在Android上使用相機API的問題

Question

我正在嘗試使用android相機API。視頻預覽效果很好。我有一個用於拍攝照片的按鈕實例，然後將其存儲在SD卡上。有時候它可以完美運行，有時不會。按下按鈕之後，視頻預覽會凍結，然後什麼都不會發生，並且在我彈出「應用程序不回覆等等」之後。當這種情況發生時（3時左右）我在logcat中沒有錯誤信息。之後，我必須重新啓動手機，因爲相機不再可用。這裏是我的代碼：

public class Test_cam extends Activity implements PictureCallback,ShutterCallback,OnClickListener{ 
    private static final String TAG = "CameraDemo"; 
     Test_cam_preview preview; // This object will create the Camera object and return it to the CameraDemo activity. 
     Button buttonClick; 
     public boolean onProgress = false; 

     /** Called when the activity is first created. */ 
     @Override 
     public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.camera); 

     preview = new Test_cam_preview(this); 
     ((FrameLayout) findViewById(R.id.preview)).addView(preview); 

     buttonClick = (Button) findViewById(R.id.buttonClick); 
     buttonClick.setOnClickListener(this);  
     Log.d(TAG, "onCreate'd"); 
     } 

     public void launch_scanpic(){ 
       Intent intent = new Intent(Test_cam.this,Test_cam_scanpic.class); 
       startActivity(intent); 
     } 



      @Override 
      public void onClick(View v) { 
        if(!onProgress) 
        { 
          onProgress = true; 
        preview.camera.takePicture(Test_cam.this, null, Test_cam.this); //bien mettre null car raw callback renvoit tjrs null! 
        //on lance scanclothe activity 
        } 
    } 


     @Override 
    public void onShutter() { 
      Log.d(getClass().getSimpleName(), "get pic...");    
    } 



     @Override 
    public void onPictureTaken(byte[] data, Camera camera) { 

      FileOutputStream outStream = null; 
      try { 
      if (data==null) 
      { 
        Log.e(TAG,"data is null !!!!!!!"); 
      } 
      else 
      { 
        // Write to SD Card 
        outStream = new FileOutputStream("/sdcard/test.jpg"); 
        outStream.write(data); 
        Log.e(TAG, "onPictureTaken - wrote bytes: " + data.length); 
        outStream.close(); 
      } 



      } catch (FileNotFoundException e) { 
       Log.e(getClass().getSimpleName(), "file not found",e); 
      e.printStackTrace(); 
      } catch (IOException e) { 
       Log.e(getClass().getSimpleName(), "Saving picture error",e); 
      e.printStackTrace(); 
      } 

      Log.e(TAG, "onPictureTaken - jpeg"); 
      SystemClock.sleep(2000); 
      onProgress=false; 
      launch_scanpic(); 
     } 

}

當應用程序的工作，我明明得到正確的logcat：

05-03 18:22:31.053: INFO/SecCamera(76): int android::SecCamera::endSnapshot() : 
05-03 18:22:31.053: INFO/SecCamera(76): munmap():virt. addr 0x41ddb000 size = 4261248 
05-03 18:22:31.061: DEBUG/dalvikvm(700): GC_FOR_MALLOC freed 506K, 57% free 2779K/6407K, external 1625K/2137K, paused 15ms 
05-03 18:22:31.061: INFO/dalvikvm-heap(700): Grow heap (frag case) to 7.734MB for 1114262-byte allocation 
05-03 18:22:31.088: DEBUG/dalvikvm(700): GC_FOR_MALLOC freed 0K, 49% free 3867K/7559K, external 1625K/2137K, paused 13ms 
05-03 18:22:31.127: DEBUG/dalvikvm(700): GC_CONCURRENT freed <1K, 49% free 3867K/7559K, external 1625K/2137K, paused 2ms+2ms 
05-03 18:22:32.022: ERROR/CameraDemo(700): onPictureTaken - wrote bytes: 1114246 
05-03 18:22:32.022: ERROR/CameraDemo(700): onPictureTaken - jpeg 

我嘗試添加計時器，以留出時間，存儲應用圖片，但沒有效果。我正在Google Nexus S（2.3.4）上進行測試。任何人都可以幫助我解決這個問題？

這裏是我的代碼預覽部分：

class Test_cam_preview extends SurfaceView implements SurfaceHolder.Callback{ 
    private static final String TAG = "Preview"; 
    SurfaceHolder mHolder; 
    public Camera camera; 

    Test_cam_preview(Context context){ 
    super(context); 
    mHolder = getHolder(); 
    mHolder.addCallback(this); 
    mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);} 

    public void surfaceCreated(SurfaceHolder holder){ 
    camera = Camera.open(); 
    Camera.Parameters params = camera.getParameters(); 
    params.setPictureFormat(PixelFormat.JPEG); 
    params.set("flash-mode", "auto"); 
    camera.setParameters(params);  
    try { 
     camera.setPreviewDisplay(holder); 

     camera.setPreviewCallback(new PreviewCallback(){ 
     public void onPreviewFrame(byte[] data, Camera camera){ 
      Test_cam_preview.this.invalidate(); 
     } 
     }); 
    } catch (IOException e) { 
     e.printStackTrace(); 
     camera.release(); 
     camera = null; 
    }} 
    public void surfaceDestroyed(SurfaceHolder holder){ 
     if(camera != null){ 
      camera.stopPreview(); 
      camera.setPreviewCallback(null); 
      camera.release(); //it is important that this is done so camera is  
      camera = null; 
     } 
    } 
    public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) { 
    camera.startPreview(); 
    }} 

在此先感謝。

約翰

Answer 1

我幾乎和你一樣。

它在onPictureTaken中崩潰，因爲拍攝圖片的JNI線程尚未完成，libcamera/SecCameraHWInterface.cpp中的mCaptureInProgress變量尚未設置爲false。

要解決您的問題，您必須刪除您的「SystemClock.sleep（2000）;」而是發送一個延遲的消息到另一個線程，它將在takePicture線程被終止後啓動你的Intent。

我想這一定是在Nexus S的攝像頭的本機代碼中的錯誤，因爲我試過幾個Android手機我的應用程序和它工作得很好，每次上除外Nexus S的:(