1page.title=Audio Capture
2page.tags=mediarecorder
3@jd:body
4
5    <div id="qv-wrapper">
6    <div id="qv">
7
8<h2>In this document</h2>
9<ol>
10<li><a href="#audiocapture">Performing Audio Capture</a>
11   <ol>
12      <li><a href='#example'>Code Example</a></li>
13   </ol>
14</li>
15</ol>
16
17<h2>Key classes</h2>
18<ol>
19<li>{@link android.media.MediaRecorder}</li>
20</ol>
21
22<h2>See also</h2>
23<ol>
24  <li><a href="{@docRoot}guide/appendix/media-formats.html">Android Supported Media Formats</a></li>
25  <li><a href="{@docRoot}guide/topics/data/data-storage.html">Data Storage</a></li>
26  <li><a href="{@docRoot}guide/topics/media/mediaplayer.html">MediaPlayer</a>
27</ol>
28
29</div>
30</div>
31
32<p>The Android multimedia framework includes support for capturing and encoding a variety of common
33audio formats, so that you can easily integrate audio into your applications. You can record audio
34using the {@link android.media.MediaRecorder} APIs if supported by the device hardware.</p>
35
36<p>This document shows you how to write an application that captures audio from a device
37microphone, save the audio and play it back.</p>
38
39<p class="note"><strong>Note:</strong> The Android Emulator does not have the ability to capture
40audio, but actual devices are likely to provide these capabilities.</p>
41
42<h2 id="audiocapture">Performing Audio Capture</h2>
43
44<p>Audio capture from the device is a bit more complicated than audio and video playback, but still
45fairly simple:</p>
46<ol>
47  <li>Create a new instance of {@link android.media.MediaRecorder android.media.MediaRecorder}.</li>
48  <li>Set the audio source using
49        {@link android.media.MediaRecorder#setAudioSource MediaRecorder.setAudioSource()}. You will
50probably want to use
51  <code>MediaRecorder.AudioSource.MIC</code>.</li>
52  <li>Set output file format using
53        {@link android.media.MediaRecorder#setOutputFormat MediaRecorder.setOutputFormat()}.
54  </li>
55  <li>Set output file name using
56        {@link android.media.MediaRecorder#setOutputFile MediaRecorder.setOutputFile()}.
57  </li>
58  <li>Set the audio encoder using
59        {@link android.media.MediaRecorder#setAudioEncoder MediaRecorder.setAudioEncoder()}.
60  </li>
61  <li>Call {@link android.media.MediaRecorder#prepare MediaRecorder.prepare()}
62   on the MediaRecorder instance.</li>
63  <li>To start audio capture, call
64  {@link android.media.MediaRecorder#start MediaRecorder.start()}. </li>
65  <li>To stop audio capture, call {@link android.media.MediaRecorder#stop MediaRecorder.stop()}.
66  <li>When you are done with the MediaRecorder instance, call
67{@link android.media.MediaRecorder#release MediaRecorder.release()} on it. Calling
68{@link android.media.MediaRecorder#release MediaRecorder.release()} is always recommended to
69free the resource immediately.</li>
70</ol>
71
72<h3 id="example">Example: Record audio and play the recorded audio</h3>
73<p>The example class below illustrates how to set up, start and stop audio capture, and to play the
74recorded audio file.</p>
75<pre>
76/*
77 * The application needs to have the permission to write to external storage
78 * if the output file is written to the external storage, and also the
79 * permission to record audio. These permissions must be set in the
80 * application's AndroidManifest.xml file, with something like:
81 *
82 * &lt;uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /&gt;
83 * &lt;uses-permission android:name="android.permission.RECORD_AUDIO" /&gt;
84 *
85 */
86package com.android.audiorecordtest;
87
88import android.app.Activity;
89import android.widget.LinearLayout;
90import android.os.Bundle;
91import android.os.Environment;
92import android.view.ViewGroup;
93import android.widget.Button;
94import android.view.View;
95import android.view.View.OnClickListener;
96import android.content.Context;
97import android.util.Log;
98import android.media.MediaRecorder;
99import android.media.MediaPlayer;
100
101import java.io.IOException;
102
103
104public class AudioRecordTest extends Activity
105{
106    private static final String LOG_TAG = "AudioRecordTest";
107    private static String mFileName = null;
108
109    private RecordButton mRecordButton = null;
110    private MediaRecorder mRecorder = null;
111
112    private PlayButton   mPlayButton = null;
113    private MediaPlayer   mPlayer = null;
114
115    private void onRecord(boolean start) {
116        if (start) {
117            startRecording();
118        } else {
119            stopRecording();
120        }
121    }
122
123    private void onPlay(boolean start) {
124        if (start) {
125            startPlaying();
126        } else {
127            stopPlaying();
128        }
129    }
130
131    private void startPlaying() {
132        mPlayer = new MediaPlayer();
133        try {
134            mPlayer.setDataSource(mFileName);
135            mPlayer.prepare();
136            mPlayer.start();
137        } catch (IOException e) {
138            Log.e(LOG_TAG, "prepare() failed");
139        }
140    }
141
142    private void stopPlaying() {
143        mPlayer.release();
144        mPlayer = null;
145    }
146
147    private void startRecording() {
148        mRecorder = new MediaRecorder();
149        mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
150        mRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
151        mRecorder.setOutputFile(mFileName);
152        mRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
153
154        try {
155            mRecorder.prepare();
156        } catch (IOException e) {
157            Log.e(LOG_TAG, "prepare() failed");
158        }
159
160        mRecorder.start();
161    }
162
163    private void stopRecording() {
164        mRecorder.stop();
165        mRecorder.release();
166        mRecorder = null;
167    }
168
169    class RecordButton extends Button {
170        boolean mStartRecording = true;
171
172        OnClickListener clicker = new OnClickListener() {
173            public void onClick(View v) {
174                onRecord(mStartRecording);
175                if (mStartRecording) {
176                    setText("Stop recording");
177                } else {
178                    setText("Start recording");
179                }
180                mStartRecording = !mStartRecording;
181            }
182        };
183
184        public RecordButton(Context ctx) {
185            super(ctx);
186            setText("Start recording");
187            setOnClickListener(clicker);
188        }
189    }
190
191    class PlayButton extends Button {
192        boolean mStartPlaying = true;
193
194        OnClickListener clicker = new OnClickListener() {
195            public void onClick(View v) {
196                onPlay(mStartPlaying);
197                if (mStartPlaying) {
198                    setText("Stop playing");
199                } else {
200                    setText("Start playing");
201                }
202                mStartPlaying = !mStartPlaying;
203            }
204        };
205
206        public PlayButton(Context ctx) {
207            super(ctx);
208            setText("Start playing");
209            setOnClickListener(clicker);
210        }
211    }
212
213    public AudioRecordTest() {
214        mFileName = Environment.getExternalStorageDirectory().getAbsolutePath();
215        mFileName += "/audiorecordtest.3gp";
216    }
217
218    &#64;Override
219    public void onCreate(Bundle icicle) {
220        super.onCreate(icicle);
221
222        LinearLayout ll = new LinearLayout(this);
223        mRecordButton = new RecordButton(this);
224        ll.addView(mRecordButton,
225            new LinearLayout.LayoutParams(
226                ViewGroup.LayoutParams.WRAP_CONTENT,
227                ViewGroup.LayoutParams.WRAP_CONTENT,
228                0));
229        mPlayButton = new PlayButton(this);
230        ll.addView(mPlayButton,
231            new LinearLayout.LayoutParams(
232                ViewGroup.LayoutParams.WRAP_CONTENT,
233                ViewGroup.LayoutParams.WRAP_CONTENT,
234                0));
235        setContentView(ll);
236    }
237
238    &#64;Override
239    public void onPause() {
240        super.onPause();
241        if (mRecorder != null) {
242            mRecorder.release();
243            mRecorder = null;
244        }
245
246        if (mPlayer != null) {
247            mPlayer.release();
248            mPlayer = null;
249        }
250    }
251}
252</pre>
253