Portable Network Graphics (PNG) format. More...

#include <stdint.h>
#include <byteswap.h>
#include <ipxe/image.h>

Data Structures
struct	png_signature
	A PNG file signature. More...

struct	png_chunk_header
	A PNG chunk header. More...

struct	png_chunk_footer
	A PNG chunk footer. More...

struct	png_image_header
	A PNG image header. More...

struct	png_palette_entry
	A PNG palette entry. More...

struct	png_palette
	A PNG palette chunk. More...

Macros
#define	PNG_SIGNATURE { { 0x89, 'P', 'N', 'G', '\r', '\n', 0x1a, '\n' } }
	PNG file signature. More...

#define	PNG_TYPE(first, second, third, fourth) ( ( (first) << 24 ) \| ( (second) << 16 ) \| ( (third) << 8 ) \| (fourth) )
	Define a canonical PNG chunk type. More...

#define	PNG_TYPE_IHDR PNG_TYPE ( 'I', 'H', 'D', 'R' )
	PNG image header chunk type. More...

#define	PNG_COLOUR_TYPE_MASK 0x07
	PNG colour type mask. More...

#define	PNG_TYPE_PLTE PNG_TYPE ( 'P', 'L', 'T', 'E' )
	PNG palette chunk type. More...

#define	PNG_PALETTE_COUNT 256
	Maximum number of PNG palette entries. More...

#define	PNG_TYPE_IDAT PNG_TYPE ( 'I', 'D', 'A', 'T' )
	PNG image data chunk type. More...

#define	PNG_TYPE_IEND PNG_TYPE ( 'I', 'E', 'N', 'D' )
	PNG image end chunk type. More...

Enumerations
enum	png_chunk_type_bits { PNG_CHUNK_ANCILLARY = 0x20000000UL, PNG_CHUNK_PRIVATE = 0x00200000UL, PNG_CHUNK_RESERVED = 0x00002000UL, PNG_CHUNK_SAFE = 0x00000020UL }
	PNG chunk type property bits. More...

enum	png_colour_type { PNG_COLOUR_TYPE_PALETTE = 0x01, PNG_COLOUR_TYPE_RGB = 0x02, PNG_COLOUR_TYPE_ALPHA = 0x04 }
	PNG colour type bits. More...

enum	png_compression_method { PNG_COMPRESSION_DEFLATE = 0x00, PNG_COMPRESSION_UNKNOWN = 0x01 }
	PNG compression methods. More...

enum	png_filter_method { PNG_FILTER_BASIC = 0x00, PNG_FILTER_UNKNOWN = 0x01 }
	PNG filter methods. More...

enum	png_interlace_method { PNG_INTERLACE_NONE = 0x00, PNG_INTERLACE_ADAM7 = 0x01, PNG_INTERLACE_UNKNOWN = 0x02 }
	PNG interlace methods. More...

enum	png_basic_filter_type { PNG_FILTER_BASIC_NONE = 0, PNG_FILTER_BASIC_SUB = 1, PNG_FILTER_BASIC_UP = 2, PNG_FILTER_BASIC_AVERAGE = 3, PNG_FILTER_BASIC_PAETH = 4 }
	PNG basic filter types. More...

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)

	FILE_SECBOOT (PERMITTED)

static uint32_t	png_canonical_type (uint32_t type)
	Canonicalise PNG chunk type. More...

struct image_type png_image_type	__image_type (PROBE_NORMAL)

Detailed Description

Portable Network Graphics (PNG) format.

Definition in file png.h.

Macro Definition Documentation

◆ PNG_SIGNATURE

#define PNG_SIGNATURE { { 0x89, 'P', 'N', 'G', '\r', '\n', 0x1a, '\n' } }

PNG file signature.

Definition at line 24 of file png.h.

◆ PNG_TYPE

#define PNG_TYPE	(	first,
		second,
		third,
		fourth
	)	( ( (first) << 24 ) \| ( (second) << 16 ) \| ( (third) << 8 ) \| (fourth) )

Define a canonical PNG chunk type.

Parameters

first	First letter (in upper case)
second	Second letter (in upper case)
third	Third letter (in upper case)
fourth	Fourth letter (in upper case)

Return values

type	Canonical chunk type

Definition at line 73 of file png.h.

◆ PNG_TYPE_IHDR

#define PNG_TYPE_IHDR PNG_TYPE ( 'I', 'H', 'D', 'R' )

PNG image header chunk type.

Definition at line 77 of file png.h.

◆ PNG_COLOUR_TYPE_MASK

#define PNG_COLOUR_TYPE_MASK 0x07

PNG colour type mask.

Definition at line 108 of file png.h.

◆ PNG_TYPE_PLTE

#define PNG_TYPE_PLTE PNG_TYPE ( 'P', 'L', 'T', 'E' )

PNG palette chunk type.

Definition at line 137 of file png.h.

◆ PNG_PALETTE_COUNT

#define PNG_PALETTE_COUNT 256

Maximum number of PNG palette entries.

Definition at line 156 of file png.h.

◆ PNG_TYPE_IDAT

#define PNG_TYPE_IDAT PNG_TYPE ( 'I', 'D', 'A', 'T' )

PNG image data chunk type.

Definition at line 159 of file png.h.

◆ PNG_TYPE_IEND

#define PNG_TYPE_IEND PNG_TYPE ( 'I', 'E', 'N', 'D' )

PNG image end chunk type.

Definition at line 176 of file png.h.

Enumeration Type Documentation

◆ png_chunk_type_bits

enum png_chunk_type_bits

PNG chunk type property bits.

Enumerator
PNG_CHUNK_ANCILLARY	Chunk is ancillary.
PNG_CHUNK_PRIVATE	Chunk is private.
PNG_CHUNK_RESERVED	Reserved.
PNG_CHUNK_SAFE	Chunk is safe to copy.

Definition at line 41 of file png.h.

                          {
         /** Chunk is ancillary */
         PNG_CHUNK_ANCILLARY = 0x20000000UL,
         /** Chunk is private */
         PNG_CHUNK_PRIVATE = 0x00200000UL,
         /** Reserved */
         PNG_CHUNK_RESERVED = 0x00002000UL,
         /** Chunk is safe to copy */
         PNG_CHUNK_SAFE = 0x00000020UL,
 };

◆ png_colour_type

enum png_colour_type

PNG colour type bits.

Enumerator
PNG_COLOUR_TYPE_PALETTE	Palette is used.
PNG_COLOUR_TYPE_RGB	RGB colour is used.
PNG_COLOUR_TYPE_ALPHA	Alpha channel is used.

Definition at line 98 of file png.h.

                      {
         /** Palette is used */
         PNG_COLOUR_TYPE_PALETTE = 0x01,
         /** RGB colour is used */
         PNG_COLOUR_TYPE_RGB = 0x02,
         /** Alpha channel is used */
         PNG_COLOUR_TYPE_ALPHA = 0x04,
 };

◆ png_compression_method

enum png_compression_method

PNG compression methods.

Enumerator
PNG_COMPRESSION_DEFLATE	DEFLATE compression with 32kB sliding window.
PNG_COMPRESSION_UNKNOWN	First unknown compression method.

Definition at line 111 of file png.h.

                             {
         /** DEFLATE compression with 32kB sliding window */
         PNG_COMPRESSION_DEFLATE = 0x00,
         /** First unknown compression method */
         PNG_COMPRESSION_UNKNOWN = 0x01,
 };

◆ png_filter_method

enum png_filter_method

PNG filter methods.

Enumerator
PNG_FILTER_BASIC	Adaptive filtering with five basic types.
PNG_FILTER_UNKNOWN	First unknown filter method.

Definition at line 119 of file png.h.

                        {
         /** Adaptive filtering with five basic types */
         PNG_FILTER_BASIC = 0x00,
         /** First unknown filter method */
         PNG_FILTER_UNKNOWN = 0x01,
 };

◆ png_interlace_method

enum png_interlace_method

PNG interlace methods.

Enumerator
PNG_INTERLACE_NONE	No interlacing.
PNG_INTERLACE_ADAM7	Adam7 interlacing.
PNG_INTERLACE_UNKNOWN	First unknown interlace method.

Definition at line 127 of file png.h.

                           {
         /** No interlacing */
         PNG_INTERLACE_NONE = 0x00,
         /** Adam7 interlacing */
         PNG_INTERLACE_ADAM7 = 0x01,
         /** First unknown interlace method */
         PNG_INTERLACE_UNKNOWN = 0x02,
 };

◆ png_basic_filter_type

enum png_basic_filter_type

PNG basic filter types.

Enumerator
PNG_FILTER_BASIC_NONE	No filtering.
PNG_FILTER_BASIC_SUB	Left byte used as predictor.
PNG_FILTER_BASIC_UP	Above byte used as predictor.
PNG_FILTER_BASIC_AVERAGE	Above and left bytes used as predictors.
PNG_FILTER_BASIC_PAETH	Paeth filter.

Definition at line 162 of file png.h.

                            {
         /** No filtering */
         PNG_FILTER_BASIC_NONE = 0,
         /** Left byte used as predictor */
         PNG_FILTER_BASIC_SUB = 1,
         /** Above byte used as predictor */
         PNG_FILTER_BASIC_UP = 2,
         /** Above and left bytes used as predictors */
         PNG_FILTER_BASIC_AVERAGE = 3,
         /** Paeth filter */
         PNG_FILTER_BASIC_PAETH = 4,
 };

Function Documentation

◆ FILE_LICENCE()

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL )

◆ FILE_SECBOOT()

FILE_SECBOOT ( PERMITTED )

◆ png_canonical_type()

static uint32_t png_canonical_type ( uint32_t type )

inlinestatic

Canonicalise PNG chunk type.