// Copyright (c) 2004-2009 Nokia Corporation and/or its subsidiary(-ies).

// All rights reserved.

// This component and the accompanying materials are made available

// under the terms of "Eclipse Public License v1.0"

// which accompanies this distribution, and is available

// at the URL "http://www.eclipse.org/legal/epl-v10.html".

//

// Initial Contributors:

// Nokia Corporation - initial contribution.

//

// Contributors:

//

// Description:

//

#ifndef __EXIFGENERALCONSTS_H__

#define __EXIFGENERALCONSTS_H__

#include <gdi.h>

#include <iclexif.h>

// Header file containing general constants used by the Exif Encoder and Decoder.

// Constants for size.

const TUint K32BitIntegerByteCount = 4;

const TUint K16BitIntegerByteCount = 2;

const TUint K8BitIntegerByteCount = 1;

const TUint16 KApp1Marker = 0xE1FF; // The Application 1 marker (APP1).

const TUint16 KApp1MarkerByteCount = K16BitIntegerByteCount; // Number of bytes in the APP1 marker.

const TUint16 KBlockEndMarker = 0xD9FF; // The Application 1 marker (APP1).

const TUint16 KBlockEndMarkerByteCount = K16BitIntegerByteCount; // Number of bytes in the APP1 marker.

const TUint KOffsetToApp1Size = K16BitIntegerByteCount; // Two bytes in from the start of the Exif header.

const TUint16 KApp1SizeLength = K16BitIntegerByteCount; // The byte count of the APP1 header length field.

const TUint KExifMarker = 0x66697845; // 'Exif' string.

const TUint16 KExifMarkerByteCount = K32BitIntegerByteCount; // i.e. number of bytes of 'Exif'

const TUint16 KExifMarkerEnd = 0x0000; // Always follows 'Exif'.

const TUint16 KExifMarkerEndByteCount = K16BitIntegerByteCount;

const TInt KExifHeaderLength = K32BitIntegerByteCount + K16BitIntegerByteCount;

const TUint16 KIntelByteAlignment = 0x4949; // Indicates little-endian byte alignment.

const TUint16 KMotorolaByteAlignment = 0x4D4D;

const TUint16 KByteAlignmentByteCount = K16BitIntegerByteCount;

const TUint KByteCountToByteAlignment = KApp1MarkerByteCount +

										KApp1SizeLength +

										KExifHeaderLength; // Number of bytes from KApp1Marker through to KIntel.

const TInt KOffsetFromExifHeaderToByteAlignment = KExifHeaderLength;

const TUint16 KFortyTwo = 0x002A;

const TUint16 KFortyTwoByteCount = K16BitIntegerByteCount;

const TUint KIfdOffset = 0x00000008; // Offset to 0th IFD.

const TUint16 KIfdOffsetByteCount = K32BitIntegerByteCount;

const TUint KOffsetToFirstIfdSize = K32BitIntegerByteCount; // A 4 byte field containing an offset to the 1st Ifd.

const TUint16 KMaxApp1Size = 0xFFFF; // Maximum size of the APP1 header.

const TUint KSizeOfEntryCount = K16BitIntegerByteCount; // Each Ifd has an entry count of 2 bytes.

const TInt KJPEGEncodedThumbnail = 6; //

// External user will call functions using either of these two constants as the Ifd argument.

const TInt16 KExternalZerothIfd = 0;

const TInt16 KExternalFirstIfd = 1;

const TInt KOffsetToZerothOffset = 	KByteAlignmentByteCount +

									KFortyTwoByteCount +

									KIfdOffsetByteCount +

									KSizeOfEntryCount; // Number of bytes from byte alignment to the offset to the 0th Ifd.

const TUint16 KExifFileHeaderLength = 	KApp1MarkerByteCount +

										KApp1SizeLength +

										KExifMarkerByteCount +

										KExifMarkerEndByteCount +

										KByteAlignmentByteCount + 

										KFortyTwoByteCount + 

										KIfdOffsetByteCount; // Length of the standard Exif Header.

// Literals used in the encoder/decoder.										

_LIT8(KUnicode, "UNICODE\0"); // The first 8 bytes of the User Comment tag, if using Unicode.

_LIT8(KExifHeader, "Exif\0\0");

const TInt KThumbnailHeight = 120;

const TInt KThumbnailWidth = 160;

const TDisplayMode KThumbnailDisplayMode= EColor256;

const TInt KIOBlockSize=4096;	// size of blocks used for IO operations

enum TIfd

	{

	EZeroth, // Main image.	

	EExifSub, // Main image.

	EInterop, // Main image.

	EFirst, // Thumbnail.

	EGpsSub = KExifGpsIfd >> 16 // (==4) Main image.		

	};

enum TTagValueIndexes

	{

	ETagValue,

	EFormatValue,

	EComponentCountValue,

	EValueOffsetValue,

	EIfdValue,

	ESupportLevelValue

	};

// Is the tag Mandatory, Optional or 

enum TSupportLevel

	{

	EOptional,

	EConditionallyMandatory,

	EMandatory

	};

// The format field in the Ifd entry is a two byte field, with an identifying short.

enum TFormat

	{

	EByte = 1,

	EAscii = 2,

	EUnsignedShort = 3,

	EUnsignedLong = 4,

	EUnsignedRational = 5,

	EUndefined = 7,

	ESignedLong = 9,

	ESignedRational = 10

	};

// Related to TFormat. Stores size (in bytes) of each enumeration, i.e. EByte size is 1 byte, 

// EUnsignedRational size is 8 bytes etc etc.

const TInt KDataFormatSize[] = {0,1,1,2,4,8, 0,1, 0,4,8};

const TUint KDataFormatSizeLength = sizeof(KDataFormatSize)/sizeof(KDataFormatSize[0]); // The length of the KDataFormatsize array.

// Used by Ifd entry

const TUint KMinimumIfdEntrySize = 12; // The number of bytes in a standard ifd entry.

const TInt KSizeOfTagField = 2; // The number of bytes in the tag field.

const TInt KSizeOfFormatField = 2; // The number of bytes in format field.

const TInt KSizeOfComponentCountField = 4; // The number of bytes in the component count field.

const TUint KSizeOfValueOffsetField = 4; // The number of bytes in the value/offset field.

const TInt KSizeOfRational = 8; // The number of bytes in a rational number.

const TInt KTagFieldPosition = 0;

const TInt KFormatFieldPosition = 2; // The start position of the format field.

const TInt KComponentCountFieldPosition = 4; // The start position of the component count field.

const TInt KValueOffsetFieldPosition = 8; // The start position of the value/offset field.

const TUint8 KThreeBytes = 3;

#endif // __EXIFGENERALCONSTS_H__