Pass start offset when reading Exif

Author: drewnoakes

Source/com/drew/metadata/exif/ExifReader.java

@@ -63,7 +63,7 @@ public void readJpegSegments(@NotNull final Iterable<byte[]> segments, @NotNull
         for (byte[] segmentBytes : segments) {
             // Segment must have the expected preamble
             if (startsWithJpegExifPreamble(segmentBytes)) {
-                extract(new ByteArrayReader(segmentBytes, JPEG_SEGMENT_PREAMBLE.length()), metadata);
+                extract(new ByteArrayReader(segmentBytes, JPEG_SEGMENT_PREAMBLE.length()), metadata, JPEG_SEGMENT_PREAMBLE.length());
             }
         }
     }
@@ -76,15 +76,15 @@ public static boolean startsWithJpegExifPreamble(byte[] bytes)
     }
 
     /** Reads TIFF formatted Exif data a specified offset within a {@link RandomAccessReader}. */
-    public void extract(@NotNull final RandomAccessReader reader, @NotNull final Metadata metadata)
+    public void extract(@NotNull final RandomAccessReader reader, @NotNull final Metadata metadata, int preambleLength)
     {
-        extract(reader, metadata, null);
+        extract(reader, metadata, null, preambleLength);
     }
 
     /** Reads TIFF formatted Exif data at a specified offset within a {@link RandomAccessReader}. */
-    public void extract(@NotNull final RandomAccessReader reader, @NotNull final Metadata metadata, @Nullable Directory parentDirectory)
+    public void extract(@NotNull final RandomAccessReader reader, @NotNull final Metadata metadata, @Nullable Directory parentDirectory, int exifStartOffset)
     {
-        ExifTiffHandler exifTiffHandler = new ExifTiffHandler(metadata, parentDirectory, /*readerOffset*/ 0); // FIXME what to do?
+        ExifTiffHandler exifTiffHandler = new ExifTiffHandler(metadata, parentDirectory, exifStartOffset);
 
         try {
             // Read the TIFF-formatted Exif data

Source/com/drew/metadata/heif/HeifPictureHandler.java

@@ -151,7 +151,7 @@ private void handleItem(@NotNull ItemInfoBox.ItemInfoEntry entry,
             }
             payloadReader.skip(tiffHeaderOffset);
             ByteArrayInputStream tiffStream = new ByteArrayInputStream(payloadReader.getBytes(payloadReader.available()));
-            new ExifReader().extract(new RandomAccessStreamReader(tiffStream), metadata);
+            new ExifReader().extract(new RandomAccessStreamReader(tiffStream), metadata, 0);
         }
     }
 

Source/com/drew/metadata/mp4/media/Mp4UuidBoxHandler.java

@@ -114,7 +114,7 @@ public Mp4Handler<?> processBox(@NotNull String type, byte[] payload, long boxSi
 
             switch (uuidType) {
                 case Exif:
-                    new ExifReader().extract(new ByteArrayReader(payload, 16), metadata, directory);
+                    new ExifReader().extract(new ByteArrayReader(payload, 16), metadata, directory, 0);
                     break;
                 case IptcIim:
                     new IptcReader().extract(new SequentialByteArrayReader(payload, 16), metadata, payload.length - 16, directory);

Source/com/drew/metadata/photoshop/PhotoshopReader.java

@@ -151,7 +151,7 @@ public void extract(@NotNull final SequentialReader reader, int length, @NotNull
                     else if (tagType == PhotoshopDirectory.TAG_ICC_PROFILE_BYTES)
                         new IccReader().extract(new ByteArrayReader(tagBytes), metadata, directory);
                     else if (tagType == PhotoshopDirectory.TAG_EXIF_DATA_1 || tagType == PhotoshopDirectory.TAG_EXIF_DATA_3)
-                        new ExifReader().extract(new ByteArrayReader(tagBytes), metadata, directory);
+                        new ExifReader().extract(new ByteArrayReader(tagBytes), metadata, directory, 0);
                     else if (tagType == PhotoshopDirectory.TAG_XMP_DATA)
                         new XmpReader().extract(tagBytes, metadata, directory);
                     else if (tagType >= 0x07D0 && tagType <= 0x0BB6) {

Source/com/drew/metadata/webp/WebpRiffHandler.java

@@ -83,7 +83,7 @@ public void processChunk(@NotNull String fourCC, @NotNull byte[] payload)
             ByteArrayReader reader = ExifReader.startsWithJpegExifPreamble(payload)
                 ? new ByteArrayReader(payload, ExifReader.JPEG_SEGMENT_PREAMBLE.length())
                 : new ByteArrayReader(payload);
-            new ExifReader().extract(reader, _metadata);
+            new ExifReader().extract(reader, _metadata, 0);
         } else if (fourCC.equals(WebpDirectory.CHUNK_ICCP)) {
             new IccReader().extract(new ByteArrayReader(payload), _metadata);
         } else if (fourCC.equals(WebpDirectory.CHUNK_XMP)) {

Tests/com/drew/metadata/exif/ExifReaderTest.java

@@ -46,7 +46,7 @@ public static Metadata processBytes(@NotNull String filePath) throws IOException
     {
         Metadata metadata = new Metadata();
         byte[] bytes = FileUtil.readBytes(filePath);
-        new ExifReader().extract(new ByteArrayReader(bytes, ExifReader.JPEG_SEGMENT_PREAMBLE.length()), metadata, null);
+        new ExifReader().extract(new ByteArrayReader(bytes, ExifReader.JPEG_SEGMENT_PREAMBLE.length()), metadata, null, ExifReader.JPEG_SEGMENT_PREAMBLE.length());
         return metadata;
     }