Android 4.2.2 - No Microphone Input

[mantao]

I'm facing an issue using Android 4.2.2 as a guest on MS Windows 7 Professional SP1 as host with VirtualBox 4.3.26 The microphone and speaker are attached to a NVIDIA GeForce Card, and both sound input as well as output function perfectly on the host machine.

Sound output within the guest is working fine but there is no microphone input. The host audio driver is Windows DirectSound with SoundBlaster 16 as the audio controller.

Wonder if anyone has faced a similar issue, and if there are any suggestions to resolve the same.

[mpack]

ISTR that it's actually "line in" on the host that is directed to the guest.

p.s. This is not actually a guest OS question since the same answer applies to all guests.

[mantao]

Thanks mpack, but connecting the microphone to the "line-in" jack on the host, still doesn't result in any audible output in the guest.

I've tested using Microphone Amplifier, PCM Recorder as well as Smart Voice Recorder to no avail. The "line-in" is not muted in the host.

Am I missing the obvious?

[mpack]

SoundBlaster 16 is rather ancient (early '90s). Would Android really include drivers for that?

[mantao]

Am facing the same issue whether I select ICH AC97 or Intel HD Audio, and opted for SoundBlaster 16 as there were some indications that this was the option that had worked for others.

The microphone, line-in as well as speakers work fine in the host. As the sound output to the speakers is working in the guest I'm assuming the sound card is being recognized.

The issue remains the sound input either by microphone or line-in ... the same being unmuted in the host.

[mpack]

The microphone, line-in as well as speakers work fine in the host.

Not surprising, since the host presumably has the correct drivers.

Your guest needs to have correct drivers too, but this time for whatever audio hardware you choose to simulate. You mention trying various audio simulation options, but don't mentioning checking that your Android guest had appropriate drivers for these choices? - and don't ask me how to do that, since I'm not an Android expert. You'd need to ask on an Android forum.

VirtualBox is responsible for providing a simulated PC. We know that the simulated audio works because others guest OSs can use it just fine.

Note that Android is not a simulated guest. One consequence of that is that VirtualBox has no Android template. A template typically chooses to simulate hardware which the targetted guest OS is known to have native drivers for. If you go for an unsupported guest then you have to solve those problems yourself. However you needn't do it all yourself: if you Google for "android virtualbox" you'll find that others have done this before.

[mantao]

Okay - I finally managed to get the microphone functioning in Android 4.4.4 guest using ICH AC97 audio setting in VirtualBox 4.3.26 on MS Windows 7 Professional SP1 host, by issuing the command "alsa_amixer -c 0 set Line 100 unmute" in root.

Trouble is doing so for some reason cause the microphone to get disabled in the host, even when the microphone is not being "used" in the guest!