Android Camera Preview Check getPhotoPreviewFpsRange(List frameRates)

Description

get Photo Preview Fps Range

License

Apache License

Declaration

public static int[] getPhotoPreviewFpsRange(List<int[]> frameRates) 

Method Source Code

/*/*w ww  . j  ava 2  s  .  c o m*/
 * Copyright (C) 2009 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import android.app.Activity;
import android.app.AlertDialog;
import android.app.admin.DevicePolicyManager;
import android.content.ActivityNotFoundException;
import android.content.ComponentName;
import android.content.ContentResolver;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Matrix;
import android.graphics.Point;
import android.graphics.Rect;
import android.graphics.RectF;
import android.hardware.Camera;
import android.hardware.Camera.CameraInfo;
import android.hardware.Camera.Parameters;
import android.hardware.Camera.Size;
import android.location.Location;
import android.net.Uri;
import android.os.Handler;
import android.os.ParcelFileDescriptor;
import android.telephony.TelephonyManager;
import android.util.DisplayMetrics;
import android.util.Log;
import android.util.TypedValue;
import android.view.Display;
import android.view.OrientationEventListener;
import android.view.Surface;
import android.view.View;
import android.view.WindowManager;
import android.view.animation.AlphaAnimation;
import android.view.animation.Animation;
import android.widget.Toast;
import com.android.camera.CameraActivity;
import com.android.camera.CameraDisabledException;
import com.android.camera.CameraHolder;
import com.android.camera.CameraManager;
import com.android.camera.util.IntentHelper;
import com.android.camera2.R;
import java.io.Closeable;
import java.io.IOException;
import java.lang.reflect.Method;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;
import java.util.Locale;
import java.util.StringTokenizer;

public class Main{
    private static final String TAG = "Util";
    private final static int MAX_PREVIEW_FPS_TIMES_1000 = 400000;
    private final static int PREFERRED_PREVIEW_FPS_TIMES_1000 = 30000;
    /**
     * For still image capture, we need to get the right fps range such that the
     * camera can slow down the framerate to allow for less-noisy/dark
     * viewfinder output in dark conditions.
     *
     * @param params Camera's parameters.
     * @return null if no appropiate fps range can't be found. Otherwise, return
     *         the right range.
     */
    public static int[] getPhotoPreviewFpsRange(Parameters params) {
        return getPhotoPreviewFpsRange(params.getSupportedPreviewFpsRange());
    }
    public static int[] getPhotoPreviewFpsRange(List<int[]> frameRates) {
        if (frameRates.size() == 0) {
            Log.e(TAG, "No suppoted frame rates returned!");
            return null;
        }

        // Find the lowest min rate in supported ranges who can cover 30fps.
        int lowestMinRate = MAX_PREVIEW_FPS_TIMES_1000;
        for (int[] rate : frameRates) {
            int minFps = rate[Parameters.PREVIEW_FPS_MIN_INDEX];
            int maxFps = rate[Parameters.PREVIEW_FPS_MAX_INDEX];
            if (maxFps >= PREFERRED_PREVIEW_FPS_TIMES_1000
                    && minFps <= PREFERRED_PREVIEW_FPS_TIMES_1000
                    && minFps < lowestMinRate) {
                lowestMinRate = minFps;
            }
        }

        // Find all the modes with the lowest min rate found above, the pick the
        // one with highest max rate.
        int resultIndex = -1;
        int highestMaxRate = 0;
        for (int i = 0; i < frameRates.size(); i++) {
            int[] rate = frameRates.get(i);
            int minFps = rate[Parameters.PREVIEW_FPS_MIN_INDEX];
            int maxFps = rate[Parameters.PREVIEW_FPS_MAX_INDEX];
            if (minFps == lowestMinRate && highestMaxRate < maxFps) {
                highestMaxRate = maxFps;
                resultIndex = i;
            }
        }

        if (resultIndex >= 0) {
            return frameRates.get(resultIndex);
        }
        Log.e(TAG, "Can't find an appropiate frame rate range!");
        return null;
    }
}

Related

1. getMaxPreviewFpsRange(Parameters params)
2. getPhotoPreviewFpsRange(Parameters params)