Add microphone support for offline recognizer (#104)

@@ -107,6 +107,11 @@ if(SHERPA_ONNX_ENABLE_PORTAUDIO)
     microphone.cc
   )
 
+  add_executable(sherpa-onnx-microphone-offline
+    sherpa-onnx-microphone-offline.cc
+    microphone.cc
+  )
+
   if(BUILD_SHARED_LIBS)
     set(PA_LIB portaudio)
   else()
@@ -114,8 +119,15 @@ if(SHERPA_ONNX_ENABLE_PORTAUDIO)
   endif()
 
   target_link_libraries(sherpa-onnx-microphone PRIVATE ${PA_LIB} sherpa-onnx-core)
+  target_link_libraries(sherpa-onnx-microphone-offline PRIVATE ${PA_LIB} sherpa-onnx-core)
 
-  install(TARGETS sherpa-onnx-microphone DESTINATION bin)
+  install(
+    TARGETS
+      sherpa-onnx-microphone
+      sherpa-onnx-microphone-offline
+    DESTINATION
+      bin
+  )
 endif()
 
 if(SHERPA_ONNX_ENABLE_WEBSOCKET)

+// sherpa-onnx/csrc/sherpa-onnx-microphone-offline.cc
+//
+// Copyright (c)  2022-2023  Xiaomi Corporation
+
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <algorithm>
+#include <cctype>  // std::tolower
+#include <thread>  // NOLINT
+
+#include "portaudio.h"  // NOLINT
+#include "sherpa-onnx/csrc/macros.h"
+#include "sherpa-onnx/csrc/microphone.h"
+#include "sherpa-onnx/csrc/offline-recognizer.h"
+
+enum class State {
+  kIdle,
+  kRecording,
+  kDecoding,
+};
+
+State state = State::kIdle;
+
+// true to stop the program and exit
+bool stop = false;
+
+std::vector<float> samples;
+std::mutex samples_mutex;
+
+static void DetectKeyPress() {
+  SHERPA_ONNX_LOGE("Press Enter to start");
+  int32_t key;
+  while (!stop && (key = getchar())) {
+    if (key != 0x0a) {
+      continue;
+    }
+
+    switch (state) {
+      case State::kIdle:
+        SHERPA_ONNX_LOGE("Start recording. Press Enter to stop recording");
+        state = State::kRecording;
+        {
+          std::lock_guard<std::mutex> lock(samples_mutex);
+          samples.clear();
+        }
+        break;
+      case State::kRecording:
+        SHERPA_ONNX_LOGE("Stop recording. Decoding ...");
+        state = State::kDecoding;
+        break;
+      case State::kDecoding:
+        break;
+    }
+  }
+}
+
+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) {
+  std::lock_guard<std::mutex> lock(samples_mutex);
+
+  auto p = reinterpret_cast<const float *>(input_buffer);
+  samples.insert(samples.end(), p, p + frames_per_buffer);
+
+  return stop ? paComplete : paContinue;
+}
+
+static void Handler(int32_t sig) {
+  stop = true;
+  fprintf(stderr, "\nCaught Ctrl + C. Press Enter to exit\n");
+}
+
+int32_t main(int32_t argc, char *argv[]) {
+  signal(SIGINT, Handler);
+
+  const char *kUsageMessage = R"usage(
+This program uses non-streaming models with microphone for speech recognition.
+Usage:
+
+(1) Transducer from icefall
+
+  ./bin/sherpa-onnx-microphone-offline \
+    --tokens=/path/to/tokens.txt \
+    --encoder=/path/to/encoder.onnx \
+    --decoder=/path/to/decoder.onnx \
+    --joiner=/path/to/joiner.onnx \
+    --num-threads=2 \
+    --decoding-method=greedy_search
+
+(2) Paraformer from FunASR
+
+  ./bin/sherpa-onnx-microphone-offline \
+    --tokens=/path/to/tokens.txt \
+    --paraformer=/path/to/model.onnx \
+    --num-threads=2 \
+    --decoding-method=greedy_search
+
+Default value for num_threads is 2.
+Valid values for decoding_method: greedy_search.
+
+Please refer to
+https://k2-fsa.github.io/sherpa/onnx/pretrained_models/index.html
+for a list of pre-trained models to download.
+)usage";
+
+  sherpa_onnx::ParseOptions po(kUsageMessage);
+  sherpa_onnx::OfflineRecognizerConfig config;
+  config.Register(&po);
+
+  po.Read(argc, argv);
+  if (po.NumArgs() != 0) {
+    po.PrintUsage();
+    exit(EXIT_FAILURE);
+  }
+
+  fprintf(stderr, "%s\n", config.ToString().c_str());
+
+  if (!config.Validate()) {
+    fprintf(stderr, "Errors in config!\n");
+    return -1;
+  }
+
+  SHERPA_ONNX_LOGE("Creating recognizer ...");
+  sherpa_onnx::OfflineRecognizer recognizer(config);
+  SHERPA_ONNX_LOGE("Recognizer created!");
+
+  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;
+  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, nullptr);
+  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::thread t(DetectKeyPress);
+  while (!stop) {
+    switch (state) {
+      case State::kIdle:
+        break;
+      case State::kRecording:
+        break;
+      case State::kDecoding: {
+        std::vector<float> buf;
+        {
+          std::lock_guard<std::mutex> lock(samples_mutex);
+          buf = std::move(samples);
+        }
+
+        auto s = recognizer.CreateStream();
+        s->AcceptWaveform(sample_rate, buf.data(), buf.size());
+        recognizer.DecodeStream(s.get());
+        SHERPA_ONNX_LOGE("Decoding Done! Result is:");
+        SHERPA_ONNX_LOGE("%s", s->GetResult().text.c_str());
+
+        state = State::kIdle;
+        SHERPA_ONNX_LOGE("Press Enter to start");
+        break;
+      }
+    }
+
+    Pa_Sleep(20);  // sleep for 20ms
+  }
+  t.join();
+
+  err = Pa_CloseStream(stream);
+  if (err != paNoError) {
+    fprintf(stderr, "portaudio error: %s\n", Pa_GetErrorText(err));
+    exit(EXIT_FAILURE);
+  }
+
+  return 0;
+}

@@ -66,6 +66,7 @@ for a list of pre-trained models to download.
     return -1;
   }
 
+  fprintf(stderr, "Creating recognizer ...\n");
   sherpa_onnx::OfflineRecognizer recognizer(config);
 
   auto begin = std::chrono::steady_clock::now();