再会！我正在学习如何使用 MediaRecorder 录制视频，但播放时录制的视频已损坏。看这个截图：http://www.4shared.com/photo/QtmJCHRi/corrupted-video.html http://www.4shared.com/photo/QtmJCHRi/corrupted-video.html。左上角红色矩形标记的图片是相机可以看到的。但它很小，而且是重复的，而且有很多绿地。请告诉我我做错了什么。硬件是三星 Galaxy S2（GT-I9100，Android 2.3.5）。我尝试按照本教程进行操作：http://developer.android.com/guide/topics/media/camera.html# saving-media http://developer.android.com/guide/topics/media/camera.html#saving-media
先感谢您！
CameraRecorderActivity.java
package cz.ryvo.android.camerarecorder;
import java.io.File;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
import android.app.Activity;
import android.content.Context;
import android.content.pm.PackageManager;
import android.hardware.Camera;
import android.hardware.Camera.CameraInfo;
import android.media.CamcorderProfile;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.FrameLayout;
public class CameraRecorderActivity extends Activity
implements SurfaceHolder.Callback, OnClickListener {
private static final String TAG = "CameraRecorderActivity";
public static final int MEDIA_TYPE_IMAGE = 1;
public static final int MEDIA_TYPE_VIDEO = 2;
private Camera mCamera;
private CameraPreview mPreview;
private MediaRecorder mMediaRecorder;
private Button captureButton;
private boolean isRecording = false;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// Create an instance of Camera.
mCamera = getCameraInstance();
// Create preview view and set it as the content of our activity.
mPreview = new CameraPreview(this, mCamera);
int i = R.id.camera_preview;
Object o = this.findViewById(i);
FrameLayout preview = (FrameLayout) o;
preview.addView(mPreview);
// Add a listener to the Capture button
captureButton = (Button) findViewById(R.id.button_capture);
captureButton.setOnClickListener(
new View.OnClickListener() {
@Override
public void onClick(View v) {
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
setCaptureButtonText("Capture");
isRecording = false;
} else {
// initialize video camera
if (prepareVideoRecorder()) {
// Camera is available and unlocked, MediaRecorder is prepared,
// now you can start recording
mMediaRecorder.start();
// inform the user that recording has started
setCaptureButtonText("Stop");
isRecording = true;
} else {
// prepare didn't work, release the camera
releaseMediaRecorder();
// inform user
}
}
}
}
);
}
public void setCaptureButtonText(String s) {
captureButton.setText(s);
}
@Override
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());
}
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
// TODO Auto-generated method stub
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
// TODO Auto-generated method stub
}
/** Create a File for saving an image or video */
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), "MyCameraApp");
// 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 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);
mMediaRecorder.setVideoSize(720, 480);
// Step 3: Set a CamcorderProfile (requires API Level 8 or higher)
mMediaRecorder.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_HIGH));
// Step 4: Set output file
mMediaRecorder.setOutputFile(getOutputMediaFile(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;
}
@Override
public void onClick(View v) {
/*
Log.i("onClick", "BEGIN");
if(!recording) {
recording = startRecording();
} else {
stopRecording();
recording = false;
}
Log.i("onClick", "END");
*/
}
@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;
}
}
private Camera getCameraInstance(){
Camera c = null;
try {
c = Camera.open(); // attempt to get a Camera instance
//c = this.open(); // attempt to get a Camera instance
}
catch (Exception e){
// Camera is not available (in use or does not exist)
}
return c; // returns null if camera is unavailable
}
public Camera open() {
int numberOfCameras = Camera.getNumberOfCameras();
CameraInfo cameraInfo = new CameraInfo();
for (int i = 0; i < numberOfCameras; i++) {
Camera.getCameraInfo(i, cameraInfo);
if (cameraInfo.facing == CameraInfo.CAMERA_FACING_BACK) {
return Camera.open(i);
}
}
return null;
}
}
相机预览.java
package cz.ryvo.android.camerarecorder;
import java.io.IOException;
import android.content.Context;
import android.hardware.Camera;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
private static final String TAG = "CameraPreview";
private 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);
// deprecated setting, but required on Android versions prior to 3.0
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
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
}
// 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());
}
}
}
