Support contextual-biasing for streaming model (#184)

* Support contextual-biasing for streaming model

* The whole pipeline runs normally

* Fix comments

sherpa-onnx/python/csrc/online-recognizer.cc

@@ -22,18 +22,19 @@ static void PybindOnlineRecognizerConfig(py::module *m) {
   py::class_<PyClass>(*m, "OnlineRecognizerConfig")
       .def(py::init<const FeatureExtractorConfig &,
                     const OnlineTransducerModelConfig &, const OnlineLMConfig &,
-                    const EndpointConfig &, bool, const std::string &,
-                    int32_t>(),
+                    const EndpointConfig &, bool, const std::string &, int32_t,
+                    float>(),
            py::arg("feat_config"), py::arg("model_config"),
            py::arg("lm_config") = OnlineLMConfig(), py::arg("endpoint_config"),
            py::arg("enable_endpoint"), py::arg("decoding_method"),
-           py::arg("max_active_paths"))
+           py::arg("max_active_paths"), py::arg("context_score"))
       .def_readwrite("feat_config", &PyClass::feat_config)
       .def_readwrite("model_config", &PyClass::model_config)
       .def_readwrite("endpoint_config", &PyClass::endpoint_config)
       .def_readwrite("enable_endpoint", &PyClass::enable_endpoint)
       .def_readwrite("decoding_method", &PyClass::decoding_method)
       .def_readwrite("max_active_paths", &PyClass::max_active_paths)
+      .def_readwrite("context_score", &PyClass::context_score)
       .def("__str__", &PyClass::ToString);
 }
 
@@ -44,7 +45,15 @@ void PybindOnlineRecognizer(py::module *m) {
   using PyClass = OnlineRecognizer;
   py::class_<PyClass>(*m, "OnlineRecognizer")
       .def(py::init<const OnlineRecognizerConfig &>(), py::arg("config"))
-      .def("create_stream", &PyClass::CreateStream)
+      .def("create_stream",
+           [](const PyClass &self) { return self.CreateStream(); })
+      .def(
+          "create_stream",
+          [](PyClass &self,
+             const std::vector<std::vector<int32_t>> &contexts_list) {
+            return self.CreateStream(contexts_list);
+          },
+          py::arg("contexts_list"))
       .def("is_ready", &PyClass::IsReady)
       .def("decode_stream", &PyClass::DecodeStream)
       .def("decode_streams",

sherpa-onnx/python/sherpa_onnx/online_recognizer.py

@@ -1,6 +1,6 @@
 # Copyright (c)  2023  Xiaomi Corporation
 from pathlib import Path
-from typing import List
+from typing import List, Optional
 
 from _sherpa_onnx import (
     EndpointConfig,
@@ -39,6 +39,7 @@ class OnlineRecognizer(object):
         rule3_min_utterance_length: float = 20.0,
         decoding_method: str = "greedy_search",
         max_active_paths: int = 4,
+        context_score: float = 1.5,
         provider: str = "cpu",
     ):
         """
@@ -124,13 +125,17 @@ class OnlineRecognizer(object):
             enable_endpoint=enable_endpoint_detection,
             decoding_method=decoding_method,
             max_active_paths=max_active_paths,
+            context_score=context_score,
         )
 
         self.recognizer = _Recognizer(recognizer_config)
         self.config = recognizer_config
 
-    def create_stream(self):
-        return self.recognizer.create_stream()
+    def create_stream(self, contexts_list : Optional[List[List[int]]] = None):
+        if contexts_list is None:
+            return self.recognizer.create_stream()
+        else:
+            return self.recognizer.create_stream(contexts_list)
 
     def decode_stream(self, s: OnlineStream):
         self.recognizer.decode_stream(s)