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