blosc2.register_filter

blosc2.register_filter(id, forward=None, backward=None, name=None)

Register an user defined filter.

Parameters:

• id (int) – Filter id, must be between 160 and 255 (both included).

• forward (Python function) – This will receive an input to apply the filter as a ndarray of dtype uint8, an output to fill as a ndarray of dtype uint8, the filter meta and the corresponding SChunk instance. If None then the filter name indicates a dynamic plugin which must be installed.

• backward (Python function) – This will receive an input as a ndarray of dtype uint8, an output to fill as a ndarray of dtype uint8, the filter meta and the SChunk instance. If None then the filter name indicates a dynamic plugin which must be installed.

• name (str) – The filter name. If both forward`and `backward are None, this parameter must be passed to correctly load the dynamic filter.

Returns:

out

Return type:

None

Notes

• Cannot use multi-threading when using an user defined filter.

• User defined filters can only be used inside a SChunk instance.

See also

register_codec()

Examples

# Define forward and backward functions
def forward(input, output, meta, schunk):
    nd_input = input.view(dtype)
    nd_output = output.view(dtype)

    nd_output[:] = nd_input + 1

def backward(input, output, meta, schunk):
    nd_input = input.view(dtype)
    nd_output = output.view(dtype)

    nd_output[:] = nd_input - 1

# Register filter
id = 160
blosc2.register_filter(id, forward, backward)