Android example source code file (CameraProfile.java)

This example Android source code file (CameraProfile.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" ^TM.

Java - Android tags/keywords

always, cameraprofile, illegalargumentexception, jpeg, lower, quality_high, quality_low, quality_medium, runtimeexception, unexpected, unsupported, util

The CameraProfile.java Android example source code

/*
 * Copyright (C) 2010 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.
 */

package android.media;

import java.util.Arrays;

/**
 * The CameraProfile class is used to retrieve the pre-defined still image
 * capture (jpeg) quality levels (0-100) used for low, medium, and high
 * quality settings in the Camera application.
 *
 */
public class CameraProfile
{
    /**
     * Define three quality levels for JPEG image encoding.
     */
    /*
     * Don't change the values for these constants unless getImageEncodingQualityLevels()
     * method is also changed accordingly.
     */
    public static final int QUALITY_LOW    = 0;
    public static final int QUALITY_MEDIUM = 1;
    public static final int QUALITY_HIGH   = 2;

    /*
     * Cache the Jpeg encoding quality parameters
     */
    private static final int[] sJpegEncodingQualityParameters;

    /**
     * Returns a pre-defined still image capture (jpeg) quality level
     * used for the given quality level in the Camera application.
     *
     * @param quality The target quality level
     */
    public static int getJpegEncodingQualityParameter(int quality) {
        if (quality < QUALITY_LOW || quality > QUALITY_HIGH) {
            throw new IllegalArgumentException("Unsupported quality level: " + quality);
        }
        return sJpegEncodingQualityParameters[quality];
    }

    static {
        System.loadLibrary("media_jni");
        native_init();
        sJpegEncodingQualityParameters = getImageEncodingQualityLevels();
    }

    private static int[] getImageEncodingQualityLevels() {
        int nLevels = native_get_num_image_encoding_quality_levels();
        if (nLevels != QUALITY_HIGH + 1) {
            throw new RuntimeException("Unexpected Jpeg encoding quality levels " + nLevels);
        }

        int[] levels = new int[nLevels];
        for (int i = 0; i < nLevels; ++i) {
            levels[i] = native_get_image_encoding_quality_level(i);
        }
        Arrays.sort(levels);  // Lower quality level ALWAYS comes before higher one
        return levels;
    }

    // Methods implemented by JNI
    private static native final void native_init();
    private static native final int native_get_num_image_encoding_quality_levels();
    private static native final int native_get_image_encoding_quality_level(int index);
}