Android AudioRecord example [closed]

Question

I am designing an Android app and I need to implement an AudioRecord class to record the user's sound. After some research (that didn't provide enough information) and few failed attempts, I was wondering if anyone could help me by posting an example (code) on how to capture high quality sound using AudioRecord. I would really appreciate it. Thank you

Answer 1

Here is an end to end solution I implemented for streaming Android microphone audio to a server for playback: Android AudioRecord to Server over UDP Playback Issues

Answer 2

Here I am posting you the some code example which record good quality of sound using AudioRecord API.

Note: If you use in emulator the sound quality will not much good because we are using sample rate 8k which only supports in emulator. In device use sample rate to 44.1k for better quality.

public class Audio_Record extends Activity {     private static final int RECORDER_SAMPLERATE = 8000;     private static final int RECORDER_CHANNELS = AudioFormat.CHANNEL_IN_MONO;     private static final int RECORDER_AUDIO_ENCODING = AudioFormat.ENCODING_PCM_16BIT;     private AudioRecord recorder = null;     private Thread recordingThread = null;     private boolean isRecording = false;      @Override     public void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.main);          setButtonHandlers();         enableButtons(false);          int bufferSize = AudioRecord.getMinBufferSize(RECORDER_SAMPLERATE,                 RECORDER_CHANNELS, RECORDER_AUDIO_ENCODING);      }      private void setButtonHandlers() {         ((Button) findViewById(R.id.btnStart)).setOnClickListener(btnClick);         ((Button) findViewById(R.id.btnStop)).setOnClickListener(btnClick);     }      private void enableButton(int id, boolean isEnable) {         ((Button) findViewById(id)).setEnabled(isEnable);     }      private void enableButtons(boolean isRecording) {         enableButton(R.id.btnStart, !isRecording);         enableButton(R.id.btnStop, isRecording);     }      int BufferElements2Rec = 1024; // want to play 2048 (2K) since 2 bytes we use only 1024     int BytesPerElement = 2; // 2 bytes in 16bit format      private void startRecording() {          recorder = new AudioRecord(MediaRecorder.AudioSource.MIC,                 RECORDER_SAMPLERATE, RECORDER_CHANNELS,                 RECORDER_AUDIO_ENCODING, BufferElements2Rec * BytesPerElement);          recorder.startRecording();         isRecording = true;         recordingThread = new Thread(new Runnable() {             public void run() {                 writeAudioDataToFile();             }         }, "AudioRecorder Thread");         recordingThread.start();     }          //convert short to byte     private byte[] short2byte(short[] sData) {         int shortArrsize = sData.length;         byte[] bytes = new byte[shortArrsize * 2];         for (int i = 0; i < shortArrsize; i++) {             bytes[i * 2] = (byte) (sData[i] & 0x00FF);             bytes[(i * 2) + 1] = (byte) (sData[i] >> 8);             sData[i] = 0;         }         return bytes;      }      private void writeAudioDataToFile() {         // Write the output audio in byte          String filePath = "/sdcard/voice8K16bitmono.pcm";         short sData[] = new short[BufferElements2Rec];          FileOutputStream os = null;         try {             os = new FileOutputStream(filePath);         } catch (FileNotFoundException e) {             e.printStackTrace();         }          while (isRecording) {             // gets the voice output from microphone to byte format              recorder.read(sData, 0, BufferElements2Rec);             System.out.println("Short writing to file" + sData.toString());             try {                 // // writes the data to file from buffer                 // // stores the voice buffer                 byte bData[] = short2byte(sData);                 os.write(bData, 0, BufferElements2Rec * BytesPerElement);             } catch (IOException e) {                 e.printStackTrace();             }         }         try {             os.close();         } catch (IOException e) {             e.printStackTrace();         }     }      private void stopRecording() {         // stops the recording activity         if (null != recorder) {             isRecording = false;             recorder.stop();             recorder.release();             recorder = null;             recordingThread = null;         }     }      private View.OnClickListener btnClick = new View.OnClickListener() {         public void onClick(View v) {             switch (v.getId()) {             case R.id.btnStart: {                 enableButtons(true);                 startRecording();                 break;             }             case R.id.btnStop: {                 enableButtons(false);                 stopRecording();                 break;             }             }         }     };      @Override     public boolean onKeyDown(int keyCode, KeyEvent event) {         if (keyCode == KeyEvent.KEYCODE_BACK) {             finish();         }         return super.onKeyDown(keyCode, event);     } } 

For more detail try this AUDIORECORD BLOG.

Happy Coding !!