OPNGCORE is a PNG Compression Optimization and Recovery Engine. More...

#include <limits.h>
#include <stddef.h>
#include "optk/bits.h"

Data Structures
struct	opng_options
	The user options structure. More...

struct	opng_version_info
	The version info structure. More...

Typedefs
typedef struct opng_optimizer	opng_optimizer_t
	The optimizer type.

typedef struct opng_image	opng_image_t
	The image type.

Enumerations
enum	{ OPNG_MSG_ALL = 0, OPNG_MSG_DEBUG = 10, OPNG_MSG_INFO = 20, OPNG_MSG_WARNING = 30, OPNG_MSG_ERROR = 40, OPNG_MSG_CRITICAL = 50, OPNG_MSG_OFF = (unsigned int)(-1), OPNG_MSG_DEFAULT = OPNG_MSG_OFF }
	Message severity levels. More...

enum	{ OPNG_MSGFMT_RAW = 0, OPNG_MSGFMT_UNIX = 1, OPNG_MSGFMT_FANCY = 2, OPNG_MSGFMT_DEFAULT = OPNG_MSGFMT_UNIX }
	Message formats.

enum	{ OPNG_OPTIM_LEVEL_MIN = -2, OPNG_OPTIM_LEVEL_MAX = 6, OPNG_OPTIM_LEVEL_FASTEST = -2, OPNG_OPTIM_LEVEL_FAST = -1, OPNG_OPTIM_LEVEL_DEFAULT = 2, OPNG_FILTER_MIN = 0, OPNG_FILTER_MAX = 5, OPNG_FILTER_SET_MASK = (1 << (5+1)) - (1 << 0), OPNG_ZCOMPR_LEVEL_MIN = 1, OPNG_ZCOMPR_LEVEL_MAX = 9, OPNG_ZCOMPR_LEVEL_SET_MASK = (1 << (9+1)) - (1 << 1), OPNG_ZMEM_LEVEL_MIN = 1, OPNG_ZMEM_LEVEL_MAX = 9, OPNG_ZMEM_LEVEL_SET_MASK = (1 << (9+1)) - (1 << 1), OPNG_ZSTRATEGY_MIN = 0, OPNG_ZSTRATEGY_MAX = 3, OPNG_ZSTRATEGY_SET_MASK = (1 << (3+1)) - (1 << 0), OPNG_ZWINDOW_BITS_MIN = 8, OPNG_ZWINDOW_BITS_MAX = 15, OPNG_ZWINDOW_BITS_SET_MASK = (1 << (15+1)) - (1 << 8) }
	Encoder constants and limits.

Functions
opng_optimizer_t *	opng_create_optimizer (void)
	Creates an optimizer object.

int	opng_set_options (opng_optimizer_t optimizer, const struct opng_options user_options)
	Sets the user options in an optimizer object.

int	opng_optimize_file (opng_optimizer_t optimizer, const char in_fname, const char out_fname, const char out_dirname)
	Optimizes an image file.

void	opng_destroy_optimizer (opng_optimizer_t *optimizer)
	Destroys an optimizer object.

void	opng_set_logging_name (const char *program_name)
	Sets the program name associated with the logger.

void	opng_set_logging_level (unsigned int level)
	Sets the logging severity level.

void	opng_set_logging_format (int format)
	Sets the logging format.

int	opng_flush_logging (unsigned int level)
	Flushes the logger at the given severity level.

int	opng_print_message (unsigned int level, const char fname, const char message)
	Prints a message of a given severity level, concerning a given file name, using the current logging message format, to the logger.

int	opng_debugf (const char *format,...)
	Prints a printf-formatted debug message (`level` = `OPNG_MSG_DEBUG`) to the logger.

int	opng_printf (const char *format,...)
	Prints a printf-formatted informational message (`level` = `OPNG_MSG_INFO`) to the logger.

int	opng_warning (const char fname, const char message)
	Prints a warning message (`level` = `OPNG_MSG_WARNING`) to the logger.

int	opng_error (const char fname, const char message, const char *submessage)
	Prints an error message (`level` = `OPNG_MSG_ERROR`), optionally accompanied by a submessage, to the logger.

struct opng_version_info *	opng_get_version_info (void)
	Returns an array of version info objects, terminated by NULLs.

Detailed Description

OPNGCORE is a PNG Compression Optimization and Recovery Engine.

This software is distributed under the zlib license. Please see the accompanying LICENSE file, or visit http://www.opensource.org/licenses/zlib-license.php

Typedef Documentation

typedef struct opng_image opng_image_t

The image type.

Image objects are currently used internally only. There is no public API to access them yet.

Todo:: 3rd-party applications may wish to use this type in order to create optimized PNG files from in-memory images (e.g. in-memory compressed files, raw pixel data, BMP handles, etc.). Your contribution will be appreciated ;-)

typedef struct opng_optimizer opng_optimizer_t

The optimizer type.

An optimizer object can optimize one or more images, sequentially.

Bug:: Multiple optimizer objects are designed to run in parallel (but they don't, yet).

Enumeration Type Documentation

anonymous enum

Message severity levels.

Each level allows up to 10 custom sub-levels. The level numbers are loosely based on the Python logging module.

Function Documentation

opng_optimizer_t* opng_create_optimizer ( void )

Creates an optimizer object.

Returns: the optimizer created, or NULL on failure.

void opng_destroy_optimizer ( opng_optimizer_t * optimizer )

Destroys an optimizer object.

Parameters

optimizer the optimizer object to be destroyed.

int opng_flush_logging ( unsigned int level )

Flushes the logger at the given severity level.

To avoid useless fflush operations, it is recommended to set the severity level to the level of the messages that have been displayed and need to be flushed.

Parameters

level the minimum severity level at which flushing is triggered.

int opng_optimize_file	(	opng_optimizer_t *	optimizer,
		const char *	in_fname,
		const char *	out_fname,
		const char *	out_dirname
	)

Optimizes an image file.

Parameters

optimizer	the optimizer object.
in_fname	the input file name.
out_fname	the output file name. It can be `NULL`, in which case the output has the same name as the input.
out_dirname	the output directory name. It can be `NULL`.

Returns: 0 on success, or a non-zero exit code on failure.

int opng_print_message	(	unsigned int	level,
		const char *	fname,
		const char *	message
	)

Prints a message of a given severity level, concerning a given file name, using the current logging message format, to the logger.

Parameters

fname	the file name associated with the message; can be `NULL`.
level	the severity level `OPNG_MSG_`...
message	the message to be displayed.

Returns: 1 if a message was displayed, 0 if nothing was displayed, or -1 if an error occurred.

void opng_set_logging_format ( int format )

Sets the logging format.

Parameters

format the format OPNG_MSGFMT_...

See Also: opng_print_message.

void opng_set_logging_level ( unsigned int level )

Sets the logging severity level.

Parameters

level the severity level OPNG_MSG_...

See Also: opng_print_message.

void opng_set_logging_name ( const char * program_name )

Sets the program name associated with the logger.

Parameters

program_name the program name displayed on warnings or errors. It can be NULL.

int opng_set_options	(	opng_optimizer_t *	optimizer,
		const struct opng_options *	user_options
	)

Sets the user options in an optimizer object.

An optimizer can run only if it has been given a set of options; there are no defaults. Options can be changed repeatedly between optimization sessions (for the benefit of interactive applications), but they shall not be changed during these sessions.

Parameters

optimizer	the optimizer object whose user options are changed.
user_options	the user options.

Returns: 0 if the options are valid, or -1 otherwise.

Data Structures

Typedefs

Enumerations

Functions

Detailed Description

Typedef Documentation

Enumeration Type Documentation

Function Documentation