Add two-pass speech recognition Android/iOS demo (#304)

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

@@ -132,4 +132,121 @@ std::unique_ptr<OfflineRecognizerImpl> OfflineRecognizerImpl::Create(
   exit(-1);
 }
 
+#if __ANDROID_API__ >= 9
+std::unique_ptr<OfflineRecognizerImpl> OfflineRecognizerImpl::Create(
+    AAssetManager *mgr, const OfflineRecognizerConfig &config) {
+  if (!config.model_config.model_type.empty()) {
+    const auto &model_type = config.model_config.model_type;
+    if (model_type == "transducer") {
+      return std::make_unique<OfflineRecognizerTransducerImpl>(mgr, config);
+    } else if (model_type == "paraformer") {
+      return std::make_unique<OfflineRecognizerParaformerImpl>(mgr, config);
+    } else if (model_type == "nemo_ctc") {
+      return std::make_unique<OfflineRecognizerCtcImpl>(mgr, config);
+    } else if (model_type == "tdnn") {
+      return std::make_unique<OfflineRecognizerCtcImpl>(mgr, config);
+    } else if (model_type == "whisper") {
+      return std::make_unique<OfflineRecognizerWhisperImpl>(mgr, config);
+    } else {
+      SHERPA_ONNX_LOGE(
+          "Invalid model_type: %s. Trying to load the model to get its type",
+          model_type.c_str());
+    }
+  }
+
+  Ort::Env env(ORT_LOGGING_LEVEL_ERROR);
+
+  Ort::SessionOptions sess_opts;
+  std::string model_filename;
+  if (!config.model_config.transducer.encoder_filename.empty()) {
+    model_filename = config.model_config.transducer.encoder_filename;
+  } else if (!config.model_config.paraformer.model.empty()) {
+    model_filename = config.model_config.paraformer.model;
+  } else if (!config.model_config.nemo_ctc.model.empty()) {
+    model_filename = config.model_config.nemo_ctc.model;
+  } else if (!config.model_config.tdnn.model.empty()) {
+    model_filename = config.model_config.tdnn.model;
+  } else if (!config.model_config.whisper.encoder.empty()) {
+    model_filename = config.model_config.whisper.encoder;
+  } else {
+    SHERPA_ONNX_LOGE("Please provide a model");
+    exit(-1);
+  }
+
+  auto buf = ReadFile(mgr, model_filename);
+
+  auto encoder_sess =
+      std::make_unique<Ort::Session>(env, buf.data(), buf.size(), sess_opts);
+
+  Ort::ModelMetadata meta_data = encoder_sess->GetModelMetadata();
+
+  Ort::AllocatorWithDefaultOptions allocator;  // used in the macro below
+
+  auto model_type_ptr =
+      meta_data.LookupCustomMetadataMapAllocated("model_type", allocator);
+  if (!model_type_ptr) {
+    SHERPA_ONNX_LOGE(
+        "No model_type in the metadata!\n\n"
+        "Please refer to the following URLs to add metadata"
+        "\n"
+        "(0) Transducer models from icefall"
+        "\n    "
+        "https://github.com/k2-fsa/icefall/blob/master/egs/librispeech/ASR/"
+        "pruned_transducer_stateless7/export-onnx.py#L303"
+        "\n"
+        "(1) Nemo CTC models\n    "
+        "https://huggingface.co/csukuangfj/"
+        "sherpa-onnx-nemo-ctc-en-citrinet-512/blob/main/add-model-metadata.py"
+        "\n"
+        "(2) Paraformer"
+        "\n    "
+        "https://huggingface.co/csukuangfj/"
+        "paraformer-onnxruntime-python-example/blob/main/add-model-metadata.py"
+        "\n    "
+        "(3) Whisper"
+        "\n    "
+        "(4) Tdnn models of the yesno recipe from icefall"
+        "\n    "
+        "https://github.com/k2-fsa/icefall/tree/master/egs/yesno/ASR/tdnn"
+        "\n"
+        "\n");
+    exit(-1);
+  }
+  std::string model_type(model_type_ptr.get());
+
+  if (model_type == "conformer" || model_type == "zipformer" ||
+      model_type == "zipformer2") {
+    return std::make_unique<OfflineRecognizerTransducerImpl>(mgr, config);
+  }
+
+  if (model_type == "paraformer") {
+    return std::make_unique<OfflineRecognizerParaformerImpl>(mgr, config);
+  }
+
+  if (model_type == "EncDecCTCModelBPE") {
+    return std::make_unique<OfflineRecognizerCtcImpl>(mgr, config);
+  }
+
+  if (model_type == "tdnn") {
+    return std::make_unique<OfflineRecognizerCtcImpl>(mgr, config);
+  }
+
+  if (strncmp(model_type.c_str(), "whisper", 7) == 0) {
+    return std::make_unique<OfflineRecognizerWhisperImpl>(mgr, config);
+  }
+
+  SHERPA_ONNX_LOGE(
+      "\nUnsupported model_type: %s\n"
+      "We support only the following model types at present: \n"
+      " - Non-streaming transducer models from icefall\n"
+      " - Non-streaming Paraformer models from FunASR\n"
+      " - EncDecCTCModelBPE models from NeMo\n"
+      " - Whisper models\n"
+      " - Tdnn models\n",
+      model_type.c_str());
+
+  exit(-1);
+}
+#endif
+
 }  // namespace sherpa_onnx