android Audio Capture

》The Android multimedia framework includes support for capturing and encoding a variety of common audio formats, so that you can easily integrate audio into your applications. You can record audio using the MediaRecorder APIs if supported by the device hardware.

》The example class below illustrates how to set up, start and stop audio capture, and to play the recorded audio file.

/* * The application needs to have the permission to write to external storage * if the output file is written to the external storage, and also the * permission to record audio. These permissions must be set in the * application's AndroidManifest.xml file, with something like: * * <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> * <uses-permission android:name="android.permission.RECORD_AUDIO" /> * */package com.android.audiorecordtest;import android.app.Activity;import android.widget.LinearLayout;import android.os.Bundle;import android.os.Environment;import android.view.ViewGroup;import android.widget.Button;import android.view.View;import android.view.View.OnClickListener;import android.content.Context;import android.util.Log;import android.media.MediaRecorder;import android.media.MediaPlayer;import java.io.IOException;public class AudioRecordTest extends Activity{    private static final String LOG_TAG = "AudioRecordTest";    private static String mFileName = null;    private RecordButton mRecordButton = null;    private MediaRecorder mRecorder = null;    private PlayButton   mPlayButton = null;    private MediaPlayer   mPlayer = null;    private void onRecord(boolean start) {        if (start) {            startRecording();        } else {            stopRecording();        }    }    private void onPlay(boolean start) {        if (start) {            startPlaying();        } else {            stopPlaying();        }    }    private void startPlaying() {        mPlayer = new MediaPlayer();        try {            mPlayer.setDataSource(mFileName);            mPlayer.prepare();            mPlayer.start();        } catch (IOException e) {            Log.e(LOG_TAG, "prepare() failed");        }    }    private void stopPlaying() {        mPlayer.release();        mPlayer = null;    }    private void startRecording() {        mRecorder = new MediaRecorder();        mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);        mRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);        mRecorder.setOutputFile(mFileName);        mRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);        try {            mRecorder.prepare();        } catch (IOException e) {            Log.e(LOG_TAG, "prepare() failed");        }        mRecorder.start();    }    private void stopRecording() {        mRecorder.stop();        mRecorder.release();        mRecorder = null;    }    class RecordButton extends Button {        boolean mStartRecording = true;        OnClickListener clicker = new OnClickListener() {            public void onClick(View v) {                onRecord(mStartRecording);                if (mStartRecording) {                    setText("Stop recording");                } else {                    setText("Start recording");                }                mStartRecording = !mStartRecording;            }        };        public RecordButton(Context ctx) {            super(ctx);            setText("Start recording");            setOnClickListener(clicker);        }    }    class PlayButton extends Button {        boolean mStartPlaying = true;        OnClickListener clicker = new OnClickListener() {            public void onClick(View v) {                onPlay(mStartPlaying);                if (mStartPlaying) {                    setText("Stop playing");                } else {                    setText("Start playing");                }                mStartPlaying = !mStartPlaying;            }        };        public PlayButton(Context ctx) {            super(ctx);            setText("Start playing");            setOnClickListener(clicker);        }    }    public AudioRecordTest() {        mFileName = Environment.getExternalStorageDirectory().getAbsolutePath();        mFileName += "/audiorecordtest.3gp";    }    @Override    public void onCreate(Bundle icicle) {        super.onCreate(icicle);        LinearLayout ll = new LinearLayout(this);        mRecordButton = new RecordButton(this);        ll.addView(mRecordButton,            new LinearLayout.LayoutParams(                ViewGroup.LayoutParams.WRAP_CONTENT,                ViewGroup.LayoutParams.WRAP_CONTENT,                0));        mPlayButton = new PlayButton(this);        ll.addView(mPlayButton,            new LinearLayout.LayoutParams(                ViewGroup.LayoutParams.WRAP_CONTENT,                ViewGroup.LayoutParams.WRAP_CONTENT,                0));        setContentView(ll);    }    @Override    public void onPause() {        super.onPause();        if (mRecorder != null) {            mRecorder.release();            mRecorder = null;        }        if (mPlayer != null) {            mPlayer.release();            mPlayer = null;        }    }}