尝试制作相机应用程序并且已经关注googles开发人员指南，但是我得到了一个runtimeException：在我的android 4.0.4设备上启动失败。然而它适用于我的朋友4.2.X三星。试图谷歌问题，但没有找到任何相关的解决方案。
错误代码
05-13 18:16:06.458: E/MediaRecorder(32701): start failed: -19
05-13 18:16:06.468: E/AndroidRuntime(32701): java.lang.RuntimeException: start failed.
05-13 18:16:06.468: E/AndroidRuntime(32701): at android.media.MediaRecorder.start(Native Method)
05-13 18:16:06.468: E/AndroidRuntime(32701): at com.example.cameeera.Main.onClick(Main.java:61)
主类
import java.io.IOException;
import android.app.Activity;
import android.hardware.Camera;
import android.media.CamcorderProfile;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.FrameLayout;
public class Main extends Activity implements OnClickListener{
private Camera mCamera;
private CameraPreview mPreview;
private MediaRecorder mMediaRecorder;
private boolean isRecording = false;
Button captureButton;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
captureButton = (Button) findViewById(R.id.button_capture);
captureButton.setOnClickListener(this);
// Create an instance of Camera
mCamera = getCameraInstance();
// Create our Preview view and set it as the content of our activity.
mPreview = new CameraPreview(this, mCamera);
FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
preview.addView(mPreview);
}
@Override
public void onClick(View v) {
if(v.getId() == R.id.button_capture){
if (isRecording) {
// stop recording and release camera
mMediaRecorder.stop(); // stop the recording
releaseMediaRecorder(); // release the MediaRecorder object
mCamera.lock(); // take camera access back from MediaRecorder
// inform the user that recording has stopped
captureButton.setText("Start");;
isRecording = false;
}
else {
// initialize video camera
if (prepareVideoRecorder()== true) {
// Camera is available and unlocked, MediaRecorder is prepared,
// now you can start recording
mMediaRecorder.start();
// inform the user that recording has started
captureButton.setText("Stop");
isRecording = true;
}
else {
// prepare didn't work, release the camera
releaseMediaRecorder();
// inform user
}
}
}
}//OnClick
private boolean prepareVideoRecorder(){
//mCamera = getCameraInstance();
mMediaRecorder = new MediaRecorder ();
// Step 1: Unlock and set camera to MediaRecorder
mCamera.unlock();
mMediaRecorder.setCamera(mCamera);
// Step 2: Set sources
mMediaRecorder.setAudioSource(MediaRecorder.AudioSource.CAMCORDER);
mMediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
// Step 3: Set a CamcorderProfile (requires API Level 8 or higher)
//mMediaRecorder.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_HIGH));
CamcorderProfile highCameraProfile = CamcorderProfile.get(CamcorderProfile.QUALITY_HIGH);
mMediaRecorder.setProfile(highCameraProfile);
mMediaRecorder.setMaxDuration(100000); // MAXDuration 10 seconds
mMediaRecorder.setMaxFileSize(20000000); // MAXSIZE 20 megabytes
// Step 4: Set output file
mMediaRecorder.setOutputFile(SaveVideoFile.getOutputMediaFile(SaveVideoFile.MEDIA_TYPE_VIDEO).toString());
// Step 5: Set the preview output
mMediaRecorder.setPreviewDisplay(mPreview.getHolder().getSurface());
// Step 6: Prepare configured MediaRecorder
try {
mMediaRecorder.prepare();
} catch (IllegalStateException e) {
Log.d("TAG", "IllegalStateException preparing MediaRecorder: " + e.getMessage());
releaseMediaRecorder();
return false;
} catch (IOException e) {
Log.d("TAG", "IOException preparing MediaRecorder: " + e.getMessage());
releaseMediaRecorder();
return false;
}
return true;
}//prepareVideorecorder
@Override
protected void onPause() {
super.onPause();
releaseMediaRecorder(); // if you are using MediaRecorder, release it first
releaseCamera(); // release the camera immediately on pause event
}
private void releaseMediaRecorder(){
if (mMediaRecorder != null) {
mMediaRecorder.reset(); // clear recorder configuration
mMediaRecorder.release(); // release the recorder object
mMediaRecorder = null;
mCamera.lock(); // lock camera for later use
}
}
private void releaseCamera(){
if (mCamera != null){
mCamera.release(); // release the camera for other applications
mCamera = null;
}
}
public static Camera getCameraInstance(){
Camera c = null;
try {
c = Camera.open(); // attempt to get a Camera instance
}
catch (Exception e){
// Camera is not available (in use or does not exist)
Log.d("TAG", "Camera is not available (in use or does not exist)" + e.getMessage());
}
return c; // returns null if camera is unavailable
}
}
这是CameraPreview类，工作正常 包com.example.cameeera;
import java.io.IOException;
import android.content.Context;
import android.hardware.Camera;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
/** Camera preview class */
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
public SurfaceHolder mHolder;
private Camera mCamera;
public CameraPreview(Context context, Camera camera) {
super(context);
mCamera = camera;
// Install a SurfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
mHolder = getHolder();
mHolder.addCallback(this);
}
public void surfaceCreated(SurfaceHolder holder) {
// The Surface has been created, now tell the camera where to draw the preview.
try {
mCamera.setPreviewDisplay(holder);
mCamera.startPreview();
} catch (IOException e) {
Log.d("TAG", "Error setting camera preview: " + e.getMessage());
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
// empty. Take care of releasing the Camera preview in your activity.
}
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
// If your preview can change or rotate, take care of those events here.
// Make sure to stop the preview before resizing or reformatting it.
if (mHolder.getSurface() == null){
// preview surface does not exist
return;
}
// stop preview before making changes
try {
mCamera.stopPreview();
} catch (Exception e){
// ignore: tried to stop a non-existent preview
}
// set preview size and make any resize, rotate or
// reformatting changes here
// start preview with new settings
try {
mCamera.setPreviewDisplay(mHolder);
mCamera.startPreview();
} catch (Exception e){
Log.d("TAG", "Error starting camera preview: " + e.getMessage());
}
}
}