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androidwebrtcmicrophonewebrtc-android

WebRTC Android: sound from phone speaker is going into conference through phone mic and causing echo

In some mobile devices(like Motorola One Power - Android 10, Redmi Note 5 Pro - Android 7.1.2), sound from the phone speaker is going into the conference through the phone mic and causes an echo. This echo issue is coming only when the Phone Speaker is in the ON state.

I have used MODE_IN_COMMUNICATION mode of AudioManager:

mAudioManager = (AudioManager) getSystemService(AUDIO_SERVICE);
mAudioManager.setMode(AudioManager.MODE_IN_COMMUNICATION);

Also, used below audio constraints to create Audio Source by using createAudioSource() API of PeerConnectionFactory:

audioConstraints = new MediaConstraints();
audioConstraints.mandatory.add(new MediaConstraints.KeyValuePair("googEchoCancellation", "true"));
audioConstraints.mandatory.add(new MediaConstraints.KeyValuePair("googAutoGainControl", "true"));
audioConstraints.mandatory.add(new MediaConstraints.KeyValuePair("googHighpassFilter", "true"));
audioConstraints.mandatory.add(new MediaConstraints.KeyValuePair("googNoiseSuppression", "true"));

Any help or guidance in resolving the issue will be well appreciated.

Solution

  • Some phones can't do hardware echo cancellation, even though they advertise it's available. Redmi Note 5 is definitely one of them, take a look at https://github.com/signalapp/Signal-Android/blob/master/app/src/main/java/org/thoughtcrime/securesms/ApplicationContext.java, search for HARDWARE_AEC_BLACKLIST. So, to enable WebRTC AEC, use below methods of JavaAudioDeviceModule.class

    setUseHardwareAcousticEchoCanceler(false)       
setUseHardwareNoiseSuppressor(false)

    (For reference, please have a look into createJavaAudioDevice() of PeerConnectionClient.java - Checkout official android example on googlesource.com