mtk平台Camera应用的全屏分析

     将摄像头的配置文件vendor/mediatek/proprietary/custom/mt6735/hal/D1/sendepfeature/xxxx_mipi_raw/config.ftbl.xxxx_mipi_raw.h

编译进系统后，选择预览大小为全屏，图片大小显示一个100万像素，拍出图片只有1280x768，

但真实的摄像头有500万像素，拍出的图片大小不应该这么小，当预览大小为4:3是，有多中图片

大小可供选择,照片大小正常．该应用的全屏为什么不对呢．

vendor/mediatek/proprietary/packages/apps/Camera/

CameraDeviceExt.java

// TODO
    @Override
    public void setPreviewSize() {
        String pictureRatio = mPreferences.getString(SettingConstants.KEY_PICTURE_RATIO, null);　
        if (pictureRatio == null) {　　//刷机第一次跑
            List<String> supportedRatios = SettingUtils.buildPreviewRatios(mActivity,
                    mParametersExt);
            if (supportedRatios != null && supportedRatios.size() > 0) {
                SharedPreferences.Editor editor = mPreferences.edit();
                String ratioString = supportedRatios.get(supportedRatios.size() - 1);
      		  editor.putString(SettingConstants.KEY_PICTURE_RATIO, ratioString);
                editor.apply();
                pictureRatio = ratioString;
            }
        }
        SettingUtils.setPreviewSize(mActivity, mParametersExt, pictureRatio);

        String pictureSize = mPreferences.getString(SettingConstants.KEY_PICTURE_SIZE, null);
        int limitedResolution = SettingUtils.getLimitResolution();
        if (limitedResolution > 0) {
            int index = pictureSize.indexOf('x');
            int width = Integer.parseInt(pictureSize.substring(0, index));
            int height = Integer.parseInt(pictureSize.substring(index + 1));
            if (width * height > limitedResolution) {
                pictureSize = null;
            }
        }
        if (pictureSize == null) {
            List<String> supportedSizes = SettingUtils
                    .buildSupportedPictureSizeByRatio(mParametersExt, pictureRatio);
            SettingUtils.sortSizesInAscending(supportedSizes);
            Log.i(TAG, "limitedResolution:" + limitedResolution);
            if (limitedResolution > 0) {
                SettingUtils.filterLimitResolution(supportedSizes);
            }

            if (supportedSizes != null && supportedSizes.size() > 0) {
                pictureSize = supportedSizes.get(supportedSizes.size() - 1);
                SharedPreferences.Editor editor = mPreferences.edit();
                editor.putString(SettingConstants.KEY_PICTURE_SIZE, pictureSize);
                editor.apply();

            }
        }
        Point ps = SettingUtils.getSize(pictureSize);
        mParametersExt.setPictureSize(ps.x, ps.y);
    }

String pictureRatio = mPreferences.getString(SettingConstants.KEY_PICTURE_RATIO, null);

这里读上次的值，所有调试的时候要将/data/data/com.mediatek.camera/shared_prefs删掉，否则看不到打印信息

SettingUtils.java

    public static List<String> buildPreviewRatios(Context context, Parameters parameters) {
        List<String> supportedRatios = new ArrayList<String>();
        String findString = null;
        if (context != null && parameters != null) {
            // Add standard preview ratio.
            supportedRatios.add(getRatioString(4d / 3));

            mCurrentFullScreenRatio = findFullscreenRatio(context);
            List<String> fullScreenPictureSizes = buildSupportedPictureSizeByRatio(parameters,
                    getRatioString(mCurrentFullScreenRatio));
            // Add full screen ratio if platform has full screen ratio picture sizes.
            if (fullScreenPictureSizes.size() > 0) {
                findString = getRatioString(mCurrentFullScreenRatio);
                if (!supportedRatios.contains(findString)) {
                    supportedRatios.add(findString);
                }
            }
        }
        Log.d(TAG, "buildPreviewRatios(" + parameters + ") add supportedRatio " + findString);
        return supportedRatios;
    }

public static final double[] RATIOS = new double[] { 1.3333, 1.5, 1.6667, 1.7778 };    
public static double findFullscreenRatio(Context context) {
        double find = 4d / 3;
        WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
        Display display = wm.getDefaultDisplay();
        Point point = new Point();
        display.getRealSize(point);
        mFullScreenWidth = point.x;
        mFullScreenHeight = point.y;

        double fullscreen;
        if (point.x > point.y) {
            fullscreen = (double) point.x / point.y;
        } else {
            fullscreen = (double) point.y / point.x;
        }
        Log.i(TAG, "fullscreen = " + fullscreen + " x = " + point.x + " y = " + point.y);
        for (int i = 0; i < RATIOS.length; i++) {
            if (Math.abs(RATIOS[i] - fullscreen) < Math.abs(fullscreen - find)) {
                find = RATIOS[i];
            }
        }
        Log.d(TAG, "findFullscreenRatiom, return ratio:" + find);
        return find;
    }

从源码看就是从4:3,5:3,3:2,16:9中找出最接近屏幕的屏比,那么在摄像头的配置文件中添加相应比例

的图片大小即可，注意不要超过摄像头像素，否则第三方应用获取到的摄像头分辨率(所有图片大小

中最大的一个对应的像素)不对.