Recording .Wav with Android AudioRecorder
I have read a lot of pages about Android's AudioRecorder. You can see a list of them below the question.
I'm trying to record audio with AudioRecorder, but it's not working well.
public class MainActivity extends Activity {
AudioRecord ar = null;
int buffsize = 0;
int blockSize = 256;
boolean isRecording = false;
private Thread recordingThread = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void baslat(View v)
{
// when click to START
buffsize = AudioRecord.getMinBufferSize(44100, AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT);
ar = new AudioRecord(MediaRecorder.AudioSource.MIC, 44100, AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT, buffsize);
ar.startRecording();
isRecording = true;
recordingThread = new Thread(new Runnable() {
public void run() {
writeAudioDataToFile();
}
}, "AudioRecorder Thread");
recordingThread.start();
}
public void durdur(View v)
{
// When click to STOP
ar.stop();
isRecording = false;
}
private void writeAudioDataToFile() {
// Write the output audio in byte
String filePath = "/sdcard/voice8K16bitmono.wav";
short sData[] = new short[buffsize/2];
FileOutputStream os = null;
try {
os = new FileOutputStream(filePath);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
while (isRecording) {
// gets the voice output from microphone to byte format
ar.read(sData, 0, buffsize/2);
Log.d("eray","Short wirting to file" + sData.toString());
try {
// // writes the data to file from buffer
// // stores the voice buffer
byte bData[] = short2byte(sData);
os.write(bData, 0, buffsize);
} catch (IOException e) {
e.printStackTrace();
}
}
try {
os.close();
} catch (IOException e) {
e.printStackTrace();
}
}
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;
}
It's creating a .wav file but, when I try to listen to it, it's not opening. I'm getting a "file not supported" error. I've tried to play the file with quite a few media player applications.
NOTE : I have to use AudioRecorder instead of MediaRecorder because my app will be doing another process while recording (displaying an equalizer) .
Here is the list of pages that I've read about this subject:
- http://developer.android.com/reference/android/media/AudioRecord.html#read(short[],%20int,%20int)
- Android AudioRecord example
- http://audiorecordandroid.blogspot.in
- AudioRecord object not initializing
- Recording a wav file from the mic in Android - problems
- http://i-liger.com/article/android-wav-audio-recording
- Creating a WAV file from raw PCM data using the Android SDK
- Capturing Sound for Analysis and Visualizing Frequencies in Android
There are a lot of different ways to go about this. I've tried lots of them but nothing works for me. I've been working on this problem for about 6 hours now so I would appreciate a definitive answer, ideally some sample code.
Answer
I wrote a simple (by which you should read, not to professional standards) class to do this yesterday, and it works.
private class Wave {
private final int LONGINT = 4;
private final int SMALLINT = 2;
private final int INTEGER = 4;
private final int ID_STRING_SIZE = 4;
private final int WAV_RIFF_SIZE = LONGINT + ID_STRING_SIZE;
private final int WAV_FMT_SIZE = (4 * SMALLINT) + (INTEGER * 2) + LONGINT + ID_STRING_SIZE;
private final int WAV_DATA_SIZE = ID_STRING_SIZE + LONGINT;
private final int WAV_HDR_SIZE = WAV_RIFF_SIZE + ID_STRING_SIZE + WAV_FMT_SIZE + WAV_DATA_SIZE;
private final short PCM = 1;
private final int SAMPLE_SIZE = 2;
int cursor, nSamples;
byte[] output;
public Wave(int sampleRate, short nChannels, short[] data, int start, int end) {
nSamples = end - start + 1;
cursor = 0;
output = new byte[nSamples * SMALLINT + WAV_HDR_SIZE];
buildHeader(sampleRate, nChannels);
writeData(data, start, end);
}
// ------------------------------------------------------------
private void buildHeader(int sampleRate, short nChannels) {
write("RIFF");
write(output.length);
write("WAVE");
writeFormat(sampleRate, nChannels);
}
// ------------------------------------------------------------
public void writeFormat(int sampleRate, short nChannels) {
write("fmt ");
write(WAV_FMT_SIZE - WAV_DATA_SIZE);
write(PCM);
write(nChannels);
write(sampleRate);
write(nChannels * sampleRate * SAMPLE_SIZE);
write((short) (nChannels * SAMPLE_SIZE));
write((short) 16);
}
// ------------------------------------------------------------
public void writeData(short[] data, int start, int end) {
write("data");
write(nSamples * SMALLINT);
for (int i = start; i <= end; write(data[i++])) ;
}
// ------------------------------------------------------------
private void write(byte b) {
output[cursor++] = b;
}
// ------------------------------------------------------------
private void write(String id) {
if (id.length() != ID_STRING_SIZE)
Utils.logError("String " + id + " must have four characters.");
else {
for (int i = 0; i < ID_STRING_SIZE; ++i) write((byte) id.charAt(i));
}
}
// ------------------------------------------------------------
private void write(int i) {
write((byte) (i & 0xFF));
i >>= 8;
write((byte) (i & 0xFF));
i >>= 8;
write((byte) (i & 0xFF));
i >>= 8;
write((byte) (i & 0xFF));
}
// ------------------------------------------------------------
private void write(short i) {
write((byte) (i & 0xFF));
i >>= 8;
write((byte) (i & 0xFF));
}
// ------------------------------------------------------------
public boolean wroteToFile(String filename) {
boolean ok = false;
try {
File path = new File(getFilesDir(), filename);
FileOutputStream outFile = new FileOutputStream(path);
outFile.write(output);
outFile.close();
ok = true;
} catch (FileNotFoundException e) {
e.printStackTrace();
ok = false;
} catch (IOException e) {
ok = false;
e.printStackTrace();
}
return ok;
}
}
Hope this helps