An encoder-decoder decoder (ed-decoder) outputs labels based on the hidden representation of the encoder and the history of decoded labels. To create a new ed-decoder you should inherit from the general EDDecoder class defined in ed-decoder.py and overwrite the abstract methods. Afterwards you should add it to the factory method in ed_decoder_factory.py. It is also very helpful to create a default configuration in the defaults directory. The name of the file should be the name of the class in lower case with the .cfg extension.