我正试图在Android上一次录制和播放音频。但录制的音频有更多像zzzzz一样的噪音......
我想过滤音频中的噪音。我的代码是
private void record() {
// Get the minimum buffer size required for the successful creation
// of an AudioRecord object.
int N = AudioRecord.getMinBufferSize(RECORDER_SAMPLERATE, RECORDER_CHANNELS, RECORDER_AUDIO_ENCODING);
audioTrack = new AudioTrack(AudioManager.STREAM_MUSIC, 8000, AudioFormat.CHANNEL_OUT_MONO, AudioFormat.ENCODING_PCM_16BIT, N * 10,
AudioTrack.MODE_STREAM);
AudioRecord audioRecorder = null;
int bufferSizeInShorts;
int shortsRead;
short audioBuffer[];
try {
bufferSizeInShorts = (N / 2);
// Initialize Audio Recorder.
audioRecorder = new AudioRecord(MediaRecorder.AudioSource.VOICE_RECOGNITION, RECORDER_SAMPLERATE, RECORDER_CHANNELS,
RECORDER_AUDIO_ENCODING, N * 10);
NoiseSuppressor.create(audioRecorder.getAudioSessionId());
// Start Recording.
audioBuffer = new short[bufferSizeInShorts];
audioRecorder.startRecording();
isRecording = true;
audioTrack.play();
while (isRecording) {
shortsRead = audioRecorder.read(audioBuffer, 0, bufferSizeInShorts);
if (shortsRead == AudioRecord.ERROR_BAD_VALUE || shortsRead == AudioRecord.ERROR_INVALID_OPERATION) {
Log.e("record()", "Error reading from microphone.");
isRecording = false;
break;
}
audioTrack.write(audioBuffer, 0, audioBuffer.length);
}
} finally {
if (audioRecorder != null) {
audioRecorder.stop();
audioRecorder.release();
}
if (audioTrack != null) {
audioTrack.stop();
audioTrack.release();
}
}
}
如何过滤背景噪音，以便我只能听到声音。
答案 0 :(得分：0)
清晰优质的声音 尝试使用 * 44100或16000采样率*
注意： - 44100采样率可能无法在Amulator上使用。 并确保您有正确的标题格式
忽略与此
无关的变量使用AudioRecord类录制
public class Mediarec extends Activity {
public static final int SAMPLE_RATE = 44100;
public static int count=0;
private AudioRecord mRecorder;
private File mRecording;
private byte[] mBuffer;
private final String startRecordingLabel = "Start recording";
private final String stopRecordingLabel = "Stop recording";
private boolean mIsRecording = false;
OnGainSelected gs;
SharedPreferences sp;
String Shared = "Shared";
String stored_gain;
AudioManager am;
protected int bitsPerSamples = 16;
private Button show_gain;
Switch bluetooth;
Button button;
@Override
public void onCreate(final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_mediarec);
sp = getSharedPreferences(Shared, Context.MODE_PRIVATE);
button = (Button) findViewById(R.id.start);
bluetooth = (Switch) findViewById(R.id.switch1);
initRecorder();
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(final View v) {
Log.d("Normal()","Recordng frm Normal MIC");
Normal();
}
});
}
protected void Normal() {
// TODO Auto-generated method stub
if (!mIsRecording ) {
button.setText(stopRecordingLabel);
mIsRecording = true;
Log.d("Normal","Rec Started");
mRecorder.startRecording();
mRecording = getFile("raw");
startBufferedWrite(mRecording);
} else {
button.setText(startRecordingLabel);
mIsRecording = false;
mRecorder.stop();
File waveFile = getFile("wav");
try {
rawToWave(mRecording, waveFile);
} catch (IOException e) {
Toast.makeText(Mediarec.this, e.getMessage(),
Toast.LENGTH_SHORT).show();
}
Toast.makeText(Mediarec.this, "Recorded to " + waveFile.getName(),
Toast.LENGTH_SHORT).show();
}
}
@Override
public void onDestroy() {
mRecorder.release();
super.onDestroy();
}
private void initRecorder() {
int bufferSize = AudioRecord.getMinBufferSize(SAMPLE_RATE,
AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT);
mBuffer = new byte[bufferSize];
mRecorder = new AudioRecord(MediaRecorder.AudioSource.MIC, SAMPLE_RATE,
AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT,
bufferSize);
}
private void startBufferedWrite(final File file) {
new Thread(new Runnable() {
@Override
public void run() {
DataOutputStream output = null;
try {
output = new DataOutputStream(new BufferedOutputStream(
new FileOutputStream(file)));
while (mIsRecording) {
int readSize = mRecorder.read(mBuffer, 0,
mBuffer.length);
for (int i = 0; i < readSize; i++) {
output.write(mBuffer[i]);
}
}
} catch (IOException e) {
Toast.makeText(Mediarec.this, e.getMessage(),
Toast.LENGTH_SHORT).show();
} finally {
if (output != null) {
try {
output.flush();
} catch (IOException e) {
Toast.makeText(Mediarec.this, e.getMessage(),
Toast.LENGTH_SHORT).show();
} finally {
try {
output.close();
} catch (IOException e) {
Toast.makeText(Mediarec.this, e.getMessage(),
Toast.LENGTH_SHORT).show();
}
}
}
}
}
}).start();
}
private void rawToWave(final File rawFile, final File waveFile)
throws IOException {
byte[] rawData = new byte[(int) rawFile.length()];
DataInputStream input = null;
try {
input = new DataInputStream(new FileInputStream(rawFile));
input.read(rawData);
} finally {
if (input != null) {
input.close();
}
}
DataOutputStream output = null;
try {
output = new DataOutputStream(new FileOutputStream(waveFile));
// WAVE header
// see http://ccrma.stanford.edu/courses/422/projects/WaveFormat/
writeString(output, "RIFF"); // chunk id
writeInt(output, 36 + rawData.length); // chunk size
writeString(output, "WAVE"); // format
writeString(output, "fmt "); // subchunk 1 id
writeInt(output, 16); // subchunk 1 size
writeShort(output, (byte) 1); // audio format (1 = PCM)
writeShort(output, (byte) 1); // number of channels
writeInt(output, SAMPLE_RATE); // sample rate
writeInt(output, SAMPLE_RATE * 2); // byte rate
writeShort(output, (byte) 2); // block align
writeShort(output, (byte) 16); // bits per sample
writeString(output, "data"); // subchunk 2 id
writeInt(output, rawData.length); // subchunk 2 size
output.write(rawData);
} catch (Exception e) {
Toast.makeText(getApplicationContext(), "" + e, Toast.LENGTH_LONG)
.show();
} finally {
if (output != null) {
output.close();
}
}
}
private File getFile(final String suffix) {
Time time = new Time();
time.setToNow();
return new File(Environment.getExternalStorageDirectory(),
time.format("%Y%m%d%H%M%S") + "." + suffix);
}
private void writeInt(final DataOutputStream output, final int value)
throws IOException {
output.write(value >> 0);
output.write(value >> 8);
output.write(value >> 16);
output.write(value >> 24);
}
private void writeShort(final DataOutputStream output, final short value)
throws IOException {
output.write(value >> 0);
output.write(value >> 8);
}
private void writeString(final DataOutputStream output, final String value)
throws IOException {
for (int i = 0; i < value.length(); i++) {
output.write(value.charAt(i));
}
}
}
答案 1 :(得分：0)
这种噪声来自您或您的电话，就像天线一样，用于接收来自房屋布线的电磁波，它们的频率为50-60Hz，您可以使用高通数字滤波器对其进行过滤（在将信号放回去之前在信号上施加的等式）