// nnet3bin/nnet3-get-egs-simple.cc
  
  // Copyright      2017  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 <sstream>
  #include "base/kaldi-common.h"
  #include "util/common-utils.h"
  #include "hmm/transition-model.h"
  #include "hmm/posterior.h"
  #include "nnet3/nnet-example.h"
  #include "nnet3/nnet-example-utils.h"
  
  namespace kaldi {
  
  // This function attempts to split a command-line argument of the
  // form 'name=rspecifier', on the first equals sign.  Will
  // call KALDI_ERR if something seems wrong.
  void SplitArgOnEquals(const std::string &arg,
                        std::string *name,
                        std::string *rspecifier) {
    size_t pos = arg.find_first_of('=');
    if (pos == std::string::npos) {
      KALDI_ERR << "Bad command line argument (expecting '='): "
                << arg;
    }
    *name = std::string(arg, 0, pos);
    *rspecifier = std::string(arg, pos + 1);
    if (!IsToken(*name)) {
      KALDI_ERR << "Bad command line argument (expecting a valid name before '='): "
                << arg;
    }
    if (ClassifyRspecifier(*rspecifier, NULL, NULL) == kNoRspecifier) {
      KALDI_ERR << "Bad command line argument (expecting an rspecifier after '='): "
                << arg;
    }
  }
  
  } // namespace kaldi
  
  int main(int argc, char *argv[]) {
    try {
      using namespace kaldi;
      using namespace kaldi::nnet3;
      typedef kaldi::int32 int32;
      typedef kaldi::int64 int64;
  
      const char *usage =
          "Get frame-by-frame examples of data for nnet3 neural network training.
  "
          "This is like nnet3-get-egs, but does not split up its inputs into pieces
  "
          "and allows more general generation of egs.  E.g. this is usable for image
  "
          "recognition tasks.
  "
          "
  "
          "Usage:  nnet3-get-egs-simple [options] <name1>=<rspecifier1> "
          "<name2>=<rspecifier2> ...
  "
          "
  "
          "e.g.:
  "
          "nnet3-get-egs-simple input=scp:images.scp \\
  "
          "output='ark,o:ali-to-post ark:labels.txt ark:- | post-to-smat --dim=10 ark:- ark:-' ark:egs.ark
  "
          "
  "
          "See also: nnet3-get-egs
  ";
  
  
      ParseOptions po(usage);
  
  
      po.Read(argc, argv);
  
      if (po.NumArgs() < 2) {
        po.PrintUsage();
        exit(1);
      }
  
  
      std::string examples_wspecifier = po.GetArg(po.NumArgs());
      NnetExampleWriter example_writer(examples_wspecifier);
  
  
      std::string first_name, first_reader_name;
      SplitArgOnEquals(po.GetArg(1), &first_name, &first_reader_name);
      SequentialGeneralMatrixReader first_reader(first_reader_name);
  
      std::vector<std::string> other_names;
  
      std::vector<RandomAccessGeneralMatrixReader*> other_readers;
  
      for (int32 i = 2; i < po.NumArgs(); i++) {
        std::string name, rspecifier;
        SplitArgOnEquals(po.GetArg(i), &name, &rspecifier);
        other_names.push_back(name);
        other_readers.push_back(new RandomAccessGeneralMatrixReader(rspecifier));
      }
  
      int32 num_done = 0, num_err = 0;
  
      for (; !first_reader.Done(); first_reader.Next()) {
        std::string key = first_reader.Key();
        NnetExample eg;
        const GeneralMatrix &feats = first_reader.Value();
        int32 t = 0;  // first 't' value; each row of the matrix gets
                      // its own 't' value.
        eg.io.push_back(NnetIo(first_name, t, feats));
        bool all_ok = true;
        for (size_t i = 0; i < other_names.size(); i++) {
          if (!other_readers[i]->HasKey(key)) {
            KALDI_WARN << "Could not find input for key " << key
                       << " for io-name=" << other_names[i];
            all_ok = false;
            break;
          }
          const GeneralMatrix &other_feats = other_readers[i]->Value(key);
          eg.io.push_back(NnetIo(other_names[i], t, other_feats));
        }
        if (!all_ok) {
          num_err++;
        } else {
          example_writer.Write(key, eg);
          num_done++;
        }
      }
      if (num_err > 0)
        KALDI_WARN << num_err << " utterances had errors and could "
            "not be processed.";
      return (num_done > 0 ? 0 : 1);
    } catch(const std::exception &e) {
      std::cerr << e.what() << '
  ';
      return -1;
    }
  }