我得到了跟踪堆栈跟踪
04-17 12:11:56.378: D/ATRecorder(10379): com.htc.autotest.dlib.RecordEngine in loader dalvik.system.DexClassLoader@40528b78
04-17 12:11:56.408: D/WindowManagerImpl(10379): addView, new view, mViews[0]: com.android.internal.policy.impl.PhoneWindow$DecorView@40520738
04-17 12:11:56.428: D/WindowManagerImpl(10379): addView, new view, mViews[1]: android.widget.LinearLayout@40525d00
04-17 12:11:56.438: D/WindowManagerImpl(10379): finishRemoveViewLocked, mViews[1]: android.widget.LinearLayout@40525d00
04-17 12:11:56.718: D/TAG(10379): Error setting camera preview: setPreviewDisplay failed
04-17 12:11:56.748: D/TAG(10379): Error starting camera preview: setPreviewDisplay failed
04-17 12:12:07.558: D/View(10379): onTouchEvent: viewFlags: 0x18004001
04-17 12:12:07.568: D/View(10379): onTouchEvent: isFocusable: true, isFocusableInTouchMode: false, isFocused: false; focusTaken: false
04-17 12:12:07.588: V/MediaRecorderJNI(10379): start
04-17 12:12:07.598: V/MediaRecorderJNI(10379): getMediaRecorder E
04-17 12:12:11.632: V/MediaRecorderJNI(10379): process_media_recorder_call
04-17 12:12:11.642: W/IMediaDeathNotifier(10379): media server died
04-17 12:12:11.642: V/MediaRecorderJNI(10379): JNIMediaRecorderListener::notify
04-17 12:12:11.642: V/MediaRecorderJNI(10379): notify msgType 0x1, ext1 0x64
04-17 12:12:11.642: W/Camera(10379): ICamera died
04-17 12:12:11.642: W/Camera(10379): Camera server died!
04-17 12:12:11.702: E/Camera(10379): Error 100
我的代码是
public class VideoDemoActivity extends Activity {
/** Called when the activity is first created. */
private Camera mCamera;
private CameraPreview mPreview;
private Button btnCapture,btnStop;
private MediaRecorder mMediaRecorder;
FrameLayout preview;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
initialize();
if (!checkCameraHardware(this)) {
Toast.makeText(this, "Camera not found", Toast.LENGTH_SHORT).show();
finish();
} else {
Toast.makeText(this, "Camera found", Toast.LENGTH_SHORT).show();
}
mCamera = getCameraInstance();
mPreview = new CameraPreview(this, mCamera);
preview.addView(mPreview);
System.out.println(prepareVideoRecorder());
btnCapture.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
try {
mMediaRecorder.start();
} catch (IllegalStateException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});
btnStop.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
mMediaRecorder.stop();
}
});
}
private void initialize() {
// TODO Auto-generated method stub
preview = (FrameLayout) findViewById(R.id.camera_preview);
btnCapture = (Button) findViewById(R.id.button_capture);
btnStop = (Button) findViewById(R.id.button_stop);
}
public Camera getCameraInstance(){
Camera c = null;
try {
c = Camera.open(); // attempt to get a Camera instance
}
catch (Exception e){
e.printStackTrace();
}
return c; // returns null if camera is unavailable
}
private boolean checkCameraHardware(Context context) {
if (context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA)){
// this device has a camera
return true;
} else {
// no camera on this device
return false;
}
}
@Override
protected void onPause() {
// TODO Auto-generated method stub
super.onPause();
releaseMediaRecorder(); // if you are using MediaRecorder, release it first
releaseCamera(); // release the camera immediately on pause event
}
private boolean prepareVideoRecorder(){
mMediaRecorder = new MediaRecorder();
mCamera.unlock();
mMediaRecorder.setCamera(mCamera);
mMediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
mMediaRecorder.setVideoSource(MediaRecorder.VideoSource.DEFAULT);
mMediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
mMediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
mMediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.MPEG_4_SP);
mMediaRecorder.setOutputFile(getOutputMediaFile().toString());
try
{
mMediaRecorder.prepare();
} catch (IllegalStateException e) {
e.printStackTrace();
releaseMediaRecorder();
return false;
} catch (IOException e) {
e.printStackTrace();
releaseMediaRecorder();
return false;
}
return true;
}
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;
}
}
private static File getOutputMediaFile(){
File mediaFile = new File(Environment.getExternalStorageDirectory()+"/video.mp4");
return mediaFile;
}
}
所以请帮我解决这个问题..如果我删除方法
prepareVideoRecorder（）
然后它正确地预览相机..但是在执行此方法之后它没有显示任何预览......它失败了
请求帮助我..mMediaRecorder.start（）;
答案 0 :(得分：8)
在创建MediaRecorder之前，您必须解锁相机。并在释放之前将其锁定。
试试这段代码，它会有用吗...
package com.marcodinacci.book.acb;
import java.io.IOException;
import android.app.Activity;
import android.content.pm.ActivityInfo;
import android.hardware.Camera;
import android.media.MediaRecorder;
import android.os.Bundle;
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;
public class MediaRecorderRecipe extends Activity implements SurfaceHolder.Callback {
private final String VIDEO_PATH_NAME = "/mnt/sdcard/VGA_30fps_512vbrate.mp4";
private MediaRecorder mMediaRecorder;
private Camera mCamera;
private SurfaceView mSurfaceView;
private SurfaceHolder mHolder;
private View mToggleButton;
private boolean mInitSuccesful;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.media_recorder_recipe);
// 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 OnClickListener() {
@Override
// toggle video recording
public void onClick(View v) {
if (((ToggleButton)v).isChecked()) {
mMediaRecorder.start();
try {
Thread.sleep(10 * 1000);
} 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);
mMediaRecorder.setVideoSource(MediaRecorder.VideoSource.DEFAULT);
// mMediaRecorder.setOutputFormat(8);
mMediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
mMediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H264);
mMediaRecorder.setVideoEncodingBitRate(512 * 1000);
mMediaRecorder.setVideoFrameRate(30);
mMediaRecorder.setVideoSize(640, 480);
mMediaRecorder.setOutputFile(VIDEO_PATH_NAME);
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;
}
}
的AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.marcodinacci.book.acb"
android:versionCode="1"
android:versionName="1.0">
<uses-sdk android:minSdkVersion="7" />
<uses-permission android:name="android.permission.CAMERA"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.RECORD_AUDIO" />
<uses-feature android:name="android.hardware.camera.autofocus" />
<application android:icon="@drawable/icon" android:label="@string/app_name">
<activity android:name="MediaRecorderRecipe"
android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
media_recorder_recipe.xml
<?xml version="1.0" encoding="utf-8"?>
<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>
答案 1 :(得分：1)
您是否已在清单中获得权限？
<uses-feature android:name="android.hardware.camera" />
<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name = "android.permission.RECORD_AUDIO"/>