Add support for context independent phones in gmm-init-biphone (for e2e)

egs/wsj/s5/steps/nnet3/chain/e2e/prepare_e2e.sh

@@ -18,6 +18,7 @@ treedir=              # if specified, the tree and model will be copied from the
                       # note that it may not be flat start anymore.
 type=mono             # can be either mono or biphone -- either way
                       # the resulting tree is full (i.e. it doesn't do any tying)
+ci_silence=false      # if true, silence phones will be treated as context independent
 
 scale_opts="--transition-scale=0.0 --self-loop-scale=0.0"
 # End configuration section.
@@ -63,12 +64,17 @@ if $shared_phones; then
   shared_phones_opt="--shared-phones=$lang/phones/sets.int"
 fi
 
+ciphonelist=`cat $lang/phones/context_indep.csl` || exit 1;
+if $ci_silence; then
+  ci_opt="--ci-phones=$ciphonelist"
+fi
+
 if [ $stage -le 0 ]; then
   if [ -z $treedir ]; then
     echo "$0: Initializing $type system."
     # feat dim does not matter here. Just set it to 10
     $cmd $dir/log/init_${type}_mdl_tree.log \
-         gmm-init-$type $shared_phones_opt $lang/topo 10 \
+         gmm-init-$type $ci_opt $shared_phones_opt $lang/topo 10 \
          $dir/0.mdl $dir/tree || exit 1;
   else
     echo "$0: Copied tree/mdl from $treedir." >$dir/log/init_mdl_tree.log

src/gmmbin/gmm-init-biphone.cc

@@ -51,10 +51,12 @@ void ReadSharedPhonesList(std::string rxfilename, std::vector<std::vector<int32>
 EventMap
 *GetFullBiphoneStubMap(const std::vector<std::vector<int32> > &phone_sets,
                        const std::vector<int32> &phone2num_pdf_classes,
-                       const std::vector<bool> &share_roots) {
+                       const std::vector<bool> &share_roots,
+                       const std::vector<int32> &ci_phones_list) {
 
   {  // Check the inputs
-    KALDI_ASSERT(!phone_sets.empty() && share_roots.size() == phone_sets.size());
+    KALDI_ASSERT(!phone_sets.empty() &&
+                 share_roots.size() == phone_sets.size());
     std::set<int32> all_phones;
     for (size_t i = 0; i < phone_sets.size(); i++) {
       KALDI_ASSERT(IsSortedAndUniq(phone_sets[i]));
@@ -66,9 +68,18 @@ EventMap
     }
   }
 
+
   int32 numpdfs_per_phone = phone2num_pdf_classes[1];
   int32 current_pdfid = 0;
   std::map<EventValueType, EventMap*> level1_map;  // key is 1
+
+  for (size_t i = 0; i < ci_phones_list.size(); i++) {
+    std::map<EventValueType, EventAnswerType> level2_map;
+    level2_map[0] = current_pdfid++;
+    if (numpdfs_per_phone == 2) level2_map[1] = current_pdfid++;
+    level1_map[ci_phones_list[i]] = new TableEventMap(kPdfClass, level2_map);
+  }
+
   for (size_t i = 0; i < phone_sets.size(); i++) {
 
     if (numpdfs_per_phone == 1) {
@@ -99,9 +110,11 @@ EventMap
           level3_map[0] = current_pdfid++;
           level3_map[1] = current_pdfid++;
           level2_map[0] = new TableEventMap(kPdfClass, level3_map);  // no-left-context case
+          for (size_t i = 0; i < ci_phones_list.size(); i++)  // ci-phone left-context cases
+            level2_map[ci_phones_list[i]] = new TableEventMap(kPdfClass, level3_map);
         }
         for (size_t j = 0; j < phone_sets.size(); j++) {
-          std::map<EventValueType, EventAnswerType> level3_map;  // key is -1
+          std::map<EventValueType, EventAnswerType> level3_map;  // key is kPdfClass
           level3_map[0] = current_pdfid++;
           level3_map[1] = current_pdfid++;
 
@@ -121,17 +134,35 @@ EventMap
   return new TableEventMap(1, level1_map);
 }
 
+
 ContextDependency*
-BiphoneContextDependencyFull(const std::vector<std::vector<int32> > phone_sets,
-                             const std::vector<int32> phone2num_pdf_classes) {
-  std::vector<bool> share_roots(phone_sets.size(), false);   // Don't share roots
+BiphoneContextDependencyFull(std::vector<std::vector<int32> > phone_sets,
+                             const std::vector<int32> phone2num_pdf_classes,
+                             const std::vector<int32> &ci_phones_list) {
+  // Remove all the CI phones from the phone sets
+  std::set<int32> ci_phones;
+  for (size_t i = 0; i < ci_phones_list.size(); i++)
+    ci_phones.insert(ci_phones_list[i]);
+  for (int32 i = phone_sets.size() - 1; i >= 0; i--) {
+    for (int32 j = phone_sets[i].size() - 1; j >= 0; j--) {
+      if (ci_phones.find(phone_sets[i][j]) != ci_phones.end()) {  // Delete it
+        phone_sets[i].erase(phone_sets[i].begin() + j);
+        if (phone_sets[i].empty())   // If empty, delete the whole entry
+          phone_sets.erase(phone_sets.begin() + i);
+      }
+    }
+  }
+
+  std::vector<bool> share_roots(phone_sets.size(), false);  // Don't share roots
   // N is context size, P = position of central phone (must be 0).
   int32 P = 1, N = 2;
   EventMap *pdf_map = GetFullBiphoneStubMap(phone_sets,
-                                            phone2num_pdf_classes, share_roots);
+                                            phone2num_pdf_classes,
+                                            share_roots, ci_phones_list);
   return new ContextDependency(N, P, pdf_map);
 }
 
+
 } // end namespace kaldi
 
 int main(int argc, char *argv[]) {
@@ -148,11 +179,17 @@ int main(int argc, char *argv[]) {
 
     bool binary = true;
     std::string shared_phones_rxfilename;
+    std::string ci_phones_str;
+    std::vector<int32> ci_phones;  // Sorted, uniqe vector of
+    // context-independent phones.
+
     ParseOptions po(usage);
     po.Register("binary", &binary, "Write output in binary mode");
     po.Register("shared-phones", &shared_phones_rxfilename,
                 "rxfilename containing, on each line, a list of phones "
                 "whose pdfs should be shared.");
+    po.Register("ci-phones", &ci_phones_str, "Colon-separated list of "
+                "integer indices of context-independent phones.");
     po.Read(argc, argv);
 
     if (po.NumArgs() != 4) {
@@ -169,6 +206,14 @@ int main(int argc, char *argv[]) {
     std::string model_filename = po.GetArg(3);
     std::string tree_filename = po.GetArg(4);
 
+    if (!ci_phones_str.empty()) {
+      SplitStringToIntegers(ci_phones_str, ":", false, &ci_phones);
+      std::sort(ci_phones.begin(), ci_phones.end());
+      if (!IsSortedAndUniq(ci_phones) || ci_phones.empty() || ci_phones[0] == 0)
+        KALDI_ERR << "Invalid --ci-phones option: " << ci_phones_str;
+    }
+
+
     Vector<BaseFloat> glob_inv_var(dim);
     glob_inv_var.Set(1.0);
     Vector<BaseFloat> glob_mean(dim);
@@ -200,7 +245,8 @@ int main(int argc, char *argv[]) {
       ReadSharedPhonesList(shared_phones_rxfilename, &shared_phones);
       // ReadSharedPhonesList crashes on error.
     }
-    ctx_dep = BiphoneContextDependencyFull(shared_phones, phone2num_pdf_classes);
+    ctx_dep = BiphoneContextDependencyFull(shared_phones, phone2num_pdf_classes,
+                                           ci_phones);
 
     int32 num_pdfs = ctx_dep->NumPdfs();