本文出自 “whithin's” 博客，请务必保留此出处http://whithin.blog.51cto.com/690417/1063573


1. add  below three permission into AndroidManifest.xml file


  
  1. <uses-permissionandroid:name= "android.permission.CAMERA"/>
  2. <uses-permissionandroid:name= "android.permission.RECORD_AUDIO"/>
  3. <uses-permissionandroid:name= "android.permission.WRITE_EXTERNAL_STORAGE"/>

  
2. get a camera instance

  

  
  1. /** A safe way to get an instance of the Camera object. */
  2. publicstatic Camera getCameraInstance(){ 
  3.     Camera c = null; 
  4. try { 
  5.         c = Camera. open(); // attempt to get a Camera instance
  6.     } 
  7. catch (Exception e){ 
  8. // Camera is not available (in use or does not exist)
  9.     } 
  10. return c; // returns null if camera is unavailable
  11. }  

  


  

   

    3. implement a preview for the user to preview the live p_w_picpath for the camera 
   

   

   

   
  1. publicclass CameraPreview extends SurfaceView implements SurfaceHolder.Callback { 
  2. private SurfaceHolder mHolder; 
  3. private Camera mCamera; 
  5.     String TAG="CAMERAAPI"; 
  7. public CameraPreview(Context context, Camera camera) { 
  8. super(context); 
  9.         mCamera = camera; 
  11. // Install a SurfaceHolder.Callback so we get notified when the
  12. // underlying surface is created and destroyed.
  13.         mHolder = getHolder(); 
  14.         mHolder.addCallback( this); 
  15. // deprecated setting, but required on Android versions prior to 3.0
  16.         mHolder. setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); 
  17.     } 
  19. publicvoid surfaceCreated(SurfaceHolder holder) { 
  20. // The Surface has been created, now tell the camera where to draw the preview.
  21. try { 
  22.             mCamera.setPreviewDisplay(holder); 
  23.             mCamera.startPreview(); 
  24.         } catch (IOException e) { 
  25.             Log. d(TAG, "Error setting camera preview: " + e.getMessage()); 
  26.         } 
  27.     } 
  29. publicvoid surfaceDestroyed(SurfaceHolder holder) { 
  30. // empty. Take care of releasing the Camera preview in your activity.
  31.     } 
  33. publicvoid surfaceChanged(SurfaceHolder holder, int format, int w, int h) { 
  34. // If your preview can change or rotate, take care of those events here.
  35. // Make sure to stop the preview before resizing or reformatting it.
  37. if (mHolder .getSurface() == null){ 
  38. // preview surface does not exist
  39. return; 
  40.         } 
  42. // stop preview before making changes
  43. try { 
  44.             mCamera.stopPreview(); 
  45.         } catch (Exception e){ 
  46. // ignore: tried to stop a non-existent preview
  47.         } 
  49. // set preview size and make any resize, rotate or
  50. // reformatting changes here
  52. // start preview with new settings
  53. try { 
  54.             mCamera.setPreviewDisplay( mHolder); 
  55.             mCamera.startPreview(); 
  57.         } catch (Exception e){ 
  58.             Log. d(TAG, "Error starting camera preview: " + e.getMessage()); 
  59.         } 
  60.     } 
  61. } 

   

    4.initialize MediaRecorder for video recording
   

   

   

   
  1. privateboolean prepareVideoRecorder(){ 
  3.     mCamera = getCameraInstance(); 
  4.     mMediaRecorder = new MediaRecorder(); 
  6. // Step 1: Unlock and set camera to MediaRecorder
  7.     mCamera.unlock(); 
  8.     mMediaRecorder.setCamera(mCamera ); 
  10. // Step 2: Set sources
  11.     mMediaRecorder.setAudioSource(MediaRecorder.AudioSource.CAMCORDER); 
  12.     mMediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA); 
  14. // Step 3: Set a CamcorderProfile (requires API Level 8 or higher)
  15.     mMediaRecorder.setProfile(CamcorderProfile.get(CamcorderProfile. QUALITY_HIGH)); 
  17. // Step 4: Set output file
  18.     mMediaRecorder.setOutputFile(getOutputMediaFile( MEDIA_TYPE_VIDEO).toString()); 
  20. // Step 5: Set the preview output
  21.     mMediaRecorder.setPreviewDisplay(mPreview .getHolder().getSurface()); 
  23. // Step 6: Prepare configured MediaRecorder
  24. try { 
  25.         mMediaRecorder.prepare(); 
  26.     } catch (IllegalStateException e) { 
  27.         Log. d(TAG, "IllegalStateException preparing MediaRecorder: " + e.getMessage()); 
  28.         releaseMediaRecorder(); 
  29. returnfalse ; 
  30.     } catch (IOException e) { 
  31.         Log. d(TAG, "IOException preparing MediaRecorder: " + e.getMessage()); 
  32.         releaseMediaRecorder(); 
  33. returnfalse ; 
  34.     } 
  35. returntrue ; 
  36. } 

  

  


  

   5.listen for the user operation to start or stop recording, the complete code for MediaRecorder is as below,remember to release the camera and MediaRecord when finished using it.
  

  

  

  
  1. publicclass MediaRecorderActivity extends Activity { 
  4. publicstaticfinalint MEDIA_TYPE_IMAGE = 1; 
  5. publicstaticfinalint MEDIA_TYPE_VIDEO = 2; 
  7. private Camera mCamera; 
  8. private CameraPreview mPreview; 
  9. private MediaRecorder mMediaRecorder; 
  10.     String TAG="CAMERAAPI"; 
  11. boolean isRecording=false ; 
  14. @Override
  15. publicvoid onCreate(Bundle savedInstanceState) { 
  16. super.onCreate(savedInstanceState); 
  17.         setContentView(R.layout. main); 
  19.         mCamera = getCameraInstance(); 
  20. //        // Create our Preview view and set it as the content of our activity.
  21.         mPreview = new CameraPreview(this, mCamera); 
  22.         FrameLayout preview = (FrameLayout) findViewById(R.id. camera_preview); 
  23.         preview.addView( mPreview); 
  25.         Button captureButton = (Button) findViewById(id. button_capture); 
  26.         captureButton.setOnClickListener( new CaptureButtonOnClickListener()); 
  27.     } 
  30. publicclass CaptureButtonOnClickListener implements View.OnClickListener{ 
  32. publicvoid onClick(View v) { 
  34.               Button captureButton = (Button)v; 
  36. if (isRecording ) { 
  37. // stop recording and release camera
  38.                 mMediaRecorder.stop();  // stop the recording
  39.                 releaseMediaRecorder(); // release the MediaRecorder object
  40.                 mCamera.lock();         // take camera access back from MediaRecorder
  42. // inform the user that recording has stopped
  43.                 captureButton.setText( "Capture"); 
  45.                 isRecording = false ; 
  46.             } else { 
  48. try{ 
  49. // initialize video camera
  50. if (prepareVideoRecorder()) { 
  51. // Camera is available and unlocked, MediaRecorder is prepared,
  52. // now you can start recording
  53.                     mMediaRecorder.start(); 
  55. // inform the user that recording has started
  56.                     captureButton.setText( "Stop"); 
  57.                     isRecording = true ; 
  58.                 } else { 
  59. // prepare didn't work, release the camera
  60.                     releaseMediaRecorder(); 
  61. // inform user
  62.                 } 
  64.               } catch(Exception ex){ 
  66.                      System. out.println(ex.toString()); 
  67.                      ex.printStackTrace(); 
  68.               } 
  69.             } 
  70.         }      
  71.     } 
  72. /** A safe way to get an instance of the Camera object. */
  73. publicstatic Camera getCameraInstance(){ 
  74.         Camera c = null; 
  75. try { 
  76.             c = Camera. open(); // attempt to get a Camera instance
  77.         } 
  78. catch (Exception e){ 
  79. // Camera is not available (in use or does not exist)
  80.         } 
  81. return c; // returns null if camera is unavailable
  82.     } 
  86. /** Create a File for saving an p_w_picpath or video */
  87. privatestatic File getOutputMediaFile(int type){ 
  88. // To be safe, you should check that the SDCard is mounted
  89. // using Environment.getExternalStorageState() before doing this.
  91.            File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory( 
  92.                      Environment. DIRECTORY_PICTURES), "MyCameraApp" ); 
  93. // This location works best if you want the created p_w_picpaths to be shared
  94. // between applications and persist after your app has been uninstalled.
  96. // Create the storage directory if it does not exist
  97. if (! mediaStorageDir.exists()){ 
  98. if (! mediaStorageDir.mkdirs()){ 
  99.                    Log. d("MyCameraApp", "failed to create directory"); 
  100. returnnull ; 
  101.                } 
  102.            } 
  104. // Create a media file name
  105.            String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss" ).format(new Date()); 
  106.            File mediaFile; 
  107. if (type == MEDIA_TYPE_IMAGE){ 
  108.                mediaFile = new File(mediaStorageDir.getPath() + File.separator + 
  109. "IMG_"+ timeStamp + ".jpg" ); 
  110.            } elseif (type == MEDIA_TYPE_VIDEO) { 
  111.                mediaFile = new File(mediaStorageDir.getPath() + File.separator + 
  112. "VID_"+ timeStamp + ".mp4" ); 
  113.            } else { 
  114. returnnull ; 
  115.            } 
  117. return mediaFile; 
  118.        } 
  120. @Override
  121. protectedvoid onPause() { 
  122. super.onPause(); 
  123.                releaseMediaRecorder();       // if you are using MediaRecorder, release it first
  124.                releaseCamera();              // release the camera immediately on pause event
  125.            } 
  127. privatevoid releaseCamera(){ 
  128. if (mCamera != null){ 
  129.                    mCamera.release();        // release the camera for other applications
  130.                    mCamera = null; 
  131.                } 
  132.            } 
  134. privatevoid releaseMediaRecorder(){ 
  135. if (mMediaRecorder != null) { 
  136.                    mMediaRecorder.reset();   // clear recorder configuration
  137.                    mMediaRecorder.release(); // release the recorder object
  138.                    mMediaRecorder = null ; 
  139.                    mCamera.lock();           // lock camera for later use
  140.                } 
  141.            }    
  142. } 

  


  
本文出自 “whithin's” 博客，请务必保留此出处http://whithin.blog.51cto.com/690417/1063573