Android 在文本视图中显示当前音频振幅
我想我已经非常接近我所需要的了,但是当我试图在textview中将当前振幅整数转换成字符串时,我遇到了一个错误 所以我的目标是:显示摄像头预览(工作),检测声音(可能工作),并在textview(textPowerUp)中显示该声音的当前振幅级别。稍后,我想用一个计数器来代替textview,当检测到声音时,计数器会向上计数,当检测不到声音时,计数器会慢慢地向下计数,但是,婴儿步 因此,如果我注释掉该行,则不会出现错误:Android 在文本视图中显示当前音频振幅,android,android-mediarecorder,Android,Android Mediarecorder,我想我已经非常接近我所需要的了,但是当我试图在textview中将当前振幅整数转换成字符串时,我遇到了一个错误 所以我的目标是:显示摄像头预览(工作),检测声音(可能工作),并在textview(textPowerUp)中显示该声音的当前振幅级别。稍后,我想用一个计数器来代替textview,当检测到声音时,计数器会向上计数,当检测不到声音时,计数器会慢慢地向下计数,但是,婴儿步 因此,如果我注释掉该行,则不会出现错误: txtPowerLevel.setText(Integer.toStrin
txtPowerLevel.setText(Integer.toString(currentAmplitude));
但我正试图用这一行将振幅整数转换成字符串,并将其插入到我的文本视图中。这一行给出了一个空引用错误
我甚至试图通过以下方式强制电流振幅至少为0:
if (mRecorder.getMaxAmplitude() > 0) {
currentAmplitude = mRecorder.getMaxAmplitude();
} else {
currentAmplitude = 0;
}
但这似乎没有帮助。我仍然得到一个空引用错误。我甚至尝试将else设置为值“1”,以防“0”被视为“null”,但也没有成功
这是全班同学。。。如果你能发现问题,请告诉我
public class DBZPowerUp extends AppCompatActivity implements TextureView.SurfaceTextureListener {
MediaRecorder mRecorder = new MediaRecorder();
private Handler mHandler = new Handler();
private Camera mCamera;
private TextureView mTextureView;
private int currentAmplitude;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.dbzpowerup);
// Variables for textureview
mTextureView = new TextureView(this);
mTextureView.setSurfaceTextureListener(this);
// Build the camera preview onto textureview
setContentView(mTextureView);
// Run methods to start audio capture
startAudioCapture();
getAmplitude();
// Repeat audio methods constantly
mHandler.postDelayed(runnable, 100);
// Input the current amplitude level into the power level textview
setCurrentAmplitude();
TextView txtPowerLevel = (TextView) findViewById(R.id.txtPowerLevel);
txtPowerLevel.setText(Integer.toString(currentAmplitude));
}
public void onSurfaceTextureAvailable(SurfaceTexture surface, int width, int height) {
mCamera = Camera.open();
try {
mCamera.setPreviewTexture(surface);
mCamera.startPreview();
} catch(IOException e) {
Log.e("DBZ_", "Camera broke");
}
mCamera.setDisplayOrientation(90);
}
@Override
public void onSurfaceTextureSizeChanged(SurfaceTexture surface, int width, int height) {
// Ignored, Camera does all the work for us
}
@Override
public boolean onSurfaceTextureDestroyed(SurfaceTexture surface) {
stopAudioCapture();
mCamera.stopPreview();
mCamera.release();
return true;
}
@Override
public void onSurfaceTextureUpdated(SurfaceTexture surface) {
// Invoked every time there's a new Camera preview frame
}
public void startAudioCapture() {
mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
mRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
mRecorder.setAudioEncoder(MediaRecorder.OutputFormat.AMR_NB);
mRecorder.setOutputFile("/dev/null");
try {
mRecorder.prepare();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
mRecorder.start();
}
catch (IllegalStateException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void stopAudioCapture() {
mRecorder.stop();
mRecorder.release();
}
public double getAmplitude() {
if (mRecorder != null)
return mRecorder.getMaxAmplitude();
else
return 0;
}
private Runnable runnable = new Runnable() {
@Override
public void run() {
/* do what you need to do */
getAmplitude();
/* and here comes the "trick" */
mHandler.postDelayed(this, 100);
}
};
private void setCurrentAmplitude() {
if (mRecorder.getMaxAmplitude() > 0) {
currentAmplitude = mRecorder.getMaxAmplitude();
} else {
currentAmplitude = 0;
}
}
}
非常感谢您的光临
李
答案(感谢Blackbelt):
我改变了:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.dbzpowerup);
// Variables for textureview
mTextureView = new TextureView(this);
mTextureView.setSurfaceTextureListener(this);
// Build the camera preview onto textureview
setContentView(mTextureView);
致:
您的NPE问题是由于
// Build the camera preview onto textureview
setContentView(mTextureView);
这样,您将覆盖对
setContentView
的上一个调用,该调用可能包含您的TextView
。您可以将TextureView
添加到dbzpowerup.xml
中,并使用findViewById
获取对它的引用,先生,您是个天才。非常感谢你!如果其他人有这个问题,我已经在我原来的问题中添加了这个决议。
// Build the camera preview onto textureview
setContentView(mTextureView);