📄 exifreader.java
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{
// This Konica data is not understood. Header identified in accordance with information at this site:
// http://www.ozhiker.com/electronics/pjmt/jpeg_info/minolta_mn.html
// TODO determine how to process the information described at the above website
exifDirectory.addError("Unsupported Konica/Minolta data ignored.");
}
else if ("KYOCERA".equals(firstSevenChars))
{
// http://www.ozhiker.com/electronics/pjmt/jpeg_info/kyocera_mn.html
processDirectory(_metadata.getDirectory(KyoceraMakernoteDirectory.class), processedDirectoryOffsets, subdirOffset + 22, tiffHeaderOffset);
}
else if ("Panasonic\u0000\u0000\u0000".equals(new String(_data, subdirOffset, 12)))
{
// NON-Standard TIFF IFD Data using Panasonic Tags. There is no Next-IFD pointer after the IFD
// Offsets are relative to the start of the TIFF header at the beginning of the EXIF segment
// more information here: http://www.ozhiker.com/electronics/pjmt/jpeg_info/panasonic_mn.html
processDirectory(_metadata.getDirectory(PanasonicMakernoteDirectory.class), processedDirectoryOffsets, subdirOffset + 12, tiffHeaderOffset);
}
else if ("AOC\u0000".equals(firstFourChars))
{
// NON-Standard TIFF IFD Data using Casio Type 2 Tags
// IFD has no Next-IFD pointer at end of IFD, and
// Offsets are relative to the start of the current IFD tag, not the TIFF header
// Observed for:
// - Pentax ist D
processDirectory(_metadata.getDirectory(CasioType2MakernoteDirectory.class), processedDirectoryOffsets, subdirOffset + 6, subdirOffset);
}
else if (cameraModel!=null && (cameraModel.toUpperCase().startsWith("PENTAX") || cameraModel.toUpperCase().startsWith("ASAHI")))
{
// NON-Standard TIFF IFD Data using Pentax Tags
// IFD has no Next-IFD pointer at end of IFD, and
// Offsets are relative to the start of the current IFD tag, not the TIFF header
// Observed for:
// - PENTAX Optio 330
// - PENTAX Optio 430
processDirectory(_metadata.getDirectory(PentaxMakernoteDirectory.class), processedDirectoryOffsets, subdirOffset, subdirOffset);
}
else
{
// TODO how to store makernote data when it's not from a supported camera model?
// this is difficult as the starting offset is not known. we could look for it...
exifDirectory.addError("Unsupported makernote data ignored.");
}
}
private boolean isDirectoryLengthValid(int dirStartOffset, int tiffHeaderOffset)
{
int dirTagCount = get16Bits(dirStartOffset);
int dirLength = (2 + (12 * dirTagCount) + 4);
if (dirLength + dirStartOffset + tiffHeaderOffset>=_data.length) {
// Note: Files that had thumbnails trimmed with jhead 1.3 or earlier might trigger this
return false;
}
return true;
}
private void processTag(Directory directory, int tagType, int tagValueOffset, int componentCount, int formatCode)
{
// Directory simply stores raw values
// The display side uses a Descriptor class per directory to turn the raw values into 'pretty' descriptions
switch (formatCode)
{
case FMT_UNDEFINED:
// this includes exif user comments
final byte[] tagBytes = new byte[componentCount];
final int byteCount = componentCount * BYTES_PER_FORMAT[formatCode];
for (int i=0; i<byteCount; i++)
tagBytes[i] = _data[tagValueOffset + i];
directory.setByteArray(tagType, tagBytes);
break;
case FMT_STRING:
directory.setString(tagType, readString(tagValueOffset, componentCount));
break;
case FMT_SRATIONAL:
case FMT_URATIONAL:
if (componentCount==1) {
Rational rational = new Rational(get32Bits(tagValueOffset), get32Bits(tagValueOffset + 4));
directory.setRational(tagType, rational);
} else {
Rational[] rationals = new Rational[componentCount];
for (int i = 0; i<componentCount; i++)
rationals[i] = new Rational(get32Bits(tagValueOffset + (8 * i)), get32Bits(tagValueOffset + 4 + (8 * i)));
directory.setRationalArray(tagType, rationals);
}
break;
case FMT_SBYTE:
case FMT_BYTE:
if (componentCount==1) {
// this may need to be a byte, but I think casting to int is fine
int b = _data[tagValueOffset];
directory.setInt(tagType, b);
} else {
int[] bytes = new int[componentCount];
for (int i = 0; i<componentCount; i++)
bytes[i] = _data[tagValueOffset + i];
directory.setIntArray(tagType, bytes);
}
break;
case FMT_SINGLE:
case FMT_DOUBLE:
if (componentCount==1) {
int i = _data[tagValueOffset];
directory.setInt(tagType, i);
} else {
int[] ints = new int[componentCount];
for (int i = 0; i<componentCount; i++)
ints[i] = _data[tagValueOffset + i];
directory.setIntArray(tagType, ints);
}
break;
case FMT_USHORT:
case FMT_SSHORT:
if (componentCount==1) {
int i = get16Bits(tagValueOffset);
directory.setInt(tagType, i);
} else {
int[] ints = new int[componentCount];
for (int i = 0; i<componentCount; i++)
ints[i] = get16Bits(tagValueOffset + (i * 2));
directory.setIntArray(tagType, ints);
}
break;
case FMT_SLONG:
case FMT_ULONG:
if (componentCount==1) {
int i = get32Bits(tagValueOffset);
directory.setInt(tagType, i);
} else {
int[] ints = new int[componentCount];
for (int i = 0; i<componentCount; i++)
ints[i] = get32Bits(tagValueOffset + (i * 4));
directory.setIntArray(tagType, ints);
}
break;
default:
directory.addError("Unknown format code " + formatCode + " for tag " + tagType);
}
}
private int calculateTagValueOffset(int byteCount, int dirEntryOffset, int tiffHeaderOffset)
{
if (byteCount>4) {
// If its bigger than 4 bytes, the dir entry contains an offset.
// dirEntryOffset must be passed, as some makernote implementations (e.g. FujiFilm) incorrectly use an
// offset relative to the start of the makernote itself, not the TIFF segment.
final int offsetVal = get32Bits(dirEntryOffset + 8);
if (offsetVal + byteCount>_data.length) {
// Bogus pointer offset and / or bytecount value
return -1; // signal error
}
return tiffHeaderOffset + offsetVal;
} else {
// 4 bytes or less and value is in the dir entry itself
return dirEntryOffset + 8;
}
}
/**
* Creates a String from the _data buffer starting at the specified offset,
* and ending where byte=='\0' or where length==maxLength.
*/
private String readString(int offset, int maxLength)
{
int length = 0;
while ((offset + length)<_data.length && _data[offset + length]!='\0' && length<maxLength)
length++;
return new String(_data, offset, length);
}
/**
* Determine the offset at which a given InteropArray entry begins within the specified IFD.
* @param dirStartOffset the offset at which the IFD starts
* @param entryNumber the zero-based entry number
*/
private int calculateTagOffset(int dirStartOffset, int entryNumber)
{
// add 2 bytes for the tag count
// each entry is 12 bytes, so we skip 12 * the number seen so far
return dirStartOffset + 2 + (12 * entryNumber);
}
/**
* Get a 16 bit value from file's native byte order. Between 0x0000 and 0xFFFF.
*/
private int get16Bits(int offset)
{
if (offset<0 || offset+2>_data.length)
throw new ArrayIndexOutOfBoundsException("attempt to read data outside of exif segment (index " + offset + " where max index is " + (_data.length - 1) + ")");
if (_isMotorollaByteOrder) {
// Motorola - MSB first
return (_data[offset] << 8 & 0xFF00) | (_data[offset + 1] & 0xFF);
} else {
// Intel ordering - LSB first
return (_data[offset + 1] << 8 & 0xFF00) | (_data[offset] & 0xFF);
}
}
/**
* Get a 32 bit value from file's native byte order.
*/
private int get32Bits(int offset)
{
if (offset<0 || offset+4>_data.length)
throw new ArrayIndexOutOfBoundsException("attempt to read data outside of exif segment (index " + offset + " where max index is " + (_data.length - 1) + ")");
if (_isMotorollaByteOrder) {
// Motorola - MSB first
return (_data[offset] << 24 & 0xFF000000) |
(_data[offset + 1] << 16 & 0xFF0000) |
(_data[offset + 2] << 8 & 0xFF00) |
(_data[offset + 3] & 0xFF);
} else {
// Intel ordering - LSB first
return (_data[offset + 3] << 24 & 0xFF000000) |
(_data[offset + 2] << 16 & 0xFF0000) |
(_data[offset + 1] << 8 & 0xFF00) |
(_data[offset] & 0xFF);
}
}
}
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