Method DecoderState

ctcdecode/ctcdecode/src/ctc_beam_search_decoder.cpp:17–53

using FSTMATCH = fst::SortedMatcher<fst::StdVectorFst>;

DecoderState::DecoderState(const std::vector<std::string> &vocabulary,
                           size_t beam_size,
                           double cutoff_prob,
                           size_t cutoff_top_n,
                           size_t blank_id,
                           int log_input,
                           Scorer *ext_scorer)
  : abs_time_step(0)
  , beam_size(beam_size)
  , cutoff_prob(cutoff_prob)
  , cutoff_top_n(cutoff_top_n)
  , blank_id(blank_id)
  , log_input(log_input)
  , vocabulary(vocabulary)
  , ext_scorer(ext_scorer)
{
  // assign space id
  auto it = std::find(vocabulary.begin(), vocabulary.end(), " ");
  // if no space in vocabulary
  if (it == vocabulary.end()) {
    space_id = -2;
  } else {
    space_id = std::distance(vocabulary.begin(), it);
  }

  // init prefixes' root
  root.score = root.log_prob_b_prev = 0.0;
  prefixes.push_back(&root);

  if (ext_scorer != nullptr && !ext_scorer->is_character_based()) {
    auto fst_dict = static_cast<fst::StdVectorFst *>(ext_scorer->dictionary);
    fst::StdVectorFst *dict_ptr = fst_dict->Copy(true);
    root.set_dictionary(dict_ptr);
    auto matcher = std::make_shared<FSTMATCH>(*dict_ptr, fst::MATCH_INPUT);
    root.set_matcher(matcher);
  }
}


void