Add Golang API for VAD (#708)

go-api-examples/vad/go.mod

@@ -0,0 +1,3 @@
+module vad
+
+go 1.12

go-api-examples/vad/main.go

@@ -0,0 +1,112 @@
+package main
+
+import (
+	"fmt"
+	"github.com/gordonklaus/portaudio"
+	sherpa "github.com/k2-fsa/sherpa-onnx-go/sherpa_onnx"
+	"log"
+)
+
+func main() {
+	log.SetFlags(log.LstdFlags | log.Lmicroseconds)
+
+	config := sherpa.VadModelConfig{}
+
+	// Please download silero_vad.onnx from
+	// https://github.com/snakers4/silero-vad/blob/master/files/silero_vad.onnx
+
+	config.SileroVad.Model = "./silero_vad.onnx"
+	config.SileroVad.Threshold = 0.5
+	config.SileroVad.MinSilenceDuration = 0.5
+	config.SileroVad.MinSpeechDuration = 0.25
+	config.SileroVad.WindowSize = 512
+	config.SampleRate = 16000
+	config.NumThreads = 1
+	config.Provider = "cpu"
+	config.Debug = 1
+
+	var bufferSizeInSeconds float32 = 5
+
+	vad := sherpa.NewVoiceActivityDetector(&config, bufferSizeInSeconds)
+	defer sherpa.DeleteVoiceActivityDetector(vad)
+
+	err := portaudio.Initialize()
+	if err != nil {
+		log.Fatalf("Unable to initialize portaudio: %v\n", err)
+	}
+	defer portaudio.Terminate()
+
+	default_device, err := portaudio.DefaultInputDevice()
+	if err != nil {
+		log.Fatal("Failed to get default input device: %v\n", err)
+	}
+	log.Printf("Selected default input device: %s\n", default_device.Name)
+	param := portaudio.StreamParameters{}
+	param.Input.Device = default_device
+	param.Input.Channels = 1
+	param.Input.Latency = default_device.DefaultLowInputLatency
+
+	param.SampleRate = float64(config.SampleRate)
+	param.FramesPerBuffer = 0
+	param.Flags = portaudio.ClipOff
+
+	// you can choose another value for 0.1 if you want
+	samplesPerCall := int32(param.SampleRate * 0.1) // 0.1 second
+	samples := make([]float32, samplesPerCall)
+
+	s, err := portaudio.OpenStream(param, samples)
+	if err != nil {
+		log.Fatalf("Failed to open the stream")
+	}
+
+	defer s.Close()
+	chk(s.Start())
+
+	log.Print("Started! Please speak")
+	printed := false
+
+	k := 0
+	for {
+		chk(s.Read())
+		vad.AcceptWaveform(samples)
+
+		if vad.IsSpeech() && !printed {
+			printed = true
+			log.Print("Detected speech\n")
+		}
+
+		if !vad.IsSpeech() {
+			printed = false
+		}
+
+		for !vad.IsEmpty() {
+			speechSegment := vad.Front()
+			vad.Pop()
+
+			duration := float32(len(speechSegment.Samples)) / float32(config.SampleRate)
+
+			audio := sherpa.GeneratedAudio{}
+			audio.Samples = speechSegment.Samples
+			audio.SampleRate = config.SampleRate
+
+			filename := fmt.Sprintf("seg-%d-%.2f-seconds.wav", k, duration)
+			ok := audio.Save(filename)
+			if ok {
+				log.Printf("Saved to %s", filename)
+			}
+
+			k += 1
+
+			log.Printf("Duration: %.2f seconds\n", duration)
+			log.Print("----------\n")
+		}
+	}
+
+	chk(s.Stop())
+}
+
+func chk(err error) {
+	if err != nil {
+		panic(err)
+	}
+}

go-api-examples/vad/run.sh

@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+
+
+if [ ! -f ./silero_vad.onnx ]; then
+  curl -SL -O https://github.com/snakers4/silero-vad/blob/master/files/silero_vad.onnx
+fi
+
+go mod tidy
+go build
+./vad