private AudioRecord startMicRecording(int sampleRate, int channel, int encoding) {
appendLogTextView(mHandler, "start recording...\n");
int recordBufSize = AudioRecord.getMinBufferSize(sampleRate, channel, encoding);
AudioRecord record =
new AudioRecord(
MediaRecorder.AudioSource.MIC, sampleRate, channel, encoding, recordBufSize);
appendLogTextView(mHandler, " -> sample rate: " + sampleRate + "\n");
appendLogTextView(mHandler, " -> buffer size:" + recordBufSize + "\n");
int sid = record.getAudioSessionId();
if (false) {
appendLogTextView(mHandler, " -> do not use AEC.\n");
} else {
AcousticEchoCanceler aec = AcousticEchoCanceler.create(sid);
if (aec == null) {
appendLogTextView(mHandler, " -> create AEC error.\n");
} else {
appendLogTextView(mHandler, " > create AEC ok.\n");
}
}
record.startRecording();
appendLogTextView(mHandler, "start recording ok.\n");
return record;
}
/** Configures echo cancellation and noise suppression effects. */
@TargetApi(Build.VERSION_CODES.JELLY_BEAN)
private void configureEffects() {
if (!AndroidUtils.hasAPI(16)) return;
AudioSystem audioSystem =
AudioSystem.getAudioSystem(AudioSystem.LOCATOR_PROTOCOL_AUDIORECORD);
// Creates echo canceler if available
if (AcousticEchoCanceler.isAvailable()) {
AcousticEchoCanceler echoCanceller =
AcousticEchoCanceler.create(audioRecord.getAudioSessionId());
if (echoCanceller != null) {
echoCanceller.setEnableStatusListener(this);
echoCanceller.setEnabled(audioSystem.isEchoCancel());
logger.info("Echo cancellation: " + echoCanceller.getEnabled());
}
}
// Automatic gain control
if (AutomaticGainControl.isAvailable()) {
AutomaticGainControl agc = AutomaticGainControl.create(audioRecord.getAudioSessionId());
if (agc != null) {
agc.setEnableStatusListener(this);
agc.setEnabled(audioSystem.isAutomaticGainControl());
logger.info("Auto gain control: " + agc.getEnabled());
}
}
// Creates noise suppressor if available
if (NoiseSuppressor.isAvailable()) {
NoiseSuppressor noiseSuppressor = NoiseSuppressor.create(audioRecord.getAudioSessionId());
if (noiseSuppressor != null) {
noiseSuppressor.setEnableStatusListener(this);
noiseSuppressor.setEnabled(audioSystem.isDenoise());
logger.info("Noise suppressor: " + noiseSuppressor.getEnabled());
}
}
}
private boolean isAcousticEchoCancelerSupported() {
return AcousticEchoCanceler.isAvailable();
}