[src] Add a new binary for chain e2e (kaldi-asr#3945)

This is for use in an external project.

Author: YiwenShaoStephen

src/chainbin/Makefile

@@ -11,7 +11,8 @@ BINFILES = chain-est-phone-lm chain-get-supervision chain-make-den-fst \
         nnet3-chain-shuffle-egs nnet3-chain-subset-egs \
         nnet3-chain-acc-lda-stats nnet3-chain-train nnet3-chain-compute-prob \
         nnet3-chain-combine nnet3-chain-normalize-egs \
-        nnet3-chain-e2e-get-egs nnet3-chain-compute-post
+        nnet3-chain-e2e-get-egs nnet3-chain-compute-post \
+        chain-make-num-fst-e2e
 
 
 OBJFILES =

src/chainbin/chain-make-num-fst-e2e.cc

@@ -0,0 +1,121 @@
+// chainbin/chain-make-num-fst-e2e.cc
+
+// Copyright 2020  Yiwen Shao
+
+// 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.
+
+/** @brief Converts fsts (containing transition-ids) to fsts (containing pdf-ids + 1).
+*/
+#include "base/kaldi-common.h"
+#include "gmm/am-diag-gmm.h"
+#include "hmm/transition-model.h"
+#include "hmm/hmm-utils.h"
+#include "util/common-utils.h"
+#include "fst/fstlib.h"
+
+namespace kaldi {
+
+bool FstTransitionToPdfPlusOne(const fst::StdVectorFst &fst_transition,
+			       const TransitionModel &trans_model,
+			       fst::StdVectorFst *fst_pdf) {
+  fst::StdVectorFst fst_tmp(fst_transition);
+  fst::RemoveEpsLocal(&fst_tmp);
+  fst::RmEpsilon(&fst_tmp);
+  // first change labels to pdf-id + 1
+  int32 num_states = fst_tmp.NumStates();
+  for (int32 state = 0; state < num_states; state++) {
+    for (fst::MutableArcIterator<fst::StdVectorFst> aiter(&fst_tmp, state);
+         !aiter.Done(); aiter.Next()) {
+      const fst::StdArc &arc = aiter.Value();
+      if (arc.ilabel == 0) {
+        KALDI_WARN << "Utterance rejected due to eps on input label";
+        return false;
+      }
+      KALDI_ASSERT(arc.ilabel != 0);
+      fst::StdArc arc2(arc);
+      arc2.ilabel = arc2.olabel = trans_model.TransitionIdToPdf(arc.ilabel) + 1;
+      aiter.SetValue(arc2);
+    }
+  }
+  *fst_pdf = fst_tmp;
+  return true;
+}
+
+bool AddWeightToFst(const fst::StdVectorFst &normalization_fst,
+		    fst::StdVectorFst *fst) {
+  // Note: by default, 'Compose' will call 'Connect', so if the
+  // resulting FST is not connected, it will end up empty.
+  fst::StdVectorFst composed_fst;
+  fst::Compose(*fst, normalization_fst,
+	       &composed_fst);
+  *fst = composed_fst;
+  if (composed_fst.NumStates() == 0)
+    return false;
+  return true;
+}
+
+}
+
+int main(int argc, char *argv[]) {
+  using namespace kaldi;
+  typedef kaldi::int32 int32;
+  try {
+    const char *usage =
+      "Converts chain e2e numerator fst (containing transition-ids) to fst (containing pdf-ids+1, \n"
+      "and composed by the normalization fst) \n"
+      "Usage:  chain-make-num-fst-e2e [options] <model> <normalization-fst>\n"
+      "<trainsition-fst-rspecifier> <pdf-fst-wspecifier>\n"
+        "e.g.: \n"
+        " chain-make-num-fst-e2e 1.mdl ark:1.fst ark,t:-\n";
+    ParseOptions po(usage);
+
+    po.Read(argc, argv);
+
+    if (po.NumArgs() != 4) {
+      po.PrintUsage();
+      exit(1);
+    }
+
+    std::string model_filename = po.GetArg(1),
+      normalization_fst_rxfilename = po.GetArg(2),
+      fsts_rspecifier = po.GetArg(3),
+      fsts_wspecifier = po.GetArg(4);
+
+    TransitionModel trans_model;
+    ReadKaldiObject(model_filename, &trans_model);
+
+    fst::StdVectorFst normalization_fst;
+    ReadFstKaldi(normalization_fst_rxfilename, &normalization_fst);
+
+    SequentialTableReader<fst::VectorFstHolder> fsts_reader(fsts_rspecifier);
+    TableWriter<fst::VectorFstHolder> fsts_writer(fsts_wspecifier);
+
+    int32 num_done = 0;
+    for (; !fsts_reader.Done(); fsts_reader.Next()) {
+      std::string key = fsts_reader.Key();
+      fst::VectorFst<fst::StdArc> fst_transition(fsts_reader.Value());
+      fst::StdVectorFst fst_pdf;
+      FstTransitionToPdfPlusOne(fst_transition, trans_model, &fst_pdf);
+      AddWeightToFst(normalization_fst, &fst_pdf);
+      fsts_writer.Write(key, fst_pdf);
+      num_done++;
+    }
+    KALDI_LOG << "Converted " << num_done << " Fsts with transition-id to Fsts with pdf-id and normalized.";
+  } catch(const std::exception &e) {
+    std::cerr << e.what();
+    return -1;
+  }
+}