def decode(self, color_mode=WebPColorMode.RGBA):
dec_config = WebPDecoderConfig.new()
dec_config.read_features(self)
if color_mode == WebPColorMode.RGBA \
or color_mode == WebPColorMode.bgrA \
or color_mode == WebPColorMode.BGRA \
or color_mode == WebPColorMode.rgbA \
or color_mode == WebPColorMode.ARGB \
or color_mode == WebPColorMode.Argb:
bytes_per_pixel = 4
elif color_mode == WebPColorMode.RGB \
or color_mode == WebPColorMode.BGR:
bytes_per_pixel = 3
elif color_mode == WebPColorMode.RGB_565 \
or color_mode == WebPColorMode.RGBA_4444 \
or color_mode == WebPColorMode.rgbA_4444:
bytes_per_pixel = 2
else:
raise WebPError('unsupported color mode: {}'.format(str(color_mode)))
arr = np.empty((dec_config.input.height, dec_config.input.width, bytes_per_pixel),
dtype=np.uint8)
dec_config.output.colorspace = color_mode.value
dec_config.output.u.RGBA.rgba = ffi.cast('uint8_t*', ffi.from_buffer(arr))
dec_config.output.u.RGBA.size = arr.size
dec_config.output.u.RGBA.stride = dec_config.input.width * bytes_per_pixel
dec_config.output.is_external_memory = 1
if lib.WebPDecode(self.ptr.bytes, self.size, dec_config.ptr) != lib.VP8_STATUS_OK:
raise WebPError('failed to decode')
lib.WebPFreeDecBuffer(ffi.addressof(dec_config.ptr, 'output'))
return arr
def encode(self, config=None):
if config is None:
config = WebPConfig.new()
writer = WebPMemoryWriter.new()
self.ptr.writer = ffi.addressof(lib, 'WebPMemoryWrite')
self.ptr.custom_ptr = writer.ptr
if lib.WebPEncode(config.ptr, self.ptr) == 0:
raise WebPError('encoding error: ' + self.ptr.error_code)
return writer.to_webp_data()
def read_features(self, webp_data):
input_ptr = ffi.addressof(self.ptr, 'input')
if lib.WebPGetFeatures(webp_data.ptr.bytes, webp_data.size,
input_ptr) != lib.VP8_STATUS_OK:
raise WebPError('failed to read features')