Camera Preview测试用例说明

Platform: RK3288
OS: Android 6.0
Kernel: 3.10.92

说明：

1.打开就预览
2. button用于控制是开启preview callback并保存为jpg

源代码：

package com.example.camerapreviewtest;

import android.content.Context;
import android.graphics.ImageFormat;
import android.graphics.Rect;
import android.graphics.YuvImage;
import android.hardware.Camera;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.ContentFrameLayout;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.widget.Button;
import android.widget.FrameLayout;

import java.io.ByteArrayOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;

public class MainActivity extends AppCompatActivity {

private Camera mCamera;
private CameraPreview mPreview;
SurfaceHolder mSurfaceHolder;

private static final String TAG = "MainActivity";



@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.camera_preview);
    Log.i(TAG, "camera number: "+Camera.getNumberOfCameras());
    mCamera = getCameraInstance();
    mPreview = new CameraPreview(this, mCamera);
    FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
    preview.addView(mPreview);

    Button button = (Button) findViewById(R.id.button);

    button.setOnClickListener(
            new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    Log.i(TAG, "onClick: ");
                    mCamera.setPreviewCallback(new Camera.PreviewCallback(){
                        @Override
                        public void onPreviewFrame(byte[] data, Camera camera) {
                            Camera.Size size = mCamera.getParameters().getPreviewSize();
                            //Log.i(TAG, "onPreviewFrame: width:"+size.width+" height:"+size.height);
                            try{
                                YuvImage image = new YuvImage(data, ImageFormat.NV21, size.width, size.height, null);
                                if(image!=null){
                                    ByteArrayOutputStream stream = new ByteArrayOutputStream();
                                    image.compressToJpeg(new Rect(0, 0, size.width, size.height), 80 ,stream);

                                    FileOutputStream output = new FileOutputStream("/sdcard/t.jpg");
                                    output.write(stream.toByteArray());
                                    output.flush();
                                    output.close();
                                    Log.i(TAG, "onPreviewFrame: to jpeg");
                                }
                            } catch (Exception e){

                            }
                        }
                    });
                }
            }
    );

}

public static Camera getCameraInstance(){
    Camera c = null;
    try {
        c = Camera.open();
        if(c==null)
            Log.i(TAG, "getCameraInstance: ");
    }catch (Exception e){
        Log.i(TAG, "getCameraInstance: exception");
    }
    return c;
}

public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback{
    private SurfaceHolder mHolder;
    private Camera mCamera;
    public CameraPreview(Context context, Camera camera){
        super(context);
        mCamera = camera;
        mHolder = getHolder();
        mHolder.addCallback(this);
    }

    public void surfaceCreated(SurfaceHolder holder){
        try {
            mCamera.setPreviewDisplay(holder);
            mCamera.startPreview();
        }catch (IOException e){

        }
    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        if(mCamera!=null){
            mCamera.stopPreview();
            mCamera.release();
            mCamera = null;
        }
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {

    }
}

}

原作者：KrisFei