Add GigaAM NeMo transducer model for Russian ASR (#1467)

sherpa-onnx/csrc/offline-recognizer-impl.cc

@@ -166,7 +166,8 @@ std::unique_ptr<OfflineRecognizerImpl> OfflineRecognizerImpl::Create(
     return std::make_unique<OfflineRecognizerParaformerImpl>(config);
   }
 
-  if (model_type == "EncDecHybridRNNTCTCBPEModel" &&
+  if ((model_type == "EncDecHybridRNNTCTCBPEModel" ||
+       model_type == "EncDecRNNTBPEModel") &&
       !config.model_config.transducer.decoder_filename.empty() &&
       !config.model_config.transducer.joiner_filename.empty()) {
     return std::make_unique<OfflineRecognizerTransducerNeMoImpl>(config);
@@ -191,6 +192,7 @@ std::unique_ptr<OfflineRecognizerImpl> OfflineRecognizerImpl::Create(
       " - EncDecCTCModelBPE models from NeMo\n"
       " - EncDecCTCModel models from NeMo\n"
       " - EncDecHybridRNNTCTCBPEModel models from NeMo\n"
+      " - EncDecRNNTBPEModel models from NeMO"
       " - Whisper models\n"
       " - Tdnn models\n"
       " - Zipformer CTC models\n"
@@ -338,7 +340,8 @@ std::unique_ptr<OfflineRecognizerImpl> OfflineRecognizerImpl::Create(
     return std::make_unique<OfflineRecognizerParaformerImpl>(mgr, config);
   }
 
-  if (model_type == "EncDecHybridRNNTCTCBPEModel" &&
+  if ((model_type == "EncDecHybridRNNTCTCBPEModel" ||
+       model_type == "EncDecRNNTBPEModel") &&
       !config.model_config.transducer.decoder_filename.empty() &&
       !config.model_config.transducer.joiner_filename.empty()) {
     return std::make_unique<OfflineRecognizerTransducerNeMoImpl>(mgr, config);
@@ -363,6 +366,7 @@ std::unique_ptr<OfflineRecognizerImpl> OfflineRecognizerImpl::Create(
       " - EncDecCTCModelBPE models from NeMo\n"
       " - EncDecCTCModel models from NeMo\n"
       " - EncDecHybridRNNTCTCBPEModel models from NeMo\n"
+      " - EncDecRNNTBPEModel models from NeMo\n"
       " - Whisper models\n"
       " - Tdnn models\n"
       " - Zipformer CTC models\n"

sherpa-onnx/csrc/offline-recognizer-transducer-nemo-impl.h

@@ -139,23 +139,29 @@ class OfflineRecognizerTransducerNeMoImpl : public OfflineRecognizerImpl {
     }
   }
 
-  OfflineRecognizerConfig GetConfig() const override {
-    return config_;
-  }
+  OfflineRecognizerConfig GetConfig() const override { return config_; }
 
  private:
   void PostInit() {
     config_.feat_config.nemo_normalize_type =
         model_->FeatureNormalizationMethod();
 
-    config_.feat_config.low_freq = 0;
-    // config_.feat_config.high_freq = 8000;
-    config_.feat_config.is_librosa = true;
-    config_.feat_config.remove_dc_offset = false;
-    // config_.feat_config.window_type = "hann";
     config_.feat_config.dither = 0;
-    config_.feat_config.nemo_normalize_type =
-        model_->FeatureNormalizationMethod();
+
+    if (model_->IsGigaAM()) {
+      config_.feat_config.low_freq = 0;
+      config_.feat_config.high_freq = 8000;
+      config_.feat_config.remove_dc_offset = false;
+      config_.feat_config.preemph_coeff = 0;
+      config_.feat_config.window_type = "hann";
+      config_.feat_config.feature_dim = 64;
+    } else {
+      config_.feat_config.low_freq = 0;
+      // config_.feat_config.high_freq = 8000;
+      config_.feat_config.is_librosa = true;
+      config_.feat_config.remove_dc_offset = false;
+      // config_.feat_config.window_type = "hann";
+    }
 
     int32_t vocab_size = model_->VocabSize();
 

sherpa-onnx/csrc/offline-transducer-nemo-model.cc

@@ -153,6 +153,8 @@ class OfflineTransducerNeMoModel::Impl {
 
   std::string FeatureNormalizationMethod() const { return normalize_type_; }
 
+  bool IsGigaAM() const { return is_giga_am_; }
+
  private:
   void InitEncoder(void *model_data, size_t model_data_length) {
     encoder_sess_ = std::make_unique<Ort::Session>(
@@ -181,9 +183,11 @@ class OfflineTransducerNeMoModel::Impl {
     vocab_size_ += 1;
 
     SHERPA_ONNX_READ_META_DATA(subsampling_factor_, "subsampling_factor");
-    SHERPA_ONNX_READ_META_DATA_STR(normalize_type_, "normalize_type");
+    SHERPA_ONNX_READ_META_DATA_STR_ALLOW_EMPTY(normalize_type_,
+                                               "normalize_type");
     SHERPA_ONNX_READ_META_DATA(pred_rnn_layers_, "pred_rnn_layers");
     SHERPA_ONNX_READ_META_DATA(pred_hidden_, "pred_hidden");
+    SHERPA_ONNX_READ_META_DATA_WITH_DEFAULT(is_giga_am_, "is_giga_am", 0);
 
     if (normalize_type_ == "NA") {
       normalize_type_ = "";
@@ -245,6 +249,7 @@ class OfflineTransducerNeMoModel::Impl {
   std::string normalize_type_;
   int32_t pred_rnn_layers_ = -1;
   int32_t pred_hidden_ = -1;
+  int32_t is_giga_am_ = 0;
 };
 
 OfflineTransducerNeMoModel::OfflineTransducerNeMoModel(
@@ -298,4 +303,6 @@ std::string OfflineTransducerNeMoModel::FeatureNormalizationMethod() const {
   return impl_->FeatureNormalizationMethod();
 }
 
+bool OfflineTransducerNeMoModel::IsGigaAM() const { return impl_->IsGigaAM(); }
+
 }  // namespace sherpa_onnx

sherpa-onnx/csrc/offline-transducer-nemo-model.h

@@ -93,6 +93,8 @@ class OfflineTransducerNeMoModel {
   // for details
   std::string FeatureNormalizationMethod() const;
 
+  bool IsGigaAM() const;
+
  private:
   class Impl;
   std::unique_ptr<Impl> impl_;

sherpa-onnx/kotlin-api/OfflineRecognizer.kt

@@ -404,6 +404,19 @@ fun getOfflineModelConfig(type: Int): OfflineModelConfig? {
                 tokens = "$modelDir/tokens.txt",
             )
         }
+
+        20 -> {
+            val modelDir = "sherpa-onnx-nemo-transducer-giga-am-russian-2024-10-24"
+            return OfflineModelConfig(
+                transducer = OfflineTransducerModelConfig(
+                    encoder = "$modelDir/encoder.int8.onnx",
+                    decoder = "$modelDir/decoder.onnx",
+                    joiner = "$modelDir/joiner.onnx",
+                ),
+                tokens = "$modelDir/tokens.txt",
+                modelType = "nemo_transducer",
+            )
+        }
     }
     return null
 }