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      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 
     17 package com.android.camera;
     18 
     19 import android.util.Log;
     20 
     21 import com.android.gallery3d.exif.ExifInvalidFormatException;
     22 import com.android.gallery3d.exif.ExifParser;
     23 import com.android.gallery3d.exif.ExifTag;
     24 
     25 import java.io.ByteArrayInputStream;
     26 import java.io.IOException;
     27 import java.io.InputStream;
     28 
     29 public class Exif {
     30     private static final String TAG = "CameraExif";
     31 
     32     // Returns the degrees in clockwise. Values are 0, 90, 180, or 270.
     33     public static int getOrientation(byte[] jpeg) {
     34         if (jpeg == null) return 0;
     35 
     36         InputStream is = new ByteArrayInputStream(jpeg);
     37 
     38         try {
     39             ExifParser parser = ExifParser.parse(is, ExifParser.OPTION_IFD_0);
     40             int event = parser.next();
     41             while(event != ExifParser.EVENT_END) {
     42                 if (event == ExifParser.EVENT_NEW_TAG) {
     43                     ExifTag tag = parser.getTag();
     44                     if (tag.getTagId() == ExifTag.TAG_ORIENTATION &&
     45                             tag.hasValue()) {
     46                         int orient = (int) tag.getValueAt(0);
     47                         switch (orient) {
     48                             case ExifTag.Orientation.TOP_LEFT:
     49                                 return 0;
     50                             case ExifTag.Orientation.BOTTOM_LEFT:
     51                                 return 180;
     52                             case ExifTag.Orientation.RIGHT_TOP:
     53                                 return 90;
     54                             case ExifTag.Orientation.RIGHT_BOTTOM:
     55                                 return 270;
     56                             default:
     57                                 Log.i(TAG, "Unsupported orientation");
     58                                 return 0;
     59                         }
     60                     }
     61                 }
     62                 event = parser.next();
     63             }
     64             Log.i(TAG, "Orientation not found");
     65             return 0;
     66         } catch (IOException e) {
     67             Log.w(TAG, "Failed to read EXIF orientation", e);
     68             return 0;
     69         } catch (ExifInvalidFormatException e) {
     70             Log.w(TAG, "Failed to read EXIF orientation", e);
     71             return 0;
     72         }
     73     }
     74 }
     75