dec_png.c File Reference

This program reads PNG stream data from memory. More...

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <png.h>

Go to the source code of this file.

Typedefs
typedef int	g2int
	Integer type. More...
typedef struct png_stream	png_stream
	location to write PNG stream More...

Functions
int	dec_png (unsigned char *pngbuf, g2int *width, g2int *height, char *cout)
	Decode some PNG compressed data. More...
static void	user_read_data (png_structp png_ptr, png_bytep data, png_uint_32 length)
	Custom read function used so that libpng will read a PNG stream from memory instead of a file on disk. More...

Detailed Description

This program reads PNG stream data from memory.

Author

Stephen Gilbert

Definition in file dec_png.c.

Typedef Documentation

g2int

typedef int g2int

Integer type.

Definition at line 12 of file dec_png.c.

png_stream

typedef struct png_stream png_stream

location to write PNG stream

Definition at line 12 of file dec_png.c.

Function Documentation

dec_png()

int dec_png	(	unsigned char *	pngbuf,
		g2int *	width,
		g2int *	height,
		char *	cout
	)

Decode some PNG compressed data.

Parameters

pngbuf	Pointer to the PNG buffer to be uncompressed.
width	Pointer to the width.
height	Pointer to the height.
cout	Pointer that gets the unpacked data.

Returns

• 0 Success
• -1 Error initializing PNG structs.
• -2 Error initializing PNG info struct.
• -3 Error initializing PNG error callbacks, or stream not valid PNG.

Author

Stephen Gilbert

Definition at line 64 of file dec_png.c.

References drstemplates::j, and user_read_data().

Referenced by pngunpack().

user_read_data()

static void user_read_data ( png_structp  png_ptr, png_bytep  data, png_uint_32  length  )

static

Custom read function used so that libpng will read a PNG stream from memory instead of a file on disk.

Parameters

png_ptr	Pointer to PNG.
data	Pointer to data.
length	Length.

Author

Stephen Gilbert

Definition at line 34 of file dec_png.c.

Referenced by dec_png().