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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozilla_image_decoders_EXIF_h
#define mozilla_image_decoders_EXIF_h
#include <stdint.h>
#include "nsDebug.h"
#include "Orientation.h"
namespace mozilla {
namespace image {
enum class ByteOrder : uint8_t {
Unknown,
LittleEndian,
BigEndian
};
struct EXIFData
{
EXIFData() { }
explicit EXIFData(Orientation aOrientation) : orientation(aOrientation) { }
const Orientation orientation;
};
class EXIFParser
{
public:
static EXIFData
Parse(const uint8_t* aData, const uint32_t aLength)
{
EXIFParser parser;
return parser.ParseEXIF(aData, aLength);
}
private:
EXIFParser()
: mStart(nullptr)
, mCurrent(nullptr)
, mLength(0)
, mRemainingLength(0)
, mByteOrder(ByteOrder::Unknown)
{ }
EXIFData ParseEXIF(const uint8_t* aData, const uint32_t aLength);
bool ParseEXIFHeader();
bool ParseTIFFHeader(uint32_t& aIFD0OffsetOut);
bool ParseIFD0(Orientation& aOrientationOut);
bool ParseOrientation(uint16_t aType, uint32_t aCount, Orientation& aOut);
bool Initialize(const uint8_t* aData, const uint32_t aLength);
void Advance(const uint32_t aDistance);
void JumpTo(const uint32_t aOffset);
bool MatchString(const char* aString, const uint32_t aLength);
bool MatchUInt16(const uint16_t aValue);
bool ReadUInt16(uint16_t& aOut);
bool ReadUInt32(uint32_t& aOut);
const uint8_t* mStart;
const uint8_t* mCurrent;
uint32_t mLength;
uint32_t mRemainingLength;
ByteOrder mByteOrder;
};
} // namespace image
} // namespace mozilla
#endif // mozilla_image_decoders_EXIF_h
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