// gmmbin/gmm-ismooth-stats.cc
  
  // Copyright 2009-2011  Petr Motlicek  Chao Weng
  
  // 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 "base/kaldi-common.h"
  #include "util/common-utils.h"
  #include "gmm/am-diag-gmm.h"
  #include "tree/context-dep.h"
  #include "hmm/transition-model.h"
  #include "gmm/ebw-diag-gmm.h"
  
  int main(int argc, char *argv[]) {
    try {
      using namespace kaldi;
      typedef kaldi::int32 int32;
  
      const char *usage =
          "Apply I-smoothing to statistics, e.g. for discriminative training
  "
          "Usage:  gmm-ismooth-stats [options] [--smooth-from-model] [<src-stats-in>|<src-model-in>] <dst-stats-in> <stats-out>
  "
          "e.g.: gmm-ismooth-stats --tau=100 ml.acc num.acc smoothed.acc
  "
          "or: gmm-ismooth-stats --tau=50 --smooth-from-model 1.mdl num.acc smoothed.acc
  "
          "or: gmm-ismooth-stats --tau=100 num.acc num.acc smoothed.acc
  ";
          
      bool binary_write = false;
      bool smooth_from_model = false;
      BaseFloat tau = 100;
      
      ParseOptions po(usage);
      po.Register("binary", &binary_write, "Write output in binary mode");
      po.Register("smooth-from-model", &smooth_from_model, "If true, "
                  "expect first argument to be a model file");
      po.Register("tau", &tau, "Tau value for I-smoothing");
      
      po.Read(argc, argv);
  
      if (po.NumArgs() != 3) {
        po.PrintUsage();
        exit(1);
      }
  
      std::string src_stats_or_model_filename = po.GetArg(1),
          dst_stats_filename = po.GetArg(2),
          stats_out_filename = po.GetArg(3);
  
      double tot_count_before, tot_count_after;
  
      if (src_stats_or_model_filename == dst_stats_filename) { // as an optimization, just read once.
        KALDI_ASSERT(!smooth_from_model);
        Vector<double> transition_accs;
        AccumAmDiagGmm stats;
        {
          bool binary;
          Input ki(dst_stats_filename, &binary);
          transition_accs.Read(ki.Stream(), binary);
          stats.Read(ki.Stream(), binary, true);  // true == add; doesn't matter here.
        }
        tot_count_before = stats.TotStatsCount();
        IsmoothStatsAmDiagGmm(stats, tau, &stats);
        tot_count_after = stats.TotStatsCount();
        Output ko(stats_out_filename, binary_write);
        transition_accs.Write(ko.Stream(), binary_write);
        stats.Write(ko.Stream(), binary_write);
      } else if (smooth_from_model) { // Smoothing from model...
        AmDiagGmm am_gmm;
        TransitionModel trans_model;
        Vector<double> dst_transition_accs;
        AccumAmDiagGmm dst_stats;
        { // read src model
          bool binary;
          Input ki(src_stats_or_model_filename, &binary);
          trans_model.Read(ki.Stream(), binary);
          am_gmm.Read(ki.Stream(), binary);
        }
        { // read dst stats.
          bool binary;
          Input ki(dst_stats_filename, &binary);
          dst_transition_accs.Read(ki.Stream(), binary);
          dst_stats.Read(ki.Stream(), binary, true);  // true == add; doesn't matter here.
        }
        tot_count_before = dst_stats.TotStatsCount();
        IsmoothStatsAmDiagGmmFromModel(am_gmm, tau, &dst_stats);
        tot_count_after = dst_stats.TotStatsCount();
        Output ko(stats_out_filename, binary_write);
        dst_transition_accs.Write(ko.Stream(), binary_write);
        dst_stats.Write(ko.Stream(), binary_write);
      } else { // Smooth from stats.
        Vector<double> src_transition_accs;
        Vector<double> dst_transition_accs;
        AccumAmDiagGmm src_stats;
        AccumAmDiagGmm dst_stats;
        { // read src stats.
          bool binary;
          Input ki(src_stats_or_model_filename, &binary);
          src_transition_accs.Read(ki.Stream(), binary);
          src_stats.Read(ki.Stream(), binary, true);  // true == add; doesn't matter here.
        }
        { // read dst stats.
          bool binary;
          Input ki(dst_stats_filename, &binary);
          dst_transition_accs.Read(ki.Stream(), binary);
          dst_stats.Read(ki.Stream(), binary, true);  // true == add; doesn't matter here.
        }
        tot_count_before = dst_stats.TotStatsCount();
        IsmoothStatsAmDiagGmm(src_stats, tau, &dst_stats);
        tot_count_after = dst_stats.TotStatsCount();
        
        Output ko(stats_out_filename, binary_write);
        dst_transition_accs.Write(ko.Stream(), binary_write);
        dst_stats.Write(ko.Stream(), binary_write);
      }
      KALDI_LOG << "Smoothed stats with tau = " << tau << ", count changed from "
                << tot_count_before << " to " << tot_count_after;
    } catch(const std::exception &e) {
      std::cerr << e.what() << '
  ';
      return -1;
    }
  }