PaddleSpeech/speechx/speechx/decoder/ctc_tlg_decoder.h

76 lines
2.2 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.
#pragma once
#include "base/common.h"
#include "decoder/decoder_itf.h"
#include "kaldi/decoder/lattice-faster-online-decoder.h"
#include "util/parse-options.h"
namespace ppspeech {
struct TLGDecoderOptions {
kaldi::LatticeFasterDecoderConfig opts;
// todo remove later, add into decode resource
std::string word_symbol_table;
std::string fst_path;
TLGDecoderOptions() : word_symbol_table(""), fst_path("") {}
};
class TLGDecoder : public DecoderInterface {
public:
explicit TLGDecoder(TLGDecoderOptions opts);
~TLGDecoder() = default;
void InitDecoder();
void Reset();
void AdvanceDecode(
const std::shared_ptr<kaldi::DecodableInterface>& decodable);
void Decode();
std::string GetFinalBestPath() override;
std::string GetPartialResult() override;
int DecodeLikelihoods(const std::vector<std::vector<BaseFloat>>& probs,
std::vector<std::string>& nbest_words);
protected:
std::string GetBestPath() override {
CHECK(false);
return {};
}
std::vector<std::pair<double, std::string>> GetNBestPath() override {
CHECK(false);
return {};
}
std::vector<std::pair<double, std::string>> GetNBestPath(int n) override {
CHECK(false);
return {};
}
private:
void AdvanceDecoding(kaldi::DecodableInterface* decodable);
std::shared_ptr<kaldi::LatticeFasterOnlineDecoder> decoder_;
std::shared_ptr<fst::Fst<fst::StdArc>> fst_;
std::shared_ptr<fst::SymbolTable> word_symbol_table_;
};
} // namespace ppspeech