openvino/model-optimizer/extensions/middle/SequenceLengthToMask.py

64 lines
2.7 KiB
Python

"""
Copyright (C) 2020 Intel Corporation
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
"""
import numpy as np
from mo.graph.graph import Graph
from mo.middle.replacement import MiddleReplacementPattern
from mo.ops.const import Const
from mo.utils.error import Error
class SequenceLengthToMask(MiddleReplacementPattern):
"""
Convert a sequence length to a sequence mask for CTCGreedyDecoder if its value is available.
"""
enabled = True
def run_before(self):
from extensions.middle.pass_separator import MiddleFinish
return [MiddleFinish]
def find_and_replace_pattern(self, graph: Graph):
for ctc_greedy_decoder in graph.get_op_nodes(op='CTCGreedyDecoder', use_mask_format=True):
ctc_greedy_decoder_name = ctc_greedy_decoder.soft_get('name', ctc_greedy_decoder.id)
sequence_length_value = ctc_greedy_decoder.in_port(1).data.get_value()
if sequence_length_value is None:
raise Error('The second input to the CTCGreedyDecoder node "{}" is not constant. This case is not '
'supported with the Inference Engine.'.format(ctc_greedy_decoder_name))
# transform a sequence length to a sequence mask
logits_shape = ctc_greedy_decoder.in_port(0).data.get_shape()
assert logits_shape is not None and len(logits_shape) == 3, \
"Incorrect shape for logits input of {} node".format(ctc_greedy_decoder_name)
batch_size = logits_shape[1]
time_size = logits_shape[0]
mask_value = np.zeros([batch_size, time_size], dtype=np.float)
for sample_ind, sample_seq_length in enumerate(sequence_length_value):
mask_value[sample_ind, 0:sample_seq_length] = 1
mask_value = np.transpose(mask_value)
# create Const node with computed mask value
mask_node = Const(graph, {'name': ctc_greedy_decoder_name + '/Mask',
'value': mask_value}).create_node()
# connect computed mask to CTCGreedyDecoder node
ctc_greedy_decoder.in_port(1).get_connection().set_source(mask_node.out_port(0))
# remove attribute-marker
del ctc_greedy_decoder['use_mask_format']