('raw', rawmode),
- timestamp,
- frame.size[0], frame.size[1],
- rawmode,
- lossless,
- quality,
- method
- )
-
- # Update timestamp and frame index
- if isinstance(duration, (list, tuple)):
- timestamp += duration[frame_idx]
- else:
- timestamp += duration
- frame_idx += 1
-
- finally:
- im.seek(cur_idx)
-
- # Force encoder to flush frames
- enc.add(
- None,
- timestamp,
- 0, 0, "", lossless, quality, 0
- )
-
- # Get the final output from the encoder
- data = enc.assemble(icc_profile, exif, xmp)
- if data is None:
- raise IOError("cannot write file as WebP (encoder returned None)")
-
- fp.write(data)
-
-
- def _save(im, fp, filename):
- lossless = im.encoderinfo.get("lossless", False)
- quality = im.encoderinfo.get("quality", 80)
- icc_profile = im.encoderinfo.get("icc_profile", "")
- exif = im.encoderinfo.get("exif", "")
- xmp = im.encoderinfo.get("xmp", "")
-
- if im.mode not in _VALID_WEBP_LEGACY_MODES:
- alpha = 'A' in im.mode or 'a' in im.mode \
- or (im.mode == 'P' and 'A' in im.im.getpalettemode())
- im = im.convert('RGBA' if alpha else 'RGB')
-
- data = _webp.WebPEncode(
- im.tobytes(),
- im.size[0],
- im.size[1],
- lossless,
- float(quality),
- im.mode,
- icc_profile,
- exif,
- xmp
- )
- if data is None:
- raise IOError("cannot write file as WebP (encoder returned None)")
-
- fp.write(data)
-
-
- Image.register_open(WebPImageFile.format, WebPImageFile, _accept)
- if SUPPORTED:
- Image.register_save(WebPImageFile.format, _save)
- if _webp.HAVE_WEBPANIM:
- Image.register_save_all(WebPImageFile.format, _save_all)
- Image.register_extension(WebPImageFile.format, ".webp")
- Image.register_mime(WebPImageFile.format, "image/webp")
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