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使用AudioRecord，我試圖編寫一個測試應用程序來記錄幾秒鐘的音頻以顯示在屏幕上。但是，我似乎得到了如下所示的零值區域的重複模式。我不確定這是否是正常行爲或我的代碼中的錯誤。AudioRecord在Android 5.01上產生0的差距
MainActivity.java
public class MainActivity extends Activity implements OnClickListener
{
private static final int SAMPLE_RATE = 44100;
private Button recordButton, playButton;
private String filePath;
private boolean recording;
private AudioRecord record;
private short[] data;
private TestView testView;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button recordButton = (Button) this.findViewById(R.id.recordButton);
recordButton.setOnClickListener(this);
Button playButton = (Button)findViewById(R.id.playButton);
playButton.setOnClickListener(this);
FrameLayout frame = (FrameLayout)findViewById(R.id.myFrame);
frame.addView(testView = new TestView(this));
}
@Override
public void onClick(View v)
{
if(v.getId() == R.id.recordButton)
{
if(!recording)
{
int bufferSize = AudioRecord.getMinBufferSize( SAMPLE_RATE,
AudioFormat.CHANNEL_IN_MONO,
AudioFormat.ENCODING_PCM_16BIT);
record = new AudioRecord( MediaRecorder.AudioSource.MIC,
SAMPLE_RATE,
AudioFormat.CHANNEL_IN_MONO,
AudioFormat.ENCODING_PCM_16BIT,
bufferSize * 2);
data = new short[10 * SAMPLE_RATE]; // Records up to 10 seconds
new Thread()
{
@Override
public void run()
{
recordAudio();
}
}.start();
recording = true;
Toast.makeText(this, "recording...", Toast.LENGTH_SHORT).show();
}
else
{
recording = false;
Toast.makeText(this, "finished", Toast.LENGTH_SHORT).show();
}
}
else if(v.getId() == R.id.playButton)
{
testView.invalidate();
Toast.makeText(this, "play/pause", Toast.LENGTH_SHORT).show();
}
}
void recordAudio()
{
record.startRecording();
int index = 0;
while(recording)
{
try {
Thread.sleep(50);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
int result = record.read(data, index, SAMPLE_RATE); // read 1 second at a time
if(result == AudioRecord.ERROR_INVALID_OPERATION || result == AudioRecord.ERROR_BAD_VALUE)
{
App.d("SOME SORT OF RECORDING ERROR MATE");
return;
}
else
{
index += result; // increment by number of bytes read
App.d("read: "+result);
}
}
record.stop();
data = Arrays.copyOf(data, index);
testView.setData(data);
}
@Override
protected void onPause()
{
super.onPause();
}
}
TestView.java
public class TestView extends View
{
private short[] data;
Paint paint = new Paint();
Path path = new Path();
float min, max;
public TestView(Context context)
{
super(context);
paint.setColor(Color.BLACK);
paint.setStrokeWidth(1);
paint.setStyle(Style.FILL_AND_STROKE);
}
void setData(short[] data)
{
min = Short.MAX_VALUE;
max = Short.MIN_VALUE;
this.data = data;
for(int i = 0; i < data.length; i++)
{
if(data[i] < min)
min = data[i];
if(data[i] > max)
max = data[i];
}
}
@Override
protected void onDraw(Canvas canvas)
{
canvas.drawRGB(255, 255, 255);
if(data != null)
{
float interval = (float)this.getWidth()/data.length;
for(int i = 0; i < data.length; i+=10)
canvas.drawCircle(i*interval,(data[i]-min)/(max - min)*this.getHeight(),5 ,paint);
}
super.onDraw(canvas);
}
}
注意：如果min == max，你的onDraw會有問題。 –
我開始認爲read方法返回的是字節數而不是短褲。另外，每個16位採樣是否放入一個短路中，或者是否將一個短路中的8位和下一個中的8位放在一起？ –