You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
60 lines
2.0 KiB
60 lines
2.0 KiB
// Copyright (c) 2021 PaddlePaddle Authors. All Rights Reserved.
|
|
//
|
|
// 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.
|
|
|
|
#include "ctc_greedy_decoder.h"
|
|
#include "decoder_utils.h"
|
|
|
|
std::string ctc_greedy_decoder(
|
|
const std::vector<std::vector<double>> &probs_seq,
|
|
const std::vector<std::string> &vocabulary) {
|
|
// dimension check
|
|
size_t num_time_steps = probs_seq.size();
|
|
for (size_t i = 0; i < num_time_steps; ++i) {
|
|
VALID_CHECK_EQ(probs_seq[i].size(),
|
|
vocabulary.size() + 1,
|
|
"The shape of probs_seq does not match with "
|
|
"the shape of the vocabulary");
|
|
}
|
|
|
|
size_t blank_id = vocabulary.size();
|
|
|
|
std::vector<size_t> max_idx_vec(num_time_steps, 0);
|
|
std::vector<size_t> idx_vec;
|
|
for (size_t i = 0; i < num_time_steps; ++i) {
|
|
double max_prob = 0.0;
|
|
size_t max_idx = 0;
|
|
const std::vector<double> &probs_step = probs_seq[i];
|
|
for (size_t j = 0; j < probs_step.size(); ++j) {
|
|
if (max_prob < probs_step[j]) {
|
|
max_idx = j;
|
|
max_prob = probs_step[j];
|
|
}
|
|
}
|
|
// id with maximum probability in current time step
|
|
max_idx_vec[i] = max_idx;
|
|
// deduplicate
|
|
if ((i == 0) || ((i > 0) && max_idx_vec[i] != max_idx_vec[i - 1])) {
|
|
idx_vec.push_back(max_idx_vec[i]);
|
|
}
|
|
}
|
|
|
|
std::string best_path_result;
|
|
for (size_t i = 0; i < idx_vec.size(); ++i) {
|
|
if (idx_vec[i] != blank_id) {
|
|
best_path_result += vocabulary[idx_vec[i]];
|
|
}
|
|
}
|
|
return best_path_result;
|
|
}
|