support reading rule FST for Android TTS (#410)

sherpa-onnx/csrc/lexicon.cc

@@ -196,8 +196,14 @@ std::vector<int64_t> Lexicon::ConvertTextToTokenIdsChinese(
 
   std::vector<int64_t> ans;
 
-  auto sil = token2id_.at("sil");
-  auto eos = token2id_.at("eos");
+  int32_t sil = -1;
+  int32_t eos = -1;
+  if (token2id_.count("sil")) {
+    sil = token2id_.at("sil");
+    eos = token2id_.at("eos");
+  } else {
+    sil = 0;
+  }
 
   ans.push_back(sil);
 
@@ -216,7 +222,9 @@ std::vector<int64_t> Lexicon::ConvertTextToTokenIdsChinese(
     ans.insert(ans.end(), token_ids.begin(), token_ids.end());
   }
   ans.push_back(sil);
-  ans.push_back(eos);
+  if (eos != -1) {
+    ans.push_back(eos);
+  }
   return ans;
 }
 

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

@@ -10,15 +10,17 @@
 #include <vector>
 
 #if __ANDROID_API__ >= 9
+#include <strstream>
+
 #include "android/asset_manager.h"
 #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/onnx-utils.h"
 #include "sherpa-onnx/csrc/text-utils.h"
 
 namespace sherpa_onnx {
@@ -52,7 +54,17 @@ class OfflineTtsVitsImpl : public OfflineTtsImpl {
                  model_->Punctuations(), model_->Language(), config.model.debug,
                  model_->IsPiper()) {
     if (!config.rule_fsts.empty()) {
-      SHERPA_ONNX_LOGE("TODO(fangjun): Implement rule FST for Android");
+      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());
+        }
+        auto buf = ReadFile(mgr, f);
+        std::istrstream is(buf.data(), buf.size());
+        tn_list_.push_back(std::make_unique<kaldifst::TextNormalizer>(is));
+      }
     }
   }
 #endif

sherpa-onnx/jni/jni.cc

@@ -566,6 +566,13 @@ static OfflineTtsConfig GetOfflineTtsConfig(JNIEnv *env, jobject config) {
   ans.model.provider = p;
   env->ReleaseStringUTFChars(s, p);
 
+  // for ruleFsts
+  fid = env->GetFieldID(cls, "ruleFsts", "Ljava/lang/String;");
+  s = (jstring)env->GetObjectField(config, fid);
+  p = env->GetStringUTFChars(s, nullptr);
+  ans.rule_fsts = p;
+  env->ReleaseStringUTFChars(s, p);
+
   return ans;
 }