1/*
2 * Copyright (C) 2011 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 com.android.gallery3d.data;
18
19import android.util.Log;
20
21import com.android.gallery3d.exif.ExifInterface;
22
23import java.io.IOException;
24import java.io.InputStream;
25
26public class Exif {
27    private static final String TAG = "GalleryExif";
28
29    /**
30     * Returns the degrees in clockwise. Values are 0, 90, 180, or 270.
31     */
32    public static int getOrientation(InputStream is) {
33        if (is == null) {
34            return 0;
35        }
36        ExifInterface exif = new ExifInterface();
37        try {
38            exif.readExif(is);
39            Integer val = exif.getTagIntValue(ExifInterface.TAG_ORIENTATION);
40            if (val == null) {
41                return 0;
42            } else {
43                return ExifInterface.getRotationForOrientationValue(val.shortValue());
44            }
45        } catch (IOException e) {
46            Log.w(TAG, "Failed to read EXIF orientation", e);
47            return 0;
48        }
49    }
50
51    /**
52     * Returns an exif interface instance for the given JPEG image.
53     *
54     * @param jpegData a valid JPEG image containing EXIF data
55     */
56    public static ExifInterface getExif(byte[] jpegData) {
57        ExifInterface exif = new ExifInterface();
58        try {
59            exif.readExif(jpegData);
60        } catch (IOException e) {
61            Log.w(TAG, "Failed to read EXIF data", e);
62        }
63        return exif;
64    }
65
66    /**
67     * Returns the degrees in clockwise. Values are 0, 90, 180, or 270.
68     */
69    public static int getOrientation(ExifInterface exif) {
70        Integer val = exif.getTagIntValue(ExifInterface.TAG_ORIENTATION);
71        if (val == null) {
72            return 0;
73        } else {
74            return ExifInterface.getRotationForOrientationValue(val.shortValue());
75        }
76    }
77
78    /**
79     * See {@link #getOrientation(byte[])}, but using the picture bytes instead.
80     */
81    public static int getOrientation(byte[] jpegData) {
82        if (jpegData == null)
83            return 0;
84
85        ExifInterface exif = getExif(jpegData);
86        return getOrientation(exif);
87    }
88}
89