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PaddleSpeech/speechx/speechx/decoder/ctc_tlg_decoder.cc

66 lines
2.1 KiB

// Copyright (c) 2022 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 "decoder/ctc_tlg_decoder.h"
namespace ppspeech {
TLGDecoder::TLGDecoder(TLGDecoderOptions opts) {
fst_.reset(fst::Fst<fst::StdArc>::Read(opts.fst_path));
CHECK(fst_ != nullptr);
word_symbol_table_.reset(
fst::SymbolTable::ReadText(opts.word_symbol_table));
decoder_.reset(new kaldi::LatticeFasterOnlineDecoder(*fst_, opts.opts));
decoder_->InitDecoding();
frame_decoded_size_ = 0;
}
void TLGDecoder::InitDecoder() {
decoder_->InitDecoding();
frame_decoded_size_ = 0;
}
void TLGDecoder::AdvanceDecode(
const std::shared_ptr<kaldi::DecodableInterface>& decodable) {
while (!decodable->IsLastFrame(frame_decoded_size_)) {
LOG(INFO) << "num frame decode: " << frame_decoded_size_;
AdvanceDecoding(decodable.get());
}
}
void TLGDecoder::AdvanceDecoding(kaldi::DecodableInterface* decodable) {
decoder_->AdvanceDecoding(decodable, 1);
frame_decoded_size_++;
}
void TLGDecoder::Reset() {
InitDecoder();
return;
}
std::string TLGDecoder::GetFinalBestPath() {
decoder_->FinalizeDecoding();
kaldi::Lattice lat;
kaldi::LatticeWeight weight;
std::vector<int> alignment;
std::vector<int> words_id;
decoder_->GetBestPath(&lat, true);
fst::GetLinearSymbolSequence(lat, &alignment, &words_id, &weight);
std::string words;
for (int32 idx = 0; idx < words_id.size(); ++idx) {
std::string word = word_symbol_table_->Find(words_id[idx]);
words += word;
}
return words;
}
}