上previewFrame不改变数据 [英] onPreviewFrame doesn't change the data

问题描述

这是在Android上我第一次编程，多的我不熟悉的Java programmation。我试图找到我在互联网上的一些问题的答案，但没有找到任何解决办法。我希望你们中的一个将能够帮助我。 我想要做的是运用一些图像处理实时视频摄像头和显示。这就是为什么我使用previewFrame该函数的结果之前显示的做一些图像处理。请告诉我，如果它是不是最好的方法。我的问题是，当我试图修改该数据阵列，作为没有任何改变的屏幕上。从我所看到的调试器函数被调用。所有这一切都完成与2.1的API。

It is my first time programming on Android, and more I am not that familiar with the java programmation. I tried to find some answer on my problem over the internet but didn't find any solution. I hope one of you will be able to help me. What I want to do is applying some image processing in real time to the video camera and display it. That is why I am using the function onPreviewFrame the make some image processing before display the result. Please tell me if it isn't the best way. my problem is that when I try to modify the data array, nothing as changed on the screen. From what I saw with the debugger the function is called. All of that is done with the 2.1 API.

是否有人知道为什么吗？我怎样才能解决这个问题？

Does someone know why? How can i solve this?

要帮助，这是我的code：

To help, here is my code :

import android.app.Activity;
import android.content.Context;
import android.hardware.Camera;
import android.os.Bundle;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.Window;
import java.io.IOException;

// ----------------------------------------------------------------------

public class CameraPreview extends Activity {    
    private Preview mPreview;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Hide the window title.
        requestWindowFeature(Window.FEATURE_NO_TITLE);

        // Create our Preview view and set it as the content of our activity.
        mPreview = new Preview(this);
        setContentView(mPreview);
    }

}

// ----------------------------------------------------------------------

class Preview extends SurfaceView implements SurfaceHolder.Callback, Camera.PreviewCallback {
    SurfaceHolder mHolder;
    Camera mCamera;

    Preview(Context context) {
        super(context);

        // Install a SurfaceHolder.Callback so we get notified when the
        // underlying surface is created and destroyed.
        mHolder = getHolder();
        mHolder.addCallback(this);
        mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    }

    public void surfaceCreated(SurfaceHolder holder) {
        // The Surface has been created, acquire the camera and tell it where
        // to draw.

        mCamera = Camera.open();
        try {
            mCamera.setPreviewDisplay(holder);      
            mCamera.setPreviewCallback(this);

        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }


    }


    public void onPreviewFrame(byte[] data, Camera camera) { 
        if (data != null) {
            for(int i=0;i<data.length;i++){
                data[i] = 0;
            }
        }

    }


    public void surfaceDestroyed(SurfaceHolder holder) {
        // Surface will be destroyed when we return, so stop the preview.
        // Because the CameraDevice object is not a shared resource, it's very
        // important to release it when the activity is paused.
        mCamera.stopPreview();
        mCamera.release();
        mCamera = null;
    }

    public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
        // Now that the size is known, set up the camera parameters and begin
        // the preview.
        Camera.Parameters parameters = mCamera.getParameters();
        parameters.setPreviewSize(w, h);
        mCamera.setParameters(parameters);
        mCamera.startPreview();
    }

}

感谢您的帮助， 摩根科米尔

Thank you for the help, Morgan Cormier

推荐答案

对于我来说只有当我安装previewCallback在SurfaceChanged方法

For me only works if I install the PreviewCallback in the method on SurfaceChanged

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