Alignment Layers¶
Forced Alignment Layer¶
- class returnn.tf.layers.basic.ForcedAlignmentLayer(align_target, topology, input_type, blank_idx=-1, blank_included=False, **kwargs)[source]¶
Calculates a forced alignment, via Viterbi algorithm.
- Parameters:
align_target (LayerBase)
topology (str) – e.g. “ctc” or “rna” (RNA is CTC without label loop)
input_type (str) – “log_prob” or “prob”
blank_idx (int) – vocab index of the blank symbol
blank_included (bool) – whether blank token of the align target is included in the vocabulary
- classmethod get_sub_layer_out_data_from_opts(layer_name, parent_layer_kwargs)[source]¶
- Parameters:
layer_name (str) – sub layer name
parent_layer_kwargs (dict[str])
- Returns:
Data template, class type of sub-layer, layer opts (transformed)
- Return type:
(Data, type, dict[str])|None
- classmethod get_available_sub_layer_names(parent_layer_kwargs)[source]¶
- Parameters:
parent_layer_kwargs (dict[str])
- Return type:
list[str]
- classmethod transform_config_dict(d, network, get_layer)[source]¶
- Parameters:
d (dict[str])
network (returnn.tf.network.TFNetwork)
get_layer
- classmethod get_out_data_from_opts(name, sources, **kwargs)[source]¶
- Parameters:
name (str)
sources (list[LayerBase])
- Return type:
Data
- output_before_activation: Optional[OutputWithActivation][source]¶
- search_choices: Optional[SearchChoices][source]¶
Fast Baum-Welch Layer¶
- class returnn.tf.layers.basic.FastBaumWelchLayer(align_target, align_target_key=None, ctc_opts=None, sprint_opts=None, input_type='log_prob', tdp_scale=1.0, am_scale=1.0, min_prob=0.0, staircase_seq_len_source=None, **kwargs)[source]¶
Calls
fast_baum_welch()
orfast_baum_welch_by_sprint_automata()
. We expect that our input are +log scores, e.g. use log-softmax.- Parameters:
align_target (str) – e.g. “sprint”, “ctc” or “staircase”
align_target_key (str|None) – e.g. “classes”, used for e.g. align_target “ctc”
ctc_opts (dict[str]) – used for align_target “ctc”
sprint_opts (dict[str]) – used for Sprint (RASR) for align_target “sprint”
input_type (str) – “log_prob” or “prob”
tdp_scale (float)
am_scale (float)
min_prob (float) – clips the minimum prob (value in [0,1])
staircase_seq_len_source (LayerBase|None)
- classmethod transform_config_dict(d, network, get_layer)[source]¶
- Parameters:
d (dict[str])
network (returnn.tf.network.TFNetwork)
get_layer
- classmethod get_out_data_from_opts(name, sources, **kwargs)[source]¶
- Parameters:
name (str)
sources (list[LayerBase])
- Return type:
Data
- output_before_activation: Optional[OutputWithActivation][source]¶
- search_choices: Optional[SearchChoices][source]¶