Golang : Record voice(audio) from microphone to .WAV file

Problem:

You need to activate your microphone, record your voice and save the data into a .wav file from command line. How to do that?

Solution:

The code example below is combination of PortAudio (https://github.com/gordonklaus/portaudio/blob/master/examples/record.go) and Golang wave file reader/writer (https://github.com/zenwerk/go-wave/blob/master/example/writing.go).

What it does is to activate your default microphone and start recording. Encode the data([]byte) to the wave.Write() function and save to a given .wav file.

Here you go!

record2wave.go

 package main

 /*
  #include <stdio.h>
  #include <unistd.h>
  #include <termios.h>
  char getch(){
 char ch = 0;
 struct termios old = {0};
 fflush(stdout);
 if( tcgetattr(0, &old) < 0 ) perror("tcsetattr()");
 old.c_lflag &= ~ICANON;
 old.c_lflag &= ~ECHO;
 old.c_cc[VMIN] = 1;
 old.c_cc[VTIME] = 0;
 if( tcsetattr(0, TCSANOW, &old) < 0 ) perror("tcsetattr ICANON");
 if( read(0, &ch,1) < 0 ) perror("read()");
 old.c_lflag |= ICANON;
 old.c_lflag |= ECHO;
 if(tcsetattr(0, TCSADRAIN, &old) < 0) perror("tcsetattr ~ICANON");
 return ch;
  }
 */
 import "C"

 // stackoverflow.com/questions/14094190/golang-function-similar-to-getchar

 import (
 "fmt"
 "github.com/gordonklaus/portaudio"
 wave "github.com/zenwerk/go-wave"
 "math/rand"
 "os"
 "strings"
 "time"
 )

 func errCheck(err error) {

 if err != nil {
 panic(err)
 }
 }

 func main() {

 if len(os.Args) != 2 {
 fmt.Printf("Usage : %s <audiofilename.wav>\n", os.Args[0])
 os.Exit(0)
 }

 audioFileName := os.Args[1]

 fmt.Println("Recording. Press ESC to quit.")

 if !strings.HasSuffix(audioFileName, ".wav") {
 audioFileName += ".wav"
 }
 waveFile, err := os.Create(audioFileName)
 errCheck(err)

 // www.people.csail.mit.edu/hubert/pyaudio/  - under the Record tab
 inputChannels := 1
 outputChannels := 0
 sampleRate := 44100
 framesPerBuffer := make([]byte, 64)

 // init PortAudio

 portaudio.Initialize()
 //defer portaudio.Terminate()

 stream, err := portaudio.OpenDefaultStream(inputChannels, outputChannels, float64(sampleRate), len(framesPerBuffer), framesPerBuffer)
 errCheck(err)
 //defer stream.Close()

 // setup Wave file writer

 param := wave.WriterParam{
 Out: waveFile,
 Channel: inputChannels,
 SampleRate: sampleRate,
 BitsPerSample: 8, // if 16, change to WriteSample16()
 }

 waveWriter, err := wave.NewWriter(param)
 errCheck(err)

 //defer waveWriter.Close()

 go func() {
 key := C.getch()
 fmt.Println()
 fmt.Println("Cleaning up ...")
 if key == 27 {
 // better to control
 // how we close then relying on defer
 waveWriter.Close()
 stream.Close()
 portaudio.Terminate()
 fmt.Println("Play", audioFileName, "with a audio player to hear the result.")
 os.Exit(0)

 }

 }()

 // recording in progress ticker. From good old DOS days.
 ticker := []string{
 "-",
 "\\",
 "/",
 "|",
 }
 rand.Seed(time.Now().UnixNano())

 // start reading from microphone
 errCheck(stream.Start())
 for {
 errCheck(stream.Read())

 fmt.Printf("\rRecording is live now. Say something to your microphone! [%v]", ticker[rand.Intn(len(ticker)-1)])

 // write to wave file
 _, err := waveWriter.Write([]byte(framesPerBuffer)) // WriteSample16 for 16 bits
 errCheck(err)
 }
 errCheck(stream.Stop())
 }

References:

https://godoc.org/github.com/gordonklaus/portaudio

http://people.csail.mit.edu/hubert/pyaudio/