Capture (loopback) desktop audio

[nurdism]

Summary

I'd like to be able to capture desktop audio (or an output device)

Motivation

The idea (for me) would to be able to record and stream the desktops audio/video and do a screen cast with that.

Describe alternatives you've considered

The other solution would to find (or create) another lib to capture desktop audio

[nurdism]

it looks like this could be done with https://github.com/gen2brain/malgo (used in the microphone driver) I was doing my own research on this and this gen2brain/malgo#34 lead me to https://github.com/mackron/miniaudio/blob/master/examples/simple_loopback.c I am not competent enough in c to understand any of that. But anyone else looking into this feature, this might save you some time.

[nurdism]

After further reading, it seems miniaudio only supports loopback via WASAPI (windows) but for Linux/Unix systems you could look into https://github.com/gordonklaus/portaudio or https://github.com/sqp/pulseaudio

miniaudio supports the pulse audio backend so this should be possible

[ZeoWorks]

Did you ever get desktop audio working?

[nurdism]

Did you ever get desktop audio working?

I have not, I need to give it another shot. But have been unable to dedicate the time to figuring it out.

[Meonardo]

Hi @nurdism @ZeoWorks , I have managed to make capture the speaker sound working on Windows,
https://github.com/Meonardo/mediadevices/blob/master/pkg/driver/speaker/speaker.go

func getAudioTrack() (*mediadevices.AudioTrack, error) {
        // Currently I use the default speaker from the system, so the device filter will not work!
	// var deviceID = ""
	devices := mediadevices.EnumerateDevices()

	for _, device := range devices {
		if device.Kind == mediadevices.AudioOutput {
			log.Printf("Found Speaker: %s", device.Name)
			//deviceID = device.DeviceID
                        //break
		}
	}

	s, err := mediadevices.GetUserMedia(mediadevices.MediaStreamConstraints{
		Audio: func(c *mediadevices.MediaTrackConstraints) {
			//c.DeviceID = prop.String(deviceID)
		},
		Codec: element.audioCodecSelector,
	})

	if err != nil {
		log.Println("Audio track create failed", err)
		return nil, err
	} else {
		audioTrack := s.GetAudioTracks()[0].(*mediadevices.AudioTrack)
		return audioTrack, err
	}
}

Notice: I also made some changes of the malgo repo in my fork.
Hope this will help you.