add portaudio for reading microphones (#55)

@@ -15,6 +15,7 @@ option(SHERPA_ONNX_ENABLE_PYTHON "Whether to build Python" OFF)
 option(SHERPA_ONNX_ENABLE_TESTS "Whether to build tests" OFF)
 option(SHERPA_ONNX_ENABLE_CHECK "Whether to build with assert" ON)
 option(BUILD_SHARED_LIBS "Whether to build shared libraries" OFF)
+option(SHERPA_ONNX_ENABLE_PORTAUDIO "Whether to build with portaudio" ON)
 
 set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib")
 set(CMAKE_LIBRARY_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib")
@@ -49,6 +50,7 @@ message(STATUS "BUILD_SHARED_LIBS ${BUILD_SHARED_LIBS}")
 message(STATUS "SHERPA_ONNX_ENABLE_PYTHON ${SHERPA_ONNX_ENABLE_PYTHON}")
 message(STATUS "SHERPA_ONNX_ENABLE_TESTS ${SHERPA_ONNX_ENABLE_TESTS}")
 message(STATUS "SHERPA_ONNX_ENABLE_CHECK ${SHERPA_ONNX_ENABLE_CHECK}")
+message(STATUS "SHERPA_ONNX_ENABLE_PORTAUDIO ${SHERPA_ONNX_ENABLE_PORTAUDIO}")
 
 set(CMAKE_CXX_STANDARD 14 CACHE STRING "The C++ version to be used.")
 set(CMAKE_CXX_EXTENSIONS OFF)
@@ -68,6 +70,10 @@ list(APPEND CMAKE_MODULE_PATH ${CMAKE_SOURCE_DIR}/cmake)
 include(kaldi-native-fbank)
 include(onnxruntime)
 
+if(SHERPA_ONNX_ENABLE_PORTAUDIO)
+  include(portaudio)
+endif()
+
 if(SHERPA_ONNX_ENABLE_PYTHON)
   include(pybind11)
 endif()

+function(download_portaudio)
+  include(FetchContent)
+
+  set(portaudio_URL  "http://files.portaudio.com/archives/pa_stable_v190700_20210406.tgz")
+  set(portaudio_HASH "SHA256=47efbf42c77c19a05d22e627d42873e991ec0c1357219c0d74ce6a2948cb2def")
+
+  # If you don't have access to the Internet, please download it to your
+  # local drive and modify the following line according to your needs.
+  set(possible_file_locations
+    $ENV{HOME}/Downloads/pa_stable_v190700_20210406.tgz
+    $ENV{HOME}/asr/pa_stable_v190700_20210406.tgz
+    ${PROJECT_SOURCE_DIR}/pa_stable_v190700_20210406.tgz
+    ${PROJECT_BINARY_DIR}/pa_stable_v190700_20210406.tgz
+    /tmp/pa_stable_v190700_20210406.tgz
+  )
+
+  foreach(f IN LISTS possible_file_locations)
+    if(EXISTS ${f})
+      set(portaudio_URL  "file://${f}")
+      break()
+    endif()
+  endforeach()
+
+  if(BUILD_SHARED_LIBS)
+    set(PA_BUILD_SHARED ON CACHE BOOL "" FORCE)
+    set(PA_BUILD_STATIC OFF CACHE BOOL "" FORCE)
+  else()
+    set(PA_BUILD_SHARED OFF CACHE BOOL "" FORCE)
+    set(PA_BUILD_STATIC ON CACHE BOOL "" FORCE)
+  endif()
+
+  FetchContent_Declare(portaudio
+    URL               ${portaudio_URL}
+    URL_HASH          ${portaudio_HASH}
+  )
+
+  FetchContent_GetProperties(portaudio)
+  if(NOT portaudio_POPULATED)
+    message(STATUS "Downloading portaudio from ${portaudio_URL}")
+    FetchContent_Populate(portaudio)
+  endif()
+  message(STATUS "portaudio is downloaded to ${portaudio_SOURCE_DIR}")
+  message(STATUS "portaudio's binary dir is ${portaudio_BINARY_DIR}")
+
+  if(APPLE)
+    set(CMAKE_MACOSX_RPATH ON) # to solve the following warning on macOS
+  endif()
+
+  add_subdirectory(${portaudio_SOURCE_DIR} ${portaudio_BINARY_DIR} EXCLUDE_FROM_ALL)
+endfunction()
+
+download_portaudio()
+
+# Note
+# See http://portaudio.com/docs/v19-doxydocs/tutorial_start.html
+# for how to use portaudio

@@ -65,6 +65,24 @@ if(SHERPA_ONNX_HAS_ALSA)
   install(TARGETS sherpa-onnx-alsa DESTINATION bin)
 endif()
 
+if(SHERPA_ONNX_ENABLE_PORTAUDIO)
+  add_executable(sherpa-onnx-microphone
+    sherpa-onnx-microphone.cc
+    microphone.cc
+  )
+
+  if(BUILD_SHARED_LIBS)
+    set(PA_LIB portaudio)
+  else()
+    set(PA_LIB portaudio_static)
+  endif()
+
+  target_link_libraries(sherpa-onnx-microphone PRIVATE ${PA_LIB} sherpa-onnx-core)
+
+  install(TARGETS sherpa-onnx-microphone DESTINATION bin)
+endif()
+
+
 if(SHERPA_ONNX_ENABLE_TESTS)
   set(sherpa_onnx_test_srcs
     cat-test.cc

+// sherpa-onnx/csrc/microphone.cc
+//
+// Copyright (c)  2022-2023  Xiaomi Corporation
+
+#include "sherpa-onnx/csrc/microphone.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "portaudio.h"  // NOLINT
+
+namespace sherpa_onnx {
+
+Microphone::Microphone() {
+  PaError err = Pa_Initialize();
+  if (err != paNoError) {
+    fprintf(stderr, "portaudio error: %s\n", Pa_GetErrorText(err));
+    exit(-1);
+  }
+}
+
+Microphone::~Microphone() {
+  PaError err = Pa_Terminate();
+  if (err != paNoError) {
+    fprintf(stderr, "portaudio error: %s\n", Pa_GetErrorText(err));
+    exit(-1);
+  }
+}
+
+}  // namespace sherpa_onnx

+// sherpa-onnx/csrc/microphone.h
+//
+// Copyright (c)  2022-2023  Xiaomi Corporation
+
+#ifndef SHERPA_ONNX_CSRC_MICROPHONE_H_
+#define SHERPA_ONNX_CSRC_MICROPHONE_H_
+
+namespace sherpa_onnx {
+
+class Microphone {
+ public:
+  Microphone();
+  ~Microphone();
+};
+
+}  // namespace sherpa_onnx
+
+#endif  // SHERPA_ONNX_CSRC_MICROPHONE_H_

+// sherpa-onnx/csrc/sherpa-onnx-microphone.cc
+//
+// Copyright (c)  2022-2023  Xiaomi Corporation
+
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <algorithm>
+#include <cctype>  // std::tolower
+
+#include "portaudio.h"  // NOLINT
+#include "sherpa-onnx/csrc/display.h"
+#include "sherpa-onnx/csrc/microphone.h"
+#include "sherpa-onnx/csrc/online-recognizer.h"
+
+bool stop = false;
+
+static int32_t RecordCallback(const void *input_buffer,
+                              void * /*output_buffer*/,
+                              unsigned long frames_per_buffer,  // NOLINT
+                              const PaStreamCallbackTimeInfo * /*time_info*/,
+                              PaStreamCallbackFlags /*status_flags*/,
+                              void *user_data) {
+  auto stream = reinterpret_cast<sherpa_onnx::OnlineStream *>(user_data);
+
+  stream->AcceptWaveform(16000, reinterpret_cast<const float *>(input_buffer),
+                         frames_per_buffer);
+
+  return stop ? paComplete : paContinue;
+}
+
+static void Handler(int32_t sig) {
+  stop = true;
+  fprintf(stderr, "\nCaught Ctrl + C. Exiting...\n");
+}
+
+int32_t main(int32_t argc, char *argv[]) {
+  if (argc < 5 || argc > 6) {
+    const char *usage = R"usage(
+Usage:
+  ./bin/sherpa-onnx-microphone \
+    /path/to/tokens.txt \
+    /path/to/encoder.onnx\
+    /path/to/decoder.onnx\
+    /path/to/joiner.onnx\
+    [num_threads]
+
+Please refer to
+https://k2-fsa.github.io/sherpa/onnx/pretrained_models/index.html
+for a list of pre-trained models to download.
+)usage";
+    fprintf(stderr, "%s\n", usage);
+    fprintf(stderr, "argc, %d\n", argc);
+
+    return 0;
+  }
+  signal(SIGINT, Handler);
+
+  sherpa_onnx::OnlineRecognizerConfig config;
+  config.tokens = argv[1];
+
+  config.model_config.debug = false;
+  config.model_config.encoder_filename = argv[2];
+  config.model_config.decoder_filename = argv[3];
+  config.model_config.joiner_filename = argv[4];
+
+  config.model_config.num_threads = 2;
+  if (argc == 6 && atoi(argv[5]) > 0) {
+    config.model_config.num_threads = atoi(argv[5]);
+  }
+
+  config.enable_endpoint = true;
+
+  config.endpoint_config.rule1.min_trailing_silence = 2.4;
+  config.endpoint_config.rule2.min_trailing_silence = 1.2;
+  config.endpoint_config.rule3.min_utterance_length = 300;
+
+  fprintf(stderr, "%s\n", config.ToString().c_str());
+
+  sherpa_onnx::OnlineRecognizer recognizer(config);
+  auto s = recognizer.CreateStream();
+
+  sherpa_onnx::Microphone mic;
+
+  PaDeviceIndex num_devices = Pa_GetDeviceCount();
+  fprintf(stderr, "Num devices: %d\n", num_devices);
+
+  PaStreamParameters param;
+
+  param.device = Pa_GetDefaultInputDevice();
+  if (param.device == paNoDevice) {
+    fprintf(stderr, "No default input device found\n");
+    exit(EXIT_FAILURE);
+  }
+  fprintf(stderr, "Use default device: %d\n", param.device);
+
+  const PaDeviceInfo *info = Pa_GetDeviceInfo(param.device);
+  fprintf(stderr, "  Name: %s\n", info->name);
+  fprintf(stderr, "  Max input channels: %d\n", info->maxInputChannels);
+
+  param.channelCount = 1;
+  param.sampleFormat = paFloat32;
+
+  param.suggestedLatency = info->defaultLowInputLatency;
+  param.hostApiSpecificStreamInfo = nullptr;
+  const float sample_rate = 16000;
+
+  PaStream *stream;
+  PaError err =
+      Pa_OpenStream(&stream, &param, nullptr, /* &outputParameters, */
+                    sample_rate,
+                    0,          // frames per buffer
+                    paClipOff,  // we won't output out of range samples
+                                // so don't bother clipping them
+                    RecordCallback, s.get());
+  if (err != paNoError) {
+    fprintf(stderr, "portaudio error: %s\n", Pa_GetErrorText(err));
+    exit(EXIT_FAILURE);
+  }
+
+  err = Pa_StartStream(stream);
+  fprintf(stderr, "Started\n");
+
+  if (err != paNoError) {
+    fprintf(stderr, "portaudio error: %s\n", Pa_GetErrorText(err));
+    exit(EXIT_FAILURE);
+  }
+
+  std::string last_text;
+  int32_t segment_index = 0;
+  sherpa_onnx::Display display;
+  while (!stop) {
+    while (recognizer.IsReady(s.get())) {
+      recognizer.DecodeStream(s.get());
+    }
+
+    auto text = recognizer.GetResult(s.get()).text;
+    bool is_endpoint = recognizer.IsEndpoint(s.get());
+
+    if (!text.empty() && last_text != text) {
+      last_text = text;
+
+      std::transform(text.begin(), text.end(), text.begin(),
+                     [](auto c) { return std::tolower(c); });
+
+      display.Print(segment_index, text);
+    }
+
+    if (!text.empty() && is_endpoint) {
+      ++segment_index;
+      recognizer.Reset(s.get());
+    }
+
+    Pa_Sleep(20);  // sleep for 20ms
+  }
+
+  err = Pa_CloseStream(stream);
+  if (err != paNoError) {
+    fprintf(stderr, "portaudio error: %s\n", Pa_GetErrorText(err));
+    exit(EXIT_FAILURE);
+  }
+
+  return 0;
+}