1/*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.media;
18
19import android.hardware.Camera;
20import android.hardware.Camera.CameraInfo;
21
22import java.util.Arrays;
23import java.util.HashMap;
24
25/**
26 * The CameraProfile class is used to retrieve the pre-defined still image
27 * capture (jpeg) quality levels (0-100) used for low, medium, and high
28 * quality settings in the Camera application.
29 *
30 */
31public class CameraProfile
32{
33    /**
34     * Define three quality levels for JPEG image encoding.
35     */
36    /*
37     * Don't change the values for these constants unless getImageEncodingQualityLevels()
38     * method is also changed accordingly.
39     */
40    public static final int QUALITY_LOW    = 0;
41    public static final int QUALITY_MEDIUM = 1;
42    public static final int QUALITY_HIGH   = 2;
43
44    /*
45     * Cache the Jpeg encoding quality parameters
46     */
47    private static final HashMap<Integer, int[]> sCache = new HashMap<Integer, int[]>();
48
49    /**
50     * Returns a pre-defined still image capture (jpeg) quality level
51     * used for the given quality level in the Camera application for
52     * the first back-facing camera on the device. If the device has no
53     * back-facing camera, this returns 0.
54     *
55     * @param quality The target quality level
56     */
57    public static int getJpegEncodingQualityParameter(int quality) {
58        int numberOfCameras = Camera.getNumberOfCameras();
59        CameraInfo cameraInfo = new CameraInfo();
60        for (int i = 0; i < numberOfCameras; i++) {
61            Camera.getCameraInfo(i, cameraInfo);
62            if (cameraInfo.facing == CameraInfo.CAMERA_FACING_BACK) {
63                return getJpegEncodingQualityParameter(i, quality);
64            }
65        }
66        return 0;
67    }
68
69    /**
70     * Returns a pre-defined still image capture (jpeg) quality level
71     * used for the given quality level in the Camera application for
72     * the specified camera.
73     *
74     * @param cameraId The id of the camera
75     * @param quality The target quality level
76     */
77    public static int getJpegEncodingQualityParameter(int cameraId, int quality) {
78        if (quality < QUALITY_LOW || quality > QUALITY_HIGH) {
79            throw new IllegalArgumentException("Unsupported quality level: " + quality);
80        }
81        synchronized (sCache) {
82            int[] levels = sCache.get(cameraId);
83            if (levels == null) {
84                levels = getImageEncodingQualityLevels(cameraId);
85                sCache.put(cameraId, levels);
86            }
87            return levels[quality];
88        }
89    }
90
91    static {
92        System.loadLibrary("media_jni");
93        native_init();
94    }
95
96    private static int[] getImageEncodingQualityLevels(int cameraId) {
97        int nLevels = native_get_num_image_encoding_quality_levels(cameraId);
98        if (nLevels != QUALITY_HIGH + 1) {
99            throw new RuntimeException("Unexpected Jpeg encoding quality levels " + nLevels);
100        }
101
102        int[] levels = new int[nLevels];
103        for (int i = 0; i < nLevels; ++i) {
104            levels[i] = native_get_image_encoding_quality_level(cameraId, i);
105        }
106        Arrays.sort(levels);  // Lower quality level ALWAYS comes before higher one
107        return levels;
108    }
109
110    // Methods implemented by JNI
111    private static native final void native_init();
112    private static native final int native_get_num_image_encoding_quality_levels(int cameraId);
113    private static native final int native_get_image_encoding_quality_level(int cameraId, int index);
114}
115