Records desktop/system audio using malgo, loopback WASAPI backend. Saves raw audio. golang

loopbackaudio.go

package main

import (
	"fmt"
	"os"

	"github.com/gen2brain/malgo"
)

func main() {
	var backends []malgo.Backend = []malgo.Backend{malgo.BackendWasapi}
	f, err := os.Create("audio")

	ctx, err := malgo.InitContext(backends, malgo.ContextConfig{}, func(message string) {
		fmt.Printf("LOG <%v>\n", message)
	})
	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}
	defer func() {
		_ = ctx.Uninit()
		ctx.Free()
	}()

	deviceConfig := malgo.DefaultDeviceConfig(malgo.Loopback)
	deviceConfig.Capture.Format = malgo.FormatF32
	deviceConfig.Capture.Channels = 2
	deviceConfig.SampleRate = 44100

	onRecvFrames := func(pSample2, pSample []byte, framecount uint32) {
		_, err := f.Write(pSample)
		if err != nil {
			fmt.Println(err)
			os.Exit(1)
		}

	}

	fmt.Println("Recording...")
	captureCallbacks := malgo.DeviceCallbacks{
		Data: onRecvFrames,
	}
	device, err := malgo.InitDevice(ctx.Context, deviceConfig, captureCallbacks)
	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}

	err = device.Start()
	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}

	fmt.Println("Press Enter to stop recording...")
	fmt.Scanln()

	device.Uninit()
	f.Close()
}