add wfst decoder (#2886)

speechx/CMakeLists.txt

@@ -33,7 +33,7 @@ set(FETCHCONTENT_BASE_DIR ${fc_patch})
 
 # compiler option
 # Keep the same with openfst, -fPIC or -fpic
-set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} --std=c++14 -pthread -fPIC -O0 -Wall -g")
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} --std=c++14 -pthread -fPIC -O0 -Wall -g -ldl")
 SET(CMAKE_CXX_FLAGS_DEBUG "$ENV{CXXFLAGS} --std=c++14 -pthread -fPIC -O0 -Wall -g -ggdb")
 SET(CMAKE_CXX_FLAGS_RELEASE "$ENV{CXXFLAGS} --std=c++14 -pthread -fPIC -O3 -Wall")
 

speechx/speechx/asr/decoder/CMakeLists.txt

@@ -1,6 +1,7 @@
 set(srcs)
 list(APPEND srcs
   ctc_prefix_beam_search_decoder.cc
+  ctc_tlg_decoder.cc
 )
 
 add_library(decoder STATIC ${srcs})
@@ -9,6 +10,7 @@ target_link_libraries(decoder PUBLIC utils fst frontend nnet kaldi-decoder)
 # test
 set(TEST_BINS 
   ctc_prefix_beam_search_decoder_main
+  ctc_tlg_decoder_main
 )
 
 foreach(bin_name IN LISTS TEST_BINS)

speechx/speechx/asr/decoder/ctc_prefix_beam_search_decoder.h

@@ -45,7 +45,7 @@ class CTCPrefixBeamSearch : public DecoderBase {
 
     void FinalizeSearch();
 
-    const std::shared_ptr<fst::SymbolTable> VocabTable() const {
+    const std::shared_ptr<fst::SymbolTable> WordSymbolTable() const override {
         return unit_table_;
     }
 
@@ -57,7 +57,6 @@ class CTCPrefixBeamSearch : public DecoderBase {
     }
     const std::vector<std::vector<int>>& Times() const { return times_; }
 
-
   protected:
     std::string GetBestPath() override;
     std::vector<std::pair<double, std::string>> GetNBestPath() override;

speechx/speechx/asr/decoder/ctc_tlg_decoder.cc

@@ -15,7 +15,7 @@
 #include "decoder/ctc_tlg_decoder.h"
 namespace ppspeech {
 
-TLGDecoder::TLGDecoder(TLGDecoderOptions opts) {
+TLGDecoder::TLGDecoder(TLGDecoderOptions opts) : opts_(opts) {
     fst_.reset(fst::Fst<fst::StdArc>::Read(opts.fst_path));
     CHECK(fst_ != nullptr);
 
@@ -68,14 +68,52 @@ std::string TLGDecoder::GetPartialResult() {
     return words;
 }
 
+void TLGDecoder::FinalizeSearch() {
+    decoder_->FinalizeDecoding();
+    kaldi::CompactLattice clat;
+    decoder_->GetLattice(&clat, true);
+    kaldi::Lattice lat, nbest_lat;
+    fst::ConvertLattice(clat, &lat);
+    fst::ShortestPath(lat, &nbest_lat, opts_.nbest);
+    std::vector<kaldi::Lattice> nbest_lats;
+    fst::ConvertNbestToVector(nbest_lat, &nbest_lats);
+
+    hypotheses_.clear();
+    hypotheses_.reserve(nbest_lats.size());
+    likelihood_.clear();
+    likelihood_.reserve(nbest_lats.size());
+    times_.clear();
+    times_.reserve(nbest_lats.size());
+    for (auto lat : nbest_lats) {
+        kaldi::LatticeWeight weight;
+        std::vector<int> hypothese;
+        std::vector<int> time;
+        std::vector<int> alignment;
+        std::vector<int> words_id;
+        fst::GetLinearSymbolSequence(lat, &alignment, &words_id, &weight);
+        int idx = 0;
+        for (; idx < alignment.size() - 1; ++idx) {
+            if (alignment[idx] == 0) continue;
+            if (alignment[idx] != alignment[idx + 1]) {
+                hypothese.push_back(alignment[idx] - 1);
+                time.push_back(idx);  // fake time, todo later
+            }
+        }
+        hypothese.push_back(alignment[idx] - 1);
+        time.push_back(idx);  // fake time, todo later
+        hypotheses_.push_back(hypothese);
+        times_.push_back(time);
+        olabels.push_back(words_id);
+        likelihood_.push_back(-(weight.Value2() + weight.Value1()));
+    }
+}
+
 std::string TLGDecoder::GetFinalBestPath() {
     if (num_frame_decoded_ == 0) {
         // Assertion failed: (this->NumFramesDecoded() > 0 && "You cannot call
         // BestPathEnd if no frames were decoded.")
         return std::string("");
     }
-
-    decoder_->FinalizeDecoding();
     kaldi::Lattice lat;
     kaldi::LatticeWeight weight;
     std::vector<int> alignment;

speechx/speechx/asr/decoder/ctc_tlg_decoder.h

@@ -19,9 +19,8 @@
 #include "kaldi/decoder/lattice-faster-online-decoder.h"
 #include "util/parse-options.h"
 
-
-DECLARE_string(graph_path);
 DECLARE_string(word_symbol_table);
+DECLARE_string(graph_path);
 DECLARE_int32(max_active);
 DECLARE_double(beam);
 DECLARE_double(lattice_beam);
@@ -33,6 +32,9 @@ struct TLGDecoderOptions {
     // todo remove later, add into decode resource
     std::string word_symbol_table;
     std::string fst_path;
+    int nbest;
+
+    TLGDecoderOptions() : word_symbol_table(""), fst_path(""), nbest(10) {}
 
     static TLGDecoderOptions InitFromFlags() {
         TLGDecoderOptions decoder_opts;
@@ -44,6 +46,7 @@ struct TLGDecoderOptions {
         decoder_opts.opts.max_active = FLAGS_max_active;
         decoder_opts.opts.beam = FLAGS_beam;
         decoder_opts.opts.lattice_beam = FLAGS_lattice_beam;
+        // decoder_opts.nbest = FLAGS_lattice_nbest;
         LOG(INFO) << "LatticeFasterDecoder max active: "
                   << decoder_opts.opts.max_active;
         LOG(INFO) << "LatticeFasterDecoder beam: " << decoder_opts.opts.beam;
@@ -59,20 +62,38 @@ class TLGDecoder : public DecoderBase {
     explicit TLGDecoder(TLGDecoderOptions opts);
     ~TLGDecoder() = default;
 
-    void InitDecoder();
-    void Reset();
+    void InitDecoder() override;
+    void Reset() override;
 
     void AdvanceDecode(
-        const std::shared_ptr<kaldi::DecodableInterface>& decodable);
+        const std::shared_ptr<kaldi::DecodableInterface>& decodable) override;
 
     void Decode();
 
     std::string GetFinalBestPath() override;
     std::string GetPartialResult() override;
 
+    const std::shared_ptr<fst::SymbolTable> WordSymbolTable() const override {
+        return word_symbol_table_;
+    }
+
     int DecodeLikelihoods(const std::vector<std::vector<BaseFloat>>& probs,
                           const std::vector<std::string>& nbest_words);
 
+    void FinalizeSearch() override;
+    const std::vector<std::vector<int>>& Inputs() const override {
+        return hypotheses_;
+    }
+    const std::vector<std::vector<int>>& Outputs() const override {
+        return olabels;
+    }  // outputs_; }
+    const std::vector<float>& Likelihood() const override {
+        return likelihood_;
+    }
+    const std::vector<std::vector<int>>& Times() const override {
+        return times_;
+    }
+
   protected:
     std::string GetBestPath() override {
         CHECK(false);
@@ -90,9 +111,15 @@ class TLGDecoder : public DecoderBase {
   private:
     void AdvanceDecoding(kaldi::DecodableInterface* decodable);
 
+    std::vector<std::vector<int>> hypotheses_;
+    std::vector<std::vector<int>> olabels;
+    std::vector<float> likelihood_;
+    std::vector<std::vector<int>> times_;
+
     std::shared_ptr<kaldi::LatticeFasterOnlineDecoder> decoder_;
     std::shared_ptr<fst::Fst<fst::StdArc>> fst_;
     std::shared_ptr<fst::SymbolTable> word_symbol_table_;
+    TLGDecoderOptions opts_;
 };
 
 

speechx/speechx/asr/decoder/ctc_tlg_decoder_main.cc

@@ -14,16 +14,16 @@
 
 // todo refactor, repalce with gtest
 
-#include "base/common.h"
 #include "decoder/ctc_tlg_decoder.h"
+#include "base/common.h"
 #include "decoder/param.h"
-#include "frontend/audio/data_cache.h"
+#include "frontend/data_cache.h"
 #include "kaldi/util/table-types.h"
 #include "nnet/decodable.h"
-#include "nnet/ds2_nnet.h"
+#include "nnet/nnet_producer.h"
 
 
-DEFINE_string(feature_rspecifier, "", "test feature rspecifier");
+DEFINE_string(nnet_prob_rspecifier, "", "test feature rspecifier");
 DEFINE_string(result_wspecifier, "", "test result wspecifier");
 
 
@@ -39,8 +39,8 @@ int main(int argc, char* argv[]) {
     google::InstallFailureSignalHandler();
     FLAGS_logtostderr = 1;
 
-    kaldi::SequentialBaseFloatMatrixReader feature_reader(
-        FLAGS_feature_rspecifier);
+    kaldi::SequentialBaseFloatMatrixReader nnet_prob_reader(
+        FLAGS_nnet_prob_rspecifier);
     kaldi::TokenWriter result_writer(FLAGS_result_wspecifier);
 
     int32 num_done = 0, num_err = 0;
@@ -53,66 +53,19 @@ int main(int argc, char* argv[]) {
 
     ppspeech::ModelOptions model_opts = ppspeech::ModelOptions::InitFromFlags();
 
-    std::shared_ptr<ppspeech::PaddleNnet> nnet(
-        new ppspeech::PaddleNnet(model_opts));
-    std::shared_ptr<ppspeech::DataCache> raw_data(new ppspeech::DataCache());
+    std::shared_ptr<ppspeech::NnetProducer> nnet_producer =
+        std::make_shared<ppspeech::NnetProducer>(nullptr);
     std::shared_ptr<ppspeech::Decodable> decodable(
-        new ppspeech::Decodable(nnet, raw_data, FLAGS_acoustic_scale));
-
-    int32 chunk_size = FLAGS_receptive_field_length +
-                       (FLAGS_nnet_decoder_chunk - 1) * FLAGS_subsampling_rate;
-    int32 chunk_stride = FLAGS_subsampling_rate * FLAGS_nnet_decoder_chunk;
-    int32 receptive_field_length = FLAGS_receptive_field_length;
-    LOG(INFO) << "chunk size (frame): " << chunk_size;
-    LOG(INFO) << "chunk stride (frame): " << chunk_stride;
-    LOG(INFO) << "receptive field (frame): " << receptive_field_length;
+        new ppspeech::Decodable(nnet_producer, FLAGS_acoustic_scale));
 
     decoder.InitDecoder();
     kaldi::Timer timer;
-    for (; !feature_reader.Done(); feature_reader.Next()) {
-        string utt = feature_reader.Key();
-        kaldi::Matrix<BaseFloat> feature = feature_reader.Value();
-        raw_data->SetDim(feature.NumCols());
-        LOG(INFO) << "process utt: " << utt;
-        LOG(INFO) << "rows: " << feature.NumRows();
-        LOG(INFO) << "cols: " << feature.NumCols();
-
-        int32 row_idx = 0;
-        int32 padding_len = 0;
-        int32 ori_feature_len = feature.NumRows();
-        if ((feature.NumRows() - chunk_size) % chunk_stride != 0) {
-            padding_len =
-                chunk_stride - (feature.NumRows() - chunk_size) % chunk_stride;
-            feature.Resize(feature.NumRows() + padding_len,
-                           feature.NumCols(),
-                           kaldi::kCopyData);
-        }
-        int32 num_chunks = (feature.NumRows() - chunk_size) / chunk_stride + 1;
-        for (int chunk_idx = 0; chunk_idx < num_chunks; ++chunk_idx) {
-            kaldi::Vector<kaldi::BaseFloat> feature_chunk(chunk_size *
-                                                          feature.NumCols());
-            int32 feature_chunk_size = 0;
-            if (ori_feature_len > chunk_idx * chunk_stride) {
-                feature_chunk_size = std::min(
-                    ori_feature_len - chunk_idx * chunk_stride, chunk_size);
-            }
-            if (feature_chunk_size < receptive_field_length) break;
-
-            int32 start = chunk_idx * chunk_stride;
-            for (int row_id = 0; row_id < chunk_size; ++row_id) {
-                kaldi::SubVector<kaldi::BaseFloat> tmp(feature, start);
-                kaldi::SubVector<kaldi::BaseFloat> f_chunk_tmp(
-                    feature_chunk.Data() + row_id * feature.NumCols(),
-                    feature.NumCols());
-                f_chunk_tmp.CopyFromVec(tmp);
-                ++start;
-            }
-            raw_data->Accept(feature_chunk);
-            if (chunk_idx == num_chunks - 1) {
-                raw_data->SetFinished();
-            }
-            decoder.AdvanceDecode(decodable);
-        }
+
+    for (; !nnet_prob_reader.Done(); nnet_prob_reader.Next()) {
+        string utt = nnet_prob_reader.Key();
+        kaldi::Matrix<BaseFloat> prob = nnet_prob_reader.Value();
+        decodable->Acceptlikelihood(prob);
+        decoder.AdvanceDecode(decodable);
         std::string result;
         result = decoder.GetFinalBestPath();
         decodable->Reset();

speechx/speechx/asr/decoder/decoder_itf.h

@@ -1,4 +1,3 @@
-
 // Copyright (c) 2022 PaddlePaddle Authors. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
@@ -16,6 +15,7 @@
 #pragma once
 
 #include "base/common.h"
+#include "fst/symbol-table.h"
 #include "kaldi/decoder/decodable-itf.h"
 
 namespace ppspeech {
@@ -41,6 +41,14 @@ class DecoderInterface {
 
     virtual std::string GetPartialResult() = 0;
 
+    virtual const std::shared_ptr<fst::SymbolTable> WordSymbolTable() const = 0;
+    virtual void FinalizeSearch() = 0;
+
+    virtual const std::vector<std::vector<int>>& Inputs() const = 0;
+    virtual const std::vector<std::vector<int>>& Outputs() const = 0;
+    virtual const std::vector<float>& Likelihood() const = 0;
+    virtual const std::vector<std::vector<int>>& Times() const = 0;
+
   protected:
     // virtual void AdvanceDecoding(kaldi::DecodableInterface* decodable) = 0;
 

speechx/speechx/asr/decoder/param.h

@@ -57,8 +57,8 @@ DEFINE_string(model_cache_shapes, "5-1-1024,5-1-1024", "model cache shapes");
 // decoder
 DEFINE_double(acoustic_scale, 1.0, "acoustic scale");
 
-DEFINE_string(graph_path, "TLG", "decoder graph");
-DEFINE_string(word_symbol_table, "words.txt", "word symbol table");
+DEFINE_string(graph_path, "", "decoder graph");
+DEFINE_string(word_symbol_table, "", "word symbol table");
 DEFINE_int32(max_active, 7500, "max active");
 DEFINE_double(beam, 15.0, "decoder beam");
 DEFINE_double(lattice_beam, 7.5, "decoder beam");

speechx/speechx/asr/nnet/decodable.h

@@ -27,8 +27,6 @@ class Decodable : public kaldi::DecodableInterface {
     explicit Decodable(const std::shared_ptr<NnetProducer>& nnet_producer,
                        kaldi::BaseFloat acoustic_scale = 1.0);
 
-    // void Init(DecodableOpts config);
-
     // nnet logprob output, used by wfst
     virtual kaldi::BaseFloat LogLikelihood(int32 frame, int32 index);
 

speechx/speechx/asr/nnet/nnet_producer.cc

@@ -23,25 +23,25 @@ using kaldi::BaseFloat;
 NnetProducer::NnetProducer(std::shared_ptr<NnetBase> nnet,
                            std::shared_ptr<FrontendInterface> frontend)
     : nnet_(nnet), frontend_(frontend) {
-        abort_ = false;
-        Reset();
-        thread_ = std::thread(RunNnetEvaluation, this);
-    }
+    abort_ = false;
+    Reset();
+    if (nnet_ != nullptr) thread_ = std::thread(RunNnetEvaluation, this);
+}
 
 void NnetProducer::Accept(const std::vector<kaldi::BaseFloat>& inputs) {
     frontend_->Accept(inputs);
     condition_variable_.notify_one();
 }
 
-void NnetProducer::UnLock() {
+void NnetProducer::WaitProduce() {
     std::unique_lock<std::mutex> lock(read_mutex_);
     while (frontend_->IsFinished() == false && cache_.empty()) {
-        condition_read_ready_.wait(lock); 
+        condition_read_ready_.wait(lock);
     }
     return;
 }
 
-void NnetProducer::RunNnetEvaluation(NnetProducer *me) {
+void NnetProducer::RunNnetEvaluation(NnetProducer* me) {
     me->RunNnetEvaluationInteral();
 }
 
@@ -55,7 +55,7 @@ void NnetProducer::RunNnetEvaluationInteral() {
             result = Compute();
         } while (result);
         if (frontend_->IsFinished() == true) {
-           if (cache_.empty()) finished_ = true;
+            if (cache_.empty()) finished_ = true;
         }
     }
     LOG(INFO) << "NnetEvaluationInteral exit";

speechx/speechx/asr/nnet/nnet_producer.h

@@ -34,9 +34,9 @@ class NnetProducer {
     // nnet
     bool Read(std::vector<kaldi::BaseFloat>* nnet_prob);
     bool ReadandCompute(std::vector<kaldi::BaseFloat>* nnet_prob);
-    static void RunNnetEvaluation(NnetProducer *me);
+    static void RunNnetEvaluation(NnetProducer* me);
     void RunNnetEvaluationInteral();
-    void UnLock();
+    void WaitProduce();
 
     void Wait() {
         abort_ = true;
@@ -56,12 +56,12 @@ class NnetProducer {
     bool IsFinished() const { return finished_; }
 
     ~NnetProducer() {
-      if (thread_.joinable()) thread_.join();
+        if (thread_.joinable()) thread_.join();
     }
 
     void Reset() {
-        frontend_->Reset();
-        nnet_->Reset();
+        if (frontend_ != NULL) frontend_->Reset();
+        if (nnet_ != NULL) nnet_->Reset();
         VLOG(3) << "feature cache reset: cache size: " << cache_.size();
         cache_.clear();
         finished_ = false;

speechx/speechx/asr/recognizer/u2_recognizer.cc

@@ -33,11 +33,15 @@ U2Recognizer::U2Recognizer(const U2RecognizerResource& resource)
     decodable_.reset(new Decodable(nnet_producer_, am_scale));
 
     CHECK_NE(resource.vocab_path, "");
-    decoder_.reset(new CTCPrefixBeamSearch(
-        resource.vocab_path, resource.decoder_opts.ctc_prefix_search_opts));
+    if (resource.decoder_opts.tlg_decoder_opts.fst_path == "") {
+        LOG(INFO) << resource.decoder_opts.tlg_decoder_opts.fst_path;
+        decoder_.reset(new CTCPrefixBeamSearch(
+            resource.vocab_path, resource.decoder_opts.ctc_prefix_search_opts));
+    } else {
+        decoder_.reset(new TLGDecoder(resource.decoder_opts.tlg_decoder_opts));
+    }
 
-    unit_table_ = decoder_->VocabTable();
-    symbol_table_ = unit_table_;
+    symbol_table_ = decoder_->WordSymbolTable();
 
     global_frame_offset_ = 0;
     input_finished_ = false;
@@ -56,11 +60,14 @@ U2Recognizer::U2Recognizer(const U2RecognizerResource& resource,
     decodable_.reset(new Decodable(nnet_producer_, am_scale));
 
     CHECK_NE(resource.vocab_path, "");
-    decoder_.reset(new CTCPrefixBeamSearch(
-        resource.vocab_path, resource.decoder_opts.ctc_prefix_search_opts));
+    if (resource.decoder_opts.tlg_decoder_opts.fst_path == "") {
+        decoder_.reset(new CTCPrefixBeamSearch(
+            resource.vocab_path, resource.decoder_opts.ctc_prefix_search_opts));
+    } else {
+        decoder_.reset(new TLGDecoder(resource.decoder_opts.tlg_decoder_opts));
+    }
 
-    unit_table_ = decoder_->VocabTable();
-    symbol_table_ = unit_table_;
+    symbol_table_ = decoder_->WordSymbolTable();
 
     global_frame_offset_ = 0;
     input_finished_ = false;
@@ -109,10 +116,11 @@ void U2Recognizer::RunDecoderSearch(U2Recognizer* me) {
 void U2Recognizer::RunDecoderSearchInternal() {
     LOG(INFO) << "DecoderSearchInteral begin";
     while (!nnet_producer_->IsFinished()) {
-        nnet_producer_->UnLock();
+        nnet_producer_->WaitProduce();
         decoder_->AdvanceDecode(decodable_);
     }
-    Decode();
+    decoder_->AdvanceDecode(decodable_);
+    UpdateResult(false);
     LOG(INFO) << "DecoderSearchInteral exit";
 }
 
@@ -140,7 +148,7 @@ void U2Recognizer::UpdateResult(bool finish) {
     const auto& times = decoder_->Times();
     result_.clear();
 
-    CHECK_EQ(hypotheses.size(), likelihood.size());
+    CHECK_EQ(inputs.size(), likelihood.size());
     for (size_t i = 0; i < hypotheses.size(); i++) {
         const std::vector<int>& hypothesis = hypotheses[i];
 
@@ -148,13 +156,9 @@ void U2Recognizer::UpdateResult(bool finish) {
         path.score = likelihood[i];
         for (size_t j = 0; j < hypothesis.size(); j++) {
             std::string word = symbol_table_->Find(hypothesis[j]);
-            // A detailed explanation of this if-else branch can be found in
-            // https://github.com/wenet-e2e/wenet/issues/583#issuecomment-907994058
-            if (decoder_->Type() == kWfstBeamSearch) {
-                path.sentence += (" " + word);
-            } else {
-                path.sentence += (word);
-            }
+            // path.sentence += (" " + word); // todo SmileGoat: add blank
+            // processor
+            path.sentence += word;  // todo SmileGoat: add blank processor
         }
 
         // TimeStamp is only supported in final result
@@ -162,7 +166,7 @@ void U2Recognizer::UpdateResult(bool finish) {
         // various FST operations when building the decoding graph. So here we
         // use time stamp of the input(e2e model unit), which is more accurate,
         // and it requires the symbol table of the e2e model used in training.
-        if (unit_table_ != nullptr && finish) {
+        if (symbol_table_ != nullptr && finish) {
             int offset = global_frame_offset_ * FrameShiftInMs();
 
             const std::vector<int>& input = inputs[i];
@@ -170,7 +174,7 @@ void U2Recognizer::UpdateResult(bool finish) {
             CHECK_EQ(input.size(), time_stamp.size());
 
             for (size_t j = 0; j < input.size(); j++) {
-                std::string word = unit_table_->Find(input[j]);
+                std::string word = symbol_table_->Find(input[j]);
 
                 int start =
                     time_stamp[j] * FrameShiftInMs() - time_stamp_gap_ > 0
@@ -214,7 +218,7 @@ void U2Recognizer::UpdateResult(bool finish) {
 
 void U2Recognizer::AttentionRescoring() {
     decoder_->FinalizeSearch();
-    UpdateResult(true);
+    UpdateResult(false);
 
     // No need to do rescoring
     if (0.0 == opts_.decoder_opts.rescoring_weight) {

speechx/speechx/asr/recognizer/u2_recognizer.h

@@ -17,6 +17,7 @@
 #include "decoder/common.h"
 #include "decoder/ctc_beam_search_opt.h"
 #include "decoder/ctc_prefix_beam_search_decoder.h"
+#include "decoder/ctc_tlg_decoder.h"
 #include "decoder/decoder_itf.h"
 #include "frontend/feature_pipeline.h"
 #include "fst/fstlib.h"
@@ -33,6 +34,8 @@ DECLARE_int32(blank);
 
 DECLARE_double(acoustic_scale);
 DECLARE_string(vocab_path);
+DECLARE_string(word_symbol_table);
+// DECLARE_string(fst_path);
 
 namespace ppspeech {
 
@@ -59,6 +62,7 @@ struct DecodeOptions {
 
     // CtcEndpointConfig ctc_endpoint_opts;
     CTCBeamSearchOptions ctc_prefix_search_opts{};
+    TLGDecoderOptions tlg_decoder_opts{};
 
     static DecodeOptions InitFromFlags() {
         DecodeOptions decoder_opts;
@@ -70,6 +74,13 @@ struct DecodeOptions {
         decoder_opts.ctc_prefix_search_opts.blank = FLAGS_blank;
         decoder_opts.ctc_prefix_search_opts.first_beam_size = FLAGS_nbest;
         decoder_opts.ctc_prefix_search_opts.second_beam_size = FLAGS_nbest;
+        // decoder_opts.tlg_decoder_opts.fst_path = "";//FLAGS_fst_path;
+        // decoder_opts.tlg_decoder_opts.word_symbol_table =
+        // FLAGS_word_symbol_table;
+        // decoder_opts.tlg_decoder_opts.nbest = FLAGS_nbest;
+        decoder_opts.tlg_decoder_opts =
+            ppspeech::TLGDecoderOptions::InitFromFlags();
+
         LOG(INFO) << "chunk_size: " << decoder_opts.chunk_size;
         LOG(INFO) << "num_left_chunks: " << decoder_opts.num_left_chunks;
         LOG(INFO) << "ctc_weight: " << decoder_opts.ctc_weight;
@@ -113,7 +124,7 @@ class U2Recognizer {
   public:
     explicit U2Recognizer(const U2RecognizerResource& resouce);
     explicit U2Recognizer(const U2RecognizerResource& resource,
-                         std::shared_ptr<NnetBase> nnet);
+                          std::shared_ptr<NnetBase> nnet);
     ~U2Recognizer();
     void InitDecoder();
     void ResetContinuousDecoding();
@@ -154,10 +165,9 @@ class U2Recognizer {
 
     std::shared_ptr<NnetProducer> nnet_producer_;
     std::shared_ptr<Decodable> decodable_;
-    std::unique_ptr<CTCPrefixBeamSearch> decoder_;
+    std::unique_ptr<DecoderBase> decoder_;
 
     // e2e unit symbol table
-    std::shared_ptr<fst::SymbolTable> unit_table_ = nullptr;
     std::shared_ptr<fst::SymbolTable> symbol_table_ = nullptr;
 
     std::vector<DecodeResult> result_;