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src/online2/online-gmm-decodable.cc 2.3 KB
8dcb6dfcb   Yannick Estève   first commit
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  // online2/online-gmm-decodable.cc
  
  // Copyright 2012  Cisco Systems (author: Matthias Paulik)
  //           2013  Vassil Panayotov
  //           2014  Johns Hopkins University (author: Daniel Povey)
  
  // See ../../COPYING for clarification regarding multiple authors
  //
  // 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
  //
  // THIS CODE IS PROVIDED *AS IS* BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  // KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED
  // WARRANTIES OR CONDITIONS OF TITLE, FITNESS FOR A PARTICULAR PURPOSE,
  // MERCHANTABLITY OR NON-INFRINGEMENT.
  // See the Apache 2 License for the specific language governing permissions and
  // limitations under the License.
  
  #include "online2/online-gmm-decodable.h"
  
  namespace kaldi {
  
  DecodableDiagGmmScaledOnline::DecodableDiagGmmScaledOnline(
      const AmDiagGmm &am, const TransitionModel &trans_model,
      const BaseFloat scale, OnlineFeatureInterface *input_feats):  
        features_(input_feats), ac_model_(am),
        ac_scale_(scale), trans_model_(trans_model),
        feat_dim_(input_feats->Dim()), cur_feats_(feat_dim_),
        cur_frame_(-1) {
    int32 num_pdfs = trans_model_.NumPdfs();
    cache_.resize(num_pdfs, std::pair<int32,BaseFloat>(-1, 0.0f));
  }
  
  void DecodableDiagGmmScaledOnline::CacheFrame(int32 frame) {
    // The call below will fail if "frame" is an invalid index, i.e. <0
    // or >= features_->NumFramesReady(), so there
    // is no need to check again.
    features_->GetFrame(frame, &cur_feats_);
    cur_frame_ = frame;
  }
  
  BaseFloat DecodableDiagGmmScaledOnline::LogLikelihood(int32 frame, int32 index) {
    if (frame != cur_frame_)
      CacheFrame(frame);
    int32 pdf_id = trans_model_.TransitionIdToPdf(index);
    if (cache_[pdf_id].first == frame)
      return cache_[pdf_id].second;
    BaseFloat ans = ac_model_.LogLikelihood(pdf_id, cur_feats_) * ac_scale_;
    cache_[pdf_id].first = frame;
    cache_[pdf_id].second = ans;
    return ans;
  }
  
  
  bool DecodableDiagGmmScaledOnline::IsLastFrame(int32 frame) const {
    return features_->IsLastFrame(frame);
  }
  
  int32 DecodableDiagGmmScaledOnline::NumFramesReady() const {
    return features_->NumFramesReady();
  }
  
  } // namespace kaldi