Add endpointing (#54)

sherpa-onnx/csrc/sherpa-onnx-alsa.cc

@@ -0,0 +1,142 @@
+// sherpa-onnx/csrc/sherpa-onnx-alsa.cc
+//
+// Copyright (c)  2022-2023  Xiaomi Corporation
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <algorithm>
+#include <cctype>  // std::tolower
+#include <cstdint>
+
+#include "sherpa-onnx/csrc/alsa.h"
+#include "sherpa-onnx/csrc/display.h"
+#include "sherpa-onnx/csrc/online-recognizer.h"
+
+bool stop = false;
+
+static void Handler(int sig) {
+  stop = true;
+  fprintf(stderr, "\nCaught Ctrl + C. Exiting...\n");
+}
+
+int main(int32_t argc, char *argv[]) {
+  if (argc < 6 || argc > 7) {
+    const char *usage = R"usage(
+Usage:
+  ./bin/sherpa-onnx-alsa \
+    /path/to/tokens.txt \
+    /path/to/encoder.onnx \
+    /path/to/decoder.onnx \
+    /path/to/joiner.onnx \
+    device_name \
+    [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.
+
+The device name specifies which microphone to use in case there are several
+on you system. You can use
+
+  arecord -l
+
+to find all available microphones on your computer. For instance, if it outputs
+
+**** List of CAPTURE Hardware Devices ****
+card 3: UACDemoV10 [UACDemoV1.0], device 0: USB Audio [USB Audio]
+  Subdevices: 1/1
+  Subdevice #0: subdevice #0
+
+and if you want to select card 3 and the device 0 on that card, please use:
+
+  hw:3,0
+
+as the device_name.
+)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];
+
+  const char *device_name = argv[5];
+
+  config.model_config.num_threads = 2;
+  if (argc == 7 && atoi(argv[6]) > 0) {
+    config.model_config.num_threads = atoi(argv[6]);
+  }
+
+  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);
+
+  int32_t expected_sample_rate = config.feat_config.sampling_rate;
+
+  sherpa_onnx::Alsa alsa(device_name);
+  fprintf(stderr, "Use recording device: %s\n", device_name);
+
+  if (alsa.GetExpectedSampleRate() != expected_sample_rate) {
+    fprintf(stderr, "sample rate: %d != %d\n", alsa.GetExpectedSampleRate(),
+            expected_sample_rate);
+    exit(-1);
+  }
+
+  int32_t chunk = 0.1 * alsa.GetActualSampleRate();
+
+  std::string last_text;
+
+  auto stream = recognizer.CreateStream();
+
+  sherpa_onnx::Display display;
+
+  int32_t segment_index = 0;
+  while (!stop) {
+    const std::vector<float> samples = alsa.Read(chunk);
+
+    stream->AcceptWaveform(expected_sample_rate, samples.data(),
+                           samples.size());
+
+    while (recognizer.IsReady(stream.get())) {
+      recognizer.DecodeStream(stream.get());
+    }
+
+    auto text = recognizer.GetResult(stream.get()).text;
+
+    bool is_endpoint = recognizer.IsEndpoint(stream.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(stream.get());
+    }
+  }
+
+  return 0;
+}