AndroidAudioRecordActivity.java
package com.exercise.AndroidAudioRecord;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import android.app.Activity;
import android.media.AudioFormat;
import android.media.AudioManager;
import android.media.AudioRecord;
import android.media.AudioTrack;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.os.Environment;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.Spinner;
import android.widget.Toast;
public class AndroidAudioRecordActivity extends Activity {
String[] freqText = {"11.025 KHz (Lowest)", "16.000 KHz", "22.050 KHz", "44.100 KHz (Highest)"};
Integer[] freqset = {11025, 16000, 22050, 44100};
private ArrayAdapter<String> adapter;
Spinner spFrequency;
Button startRec, stopRec, playBack;
Boolean recording;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
startRec = (Button)findViewById(R.id.startrec);
stopRec = (Button)findViewById(R.id.stoprec);
playBack = (Button)findViewById(R.id.playback);
startRec.setOnClickListener(startRecOnClickListener);
stopRec.setOnClickListener(stopRecOnClickListener);
playBack.setOnClickListener(playBackOnClickListener);
spFrequency = (Spinner)findViewById(R.id.frequency);
adapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, freqText);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spFrequency.setAdapter(adapter);
stopRec.setEnabled(false);
}
OnClickListener startRecOnClickListener
= new OnClickListener(){
@Override
public void onClick(View arg0) {
Thread recordThread = new Thread(new Runnable(){
@Override
public void run() {
recording = true;
startRecord();
}
});
recordThread.start();
startRec.setEnabled(false);
stopRec.setEnabled(true);
}};
OnClickListener stopRecOnClickListener
= new OnClickListener(){
@Override
public void onClick(View arg0) {
recording = false;
startRec.setEnabled(true);
stopRec.setEnabled(false);
}};
OnClickListener playBackOnClickListener
= new OnClickListener(){
@Override
public void onClick(View v) {
playRecord();
}
};
private void startRecord(){
File file = new File(Environment.getExternalStorageDirectory(), "test.pcm");
int selectedPos = spFrequency.getSelectedItemPosition();
int sampleFreq = freqset[selectedPos];
final String promptStartRecord =
"startRecord()\n"
+ file.getAbsolutePath() + "\n"
+ (String)spFrequency.getSelectedItem();
runOnUiThread(new Runnable(){
@Override
public void run() {
Toast.makeText(AndroidAudioRecordActivity.this,
promptStartRecord,
Toast.LENGTH_LONG).show();
}});
try {
file.createNewFile();
OutputStream outputStream = new FileOutputStream(file);
BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(outputStream);
DataOutputStream dataOutputStream = new DataOutputStream(bufferedOutputStream);
int minBufferSize = AudioRecord.getMinBufferSize(sampleFreq,
AudioFormat.CHANNEL_CONFIGURATION_MONO,
AudioFormat.ENCODING_PCM_16BIT);
short[] audioData = new short[minBufferSize];
AudioRecord audioRecord = new AudioRecord(MediaRecorder.AudioSource.MIC,
sampleFreq,
AudioFormat.CHANNEL_CONFIGURATION_MONO,
AudioFormat.ENCODING_PCM_16BIT,
minBufferSize);
audioRecord.startRecording();
while(recording){
int numberOfShort = audioRecord.read(audioData, 0, minBufferSize);
for(int i = 0; i < numberOfShort; i++){
dataOutputStream.writeShort(audioData[i]);
}
}
audioRecord.stop();
dataOutputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
void playRecord(){
File file = new File(Environment.getExternalStorageDirectory(), "test.pcm");
int shortSizeInBytes = Short.SIZE/Byte.SIZE;
int bufferSizeInBytes = (int)(file.length()/shortSizeInBytes);
short[] audioData = new short[bufferSizeInBytes];
try {
InputStream inputStream = new FileInputStream(file);
BufferedInputStream bufferedInputStream = new BufferedInputStream(inputStream);
DataInputStream dataInputStream = new DataInputStream(bufferedInputStream);
int i = 0;
while(dataInputStream.available() > 0){
audioData[i] = dataInputStream.readShort();
i++;
}
dataInputStream.close();
int selectedPos = spFrequency.getSelectedItemPosition();
int sampleFreq = freqset[selectedPos];
final String promptPlayRecord =
"PlayRecord()\n"
+ file.getAbsolutePath() + "\n"
+ (String)spFrequency.getSelectedItem();
Toast.makeText(AndroidAudioRecordActivity.this,
promptPlayRecord,
Toast.LENGTH_LONG).show();
AudioTrack audioTrack = new AudioTrack(
AudioManager.STREAM_MUSIC,
sampleFreq,
AudioFormat.CHANNEL_CONFIGURATION_MONO,
AudioFormat.ENCODING_PCM_16BIT,
bufferSizeInBytes,
AudioTrack.MODE_STREAM);
audioTrack.play();
audioTrack.write(audioData, 0, bufferSizeInBytes);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/hello" />
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Sampling Frequency" />
<Spinner
android:id = "@+id/frequency"
android:layout_width="fill_parent"
android:layout_height="wrap_content"/>
<Button
android:id="@+id/startrec"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Start Recording" />
<Button
android:id="@+id/stoprec"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Stop Recording" />
<Button
android:id="@+id/playback"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Play Back" />
</LinearLayout>
Permission of "android.permission.RECORD_AUDIO" and "android.permission.WRITE_EXTERNAL_STORAGE" are needed in AndroidManifest.xml.
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.exercise.AndroidAudioRecord"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="10" />
<uses-permission android:name="android.permission.RECORD_AUDIO"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<application
android:icon="@drawable/ic_launcher"
android:label="@string/app_name" >
<activity
android:name=".AndroidAudioRecordActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
Download the files.Download and try the APK HERE.
