Я просто сгенерирую приложение для записи видео с помощью камеры. но это сбой и выдайте мне ошибку:
Попытка вызвать виртуальный метод
'android.view.SurfaceHolderandroid.view.SurfaceView.getHolder ()' на
ссылка на нулевой объект`
Capture Video Activity.class
import java.io.File;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
import android.app.Activity;
import android.content.pm.ActivityInfo;
import android.hardware.Camera;
import android.hardware.camera2.CameraCharacteristics;
import android.media.CamcorderProfile;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.view.Surface;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ToggleButton;
import static android.provider.MediaStore.Files.FileColumns.MEDIA_TYPE_IMAGE;
import static android.provider.MediaStore.Files.FileColumns.MEDIA_TYPE_VIDEO;
public class CaptureVideoActivity extends Activity implements SurfaceHolder.Callback {
private MediaRecorder mMediaRecorder;
private Camera mCamera;
private SurfaceView mSurfaceView;
private SurfaceHolder mHolder;
private View mToggleButton;
private boolean mInitSuccesful;
CameraCharacteristics characteristics;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_capture_video);
// we shall take the video in landscape orientation
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
mSurfaceView = (SurfaceView) findViewById(R.id.surfaceView);
mHolder = mSurfaceView.getHolder();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
mToggleButton = (ToggleButton) findViewById(R.id.toggleRecordingButton);
mToggleButton.setOnClickListener(new View.OnClickListener() {
@Override
// toggle video recording
public void onClick(View v) {
if (((ToggleButton) v).isChecked()) {
mMediaRecorder.start();
try {
Thread.sleep(7 * 1000); // This will recode for 10 seconds, if you don't want then just remove it.
} catch (Exception e) {
e.printStackTrace();
}
//finish();
} else {
mMediaRecorder.stop();
mMediaRecorder.reset();
try {
initRecorder(mHolder.getSurface());
} catch (IOException e) {
e.printStackTrace();
}
}
}
});
}
/* Init the MediaRecorder, the order the methods are called is vital to
* its correct functioning */
private void initRecorder(Surface surface) throws IOException {
// It is very important to unlock the camera before doing setCamera
// or it will results in a black preview
if (mCamera == null) {
mCamera = Camera.open();
mCamera.unlock();
}
if (mMediaRecorder == null) mMediaRecorder = new MediaRecorder();
mMediaRecorder.setPreviewDisplay(surface);
mMediaRecorder.setCamera(mCamera);
File file = getOutputMediaFile(2);
mMediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
mMediaRecorder.setVideoSource(MediaRecorder.VideoSource.SURFACE);
// mMediaRecorder.setOutputFormat(8);
// mMediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
mMediaRecorder.setOutputFile(file.getAbsolutePath());
mMediaRecorder.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_720P));
/*mMediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H264);
mMediaRecorder.setVideoEncodingBitRate(512 * 1000);
mMediaRecorder.setVideoFrameRate(30);
mMediaRecorder.setVideoSize(640, 480);*/
int deviceorientation = getResources().getConfiguration().orientation;
mMediaRecorder.setOrientationHint(getJpegOrientation(characteristics, deviceorientation));
try {
mMediaRecorder.prepare();
} catch (IllegalStateException e) {
// This is thrown if the previous calls are not called with the
// proper order
e.printStackTrace();
}
mInitSuccesful = true;
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
try {
if (!mInitSuccesful)
initRecorder(mHolder.getSurface());
} catch (IOException e) {
e.printStackTrace();
}
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
shutdown();
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
}
private void shutdown() {
// Release MediaRecorder and especially the Camera as it's a shared
// object that can be used by other applications
mMediaRecorder.reset();
mMediaRecorder.release();
mCamera.release();
// once the objects have been released they can't be reused
mMediaRecorder = null;
mCamera = null;
}
private static File getOutputMediaFile(int type){
// To be safe, you should check that the SDCard is mounted
// using Environment.getExternalStorageState() before doing this.
File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_PICTURES), "Test Capture");
// This location works best if you want the created images to be shared
// between applications and persist after your app has been uninstalled.
// Create the storage directory if it does not exist
if (! mediaStorageDir.exists()){
if (! mediaStorageDir.mkdirs()){
Log.d("MyCameraApp", "failed to create directory");
return null;
}
}
// Create a media file name
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
File mediaFile;
if (type == MEDIA_TYPE_IMAGE){
mediaFile = new File(mediaStorageDir.getPath() + File.separator +
"IMG_"+ timeStamp + ".jpg");
} else if(type == MEDIA_TYPE_VIDEO) {
mediaFile = new File(mediaStorageDir.getPath() + File.separator +
"VID_"+ timeStamp + ".mp4");
} else {
return null;
}
return mediaFile;
}
private int getJpegOrientation(CameraCharacteristics c, int deviceOrientation) {
if (deviceOrientation == android.view.OrientationEventListener.ORIENTATION_UNKNOWN)
return 0;
int sensorOrientation = c.get(CameraCharacteristics.SENSOR_ORIENTATION);
// Round device orientation to a multiple of 90
deviceOrientation = (deviceOrientation + 45) / 90 * 90;
// Reverse device orientation for front-facing cameras
boolean facingFront = c.get(CameraCharacteristics.LENS_FACING) == CameraCharacteristics.LENS_FACING_FRONT;
if (facingFront) deviceOrientation = -deviceOrientation;
// Calculate desired JPEG orientation relative to camera orientation to make
// the image upright relative to the device orientation
return (sensorOrientation + deviceOrientation + 360) % 360;
}
}
activity_capture_video.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<ToggleButton
android:id="@+id/toggleRecordingButton"
android:layout_width="fill_parent"
android:textOff="Start Recording"
android:textOn="Stop Recording"
android:layout_height="wrap_content"
/>
<FrameLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<SurfaceView android:id="@+id/surfaceView"
android:layout_width="fill_parent"
android:layout_height="fill_parent"></SurfaceView>
</FrameLayout>
</LinearLayout>
Я уже прочитал все детали ссылки:
но не полезно для меня.