1 /* 2 * Copyright (C) 2012 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.gallery3d.exif; 18 19 import android.util.Log; 20 21 import java.io.IOException; 22 import java.io.InputStream; 23 24 /** 25 * This class reads the EXIF header of a JPEG file and stores it in 26 * {@link ExifData}. 27 */ 28 class ExifReader { 29 private static final String TAG = "ExifReader"; 30 31 private final ExifInterface mInterface; 32 ExifReader(ExifInterface iRef)33 ExifReader(ExifInterface iRef) { 34 mInterface = iRef; 35 } 36 37 /** 38 * Parses the inputStream and and returns the EXIF data in an 39 * {@link ExifData}. 40 * 41 * @throws ExifInvalidFormatException 42 * @throws IOException 43 */ read(InputStream inputStream)44 protected ExifData read(InputStream inputStream) throws ExifInvalidFormatException, 45 IOException { 46 ExifParser parser = ExifParser.parse(inputStream, mInterface); 47 ExifData exifData = new ExifData(parser.getByteOrder()); 48 ExifTag tag = null; 49 50 int event = parser.next(); 51 while (event != ExifParser.EVENT_END) { 52 switch (event) { 53 case ExifParser.EVENT_START_OF_IFD: 54 exifData.addIfdData(new IfdData(parser.getCurrentIfd())); 55 break; 56 case ExifParser.EVENT_NEW_TAG: 57 tag = parser.getTag(); 58 if (!tag.hasValue()) { 59 parser.registerForTagValue(tag); 60 } else { 61 exifData.getIfdData(tag.getIfd()).setTag(tag); 62 } 63 break; 64 case ExifParser.EVENT_VALUE_OF_REGISTERED_TAG: 65 tag = parser.getTag(); 66 if (tag.getDataType() == ExifTag.TYPE_UNDEFINED) { 67 parser.readFullTagValue(tag); 68 } 69 exifData.getIfdData(tag.getIfd()).setTag(tag); 70 break; 71 case ExifParser.EVENT_COMPRESSED_IMAGE: 72 byte buf[] = new byte[parser.getCompressedImageSize()]; 73 if (buf.length == parser.read(buf)) { 74 exifData.setCompressedThumbnail(buf); 75 } else { 76 Log.w(TAG, "Failed to read the compressed thumbnail"); 77 } 78 break; 79 case ExifParser.EVENT_UNCOMPRESSED_STRIP: 80 buf = new byte[parser.getStripSize()]; 81 if (buf.length == parser.read(buf)) { 82 exifData.setStripBytes(parser.getStripIndex(), buf); 83 } else { 84 Log.w(TAG, "Failed to read the strip bytes"); 85 } 86 break; 87 } 88 event = parser.next(); 89 } 90 return exifData; 91 } 92 } 93