352 lines
11 KiB
Python
352 lines
11 KiB
Python
from io import BytesIO
|
|
|
|
from . import Image, ImageFile
|
|
|
|
try:
|
|
from . import _webp
|
|
|
|
SUPPORTED = True
|
|
except ImportError:
|
|
SUPPORTED = False
|
|
|
|
|
|
_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"
|
|
__loaded = 0
|
|
__logical_frame = 0
|
|
|
|
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
|
|
self.is_animated = False
|
|
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.is_animated = self.n_frames > 1
|
|
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)
|
|
|
|
def _getexif(self):
|
|
if "exif" not in self.info:
|
|
return None
|
|
return self.getexif()._get_merged_dict()
|
|
|
|
def seek(self, frame):
|
|
if not self._seek_check(frame):
|
|
return
|
|
|
|
# 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 and self._exclusive_fp:
|
|
self.fp.close()
|
|
self.fp = BytesIO(data)
|
|
self.tile = [("raw", (0, 0) + self.size, 0, self.rawmode)]
|
|
|
|
return super().load()
|
|
|
|
def tell(self):
|
|
if not _webp.HAVE_WEBPANIM:
|
|
return super().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 += getattr(ims, "n_frames", 1)
|
|
if total == 1:
|
|
_save(im, fp, filename)
|
|
return
|
|
|
|
background = (0, 0, 0, 0)
|
|
if "background" in encoderinfo:
|
|
background = encoderinfo["background"]
|
|
elif "background" in im.info:
|
|
background = im.info["background"]
|
|
if isinstance(background, int):
|
|
# GifImagePlugin stores a global color table index in
|
|
# info["background"]. So it must be converted to an RGBA value
|
|
palette = im.getpalette()
|
|
if palette:
|
|
r, g, b = palette[background * 3 : (background + 1) * 3]
|
|
background = (r, g, b, 0)
|
|
|
|
duration = im.encoderinfo.get("duration", im.info.get("duration"))
|
|
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", "")
|
|
if isinstance(exif, Image.Exif):
|
|
exif = exif.tobytes()
|
|
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 OSError(
|
|
"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
|
|
nfr = getattr(ims, "n_frames", 1)
|
|
|
|
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 OSError("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", "")
|
|
if isinstance(exif, Image.Exif):
|
|
exif = exif.tobytes()
|
|
xmp = im.encoderinfo.get("xmp", "")
|
|
method = im.encoderinfo.get("method", 0)
|
|
|
|
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,
|
|
method,
|
|
exif,
|
|
xmp,
|
|
)
|
|
if data is None:
|
|
raise OSError("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")
|