Android录音并根据音量大小实现简单动画效果
Android录音并根据音量大小实现简单动画效果
最终效果:
录音使用的是Android提供的 AudioRecord，可以在录音的同时判断音量，动画效果使用的是 clipDrawable 对象的 setLevel 方法，具体的过程如下：
clipDrawable
准备两张图片，一张作为背景（灰色），一张作为前景，用于生产动画效果:
新建一个drawable资源文件，其中的属性也容易理解，本质上就是将前景裁剪一部分然后覆盖到背景上。具体内容如下；
<layer-list xmlns:android="http://schemas.android.com/apk/res/android"> <item android:id="@android:id/background" android:drawable="@drawable/voice_gray" /> <item android:id="@android:id/progress"> <clip android:clipOrientation="vertical" android:drawable="@drawable/voice_accent" android:gravity="bottom" /> item> layer-list>之后就是在布局文件中的
ImageView中设置src为新建的drawable文件，并在活动中获得它的引用：<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity"> <ImageView android:id="@+id/img" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerInParent="true" android:src="@drawable/clip_test" /> <Button android:id="@+id/button" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentBottom="true" android:layout_centerHorizontal="true" android:layout_marginBottom="20dp" android:text="按住说话" /> RelativeLayout>ImageView imageView = findViewById(R.id.img); drawable = imageView.getDrawable();
使用AudioRecord
使用
AudioRecord类的大致过程为（暂时忽略录音机不可用等异常情况）：构造
AudioRecord对象 -> 在新线程中执行startRecording方法 -> 调用read方法获取录取的声音信息 -> 停止录制，释放资源。
AudioRecord对象会每次讲录制到的声音存放到缓冲区中，通过read方法即可以获取其内容。具体过程如下：
构造
AuidioRecord对象record = new AudioRecord(MediaRecorder.AudioSource.MIC, 8000, AudioFormat.CHANNEL_IN_DEFAULT, AudioFormat.ENCODING_PCM_16BIT, bufferSize);参数分别为 音源，采样率，信道配置，格式配置，缓冲区大小，其中缓冲区大小
bufferSize取值以如下方式获得：
bufferSize = AudioRecord.getMinBufferSize(sampleRateInHz, channelConfig, audioFormat);其他参数涉及音频方面的专业知识，大家可以自行百度。
判断
record对象状态，开始录制。if (record.getState() == AudioRecord.STATE_UNINITIALIZED) { Log.e(TAG, "start: record state uninitialized"); return; } record.startRecording();关于状态的取值，通过查看
getState的源码就可以看到，有STATE_INITIALIZED和STATE_UNINITIALIZED两个 ：/** * Returns the state of the AudioRecord instance. This is useful after the * AudioRecord instance has been created to check if it was initialized * properly. This ensures that the appropriate hardware resources have been * acquired. * @see AudioRecord#STATE_INITIALIZED * @see AudioRecord#STATE_UNINITIALIZED */ public int getState() { return mState; }通过调用
record对象的read方法，读取数据，需要注意的是， 该方法有许多的重载，主要的区别在于缓冲区buffer为byte还是short，后者一般用于计算声音分贝，而前者则多用于写入数据。并且Android规定，如果使用short类型的缓冲区，则构造record对象时需要将audioFormat设置为AudioFormat.ENCODING_PCM_16BIT。
数据读取后即可以计算出音量大小，进而得出分贝值 vol ，然后通过clipDrawable的setLevel方法设置裁剪的高度，setLevel方法的取值为 0-10000， 可以参考源码理解。short[] buffer = new short[bufferSize]; int sz = record.read(buffer, 0, bufferSize); long v = 0; for (int tmp : buffer) v += tmp * tmp; double vol = 10 * Math.log10(v / (double) sz); Message message = new Message(); message.what = VOICE_VOLUME; message.arg1 = (int) (vol * 50 + 3000); handler.sendMessage(message); try { Thread.sleep(100); } catch (InterruptedException e) { e.printStackTrace(); }额，这里涉及到一个音量的计算，我参考的是 https://blog.csdn.net/greatpresident/article/details/38402147 这篇博客中的方法，具体原理。。。我也不是很清楚。使用
handler是因为这是在子线程中运行的。最后就是停止录音，释放资源了：
record.stop(); record.release(); record = null;
下面是我做得一个简单的demo（删除了package和import语句以精简。。。好像也没怎么精简）：
封装后的 AudioRecorder 类：
public class AudioRecorder {
public final static int VOICE_VOLUME = 1;
public final static int RECORD_STOP = 2;
private static final String TAG = "AudioRecorder";
private static int sampleRateInHz = 8000;
private static int channelConfig = AudioFormat.CHANNEL_IN_DEFAULT;
private static int audioFormat = AudioFormat.ENCODING_PCM_16BIT;
private static AudioRecorder recorder;
private int bufferSize;
private AudioRecord record;
private boolean on;
private AudioRecorder() {
on = false;
record = null;
bufferSize = AudioRecord.getMinBufferSize(sampleRateInHz, channelConfig, audioFormat);
}
/**
* singleton
* @return an AudioRecorder object
*/
public static AudioRecorder getInstance() {
if (recorder == null)
recorder = new AudioRecorder();
return recorder;
}
/**
* start recorder
* @param handler a handler to send back message for ui changing
*/
public void start(final Handler handler) {
if (record != null || on)
return;
record = new AudioRecord(MediaRecorder.AudioSource.MIC,
sampleRateInHz,
channelConfig,
audioFormat,
bufferSize);
if (record.getState() == AudioRecord.STATE_UNINITIALIZED) {
Log.e(TAG, "start: record state uninitialized");
return;
}
new Thread(new Runnable() {
@Override
public void run() {
record.startRecording();
on = true;
while (on) {
short[] buffer = new short[bufferSize];
int sz = record.read(buffer, 0, bufferSize);
long v = 0;
for (int tmp : buffer)
v += tmp * tmp;
double vol = 10 * Math.log10(v / (double) sz);
Message message = new Message();
message.what = VOICE_VOLUME;
message.arg1 = (int) (vol * 50 + 3000);
handler.sendMessage(message);
try {
Thread.sleep(100);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
record.stop();
record.release();
record = null;
Message message = new Message();
message.what = RECORD_STOP;
handler.sendMessage(message);
}
}).start();
}
/**
* stop recording
*/
public void stop() {
on = false;
}
}
活动中逻辑流程（需要在manifest中配置并动态申请权限：
public class MainActivity extends AppCompatActivity {
private static final String TAG = "MainActivity";
private Drawable drawable;
private boolean recording = false;
private Button button;
private Handler handler = new Handler(new Handler.Callback() {
@Override
public boolean handleMessage(Message msg) {
switch (msg.what){
case AudioRecorder.VOICE_VOLUME:
drawable.setLevel(msg.arg1);
break;
case AudioRecorder.RECORD_STOP:
drawable.setLevel(0);
break;
default:
break;
}
return true;
}
});
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button = findViewById(R.id.button);
ImageView imageView = findViewById(R.id.img);
drawable = imageView.getDrawable();
button.setOnLongClickListener(new View.OnLongClickListener() {
@Override
public boolean onLongClick(View v) {
Log.e(TAG, "onLongClick: long clicking");
return false;
}
});
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.RECORD_AUDIO) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.RECORD_AUDIO}, 1);
return;
}
if (!recording)
startRecorder();
else
stopRecorder();
}
});
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
if (requestCode == 1){
if (grantResults.length <= 0 || grantResults[0] == PackageManager.PERMISSION_DENIED){
Toast.makeText(this, "不能录音玩个鬼？！！！", Toast.LENGTH_SHORT).show();
if (!ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.RECORD_AUDIO))
Toast.makeText(this, "你就是头猪！", Toast.LENGTH_SHORT).show();
}
else if (grantResults[0] == PackageManager.PERMISSION_GRANTED){
startRecorder();
}
}
}
private void startRecorder(){
Toast.makeText(MainActivity.this, "正在录音", Toast.LENGTH_SHORT).show();
button.setText("停止录音");
AudioRecorder.getInstance().start(handler);
recording = !recording;
}
private void stopRecorder(){
Toast.makeText(MainActivity.this, "已停止录音", Toast.LENGTH_SHORT).show();
button.setText("开始录音");
AudioRecorder.getInstance().stop();
recording = !recording;
}
}
drawable文件:
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<item
android:id="@android:id/background"
android:drawable="@drawable/voice_gray" />
<item android:id="@android:id/progress">
<clip
android:clipOrientation="vertical"
android:drawable="@drawable/voice_accent"
android:gravity="bottom" />
item>
layer-list>
MAinActivity布局文件：
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<ImageView
android:id="@+id/img"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:contentDescription="@string/app_name"
android:src="@drawable/clip_test" />
<Button
android:id="@+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:layout_marginBottom="20dp"
android:text="按住说话" />
RelativeLayout>
参考了多个csdn和简书的博客，就不一一列举了
这是谷歌官方的介绍，也挺有用的 https://developer.android.google.cn/reference/android/media/AudioRecord
有问题还请指正，欢迎评论交流。