SkTiff Namespace Reference

Classes
class	ImageFileDirectory

Functions
static const uint8_t *	get_entry_address (const SkData *data, uint32_t ifdOffset, uint16_t entryIndex)
static bool	validate_ifd (const SkData *data, bool littleEndian, uint32_t ifdOffset, bool allowTruncated, uint16_t *outNumEntries, uint32_t *outNextIfdOffset)

Variables
constexpr size_t	kSizeEntry = 12
constexpr size_t	kSizeShort = 2
constexpr size_t	kSizeLong = 4
constexpr size_t	kEndianSize = 4
constexpr uint8_t	kEndianBig [kEndianSize] = {'M', 'M', 0, 42}
constexpr uint8_t	kEndianLittle [kEndianSize] = {'I', 'I', 42, 0}
constexpr uint16_t	kTypeUnsignedByte = 1
constexpr uint16_t	kTypeAsciiString = 2
constexpr uint16_t	kTypeUnsignedShort = 3
constexpr uint16_t	kTypeUnsignedLong = 4
constexpr uint16_t	kTypeUnsignedRational = 5
constexpr uint16_t	kTypeSignedByte = 6
constexpr uint16_t	kTypeUndefined = 7
constexpr uint16_t	kTypeSignedShort = 8
constexpr uint16_t	kTypeSignedLong = 9
constexpr uint16_t	kTypeSignedRational = 10
constexpr uint16_t	kTypeSingleFloat = 11
constexpr uint16_t	kTypeDoubleFloat = 12

Function Documentation

get_entry_address()

static const uint8_t * SkTiff::get_entry_address ( const SkData *  data, uint32_t  ifdOffset, uint16_t  entryIndex  )

static

Definition at line 55 of file SkTiffUtility.cpp.

                                                             {
    return data->bytes() +           // Base address
           ifdOffset +               // IFD offset
           kSizeShort +              // IFD number of entries
           kSizeEntry * entryIndex;  // Entries
}

validate_ifd()

static bool SkTiff::validate_ifd ( const SkData *  data, bool  littleEndian, uint32_t  ifdOffset, bool  allowTruncated, uint16_t *  outNumEntries, uint32_t *  outNextIfdOffset  )

static

Definition at line 66 of file SkTiffUtility.cpp.

                                                     {
    const uint8_t* dataCurrent = data->bytes();
    size_t dataSize = data->size();
 
    // Seek to the IFD offset.
    if (dataSize < ifdOffset) {
        SkCodecPrintf("IFD offset is too large.\n");
        return false;
    }
    dataCurrent += ifdOffset;
    dataSize -= ifdOffset;
 
    // Read the number of entries.
    if (dataSize < kSizeShort) {
        SkCodecPrintf("Insufficient space to store number of entries.\n");
        return false;
    }
    uint16_t numEntries = get_endian_short(dataCurrent, littleEndian);
    dataCurrent += kSizeShort;
    dataSize -= kSizeShort;
 
    // Check that there is enough space for all entries.
    if (dataSize < kSizeEntry * numEntries) {
        SkCodecPrintf("Insufficient space (%u) to store all %u entries.\n",
                      static_cast<uint32_t>(data->size()),
                      numEntries);
        if (allowTruncated) {
            // Set the number of entries to the number of entries that can be fully read, and set
            // the next IFD offset to 0 (indicating that there is no next IFD).
            *outNumEntries = dataSize / kSizeEntry;
            *outNextIfdOffset = 0;
            return true;
        }
        return false;
    }
 
    // Save the number of entries.
    *outNumEntries = numEntries;
 
    // Seek past the entries.
    dataCurrent += kSizeEntry * numEntries;
    dataSize -= kSizeEntry * numEntries;
 
    // Read the next IFD offset.
    if (dataSize < kSizeLong) {
        SkCodecPrintf("Insufficient space to store next IFD offset.\n");
        if (allowTruncated) {
            // Set the next IFD offset to 0 (indicating that there is no next IFD).
            *outNextIfdOffset = 0;
            return true;
        }
        return false;
    }
 
    // Save the next IFD offset.
    *outNextIfdOffset = get_endian_int(dataCurrent, littleEndian);
    return true;
}

Variable Documentation

kEndianBig

constexpr uint8_t SkTiff::kEndianBig[kEndianSize] = {'M', 'M', 0, 42}

inlineconstexpr

Definition at line 22 of file SkTiffUtility.h.

kEndianLittle

constexpr uint8_t SkTiff::kEndianLittle[kEndianSize] = {'I', 'I', 42, 0}

inlineconstexpr

Definition at line 23 of file SkTiffUtility.h.

kEndianSize

constexpr size_t SkTiff::kEndianSize = 4

inlineconstexpr

Definition at line 21 of file SkTiffUtility.h.

kSizeEntry

constexpr size_t SkTiff::kSizeEntry = 12

constexpr

Definition at line 18 of file SkTiffUtility.cpp.

kSizeLong

constexpr size_t SkTiff::kSizeLong = 4

constexpr

Definition at line 20 of file SkTiffUtility.cpp.

kSizeShort

constexpr size_t SkTiff::kSizeShort = 2

constexpr

Definition at line 19 of file SkTiffUtility.cpp.

kTypeAsciiString

constexpr uint16_t SkTiff::kTypeAsciiString = 2

inlineconstexpr

Definition at line 27 of file SkTiffUtility.h.

kTypeDoubleFloat

constexpr uint16_t SkTiff::kTypeDoubleFloat = 12

inlineconstexpr

Definition at line 37 of file SkTiffUtility.h.

kTypeSignedByte

constexpr uint16_t SkTiff::kTypeSignedByte = 6

inlineconstexpr

Definition at line 31 of file SkTiffUtility.h.

kTypeSignedLong

constexpr uint16_t SkTiff::kTypeSignedLong = 9

inlineconstexpr

Definition at line 34 of file SkTiffUtility.h.

kTypeSignedRational

constexpr uint16_t SkTiff::kTypeSignedRational = 10

inlineconstexpr

Definition at line 35 of file SkTiffUtility.h.

kTypeSignedShort

constexpr uint16_t SkTiff::kTypeSignedShort = 8

inlineconstexpr

Definition at line 33 of file SkTiffUtility.h.

kTypeSingleFloat

constexpr uint16_t SkTiff::kTypeSingleFloat = 11

inlineconstexpr

Definition at line 36 of file SkTiffUtility.h.

kTypeUndefined

constexpr uint16_t SkTiff::kTypeUndefined = 7

inlineconstexpr

Definition at line 32 of file SkTiffUtility.h.

kTypeUnsignedByte

constexpr uint16_t SkTiff::kTypeUnsignedByte = 1

inlineconstexpr

Definition at line 26 of file SkTiffUtility.h.

kTypeUnsignedLong

constexpr uint16_t SkTiff::kTypeUnsignedLong = 4

inlineconstexpr

Definition at line 29 of file SkTiffUtility.h.

kTypeUnsignedRational

constexpr uint16_t SkTiff::kTypeUnsignedRational = 5

inlineconstexpr

Definition at line 30 of file SkTiffUtility.h.

kTypeUnsignedShort

constexpr uint16_t SkTiff::kTypeUnsignedShort = 3

inlineconstexpr

Definition at line 28 of file SkTiffUtility.h.