Version 19, May 2018

[GpsPrune.git] / tim / prune / jpeg / drew / ExifTiffHandler.java

diff --git a/tim/prune/jpeg/drew/ExifTiffHandler.java b/tim/prune/jpeg/drew/ExifTiffHandler.java
new file mode 100644 (file)
index 0000000..a98e720
--- /dev/null
+++ b/tim/prune/jpeg/drew/ExifTiffHandler.java
@@ -0,0 +1,171 @@
+/*
+ * Copyright 2002-2015 Drew Noakes
+ *
+ * More information about this project is available at:
+ *
+ *    https://drewnoakes.com/code/exif/
+ *    https://github.com/drewnoakes/metadata-extractor
+ */
+package tim.prune.jpeg.drew;
+
+import tim.prune.jpeg.JpegData;
+
+/**
+ * Implementation of TiffHandler used for handling TIFF tags according to the Exif standard.
+ *
+ * @author Drew Noakes https://drewnoakes.com
+ */
+public class ExifTiffHandler
+{
+       private JpegData _jpegData = null;
+       private long _thumbnailOffset = -1L, _thumbnailLength = -1L;
+
+       /** This tag is a pointer to the Exif SubIFD. */
+       final int DIR_EXIF_SUB_IFD_OFFSET = 0x8769;
+       /** This tag is a pointer to the Exif GPS IFD. */
+       final int DIR_GPS_INFO_OFFSET = 0x8825;
+
+       private static final int TAG_GPS_LATITUDE_REF  = 0x0001;
+       private static final int TAG_GPS_LATITUDE      = 0x0002;
+       private static final int TAG_GPS_LONGITUDE_REF = 0x0003;
+       private static final int TAG_GPS_LONGITUDE     = 0x0004;
+       private static final int TAG_GPS_ALTITUDE      = 0x0006;
+       private static final int TAG_GPS_BEARING       = 0x0011;
+
+       private static final int TAG_ORIENTATION       = 0x0112;
+       private static final int TAG_THUMBNAIL_OFFSET  = 0x0201;
+       private static final int TAG_THUMBNAIL_LENGTH  = 0x0202;
+
+       private static final int TAG_SUB_ORITIME       = 0x9003;
+       private static final int TAG_SUB_DIGITIME      = 0x9004;
+
+
+       /**
+        * Constructor
+        * @param jpegData data object to populate with received results
+        */
+       public ExifTiffHandler(JpegData jpegData)
+       {
+               _jpegData = jpegData;
+               _thumbnailOffset = _thumbnailLength = -1L;
+       }
+
+       public boolean isTagIfdPointer(int tagType)
+       {
+               if (tagType == DIR_EXIF_SUB_IFD_OFFSET) {
+                       return true;
+               } else if (tagType == DIR_GPS_INFO_OFFSET) {
+                       return true;
+               }
+
+               return false;
+       }
+
+       public void completed(final ByteArrayReader reader, final int tiffHeaderOffset)
+       {
+               // after the extraction process, if we have the correct tags, we may be able to store thumbnail information
+               if (_thumbnailOffset >= 0L && _thumbnailLength > 0L)
+               {
+                       try {
+                               byte[] thumbData = reader.getBytes(tiffHeaderOffset + (int) _thumbnailOffset, (int) _thumbnailLength);
+                               if (thumbData != null)
+                               {
+                                       byte[] thumbCopy = new byte[thumbData.length];
+                                       System.arraycopy(thumbData, 0, thumbCopy, 0, thumbData.length);
+                                       _jpegData.setThumbnailImage(thumbCopy);
+                               }
+                       } catch (ExifException ex) {}
+               }
+       }
+
+       public void setRationalArray(int tagId, Rational[] array)
+       {
+               switch (tagId)
+               {
+                       case TAG_GPS_LATITUDE:
+                               _jpegData.setLatitude(new double[] {array[0].doubleValue(), array[1].doubleValue(),
+                                       array[2].convertToPositiveValue()});
+                               break;
+                       case TAG_GPS_LONGITUDE:
+                               _jpegData.setLongitude(new double[] {array[0].doubleValue(), array[1].doubleValue(),
+                                       array[2].convertToPositiveValue()});
+                               break;
+               }
+       }
+
+       public void setRational(int tagId, Rational rational)
+       {
+               switch (tagId)
+               {
+                       case TAG_GPS_ALTITUDE:
+                               _jpegData.setAltitude(rational.intValue());
+                               return;
+                       case TAG_GPS_BEARING:
+                               _jpegData.setBearing(rational.doubleValue());
+                               return;
+               }
+               // maybe it was an integer passed as a rational?
+               if (rational.getDenominator() == 1L) {
+                       setIntegerValue(tagId, rational.intValue());
+               }
+       }
+
+       public void setString(int tagId, String string)
+       {
+               switch (tagId)
+               {
+                       case TAG_SUB_ORITIME:
+                               _jpegData.setOriginalTimestamp(string);
+                               break;
+                       case TAG_SUB_DIGITIME:
+                               _jpegData.setDigitizedTimestamp(string);
+                               break;
+                       case TAG_GPS_LATITUDE_REF:
+                               _jpegData.setLatitudeRef(string);
+                               break;
+                       case TAG_GPS_LONGITUDE_REF:
+                               _jpegData.setLongitudeRef(string);
+                               break;
+               }
+       }
+
+       public void setIntegerValue(int tagId, int intVal)
+       {
+               switch (tagId)
+               {
+                       case TAG_ORIENTATION:
+                               _jpegData.setOrientationCode(intVal);
+                               break;
+                       case TAG_THUMBNAIL_OFFSET:
+                               _thumbnailOffset = intVal;
+                               break;
+                       case TAG_THUMBNAIL_LENGTH:
+                               _thumbnailLength = intVal;
+                               break;
+               }
+       }
+
+
+       /**
+        * Decide, based on the directory id and the tag id, if we want to parse and process it
+        * @param inDirectoryId
+        * @param childTagId
+        * @return true if the tag should be parsed
+        */
+       public boolean isInterestingTag(int inDirectoryId, int childTagId)
+       {
+               switch (inDirectoryId)
+               {
+                       case DIR_GPS_INFO_OFFSET:
+                               return true;
+                       case DIR_EXIF_SUB_IFD_OFFSET:
+                               return childTagId == TAG_SUB_ORITIME
+                                       || childTagId == TAG_SUB_DIGITIME;
+                       case 0:
+                               return childTagId == TAG_THUMBNAIL_OFFSET
+                                       || childTagId == TAG_THUMBNAIL_LENGTH
+                                       || childTagId == TAG_ORIENTATION;
+               }
+               return false;
+       }
+}