+++ /dev/null
-/*
- * 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 java.io.IOException;
-import java.util.HashSet;
-import java.util.Set;
-
-import tim.prune.jpeg.JpegData;
-
-/**
- * Processes TIFF-formatted data, using an ExifTiffHandler
- *
- * @author Drew Noakes https://drewnoakes.com
- */
-public class TiffProcessor
-{
- /**
- * Processes a TIFF data sequence.
- *
- * @param reader the {@link RandomAccessReader} from which the data should be read
- * @param jpegData the data to populate
- * @param tiffHeaderOffset the offset within <code>reader</code> at which the TIFF header starts
- * @throws ExifException if an error occurred during the processing of TIFF data that could
- * not be ignored or recovered from
- * @throws IOException an error occurred while accessing the required data
- */
- public static void processTiff(final ByteArrayReader reader, JpegData jpegData,
- final int tiffHeaderOffset) throws ExifException, IOException
- {
- // This must be either "MM" or "II".
- short byteOrderIdentifier = reader.getInt16(tiffHeaderOffset);
-
- if (byteOrderIdentifier == 0x4d4d) { // "MM"
- reader.setMotorolaByteOrder(true);
- } else if (byteOrderIdentifier == 0x4949) { // "II"
- reader.setMotorolaByteOrder(false);
- } else {
- throw new ExifException("Unclear distinction between Motorola/Intel byte ordering: " + byteOrderIdentifier);
- }
-
-
- int firstIfdOffset = reader.getInt32(4 + tiffHeaderOffset) + tiffHeaderOffset;
-
- // David Ekholm sent a digital camera image that has this problem
- if (firstIfdOffset >= reader.getLength() - 1) {
- //handler.warn("First IFD offset is beyond the end of the TIFF data segment -- trying default offset");
- // First directory normally starts immediately after the offset bytes, so try that
- firstIfdOffset = tiffHeaderOffset + 2 + 2 + 4;
- }
-
- // Make a handler object to use for the processing
- ExifTiffHandler handler = new ExifTiffHandler(jpegData);
-
- Set<Integer> processedIfdOffsets = new HashSet<Integer>();
- processDirectory(handler, reader, processedIfdOffsets, firstIfdOffset, tiffHeaderOffset, 0);
-
- handler.completed(reader, tiffHeaderOffset);
- }
-
- /**
- * Processes a TIFF IFD.
- *
- * IFD Header:
- * <ul>
- * <li><b>2 bytes</b> number of tags</li>
- * </ul>
- * Tag structure:
- * <ul>
- * <li><b>2 bytes</b> tag type</li>
- * <li><b>2 bytes</b> format code (values 1 to 12, inclusive)</li>
- * <li><b>4 bytes</b> component count</li>
- * <li><b>4 bytes</b> inline value, or offset pointer if too large to fit in four bytes</li>
- * </ul>
- *
- * @param handler the {@link ExifTiffHandler} that will coordinate processing and accept read values
- * @param reader the byte reader from which the data should be read
- * @param processedIfdOffsets the set of visited IFD offsets, to avoid revisiting the same IFD in an endless loop
- * @param ifdOffset the offset within <code>reader</code> at which the IFD data starts
- * @param tiffHeaderOffset the offset within <code>reader</code> at which the TIFF header starts
- * @param inDirectoryId directory id
- * @throws IOException an error occurred while accessing the required data
- */
- private static void processDirectory(final ExifTiffHandler handler,
- final ByteArrayReader reader, final Set<Integer> processedIfdOffsets,
- final int ifdOffset, final int tiffHeaderOffset, int inDirectoryId) throws ExifException
- {
- // check for directories we've already visited to avoid stack overflows when recursive/cyclic directory structures exist
- if (processedIfdOffsets.contains(Integer.valueOf(ifdOffset))) {
- return;
- }
-
- // remember that we've visited this directory so that we don't visit it again later
- processedIfdOffsets.add(ifdOffset);
-
- if (ifdOffset >= reader.getLength() || ifdOffset < 0) {
- //handler.error("Ignored IFD marked to start outside data segment");
- return;
- }
-
- // First two bytes in the IFD are the number of tags in this directory
- int dirTagCount = reader.getUInt16(ifdOffset);
-
- int dirLength = (2 + (12 * dirTagCount) + 4);
- if (dirLength + ifdOffset > reader.getLength()) {
- //handler.error("Illegally sized IFD");
- return;
- }
-
-
- // Handle each tag in this directory
- //
- int invalidTiffFormatCodeCount = 0;
- for (int tagNumber = 0; tagNumber < dirTagCount; tagNumber++)
- {
- final int tagOffset = calculateTagOffset(ifdOffset, tagNumber);
-
- // 2 bytes for the tag id
- final int childTagId = reader.getUInt16(tagOffset);
-
- // 2 bytes for the format code
- final int formatCode = reader.getUInt16(tagOffset + 2);
- final int componentSizeInBytes = TiffDataFormat.getComponentSize(formatCode);
-
- if (componentSizeInBytes == 0)
- {
- // This error suggests that we are processing at an incorrect index and will generate
- // rubbish until we go out of bounds (which may be a while).
- if (++invalidTiffFormatCodeCount > 5) {
- //handler.error("Stopping processing as too many errors seen in TIFF IFD");
- return;
- }
- continue;
- }
-
- // 4 bytes dictate the number of components in this tag's data
- final int componentCount = reader.getInt32(tagOffset + 4);
- if (componentCount < 0) {
- //handler.error("Negative TIFF tag component count");
- continue;
- }
-
- final int byteCount = componentCount * componentSizeInBytes;
-
- final int tagValueOffset;
- if (byteCount > 4)
- {
- // If it's bigger than 4 bytes, the dir entry contains an offset.
- final int offsetVal = reader.getInt32(tagOffset + 8);
- if (offsetVal + byteCount > reader.getLength()) {
- // Bogus pointer offset and / or byteCount value
- //handler.error("Illegal TIFF tag pointer offset");
- continue;
- }
- tagValueOffset = tiffHeaderOffset + offsetVal;
- }
- else {
- // 4 bytes or less and value is in the dir entry itself.
- tagValueOffset = tagOffset + 8;
- }
-
- if (tagValueOffset < 0 || tagValueOffset > reader.getLength()) {
- //handler.error("Illegal TIFF tag pointer offset");
- continue;
- }
-
- // Check that this tag isn't going to allocate outside the bounds of the data array.
- // This addresses an uncommon OutOfMemoryError.
- if (byteCount < 0 || tagValueOffset + byteCount > reader.getLength()) {
- //handler.error("Illegal number of bytes for TIFF tag data: " + byteCount);
- continue;
- }
-
- // Special handling for tags that point to other IFDs
- if (byteCount == 4 && handler.isTagIfdPointer(childTagId)) {
- final int subDirOffset = tiffHeaderOffset + reader.getInt32(tagValueOffset);
- processDirectory(handler, reader, processedIfdOffsets, subDirOffset, tiffHeaderOffset, childTagId);
- }
- else if (handler.isInterestingTag(inDirectoryId, childTagId))
- {
- processTag(handler, childTagId, tagValueOffset, componentCount, formatCode, reader);
- }
- }
-
- // at the end of each IFD is an optional link to the next IFD
- final int finalTagOffset = calculateTagOffset(ifdOffset, dirTagCount);
- int nextIfdOffset = reader.getInt32(finalTagOffset);
- if (nextIfdOffset != 0)
- {
- nextIfdOffset += tiffHeaderOffset;
- if (nextIfdOffset >= reader.getLength()) {
- // Last 4 bytes of IFD reference another IFD with an address that is out of bounds
- // Note this could have been caused by jhead 1.3 cropping too much
- return;
- }
- else if (nextIfdOffset < ifdOffset) {
- // Last 4 bytes of IFD reference another IFD with an address that is before the start of this directory
- return;
- }
-
- processDirectory(handler, reader, processedIfdOffsets, nextIfdOffset, tiffHeaderOffset, inDirectoryId);
- }
- }
-
-
- /**
- * Process a single tag value
- */
- private static void processTag(final ExifTiffHandler handler,
- final int tagId, final int tagValueOffset,
- final int componentCount, final int formatCode,
- final ByteArrayReader reader) throws ExifException
- {
- switch (formatCode)
- {
- case TiffDataFormat.CODE_STRING:
- handler.setString(tagId, reader.getNullTerminatedString(tagValueOffset, componentCount));
- break;
- case TiffDataFormat.CODE_RATIONAL_S:
- if (componentCount == 1) {
- handler.setRational(tagId, new Rational(reader.getInt32(tagValueOffset), reader.getInt32(tagValueOffset + 4)));
- } else if (componentCount > 1) {
- Rational[] array = new Rational[componentCount];
- for (int i = 0; i < componentCount; i++)
- array[i] = new Rational(reader.getInt32(tagValueOffset + (8 * i)), reader.getInt32(tagValueOffset + 4 + (8 * i)));
- handler.setRationalArray(tagId, array);
- }
- break;
- case TiffDataFormat.CODE_RATIONAL_U:
- if (componentCount == 1) {
- handler.setRational(tagId, new Rational(reader.getUInt32(tagValueOffset), reader.getUInt32(tagValueOffset + 4)));
- } else if (componentCount > 1) {
- Rational[] array = new Rational[componentCount];
- for (int i = 0; i < componentCount; i++)
- array[i] = new Rational(reader.getUInt32(tagValueOffset + (8 * i)), reader.getUInt32(tagValueOffset + 4 + (8 * i)));
- handler.setRationalArray(tagId, array);
- }
- break;
- case TiffDataFormat.CODE_INT8_S:
- if (componentCount == 1) {
- handler.setIntegerValue(tagId, reader.getInt8(tagValueOffset));
- }
- break;
- case TiffDataFormat.CODE_INT8_U:
- if (componentCount == 1) {
- handler.setIntegerValue(tagId, reader.getUInt8(tagValueOffset));
- }
- break;
- case TiffDataFormat.CODE_INT16_S:
- if (componentCount == 1) {
- handler.setIntegerValue(tagId, reader.getInt16(tagValueOffset));
- }
- break;
- case TiffDataFormat.CODE_INT16_U:
- if (componentCount == 1) {
- handler.setIntegerValue(tagId, reader.getUInt16(tagValueOffset));
- }
- break;
- case TiffDataFormat.CODE_INT32_S:
- // NOTE 'long' in this case means 32 bit, not 64
- if (componentCount == 1) {
- handler.setIntegerValue(tagId, reader.getInt32(tagValueOffset));
- }
- break;
- case TiffDataFormat.CODE_INT32_U:
- // NOTE 'long' in this case means 32 bit, not 64
- if (componentCount == 1) {
- handler.setRational(tagId, new Rational(reader.getUInt32(tagValueOffset), 1L));
- }
- break;
- case TiffDataFormat.CODE_SINGLE:
- case TiffDataFormat.CODE_DOUBLE:
- case TiffDataFormat.CODE_UNDEFINED:
- default:
- break;
- }
- }
-
- /**
- * Determine the offset of a given tag within the specified IFD.
- *
- * @param ifdStartOffset the offset at which the IFD starts
- * @param entryNumber the zero-based entry number
- */
- private static int calculateTagOffset(int ifdStartOffset, int entryNumber)
- {
- // Add 2 bytes for the tag count.
- // Each entry is 12 bytes.
- return ifdStartOffset + 2 + (12 * entryNumber);
- }
-}
projects / GpsPrune.git / blobdiff