media_stream.addTrack(audio_track);
}
void setup_peer_connection() {
MediaConstraints media_constraints = new MediaConstraints();
media_constraints.mandatory.add(new MediaConstraints.KeyValuePair("DtlsSrtpKeyAgreement", "true"));
media_constraints.optional.add(new MediaConstraints.KeyValuePair("RtpDataChannels", "true"));
peer_connection = factory.createPeerConnection(ice_servers, media_constraints, this);
peer_connection.addStream(media_stream, new MediaConstraints());
}