Android开发：调用camera API 创建MediaRecorder
本文出自 “whithin's” 博客，請(qǐng)務(wù)必保留此出處http://whithin.blog.51cto.com/690417/1063573
1. add ?below three permission into AndroidManifest.xml file
<uses-permissionandroid:name= "android.permission.CAMERA"/>
<uses-permissionandroid:name= "android.permission.RECORD_AUDIO"/>
<uses-permissionandroid:name= "android.permission.WRITE_EXTERNAL_STORAGE"/>
2. get a camera instance
/** A safe way to get an instance of the Camera object. */
publicstatic 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)
? ?}
return c; // returns null if camera is unavailable
} ?
publicclass CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
private SurfaceHolder mHolder;
private Camera mCamera;
? ?String TAG="CAMERAAPI";
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);
? ?}
publicvoid 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());
? ? ? ?}
? ?}
publicvoid surfaceDestroyed(SurfaceHolder holder) {
// empty. Take care of releasing the Camera preview in your activity.
? ?}
publicvoid 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());
? ? ? ?}
? ?}
}
privateboolean 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));
// 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();
returnfalse ;
? ?} catch (IOException e) {
? ? ? ?Log. d(TAG, "IOException preparing MediaRecorder: " + e.getMessage());
? ? ? ?releaseMediaRecorder();
returnfalse ;
? ?}
returntrue ;
}
publicclass MediaRecorderActivity extends Activity {
publicstaticfinalint MEDIA_TYPE_IMAGE = 1;
publicstaticfinalint MEDIA_TYPE_VIDEO = 2;
private Camera mCamera;
private CameraPreview mPreview;
private MediaRecorder mMediaRecorder;
? ?String TAG="CAMERAAPI";
boolean isRecording=false ;
@Override
publicvoid onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
? ? ? ?setContentView(R.layout. main);
? ? ? ?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);
? ? ? ?Button captureButton = (Button) findViewById(id. button_capture);
? ? ? ?captureButton.setOnClickListener( new CaptureButtonOnClickListener());
? ?}
publicclass CaptureButtonOnClickListener implements View.OnClickListener{
publicvoid onClick(View v) {
? ? ? ? ? ? ?Button captureButton = (Button)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
? ? ? ? ? ? ? ?captureButton.setText( "Capture");
? ? ? ? ? ? ? ?isRecording = false ;
? ? ? ? ? ?} else {
try{
// 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
? ? ? ? ? ? ? ? ? ?captureButton.setText( "Stop");
? ? ? ? ? ? ? ? ? ?isRecording = true ;
? ? ? ? ? ? ? ?} else {
// prepare didn't work, release the camera
? ? ? ? ? ? ? ? ? ?releaseMediaRecorder();
// inform user
? ? ? ? ? ? ? ?}
? ? ? ? ? ? ?} catch(Exception ex){
? ? ? ? ? ? ? ? ? ? System. out.println(ex.toString());
? ? ? ? ? ? ? ? ? ? ex.printStackTrace();
? ? ? ? ? ? ?}
? ? ? ? ? ?}
? ? ? ?} ? ? ?
? ?}
/** A safe way to get an instance of the Camera object. */
publicstatic 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)
? ? ? ?}
return c; // returns null if camera is unavailable
? ?}
/** Create a File for saving an p_w_picpath or video */
privatestatic 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 p_w_picpaths 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");
returnnull ;
? ? ? ? ? ? ? }
? ? ? ? ? }
// 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" );
? ? ? ? ? } elseif (type == MEDIA_TYPE_VIDEO) {
? ? ? ? ? ? ? mediaFile = new File(mediaStorageDir.getPath() + File.separator +
"VID_"+ timeStamp + ".mp4" );
? ? ? ? ? } else {
returnnull ;
? ? ? ? ? }
return mediaFile;
? ? ? }
@Override
protectedvoid onPause() {
super.onPause();
? ? ? ? ? ? ? releaseMediaRecorder(); ? ? ? // if you are using MediaRecorder, release it first
? ? ? ? ? ? ? releaseCamera(); ? ? ? ? ? ? ?// release the camera immediately on pause event
? ? ? ? ? }
privatevoid releaseCamera(){
if (mCamera != null){
? ? ? ? ? ? ? ? ? mCamera.release(); ? ? ? ?// release the camera for other applications
? ? ? ? ? ? ? ? ? mCamera = null;
? ? ? ? ? ? ? }
? ? ? ? ? }
privatevoid releaseMediaRecorder(){
if (mMediaRecorder != null) {
? ? ? ? ? ? ? ? ? mMediaRecorder.reset(); ? // clear recorder configuration
? ? ? ? ? ? ? ? ? mMediaRecorder.release(); // release the recorder object
? ? ? ? ? ? ? ? ? mMediaRecorder = null ;
? ? ? ? ? ? ? ? ? mCamera.lock(); ? ? ? ? ? // lock camera for later use
? ? ? ? ? ? ? }
? ? ? ? ? } ? ?
}
本文出自 “whithin's” 博客，請(qǐng)務(wù)必保留此出處http://whithin.blog.51cto.com/690417/1063573
轉(zhuǎn)載于:https://blog.51cto.com/yuzuolin/1330360
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