Exiv2
pngchunk_int.hpp
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 
3 #ifndef PNGCHUNK_INT_HPP_
4 #define PNGCHUNK_INT_HPP_
5 
6 // *****************************************************************************
7 // included header files
8 #include "pngimage.hpp"
9 #include "types.hpp"
10 
11 // *****************************************************************************
12 // namespace extensions
13 namespace Exiv2::Internal {
14 // *****************************************************************************
15 // class definitions
16 
21 class PngChunk {
22  public:
26  enum TxtChunkType { tEXt_Chunk = 0, zTXt_Chunk = 1, iTXt_Chunk = 2 };
27 
36  static void decodeIHDRChunk(const DataBuf& data, uint32_t* outWidth, uint32_t* outHeight);
37 
46  static void decodeTXTChunk(Image* pImage, const DataBuf& data, TxtChunkType type);
47 
55  static DataBuf decodeTXTChunk(const DataBuf& data, TxtChunkType type);
56 
63  static DataBuf keyTXTChunk(const DataBuf& data, bool stripHeader = false);
64 
73  static std::string makeMetadataChunk(const std::string& metadata, MetadataId type);
74 
75  private:
80  static DataBuf parseTXTChunk(const DataBuf& data, size_t keysize, TxtChunkType type);
81 
91  static void parseChunkContent(Image* pImage, const byte* key, size_t keySize, const DataBuf& arr);
92 
103  static std::string makeAsciiTxtChunk(const std::string& keyword, const std::string& text, bool compress);
104 
113  static std::string makeUtf8TxtChunk(const std::string& keyword, const std::string& text, bool compress);
114 
118  static void zlibUncompress(const byte* compressedText, unsigned int compressedTextSize, DataBuf& arr);
119 
123  static std::string zlibCompress(const std::string& text);
124 
128  static DataBuf readRawProfile(const DataBuf& text, bool iTXt);
129 
134  static std::string writeRawProfile(const std::string& profileData, const char* profileType);
135 
136  friend class Exiv2::PngImage;
137 
138 }; // class PngChunk
139 
140 } // namespace Exiv2::Internal
141 
142 #endif // #ifndef PNGCHUNK_INT_HPP_
TxtChunkType
Text Chunk types.
Definition: pngchunk_int.hpp:26
uint8_t byte
1 byte unsigned integer type.
Definition: types.hpp:26
Abstract base class defining the interface for an image. This is the top-level interface to the Exiv2...
Definition: image.hpp:50
MetadataId
An identifier for each type of metadata.
Definition: types.hpp:47
Utility class containing a character array. All it does is to take care of memory allocation and dele...
Definition: types.hpp:124
Stateless parser class for data in PNG chunk format. Images use this class to decode and encode PNG-b...
Definition: pngchunk_int.hpp:21
static void decodeIHDRChunk(const DataBuf &data, uint32_t *outWidth, uint32_t *outHeight)
Decode PNG IHDR chunk data from a data buffer data and return image size to outWidth and outHeight...
static std::string makeMetadataChunk(const std::string &metadata, MetadataId type)
Return a complete PNG chunk data compressed or not as buffer. Data returned is formated accordingly w...
Helper structure for the Matroska tags lookup table.
Definition: matroskavideo.hpp:39
static void decodeTXTChunk(Image *pImage, const DataBuf &data, TxtChunkType type)
Decode PNG tEXt, zTXt, or iTXt chunk data from pImage passed by data buffer data and extract Comment...
static DataBuf keyTXTChunk(const DataBuf &data, bool stripHeader=false)
Return PNG TXT chunk key as data buffer.
Class to access PNG images. Exif and IPTC metadata are supported directly.
Definition: pngimage.hpp:22