Support text normalization via rule FST (#407)

sherpa-onnx/csrc/offline-tts-vits-impl.h

@@ -14,30 +14,50 @@
 #include "android/asset_manager_jni.h"
 #endif
 
+#include "kaldifst/csrc/text-normalizer.h"
 #include "sherpa-onnx/csrc/lexicon.h"
 #include "sherpa-onnx/csrc/macros.h"
 #include "sherpa-onnx/csrc/offline-tts-impl.h"
 #include "sherpa-onnx/csrc/offline-tts-vits-model.h"
+#include "sherpa-onnx/csrc/text-utils.h"
 
 namespace sherpa_onnx {
 
 class OfflineTtsVitsImpl : public OfflineTtsImpl {
  public:
   explicit OfflineTtsVitsImpl(const OfflineTtsConfig &config)
-      : model_(std::make_unique<OfflineTtsVitsModel>(config.model)),
+      : config_(config),
+        model_(std::make_unique<OfflineTtsVitsModel>(config.model)),
         lexicon_(config.model.vits.lexicon, config.model.vits.tokens,
                  model_->Punctuations(), model_->Language(), config.model.debug,
-                 model_->IsPiper()) {}
+                 model_->IsPiper()) {
+    if (!config.rule_fsts.empty()) {
+      std::vector<std::string> files;
+      SplitStringToVector(config.rule_fsts, ",", false, &files);
+      tn_list_.reserve(files.size());
+      for (const auto &f : files) {
+        if (config.model.debug) {
+          SHERPA_ONNX_LOGE("rule fst: %s", f.c_str());
+        }
+        tn_list_.push_back(std::make_unique<kaldifst::TextNormalizer>(f));
+      }
+    }
+  }
 
 #if __ANDROID_API__ >= 9
   OfflineTtsVitsImpl(AAssetManager *mgr, const OfflineTtsConfig &config)
-      : model_(std::make_unique<OfflineTtsVitsModel>(mgr, config.model)),
+      : config_(config),
+        model_(std::make_unique<OfflineTtsVitsModel>(mgr, config.model)),
         lexicon_(mgr, config.model.vits.lexicon, config.model.vits.tokens,
                  model_->Punctuations(), model_->Language(), config.model.debug,
-                 model_->IsPiper()) {}
+                 model_->IsPiper()) {
+    if (!config.rule_fsts.empty()) {
+      SHERPA_ONNX_LOGE("TODO(fangjun): Implement rule FST for Android");
+    }
+  }
 #endif
 
-  GeneratedAudio Generate(const std::string &text, int64_t sid = 0,
+  GeneratedAudio Generate(const std::string &_text, int64_t sid = 0,
                           float speed = 1.0) const override {
     int32_t num_speakers = model_->NumSpeakers();
     if (num_speakers == 0 && sid != 0) {
@@ -55,6 +75,20 @@ class OfflineTtsVitsImpl : public OfflineTtsImpl {
       sid = 0;
     }
 
+    std::string text = _text;
+    if (config_.model.debug) {
+      SHERPA_ONNX_LOGE("Raw text: %s", text.c_str());
+    }
+
+    if (!tn_list_.empty()) {
+      for (const auto &tn : tn_list_) {
+        text = tn->Normalize(text);
+        if (config_.model.debug) {
+          SHERPA_ONNX_LOGE("After normalizing: %s", text.c_str());
+        }
+      }
+    }
+
     std::vector<int64_t> x = lexicon_.ConvertTextToTokenIds(text);
     if (x.empty()) {
       SHERPA_ONNX_LOGE("Failed to convert %s to token IDs", text.c_str());
@@ -98,7 +132,9 @@ class OfflineTtsVitsImpl : public OfflineTtsImpl {
   }
 
  private:
+  OfflineTtsConfig config_;
   std::unique_ptr<OfflineTtsVitsModel> model_;
+  std::vector<std::unique_ptr<kaldifst::TextNormalizer>> tn_list_;
   Lexicon lexicon_;
 };
 

sherpa-onnx/csrc/offline-tts.cc

@@ -6,19 +6,44 @@
 
 #include <string>
 
+#include "sherpa-onnx/csrc/file-utils.h"
+#include "sherpa-onnx/csrc/macros.h"
 #include "sherpa-onnx/csrc/offline-tts-impl.h"
+#include "sherpa-onnx/csrc/text-utils.h"
 
 namespace sherpa_onnx {
 
-void OfflineTtsConfig::Register(ParseOptions *po) { model.Register(po); }
+void OfflineTtsConfig::Register(ParseOptions *po) {
+  model.Register(po);
 
-bool OfflineTtsConfig::Validate() const { return model.Validate(); }
+  po->Register("tts-rule-fsts", &rule_fsts,
+               "It not empty, it contains a list of rule FST filenames."
+               "Multiple filenames are separated by a comma and they are "
+               "applied from left to right. An example value: "
+               "rule1.fst,rule2,fst,rule3.fst");
+}
+
+bool OfflineTtsConfig::Validate() const {
+  if (!rule_fsts.empty()) {
+    std::vector<std::string> files;
+    SplitStringToVector(rule_fsts, ",", false, &files);
+    for (const auto &f : files) {
+      if (!FileExists(f)) {
+        SHERPA_ONNX_LOGE("Rule fst %s does not exist. ", f.c_str());
+        return false;
+      }
+    }
+  }
+
+  return model.Validate();
+}
 
 std::string OfflineTtsConfig::ToString() const {
   std::ostringstream os;
 
   os << "OfflineTtsConfig(";
-  os << "model=" << model.ToString() << ")";
+  os << "model=" << model.ToString() << ", ";
+  os << "rule_fsts=\"" << rule_fsts << "\")";
 
   return os.str();
 }

sherpa-onnx/csrc/offline-tts.h

@@ -21,10 +21,17 @@ namespace sherpa_onnx {
 
 struct OfflineTtsConfig {
   OfflineTtsModelConfig model;
+  // If not empty, it contains a list of rule FST filenames.
+  // Filenames are separated by a comma.
+  // Example value: rule1.fst,rule2,fst,rule3.fst
+  //
+  // If there are multiple rules, they are applied from left to right.
+  std::string rule_fsts;
 
   OfflineTtsConfig() = default;
-  explicit OfflineTtsConfig(const OfflineTtsModelConfig &model)
-      : model(model) {}
+  OfflineTtsConfig(const OfflineTtsModelConfig &model,
+                   const std::string &rule_fsts)
+      : model(model), rule_fsts(rule_fsts) {}
 
   void Register(ParseOptions *po);
   bool Validate() const;