in an idat chunk, each scanline is a multiple of 8 bits, unlike the lodepng output buffer*/

Calculate the CRC over a section of data. We can only pass as * much data to this routine as the largest single buffer size. We * also check that

This function frees the memory associated with a single info struct. * Normally, one would use either png_destroy_read_struct() or * png_destroy_wri

This does the right thing based on the bit_depth field of the * png_struct, interpreting values as 8-bit or 16-bit. While the result * is nominally

Manage the read buffer; this simply reallocates the buffer if it is not small * enough (or if it is not allocated). The routine returns a pointer to

The point counter-clockwise to given point

========================================================================= */

=========================================================================== * Fill the window when the lookahead becomes insufficient. * Updates str

========================================================================= * Flush as much pending output as possible. All deflate() output goes * th

Compress len zeros to output. Return -1 on error, 0 on success. */

* Deallocate memory in a manner that is compatible with libpng's memory * allocation/deallocation routines, png_malloc() and png_free(). * If those

* Prints a warning message (level = OPNG_MSG_WARNING) to the logger. */

bitlen is the size in bits of the code*/

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

* Determines if the accessibility of the specified path satisfies * the specified access mode. */

Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification, * and if invalid, correct the keyword rather than discarding the entire * ch

The inverse of the above. */

Handle alpha and tRNS via a background color */

Turn on pixel packing */

This function allows the application to supply a new input function * for libpng if standard C streams aren't being used. * * This function takes a

Called by user to write a row of image data */

free the above pair again*/

init a {char*, size_t} pair for use as string*/

given the code lengths (as stored in the PNG file), generate the tree as defined by Deflate. maxbitlen is the maximum bits that a code in the tree can

The point counter-clockwise to given point

creates a new chain node with the given parameters, from the memory in the lists */

========================================================================= */

* Build a color+alpha palette in which the entries are sorted by * (alpha, red, green, blue), in this particular order. * Use the insertion sort alg

* Counts the number of elements in a bitset. */

This function allows the application to supply new output functions for * libpng if standard C streams aren't being used. * * This function takes a

========================================================================= * Put a short in the pending buffer. The 16-bit value is put in MSB order.

returns 1 if success, 0 if failure ==> nothing done*/

resize and give all new elements the value*/

compress using the default or custom zlib function */

Outputs various dimensions and positions in the image related to the Adam7 reduced images. passw: output containing the width of the 7 passes passh: o