自己写的照相机预览(SurfaceView)

可能隔得一段时间,自己写的东西就忘记了。所以记录下
这是在一家公司做图片识别时写的一个照相机预览。
转载注明出处:http://blog.youkuaiyun.com/ning_gg/article/details/54090446
需要TextureView的在这里http://blog.youkuaiyun.com/ning_gg/article/details/54134918

import android.content.Context;
import android.content.pm.PackageManager;
import android.hardware.Camera;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

import com.imapedia.ykdemo.utils.L;

import java.io.IOException;
import java.util.List;

/**
 * Created by ning_gg on 2017/1/6.
 */
public class CameraSurfaceView extends SurfaceView implements SurfaceHolder.Callback {
    private String TAG=CameraSurfaceView.class.getSimpleName();
    private Context mContext;
    private Camera mCamera;
    private SurfaceHolder mHolder;
    private int screenHeight;//屏幕的高度
    private int screenWidth;//屏幕的宽度

    /***
     * 是否支持自动对焦
     */
    private boolean isSupportAutoFocus;
    public static Camera.Size pictureSize;
    private Camera.Size previewSize;
    public CameraSurfaceView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init(context);
        mHolder=this.getHolder();
        mHolder.addCallback(this);
    }

    private void init(Context context) {
        mContext = context;

        DisplayMetrics dm = getResources().getDisplayMetrics();
        screenWidth = dm.widthPixels;
        screenHeight = dm.heightPixels;
        isSupportAutoFocus = context.getPackageManager().hasSystemFeature(
                PackageManager.FEATURE_CAMERA_AUTOFOCUS);
    }

    @Override
    public void surfaceCreated(SurfaceHolder surfaceHolder) {
        try {
            mCamera = Camera.open();
            if (mCamera == null) {
                return;
            }
            mCamera.setDisplayOrientation(90);
            // 设置holder主要是用于surfaceView的图片的实时预览，以及获取图片等功能，可以理解为控制camera的操作..

            mCamera.setPreviewDisplay(surfaceHolder);
            setCameraParms();
            //mCamera.setPreviewCallback(this);
            mCamera.startPreview();
            mCamera.cancelAutoFocus();
            requestLayout();

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

    private void setCameraParms() {
        Camera.Parameters myParam = mCamera.getParameters();
        List<String> flashModes = myParam.getSupportedFlashModes();
        String flashMode = myParam.getFlashMode();
        // Check if camera flash exists
        if (flashModes == null) {
            return;
        }
        if (!Camera.Parameters.FLASH_MODE_OFF.equals(flashMode)) {
            // Turn off the flash
            if (flashModes.contains(Camera.Parameters.FLASH_MODE_OFF)) {
                myParam.setFlashMode(Camera.Parameters.FLASH_MODE_OFF);
            } else {
            }
        }

        float percent = calcPreviewPercent();
        List<Camera.Size> supportedPreviewSizes = myParam.getSupportedPreviewSizes();
        previewSize = getPreviewMaxSize(supportedPreviewSizes, percent);
        L.e(TAG, "预览尺寸w===" + previewSize.width + ",h==="
                + previewSize.height);
        // 获取摄像头支持的各种分辨率
        List<Camera.Size> supportedPictureSizes = myParam.getSupportedPictureSizes();
        pictureSize = findSizeFromList(supportedPictureSizes, previewSize);
        if (pictureSize == null) {
            pictureSize = getPictureMaxSize(supportedPictureSizes, previewSize);
        }
        L.e(TAG, "照片尺寸w===" + pictureSize.width + ",h==="
                + pictureSize.height);
        // 设置照片分辨率，注意要在摄像头支持的范围内选择
        myParam.setPictureSize(pictureSize.width, pictureSize.height);
        // 设置预浏尺寸，注意要在摄像头支持的范围内选择
        myParam.setPreviewSize(previewSize.width, previewSize.height);
        myParam.setJpegQuality(70);

        mCamera.setParameters(myParam);
    }

    private float calcPreviewPercent() {
        float d = screenHeight;
        return d / screenWidth;
    }

    private Camera.Size findSizeFromList(List<Camera.Size> supportedPictureSizes, Camera.Size size) {
        Camera.Size s = null;
        if (supportedPictureSizes != null && !supportedPictureSizes.isEmpty()) {
            for (Camera.Size su : supportedPictureSizes) {
                if (size.width == su.width && size.height == su.height) {
                    s = su;
                    break;
                }
            }
        }
        return s;
    }

    // 根据摄像头的获取与屏幕分辨率最为接近的一个分辨率
    private Camera.Size getPictureMaxSize(List<Camera.Size> l, Camera.Size size) {
        Camera.Size s = null;
        for (int i = 0; i < l.size(); i++) {
            if (l.get(i).width >= size.width && l.get(i).height >= size.width
                    && l.get(i).height != l.get(i).width) {
                if (s == null) {
                    s = l.get(i);
                } else {
                    if (s.height * s.width > l.get(i).width * l.get(i).height) {
                        s = l.get(i);
                    }
                }
            }
        }
        return s;
    }

    // 获取预览的最大分辨率
    private Camera.Size getPreviewMaxSize(List<Camera.Size> l, float j) {
        int idx_best = 0;
        int best_width = 0;
        float best_diff = 100.0f;
        for (int i = 0; i < l.size(); i++) {
            int w = l.get(i).width;
            int h = l.get(i).height;
            if (w * h < screenHeight * screenWidth)
                continue;
            float previewPercent = (float) w / h;
            float diff = Math.abs(previewPercent - j);
            if (diff < best_diff) {
                idx_best = i;
                best_diff = diff;
                best_width = w;
            } else if (diff == best_diff && w > best_width) {
                idx_best = i;
                best_diff = diff;
                best_width = w;
            }
        }
        return l.get(idx_best);
    }

    @Override
    public void surfaceChanged(SurfaceHolder surfaceHolder, int i, int i1, int i2) {

    }

    @Override
    public void surfaceDestroyed(SurfaceHolder surfaceHolder) {
        L.e(TAG,"surfaceDestroyed");
        if (mCamera != null) {
            mCamera.setPreviewCallback(null);
            mCamera.stopPreview();
            mCamera.release();
            mCamera = null;
        }
    }
}

Camera有一组预览尺寸,也有一组录像尺寸，还有一组照片尺寸，有人说的录像时尺寸会变形那是因为预览跟录像不搭配的问题导致的,我也做了这个修改,最起码我自己的多个测试手机没有这种变形的问题了。过几天再贴这个录像的吧。
转载注明出处:http://blog.youkuaiyun.com/ning_gg/article/details/54090446