Code refactoring (#74)

* Don't reset model state and feature extractor on endpointing

* support passing decoding_method from commandline

* Add modified_beam_search to Python API

* fix C API example

* Fix style issues

sherpa-onnx/python/csrc/CMakeLists.txt

@@ -1,12 +1,13 @@
 include_directories(${CMAKE_SOURCE_DIR})
 
 pybind11_add_module(_sherpa_onnx
+  display.cc
+  endpoint.cc
   features.cc
+  online-recognizer.cc
+  online-stream.cc
   online-transducer-model-config.cc
   sherpa-onnx.cc
-  endpoint.cc
-  online-stream.cc
-  online-recognizer.cc
 )
 
 if(APPLE)

sherpa-onnx/python/csrc/display.cc

@@ -0,0 +1,18 @@
+// sherpa-onnx/python/csrc/display.cc
+//
+// Copyright (c)  2023  Xiaomi Corporation
+
+#include "sherpa-onnx/python/csrc/display.h"
+
+#include "sherpa-onnx/csrc/display.h"
+
+namespace sherpa_onnx {
+
+void PybindDisplay(py::module *m) {
+  using PyClass = Display;
+  py::class_<PyClass>(*m, "Display")
+      .def(py::init<int32_t>(), py::arg("max_word_per_line") = 60)
+      .def("print", &PyClass::Print, py::arg("idx"), py::arg("s"));
+}
+
+}  // namespace sherpa_onnx

sherpa-onnx/python/csrc/display.h

@@ -0,0 +1,16 @@
+// sherpa-onnx/python/csrc/display.h
+//
+// Copyright (c)  2023  Xiaomi Corporation
+
+#ifndef SHERPA_ONNX_PYTHON_CSRC_DISPLAY_H_
+#define SHERPA_ONNX_PYTHON_CSRC_DISPLAY_H_
+
+#include "sherpa-onnx/python/csrc/sherpa-onnx.h"
+
+namespace sherpa_onnx {
+
+void PybindDisplay(py::module *m);
+
+}  // namespace sherpa_onnx
+
+#endif  // SHERPA_ONNX_PYTHON_CSRC_DISPLAY_H_

sherpa-onnx/python/csrc/features.cc

@@ -11,10 +11,12 @@ namespace sherpa_onnx {
 static void PybindFeatureExtractorConfig(py::module *m) {
   using PyClass = FeatureExtractorConfig;
   py::class_<PyClass>(*m, "FeatureExtractorConfig")
-      .def(py::init<float, int32_t>(), py::arg("sampling_rate") = 16000,
-           py::arg("feature_dim") = 80)
+      .def(py::init<float, int32_t, int32_t>(),
+           py::arg("sampling_rate") = 16000, py::arg("feature_dim") = 80,
+           py::arg("max_feature_vectors") = -1)
       .def_readwrite("sampling_rate", &PyClass::sampling_rate)
       .def_readwrite("feature_dim", &PyClass::feature_dim)
+      .def_readwrite("max_feature_vectors", &PyClass::max_feature_vectors)
       .def("__str__", &PyClass::ToString);
 }
 

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

@@ -22,13 +22,16 @@ static void PybindOnlineRecognizerConfig(py::module *m) {
   py::class_<PyClass>(*m, "OnlineRecognizerConfig")
       .def(py::init<const FeatureExtractorConfig &,
                     const OnlineTransducerModelConfig &, const EndpointConfig &,
-                    bool>(),
+                    bool, const std::string &, int32_t>(),
            py::arg("feat_config"), py::arg("model_config"),
-           py::arg("endpoint_config"), py::arg("enable_endpoint"))
+           py::arg("endpoint_config"), py::arg("enable_endpoint"),
+           py::arg("decoding_method"), py::arg("max_active_paths"))
       .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("__str__", &PyClass::ToString);
 }
 

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

@@ -4,6 +4,7 @@
 
 #include "sherpa-onnx/python/csrc/sherpa-onnx.h"
 
+#include "sherpa-onnx/python/csrc/display.h"
 #include "sherpa-onnx/python/csrc/endpoint.h"
 #include "sherpa-onnx/python/csrc/features.h"
 #include "sherpa-onnx/python/csrc/online-recognizer.h"
@@ -19,6 +20,8 @@ PYBIND11_MODULE(_sherpa_onnx, m) {
   PybindOnlineStream(&m);
   PybindEndpoint(&m);
   PybindOnlineRecognizer(&m);
+
+  PybindDisplay(&m);
 }
 
 }  // namespace sherpa_onnx

sherpa-onnx/python/sherpa_onnx/__init__.py

@@ -1,9 +1,3 @@
-from _sherpa_onnx import (
-    EndpointConfig,
-    FeatureExtractorConfig,
-    OnlineRecognizerConfig,
-    OnlineStream,
-    OnlineTransducerModelConfig,
-)
+from _sherpa_onnx import Display
 
 from .online_recognizer import OnlineRecognizer

sherpa-onnx/python/sherpa_onnx/online_recognizer.py

@@ -32,6 +32,9 @@ class OnlineRecognizer(object):
         rule1_min_trailing_silence: int = 2.4,
         rule2_min_trailing_silence: int = 1.2,
         rule3_min_utterance_length: int = 20,
+        decoding_method: str = "greedy_search",
+        max_active_paths: int = 4,
+        max_feature_vectors: int = -1,
     ):
         """
         Please refer to
@@ -74,6 +77,14 @@ class OnlineRecognizer(object):
             Used only when enable_endpoint_detection is True. If the utterance
             length in seconds is larger than this value, we assume an endpoint
             is detected.
+          decoding_method:
+            Valid values are greedy_search, modified_beam_search.
+          max_active_paths:
+            Use only when decoding_method is modified_beam_search. It specifies
+            the maximum number of active paths during beam search.
+          max_feature_vectors:
+            Number of feature vectors to cache. -1 means to cache all feature
+            frames that have been processed.
         """
         _assert_file_exists(tokens)
         _assert_file_exists(encoder)
@@ -93,6 +104,7 @@ class OnlineRecognizer(object):
         feat_config = FeatureExtractorConfig(
             sampling_rate=sample_rate,
             feature_dim=feature_dim,
+            max_feature_vectors=max_feature_vectors,
         )
 
         endpoint_config = EndpointConfig(
@@ -106,6 +118,8 @@ class OnlineRecognizer(object):
             model_config=model_config,
             endpoint_config=endpoint_config,
             enable_endpoint=enable_endpoint_detection,
+            decoding_method=decoding_method,
+            max_active_paths=max_active_paths,
         )
 
         self.recognizer = _Recognizer(recognizer_config)