使用AudioRecord和AudioTrack来录制和播放音频
【摘要】
1.使用AudioRecord录制原始音频
除了通过意图启动录音机和使用MediaRecorder之外，Android还提供了第三种方法来捕获音频：使用成为AudioRecord的类。AudioRecord是三种方法里最灵活的（因为允许访问原始音频流），但是它拥有的内置功能也是最少的，如不会自动压缩音频。
使用AudioRecord...
1.使用AudioRecord录制原始音频
除了通过意图启动录音机和使用MediaRecorder之外，Android还提供了第三种方法来捕获音频：使用成为AudioRecord的类。AudioRecord是三种方法里最灵活的（因为允许访问原始音频流），但是它拥有的内置功能也是最少的，如不会自动压缩音频。
使用AudioRecord的基础知识非常简单。我们只需要构造一个AudioRecord类型的对象，并传入各种不同的配置参数。
需要指定的第一个值是音频源。下面使用的值与用于MediaRecorder的值相同，其在MediaRecorder.AudioSource中定义。实际上，这意味着可以使用MediaRecorder.AudioSource.MIC。
int audioSource=MediaRecorder.AudioSource.MIC;
int frequency = 11025;
捕获的音频通道的数量
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AudioFormat.CHANNEL_CONFIGURATION_MONO;//channelConfiguration
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AudioFormat.CHANNEL_CONFIGURATION_STEREO;
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AudioFormat.CHANNEL_CONFIGURATION_INVALID;
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AudioFormat.CHANNEL_CONFIGURATION_DEFAULT;
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AudioFormat.ENCODING_DEFAULT;//audioEncoding
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AudioFormat.ENCODING_INVALID;
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AudioFormat.ENCODING_PCM_16BIT;
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AudioFormat.ENCODING_PCM_8BIT;
最后，需要指定的是第五个值是缓冲区大小。实际上可以查询AudioRecord类以获得最小缓冲区大小，查询方式是调用getMinBufferSize静态方法，同时传入采样率、通道配置以及音频格式。
int bufferSize = AudioTrack.getMinBufferSize(frequency,channelConfiguration, audioEncoding);
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AudioRecord audioRecord = new AudioRecord(MediaRecorder.AudioSource.MIC, frequency,
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channelConfiguration, audioEncoding, bufferSize);
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File path = new File(
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Environment.getExternalStorageDirectory().getAbsolutePath()
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+ "/AudioRecorder/files/");
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path.mkdirs();
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try
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{
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recordingFile = File.createTempFile("recording", ".pcm", path);
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} catch (IOException e)
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{
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throw new RuntimeException("Couldn't create file on SD card", e);
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}
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DataOutputStream dos = new DataOutputStream(
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new BufferedOutputStream(new FileOutputStream(
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recordingFile)));
short[] audiodata = new short[bufferSize / 4];
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while (isRecording)
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{
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int bufferReadResult = audioRecord.read(buffer, 0,bufferSize);
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for (int i = 0; i < bufferReadResult; i++)
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{
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dos.writeShort(buffer[i]);
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}
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}
2.使用AudioTrack来播放原始音频
AudioTrack允许播放AudioRecord捕获的原始音频类，而它们并不能使用MediaPlayer对象播放。
为了构造一个AudioTrack对象，需要传入以下一系列配置变量来描述待播放的音频
第一个参数是流类型。可能的值定义为AudioManager类的常量。例如
AudioManager.STREAM_MUSIC//正常播放音乐的音频流
第三个参数是通道配置。可能的值与构造AudioRecord的值相同。
第四个参数是音频格式。可能的值与构造AudioRecord的值相同。
第五个参数是将在对象中用于存储音频的缓冲区大小。为了确定使用最小的缓冲区大小，可以调用getMinBufferSize方法，同时传入采样率、通道配置和音频格式。
最后一个参数是模式。可能的值定义为AudioTrack类中的常量。
-
AudioTrack.MODE_STATIC://在播放发生之前将所有的音频数据转移到AudioTrack对象
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AudioTrack.MODE_STREAM://在播放的同时将音频数据持续地转移到AudioTrack对象。
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AudioTrack audioTrack = new AudioTrack(
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AudioManager.STREAM_MUSIC, frequency,
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channelConfiguration, audioEncoding, bufferSize,
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AudioTrack.MODE_STREAM);
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DataInputStream dis = new DataInputStream(
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new BufferedInputStream(new FileInputStream(
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recordingFile)));
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audioTrack.play();
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while (isPlaying && dis.available() > 0)
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{
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int i = 0;
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while (dis.available() > 0 && i < audiodata.length)
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{
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audiodata[i] = dis.readShort();
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i++;
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}
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audioTrack.write(audiodata, 0, audiodata.length);
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}
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dis.close();
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public class AltAudioRecorder extends Activity implements OnClickListener
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{
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RecordAudio recordTask;
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PlayAudio playTask;
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Button startRecordingButton, stopRecordingButton, startPlaybackButton,
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stopPlaybackButton;
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TextView statusText;
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File recordingFile;
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boolean isRecording = false;
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boolean isPlaying = false;
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int frequency = 11025;
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int channelConfiguration = AudioFormat.CHANNEL_CONFIGURATION_MONO;
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int audioEncoding = AudioFormat.ENCODING_PCM_16BIT;
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@Override
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public void onCreate(Bundle savedInstanceState)
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{
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super.onCreate(savedInstanceState);
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setContentView(R.layout.main);
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statusText = (TextView) this.findViewById(R.id.StatusTextView);
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startRecordingButton = (Button) this
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.findViewById(R.id.StartRecordingButton);
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stopRecordingButton = (Button) this
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.findViewById(R.id.StopRecordingButton);
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startPlaybackButton = (Button) this
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.findViewById(R.id.StartPlaybackButton);
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stopPlaybackButton = (Button) this
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.findViewById(R.id.StopPlaybackButton);
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startRecordingButton.setOnClickListener(this);
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stopRecordingButton.setOnClickListener(this);
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startPlaybackButton.setOnClickListener(this);
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stopPlaybackButton.setOnClickListener(this);
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stopRecordingButton.setEnabled(false);
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startPlaybackButton.setEnabled(false);
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stopPlaybackButton.setEnabled(false);
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File path = new File(
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Environment.getExternalStorageDirectory().getAbsolutePath()
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+ "/Android/data/AudioRecorder/files/");
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path.mkdirs();
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try
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{
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recordingFile = File.createTempFile("recording", ".pcm", path);
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} catch (IOException e)
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{
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throw new RuntimeException("Couldn't create file on SD card", e);
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}
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}
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public void onClick(View v)
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{
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if (v == startRecordingButton)
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{
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record();
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} else if (v == stopRecordingButton)
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{
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stopRecording();
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} else if (v == startPlaybackButton)
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{
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play();
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} else if (v == stopPlaybackButton)
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{
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stopPlaying();
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}
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}
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public void play()
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{
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startPlaybackButton.setEnabled(true);
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playTask = new PlayAudio();
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playTask.execute();
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stopPlaybackButton.setEnabled(true);
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}
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public void stopPlaying()
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{
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isPlaying = false;
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stopPlaybackButton.setEnabled(false);
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startPlaybackButton.setEnabled(true);
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}
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public void record()
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{
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startRecordingButton.setEnabled(false);
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stopRecordingButton.setEnabled(true);
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// For Fun
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startPlaybackButton.setEnabled(true);
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recordTask = new RecordAudio();
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recordTask.execute();
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}
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public void stopRecording()
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{
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isRecording = false;
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}
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private class PlayAudio extends AsyncTask<Void, Integer, Void>
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{
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@Override
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protected Void doInBackground(Void... params)
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{
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isPlaying = true;
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int bufferSize = AudioTrack.getMinBufferSize(frequency,
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channelConfiguration, audioEncoding);
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short[] audiodata = new short[bufferSize / 4];
-
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try
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{
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DataInputStream dis = new DataInputStream(
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new BufferedInputStream(new FileInputStream(
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recordingFile)));
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AudioTrack audioTrack = new AudioTrack(
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AudioManager.STREAM_MUSIC, frequency,
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channelConfiguration, audioEncoding, bufferSize,
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AudioTrack.MODE_STREAM);
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audioTrack.play();
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while (isPlaying && dis.available() > 0)
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{
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int i = 0;
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while (dis.available() > 0 && i < audiodata.length)
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{
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audiodata[i] = dis.readShort();
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i++;
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}
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audioTrack.write(audiodata, 0, audiodata.length);
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}
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dis.close();
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startPlaybackButton.setEnabled(false);
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stopPlaybackButton.setEnabled(true);
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} catch (Throwable t)
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{
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Log.e("AudioTrack", "Playback Failed");
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}
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return null;
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}
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}
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private class RecordAudio extends AsyncTask<Void, Integer, Void>
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{
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@Override
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protected Void doInBackground(Void... params)
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{
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isRecording = true;
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try
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{
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DataOutputStream dos = new DataOutputStream(
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new BufferedOutputStream(new FileOutputStream(
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recordingFile)));
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int bufferSize = AudioRecord.getMinBufferSize(frequency,
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channelConfiguration, audioEncoding);
-
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AudioRecord audioRecord = new AudioRecord(
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MediaRecorder.AudioSource.MIC, frequency,
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channelConfiguration, audioEncoding, bufferSize);
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short[] buffer = new short[bufferSize];
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audioRecord.startRecording();
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int r = 0;
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while (isRecording)
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{
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int bufferReadResult = audioRecord.read(buffer, 0,
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bufferSize);
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for (int i = 0; i < bufferReadResult; i++)
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{
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dos.writeShort(buffer[i]);
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}
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publishProgress(new Integer(r));
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r++;
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}
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audioRecord.stop();
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dos.close();
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} catch (Throwable t)
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{
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Log.e("AudioRecord", "Recording Failed");
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}
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return null;
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}
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protected void onProgressUpdate(Integer... progress)
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{
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statusText.setText(progress[0].toString());
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}
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protected void onPostExecute(Void result)
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{
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startRecordingButton.setEnabled(true);
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stopRecordingButton.setEnabled(false);
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startPlaybackButton.setEnabled(true);
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}
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}
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}
文章来源: panda1234lee.blog.csdn.net，作者：panda1234lee，版权归原作者所有，如需转载，请联系作者。
原文链接：panda1234lee.blog.csdn.net/article/details/8774182
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