Inconsistent echo behavior on certain android devices

[davidzhao]

Reported in Slack community.

I’m playing a lot with RoomOptions.audioTrackCaptureDefaults flags and with LiveKitOverrides.javaAudioDeviceModuleCustomizer (to set UseHardwareAcousticEchoCanceler and UseHardwareNoiseSuppressor). Sometimes I find combination that seems to solve the problem, but the flags configurations end up being completely different on every device I try. On some other devices I don’t find a working configuration at all.

Examples

• Samsung S8 (with Android 9): this one generates echo for all the other participants in the room if the audioTrackCaptureDefaults are true, but it doesn’t if they are false
• pixel 2 we need to enable hardware cancellation not to get echoes & audio artifacts (by setting UseHardwareAcousticEchoCanceler to true in the audio module)

[symphonybiz]

Hello! I think I managed to solve it for all my use cases/devices by not touching the audioTrackCaptureDefaults and only tweaking the setUseHardwareAcousticEchoCanceler() in the JavaAudioDeviceModule. I connect by doing something like this:

LiveKit.connect(
            context, url, token,
            roomOptions = RoomOptions(adaptiveStream = true),
            overrides = LiveKitOverrides(
                javaAudioDeviceModuleCustomizer = { builder ->
                    val useHardwareAudioProcessing = Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q
                    builder.setUseHardwareAcousticEchoCanceler(useHardwareAudioProcessing)
                        .setUseHardwareNoiseSuppressor(useHardwareAudioProcessing)
                }
            )
        )

[davidliu]

@symphonybiz If it's not too much trouble, could you list the devices this worked on?

[symphonybiz]

Sure:

• Samsung Galaxy S8 (Android 9)
• Pixel 2 (Android 11)
• Sony Xperia Z5 Compact (Android 7)
• Xiaomi Mi 9T (Android 11)

[davidzhao]

@symphonybiz how did you get echo to reproduce? Is this by holding two devices close to each other so they are picking up each other's feedback?

[symphonybiz]

@davidzhao no, actually the opposite. I put one in a different room.

I encountered 2 types of "echo": one is basically a single repetition of what's being said coming back from the offending device, while the other is a very noisy feedback loop. From the Samsung s8 I would get the first type, while from the Sony Xperia I would get the other.

[davidliu]

@symphonybiz just to confirm, the proposed solution is to turn on the hardware cancellers in devices Q and above?

This issue seems to imply the opposite, so just want to confirm.

[symphonybiz]

yes @davidliu this is what it seems to work for us: disabling HW cancellation on < API 29

[symphonybiz]

@davidliu from my POV this can be closed, because we're using the javaAudioDeviceModuleCustomizer customization above and have no problems now