cheng/libpng
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
9f7b16ad19
libpng/pngwrite.c
Glenn Randers-Pehrson 9f7b16ad19 Imported from libpng-1.2.27.tar
2009-04-06 16:16:49 -05:00

1533 lines
48 KiB
C
Raw Blame History

/* pngwrite.c - general routines to write a PNG file
*
* Last changed in libpng 1.2.27 [April 29, 2008]
* For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1998-2008 Glenn Randers-Pehrson
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
*/
/* get internal access to png.h */
#define PNG_INTERNAL
#include "png.h"
#ifdef PNG_WRITE_SUPPORTED
/* Writes all the PNG information. This is the suggested way to use the
* library. If you have a new chunk to add, make a function to write it,
* and put it in the correct location here. If you want the chunk written
* after the image data, put it in png_write_end(). I strongly encourage
* you to supply a PNG_INFO_ flag, and check info_ptr->valid before writing
* the chunk, as that will keep the code from breaking if you want to just
* write a plain PNG file. If you have long comments, I suggest writing
* them in png_write_end(), and compressing them.
*/
void PNGAPI
png_write_info_before_PLTE(png_structp png_ptr, png_infop info_ptr)
{
png_debug(1, "in png_write_info_before_PLTE\n");
if (png_ptr == NULL || info_ptr == NULL)
return;
if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
{
png_write_sig(png_ptr); /* write PNG signature */
#if defined(PNG_MNG_FEATURES_SUPPORTED)
if((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE)&&(png_ptr->mng_features_permitted))
{
png_warning(png_ptr,"MNG features are not allowed in a PNG datastream");
png_ptr->mng_features_permitted=0;
}
#endif
/* write IHDR information. */
png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height,
info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type,
info_ptr->filter_type,
#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
info_ptr->interlace_type);
#else
0);
#endif
/* the rest of these check to see if the valid field has the appropriate
flag set, and if it does, writes the chunk. */
#if defined(PNG_WRITE_gAMA_SUPPORTED)
if (info_ptr->valid & PNG_INFO_gAMA)
{
# ifdef PNG_FLOATING_POINT_SUPPORTED
png_write_gAMA(png_ptr, info_ptr->gamma);
#else
#ifdef PNG_FIXED_POINT_SUPPORTED
png_write_gAMA_fixed(png_ptr, info_ptr->int_gamma);
# endif
#endif
}
#endif
#if defined(PNG_WRITE_sRGB_SUPPORTED)
if (info_ptr->valid & PNG_INFO_sRGB)
png_write_sRGB(png_ptr, (int)info_ptr->srgb_intent);
#endif
#if defined(PNG_WRITE_iCCP_SUPPORTED)
if (info_ptr->valid & PNG_INFO_iCCP)
png_write_iCCP(png_ptr, info_ptr->iccp_name, PNG_COMPRESSION_TYPE_BASE,
info_ptr->iccp_profile, (int)info_ptr->iccp_proflen);
#endif
#if defined(PNG_WRITE_sBIT_SUPPORTED)
if (info_ptr->valid & PNG_INFO_sBIT)
png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type);
#endif
#if defined(PNG_WRITE_cHRM_SUPPORTED)
if (info_ptr->valid & PNG_INFO_cHRM)
{
#ifdef PNG_FLOATING_POINT_SUPPORTED
png_write_cHRM(png_ptr,
info_ptr->x_white, info_ptr->y_white,
info_ptr->x_red, info_ptr->y_red,
info_ptr->x_green, info_ptr->y_green,
info_ptr->x_blue, info_ptr->y_blue);
#else
# ifdef PNG_FIXED_POINT_SUPPORTED
png_write_cHRM_fixed(png_ptr,
info_ptr->int_x_white, info_ptr->int_y_white,
info_ptr->int_x_red, info_ptr->int_y_red,
info_ptr->int_x_green, info_ptr->int_y_green,
info_ptr->int_x_blue, info_ptr->int_y_blue);
# endif
#endif
}
#endif
#if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
if (info_ptr->unknown_chunks_num)
{
png_unknown_chunk *up;
png_debug(5, "writing extra chunks\n");
for (up = info_ptr->unknown_chunks;
up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
up++)
{
int keep=png_handle_as_unknown(png_ptr, up->name);
if (keep != PNG_HANDLE_CHUNK_NEVER &&
up->location && !(up->location & PNG_HAVE_PLTE) &&
!(up->location & PNG_HAVE_IDAT) &&
((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
(png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
{
if (up->size == 0)
png_warning(png_ptr, "Writing zero-length unknown chunk");
png_write_chunk(png_ptr, up->name, up->data, up->size);
}
}
}
#endif
png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE;
}
}
void PNGAPI
png_write_info(png_structp png_ptr, png_infop info_ptr)
{
#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
int i;
#endif
png_debug(1, "in png_write_info\n");
if (png_ptr == NULL || info_ptr == NULL)
return;
png_write_info_before_PLTE(png_ptr, info_ptr);
if (info_ptr->valid & PNG_INFO_PLTE)
png_write_PLTE(png_ptr, info_ptr->palette,
(png_uint_32)info_ptr->num_palette);
else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
png_error(png_ptr, "Valid palette required for paletted images");
#if defined(PNG_WRITE_tRNS_SUPPORTED)
if (info_ptr->valid & PNG_INFO_tRNS)
{
#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
/* invert the alpha channel (in tRNS) */
if ((png_ptr->transformations & PNG_INVERT_ALPHA) &&
info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
{
int j;
for (j=0; j<(int)info_ptr->num_trans; j++)
info_ptr->trans[j] = (png_byte)(255 - info_ptr->trans[j]);
}
#endif
png_write_tRNS(png_ptr, info_ptr->trans, &(info_ptr->trans_values),
info_ptr->num_trans, info_ptr->color_type);
}
#endif
#if defined(PNG_WRITE_bKGD_SUPPORTED)
if (info_ptr->valid & PNG_INFO_bKGD)
png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type);
#endif
#if defined(PNG_WRITE_hIST_SUPPORTED)
if (info_ptr->valid & PNG_INFO_hIST)
png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette);
#endif
#if defined(PNG_WRITE_oFFs_SUPPORTED)
if (info_ptr->valid & PNG_INFO_oFFs)
png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset,
info_ptr->offset_unit_type);
#endif
#if defined(PNG_WRITE_pCAL_SUPPORTED)
if (info_ptr->valid & PNG_INFO_pCAL)
png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0,
info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams,
info_ptr->pcal_units, info_ptr->pcal_params);
#endif
#if defined(PNG_WRITE_sCAL_SUPPORTED)
if (info_ptr->valid & PNG_INFO_sCAL)
#if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
png_write_sCAL(png_ptr, (int)info_ptr->scal_unit,
info_ptr->scal_pixel_width, info_ptr->scal_pixel_height);
#else
#ifdef PNG_FIXED_POINT_SUPPORTED
png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit,
info_ptr->scal_s_width, info_ptr->scal_s_height);
#else
png_warning(png_ptr,
"png_write_sCAL not supported; sCAL chunk not written.");
#endif
#endif
#endif
#if defined(PNG_WRITE_pHYs_SUPPORTED)
if (info_ptr->valid & PNG_INFO_pHYs)
png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit,
info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type);
#endif
#if defined(PNG_WRITE_tIME_SUPPORTED)
if (info_ptr->valid & PNG_INFO_tIME)
{
png_write_tIME(png_ptr, &(info_ptr->mod_time));
png_ptr->mode |= PNG_WROTE_tIME;
}
#endif
#if defined(PNG_WRITE_sPLT_SUPPORTED)
if (info_ptr->valid & PNG_INFO_sPLT)
for (i = 0; i < (int)info_ptr->splt_palettes_num; i++)
png_write_sPLT(png_ptr, info_ptr->splt_palettes + i);
#endif
#if defined(PNG_WRITE_TEXT_SUPPORTED)
/* Check to see if we need to write text chunks */
for (i = 0; i < info_ptr->num_text; i++)
{
png_debug2(2, "Writing header text chunk %d, type %d\n", i,
info_ptr->text[i].compression);
/* an internationalized chunk? */
if (info_ptr->text[i].compression > 0)
{
#if defined(PNG_WRITE_iTXt_SUPPORTED)
/* write international chunk */
png_write_iTXt(png_ptr,
info_ptr->text[i].compression,
info_ptr->text[i].key,
info_ptr->text[i].lang,
info_ptr->text[i].lang_key,
info_ptr->text[i].text);
#else
png_warning(png_ptr, "Unable to write international text");
#endif
/* Mark this chunk as written */
info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
}
/* If we want a compressed text chunk */
else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_zTXt)
{
#if defined(PNG_WRITE_zTXt_SUPPORTED)
/* write compressed chunk */
png_write_zTXt(png_ptr, info_ptr->text[i].key,
info_ptr->text[i].text, 0,
info_ptr->text[i].compression);
#else
png_warning(png_ptr, "Unable to write compressed text");
#endif
/* Mark this chunk as written */
info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
}
else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
{
#if defined(PNG_WRITE_tEXt_SUPPORTED)
/* write uncompressed chunk */
png_write_tEXt(png_ptr, info_ptr->text[i].key,
info_ptr->text[i].text,
0);
#else
png_warning(png_ptr, "Unable to write uncompressed text");
#endif
/* Mark this chunk as written */
info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
}
}
#endif
#if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
if (info_ptr->unknown_chunks_num)
{
png_unknown_chunk *up;
png_debug(5, "writing extra chunks\n");
for (up = info_ptr->unknown_chunks;
up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
up++)
{
int keep=png_handle_as_unknown(png_ptr, up->name);
if (keep != PNG_HANDLE_CHUNK_NEVER &&
up->location && (up->location & PNG_HAVE_PLTE) &&
!(up->location & PNG_HAVE_IDAT) &&
((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
(png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
{
png_write_chunk(png_ptr, up->name, up->data, up->size);
}
}
}
#endif
}
/* Writes the end of the PNG file. If you don't want to write comments or
* time information, you can pass NULL for info. If you already wrote these
* in png_write_info(), do not write them again here. If you have long
* comments, I suggest writing them here, and compressing them.
*/
void PNGAPI
png_write_end(png_structp png_ptr, png_infop info_ptr)
{
png_debug(1, "in png_write_end\n");
if (png_ptr == NULL)
return;
if (!(png_ptr->mode & PNG_HAVE_IDAT))
png_error(png_ptr, "No IDATs written into file");
/* see if user wants us to write information chunks */
if (info_ptr != NULL)
{
#if defined(PNG_WRITE_TEXT_SUPPORTED)
int i; /* local index variable */
#endif
#if defined(PNG_WRITE_tIME_SUPPORTED)
/* check to see if user has supplied a time chunk */
if ((info_ptr->valid & PNG_INFO_tIME) &&
!(png_ptr->mode & PNG_WROTE_tIME))
png_write_tIME(png_ptr, &(info_ptr->mod_time));
#endif
#if defined(PNG_WRITE_TEXT_SUPPORTED)
/* loop through comment chunks */
for (i = 0; i < info_ptr->num_text; i++)
{
png_debug2(2, "Writing trailer text chunk %d, type %d\n", i,
info_ptr->text[i].compression);
/* an internationalized chunk? */
if (info_ptr->text[i].compression > 0)
{
#if defined(PNG_WRITE_iTXt_SUPPORTED)
/* write international chunk */
png_write_iTXt(png_ptr,
info_ptr->text[i].compression,
info_ptr->text[i].key,
info_ptr->text[i].lang,
info_ptr->text[i].lang_key,
info_ptr->text[i].text);
#else
png_warning(png_ptr, "Unable to write international text");
#endif
/* Mark this chunk as written */
info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
}
else if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt)
{
#if defined(PNG_WRITE_zTXt_SUPPORTED)
/* write compressed chunk */
png_write_zTXt(png_ptr, info_ptr->text[i].key,
info_ptr->text[i].text, 0,
info_ptr->text[i].compression);
#else
png_warning(png_ptr, "Unable to write compressed text");
#endif
/* Mark this chunk as written */
info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR;
}
else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE)
{
#if defined(PNG_WRITE_tEXt_SUPPORTED)
/* write uncompressed chunk */
png_write_tEXt(png_ptr, info_ptr->text[i].key,
info_ptr->text[i].text, 0);
#else
png_warning(png_ptr, "Unable to write uncompressed text");
#endif
/* Mark this chunk as written */
info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR;
}
}
#endif
#if defined(PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED)
if (info_ptr->unknown_chunks_num)
{
png_unknown_chunk *up;
png_debug(5, "writing extra chunks\n");
for (up = info_ptr->unknown_chunks;
up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num;
up++)
{
int keep=png_handle_as_unknown(png_ptr, up->name);
if (keep != PNG_HANDLE_CHUNK_NEVER &&
up->location && (up->location & PNG_AFTER_IDAT) &&
((up->name[3] & 0x20) || keep == PNG_HANDLE_CHUNK_ALWAYS ||
(png_ptr->flags & PNG_FLAG_KEEP_UNSAFE_CHUNKS)))
{
png_write_chunk(png_ptr, up->name, up->data, up->size);
}
}
}
#endif
}
png_ptr->mode |= PNG_AFTER_IDAT;
/* write end of PNG file */
png_write_IEND(png_ptr);
}
#if defined(PNG_WRITE_tIME_SUPPORTED)
#if !defined(_WIN32_WCE)
/* "time.h" functions are not supported on WindowsCE */
void PNGAPI
png_convert_from_struct_tm(png_timep ptime, struct tm FAR * ttime)
{
png_debug(1, "in png_convert_from_struct_tm\n");
ptime->year = (png_uint_16)(1900 + ttime->tm_year);
ptime->month = (png_byte)(ttime->tm_mon + 1);
ptime->day = (png_byte)ttime->tm_mday;
ptime->hour = (png_byte)ttime->tm_hour;
ptime->minute = (png_byte)ttime->tm_min;
ptime->second = (png_byte)ttime->tm_sec;
}
void PNGAPI
png_convert_from_time_t(png_timep ptime, time_t ttime)
{
struct tm *tbuf;
png_debug(1, "in png_convert_from_time_t\n");
tbuf = gmtime(&ttime);
png_convert_from_struct_tm(ptime, tbuf);
}
#endif
#endif
/* Initialize png_ptr structure, and allocate any memory needed */
png_structp PNGAPI
png_create_write_struct(png_const_charp user_png_ver, png_voidp error_ptr,
png_error_ptr error_fn, png_error_ptr warn_fn)
{
#ifdef PNG_USER_MEM_SUPPORTED
return (png_create_write_struct_2(user_png_ver, error_ptr, error_fn,
warn_fn, png_voidp_NULL, png_malloc_ptr_NULL, png_free_ptr_NULL));
}
/* Alternate initialize png_ptr structure, and allocate any memory needed */
png_structp PNGAPI
png_create_write_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
png_malloc_ptr malloc_fn, png_free_ptr free_fn)
{
#endif /* PNG_USER_MEM_SUPPORTED */
png_structp png_ptr;
#ifdef PNG_SETJMP_SUPPORTED
#ifdef USE_FAR_KEYWORD
jmp_buf jmpbuf;
#endif
#endif
int i;
png_debug(1, "in png_create_write_struct\n");
#ifdef PNG_USER_MEM_SUPPORTED
png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
(png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr);
#else
png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
#endif /* PNG_USER_MEM_SUPPORTED */
if (png_ptr == NULL)
return (NULL);
/* added at libpng-1.2.6 */
#ifdef PNG_SET_USER_LIMITS_SUPPORTED
png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
#endif
#ifdef PNG_SETJMP_SUPPORTED
#ifdef USE_FAR_KEYWORD
if (setjmp(jmpbuf))
#else
if (setjmp(png_ptr->jmpbuf))
#endif
{
png_free(png_ptr, png_ptr->zbuf);
png_ptr->zbuf=NULL;
png_destroy_struct(png_ptr);
return (NULL);
}
#ifdef USE_FAR_KEYWORD
png_memcpy(png_ptr->jmpbuf,jmpbuf,png_sizeof(jmp_buf));
#endif
#endif
#ifdef PNG_USER_MEM_SUPPORTED
png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
#endif /* PNG_USER_MEM_SUPPORTED */
png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);
if(user_png_ver)
{
i=0;
do
{
if(user_png_ver[i] != png_libpng_ver[i])
png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
} while (png_libpng_ver[i++]);
}
if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH)
{
/* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
* we must recompile any applications that use any older library version.
* For versions after libpng 1.0, we will be compatible, so we need
* only check the first digit.
*/
if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
(user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) ||
(user_png_ver[0] == '0' && user_png_ver[2] < '9'))
{
#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
char msg[80];
if (user_png_ver)
{
png_snprintf(msg, 80,
"Application was compiled with png.h from libpng-%.20s",
user_png_ver);
png_warning(png_ptr, msg);
}
png_snprintf(msg, 80,
"Application is running with png.c from libpng-%.20s",
png_libpng_ver);
png_warning(png_ptr, msg);
#endif
#ifdef PNG_ERROR_NUMBERS_SUPPORTED
png_ptr->flags=0;
#endif
png_error(png_ptr,
"Incompatible libpng version in application and library");
}
}
/* initialize zbuf - compression buffer */
png_ptr->zbuf_size = PNG_ZBUF_SIZE;
png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
(png_uint_32)png_ptr->zbuf_size);
png_set_write_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL,
png_flush_ptr_NULL);
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,
1, png_doublep_NULL, png_doublep_NULL);
#endif
#ifdef PNG_SETJMP_SUPPORTED
/* Applications that neglect to set up their own setjmp() and then encounter
a png_error() will longjmp here. Since the jmpbuf is then meaningless we
abort instead of returning. */
#ifdef USE_FAR_KEYWORD
if (setjmp(jmpbuf))
PNG_ABORT();
png_memcpy(png_ptr->jmpbuf,jmpbuf,png_sizeof(jmp_buf));
#else
if (setjmp(png_ptr->jmpbuf))
PNG_ABORT();
#endif
#endif
return (png_ptr);
}
/* Initialize png_ptr structure, and allocate any memory needed */
#if defined(PNG_1_0_X) || defined(PNG_1_2_X)
/* Deprecated. */
#undef png_write_init
void PNGAPI
png_write_init(png_structp png_ptr)
{
/* We only come here via pre-1.0.7-compiled applications */
png_write_init_2(png_ptr, "1.0.6 or earlier", 0, 0);
}
void PNGAPI
png_write_init_2(png_structp png_ptr, png_const_charp user_png_ver,
png_size_t png_struct_size, png_size_t png_info_size)
{
/* We only come here via pre-1.0.12-compiled applications */
if(png_ptr == NULL) return;
#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
if(png_sizeof(png_struct) > png_struct_size ||
png_sizeof(png_info) > png_info_size)
{
char msg[80];
png_ptr->warning_fn=NULL;
if (user_png_ver)
{
png_snprintf(msg, 80,
"Application was compiled with png.h from libpng-%.20s",
user_png_ver);
png_warning(png_ptr, msg);
}
png_snprintf(msg, 80,
"Application is running with png.c from libpng-%.20s",
png_libpng_ver);
png_warning(png_ptr, msg);
}
#endif
if(png_sizeof(png_struct) > png_struct_size)
{
png_ptr->error_fn=NULL;
#ifdef PNG_ERROR_NUMBERS_SUPPORTED
png_ptr->flags=0;
#endif
png_error(png_ptr,
"The png struct allocated by the application for writing is too small.");
}
if(png_sizeof(png_info) > png_info_size)
{
png_ptr->error_fn=NULL;
#ifdef PNG_ERROR_NUMBERS_SUPPORTED
png_ptr->flags=0;
#endif
png_error(png_ptr,
"The info struct allocated by the application for writing is too small.");
}
png_write_init_3(&png_ptr, user_png_ver, png_struct_size);
}
#endif /* PNG_1_0_X || PNG_1_2_X */
void PNGAPI
png_write_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
png_size_t png_struct_size)
{
png_structp png_ptr=*ptr_ptr;
#ifdef PNG_SETJMP_SUPPORTED
jmp_buf tmp_jmp; /* to save current jump buffer */
#endif
int i = 0;
if (png_ptr == NULL)
return;
do
{
if (user_png_ver[i] != png_libpng_ver[i])
{
#ifdef PNG_LEGACY_SUPPORTED
png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
#else
png_ptr->warning_fn=NULL;
png_warning(png_ptr,
"Application uses deprecated png_write_init() and should be recompiled.");
break;
#endif
}
} while (png_libpng_ver[i++]);
png_debug(1, "in png_write_init_3\n");
#ifdef PNG_SETJMP_SUPPORTED
/* save jump buffer and error functions */
png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof (jmp_buf));
#endif
if (png_sizeof(png_struct) > png_struct_size)
{
png_destroy_struct(png_ptr);
png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
*ptr_ptr = png_ptr;
}
/* reset all variables to 0 */
png_memset(png_ptr, 0, png_sizeof (png_struct));
/* added at libpng-1.2.6 */
#ifdef PNG_SET_USER_LIMITS_SUPPORTED
png_ptr->user_width_max=PNG_USER_WIDTH_MAX;
png_ptr->user_height_max=PNG_USER_HEIGHT_MAX;
#endif
#ifdef PNG_SETJMP_SUPPORTED
/* restore jump buffer */
png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof (jmp_buf));
#endif
png_set_write_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL,
png_flush_ptr_NULL);
/* initialize zbuf - compression buffer */
png_ptr->zbuf_size = PNG_ZBUF_SIZE;
png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
(png_uint_32)png_ptr->zbuf_size);
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,
1, png_doublep_NULL, png_doublep_NULL);
#endif
}
/* Write a few rows of image data. If the image is interlaced,
* either you will have to write the 7 sub images, or, if you
* have called png_set_interlace_handling(), you will have to
* "write" the image seven times.
*/
void PNGAPI
png_write_rows(png_structp png_ptr, png_bytepp row,
png_uint_32 num_rows)
{
png_uint_32 i; /* row counter */
png_bytepp rp; /* row pointer */
png_debug(1, "in png_write_rows\n");
if (png_ptr == NULL)
return;
/* loop through the rows */
for (i = 0, rp = row; i < num_rows; i++, rp++)
{
png_write_row(png_ptr, *rp);
}
}
/* Write the image. You only need to call this function once, even
* if you are writing an interlaced image.
*/
void PNGAPI
png_write_image(png_structp png_ptr, png_bytepp image)
{
png_uint_32 i; /* row index */
int pass, num_pass; /* pass variables */
png_bytepp rp; /* points to current row */
if (png_ptr == NULL)
return;
png_debug(1, "in png_write_image\n");
#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
/* intialize interlace handling. If image is not interlaced,
this will set pass to 1 */
num_pass = png_set_interlace_handling(png_ptr);
#else
num_pass = 1;
#endif
/* loop through passes */
for (pass = 0; pass < num_pass; pass++)
{
/* loop through image */
for (i = 0, rp = image; i < png_ptr->height; i++, rp++)
{
png_write_row(png_ptr, *rp);
}
}
}
/* called by user to write a row of image data */
void PNGAPI
png_write_row(png_structp png_ptr, png_bytep row)
{
if (png_ptr == NULL)
return;
png_debug2(1, "in png_write_row (row %ld, pass %d)\n",
png_ptr->row_number, png_ptr->pass);
/* initialize transformations and other stuff if first time */
if (png_ptr->row_number == 0 && png_ptr->pass == 0)
{
/* make sure we wrote the header info */
if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE))
png_error(png_ptr,
"png_write_info was never called before png_write_row.");
/* check for transforms that have been set but were defined out */
#if !defined(PNG_WRITE_INVERT_SUPPORTED) && defined(PNG_READ_INVERT_SUPPORTED)
if (png_ptr->transformations & PNG_INVERT_MONO)
png_warning(png_ptr, "PNG_WRITE_INVERT_SUPPORTED is not defined.");
#endif
#if !defined(PNG_WRITE_FILLER_SUPPORTED) && defined(PNG_READ_FILLER_SUPPORTED)
if (png_ptr->transformations & PNG_FILLER)
png_warning(png_ptr, "PNG_WRITE_FILLER_SUPPORTED is not defined.");
#endif
#if !defined(PNG_WRITE_PACKSWAP_SUPPORTED) && defined(PNG_READ_PACKSWAP_SUPPORTED)
if (png_ptr->transformations & PNG_PACKSWAP)
png_warning(png_ptr, "PNG_WRITE_PACKSWAP_SUPPORTED is not defined.");
#endif
#if !defined(PNG_WRITE_PACK_SUPPORTED) && defined(PNG_READ_PACK_SUPPORTED)
if (png_ptr->transformations & PNG_PACK)
png_warning(png_ptr, "PNG_WRITE_PACK_SUPPORTED is not defined.");
#endif
#if !defined(PNG_WRITE_SHIFT_SUPPORTED) && defined(PNG_READ_SHIFT_SUPPORTED)
if (png_ptr->transformations & PNG_SHIFT)
png_warning(png_ptr, "PNG_WRITE_SHIFT_SUPPORTED is not defined.");
#endif
#if !defined(PNG_WRITE_BGR_SUPPORTED) && defined(PNG_READ_BGR_SUPPORTED)
if (png_ptr->transformations & PNG_BGR)
png_warning(png_ptr, "PNG_WRITE_BGR_SUPPORTED is not defined.");
#endif
#if !defined(PNG_WRITE_SWAP_SUPPORTED) && defined(PNG_READ_SWAP_SUPPORTED)
if (png_ptr->transformations & PNG_SWAP_BYTES)
png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined.");
#endif
png_write_start_row(png_ptr);
}
#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
/* if interlaced and not interested in row, return */
if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
{
switch (png_ptr->pass)
{
case 0:
if (png_ptr->row_number & 0x07)
{
png_write_finish_row(png_ptr);
return;
}
break;
case 1:
if ((png_ptr->row_number & 0x07) || png_ptr->width < 5)
{
png_write_finish_row(png_ptr);
return;
}
break;
case 2:
if ((png_ptr->row_number & 0x07) != 4)
{
png_write_finish_row(png_ptr);
return;
}
break;
case 3:
if ((png_ptr->row_number & 0x03) || png_ptr->width < 3)
{
png_write_finish_row(png_ptr);
return;
}
break;
case 4:
if ((png_ptr->row_number & 0x03) != 2)
{
png_write_finish_row(png_ptr);
return;
}
break;
case 5:
if ((png_ptr->row_number & 0x01) || png_ptr->width < 2)
{
png_write_finish_row(png_ptr);
return;
}
break;
case 6:
if (!(png_ptr->row_number & 0x01))
{
png_write_finish_row(png_ptr);
return;
}
break;
}
}
#endif
/* set up row info for transformations */
png_ptr->row_info.color_type = png_ptr->color_type;
png_ptr->row_info.width = png_ptr->usr_width;
png_ptr->row_info.channels = png_ptr->usr_channels;
png_ptr->row_info.bit_depth = png_ptr->usr_bit_depth;
png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth *
png_ptr->row_info.channels);
png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
png_ptr->row_info.width);
png_debug1(3, "row_info->color_type = %d\n", png_ptr->row_info.color_type);
png_debug1(3, "row_info->width = %lu\n", png_ptr->row_info.width);
png_debug1(3, "row_info->channels = %d\n", png_ptr->row_info.channels);
png_debug1(3, "row_info->bit_depth = %d\n", png_ptr->row_info.bit_depth);
png_debug1(3, "row_info->pixel_depth = %d\n", png_ptr->row_info.pixel_depth);
png_debug1(3, "row_info->rowbytes = %lu\n", png_ptr->row_info.rowbytes);
/* Copy user's row into buffer, leaving room for filter byte. */
png_memcpy_check(png_ptr, png_ptr->row_buf + 1, row,
png_ptr->row_info.rowbytes);
#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
/* handle interlacing */
if (png_ptr->interlaced && png_ptr->pass < 6 &&
(png_ptr->transformations & PNG_INTERLACE))
{
png_do_write_interlace(&(png_ptr->row_info),
png_ptr->row_buf + 1, png_ptr->pass);
/* this should always get caught above, but still ... */
if (!(png_ptr->row_info.width))
{
png_write_finish_row(png_ptr);
return;
}
}
#endif
/* handle other transformations */
if (png_ptr->transformations)
png_do_write_transformations(png_ptr);
#if defined(PNG_MNG_FEATURES_SUPPORTED)
/* Write filter_method 64 (intrapixel differencing) only if
* 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
* 2. Libpng did not write a PNG signature (this filter_method is only
* used in PNG datastreams that are embedded in MNG datastreams) and
* 3. The application called png_permit_mng_features with a mask that
* included PNG_FLAG_MNG_FILTER_64 and
* 4. The filter_method is 64 and
* 5. The color_type is RGB or RGBA
*/
if((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
(png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING))
{
/* Intrapixel differencing */
png_do_write_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1);
}
#endif
/* Find a filter if necessary, filter the row and write it out. */
png_write_find_filter(png_ptr, &(png_ptr->row_info));
if (png_ptr->write_row_fn != NULL)
(*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass);
}
#if defined(PNG_WRITE_FLUSH_SUPPORTED)
/* Set the automatic flush interval or 0 to turn flushing off */
void PNGAPI
png_set_flush(png_structp png_ptr, int nrows)
{
png_debug(1, "in png_set_flush\n");
if (png_ptr == NULL)
return;
png_ptr->flush_dist = (nrows < 0 ? 0 : nrows);
}
/* flush the current output buffers now */
void PNGAPI
png_write_flush(png_structp png_ptr)
{
int wrote_IDAT;
png_debug(1, "in png_write_flush\n");
if (png_ptr == NULL)
return;
/* We have already written out all of the data */
if (png_ptr->row_number >= png_ptr->num_rows)
return;
do
{
int ret;
/* compress the data */
ret = deflate(&png_ptr->zstream, Z_SYNC_FLUSH);
wrote_IDAT = 0;
/* check for compression errors */
if (ret != Z_OK)
{
if (png_ptr->zstream.msg != NULL)
png_error(png_ptr, png_ptr->zstream.msg);
else
png_error(png_ptr, "zlib error");
}
if (!(png_ptr->zstream.avail_out))
{
/* write the IDAT and reset the zlib output buffer */
png_write_IDAT(png_ptr, png_ptr->zbuf,
png_ptr->zbuf_size);
png_ptr->zstream.next_out = png_ptr->zbuf;
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
wrote_IDAT = 1;
}
} while(wrote_IDAT == 1);
/* If there is any data left to be output, write it into a new IDAT */
if (png_ptr->zbuf_size != png_ptr->zstream.avail_out)
{
/* write the IDAT and reset the zlib output buffer */
png_write_IDAT(png_ptr, png_ptr->zbuf,
png_ptr->zbuf_size - png_ptr->zstream.avail_out);
png_ptr->zstream.next_out = png_ptr->zbuf;
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
}
png_ptr->flush_rows = 0;
png_flush(png_ptr);
}
#endif /* PNG_WRITE_FLUSH_SUPPORTED */
/* free all memory used by the write */
void PNGAPI
png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)
{
png_structp png_ptr = NULL;
png_infop info_ptr = NULL;
#ifdef PNG_USER_MEM_SUPPORTED
png_free_ptr free_fn = NULL;
png_voidp mem_ptr = NULL;
#endif
png_debug(1, "in png_destroy_write_struct\n");
if (png_ptr_ptr != NULL)
{
png_ptr = *png_ptr_ptr;
#ifdef PNG_USER_MEM_SUPPORTED
free_fn = png_ptr->free_fn;
mem_ptr = png_ptr->mem_ptr;
#endif
}
#ifdef PNG_USER_MEM_SUPPORTED
if (png_ptr != NULL)
{
free_fn = png_ptr->free_fn;
mem_ptr = png_ptr->mem_ptr;
}
#endif
if (info_ptr_ptr != NULL)
info_ptr = *info_ptr_ptr;
if (info_ptr != NULL)
{
if (png_ptr != NULL)
{
png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
#if defined(PNG_UNKNOWN_CHUNKS_SUPPORTED)
if (png_ptr->num_chunk_list)
{
png_free(png_ptr, png_ptr->chunk_list);
png_ptr->chunk_list=NULL;
png_ptr->num_chunk_list=0;
}
#endif
}
#ifdef PNG_USER_MEM_SUPPORTED
png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn,
(png_voidp)mem_ptr);
#else
png_destroy_struct((png_voidp)info_ptr);
#endif
*info_ptr_ptr = NULL;
}
if (png_ptr != NULL)
{
png_write_destroy(png_ptr);
#ifdef PNG_USER_MEM_SUPPORTED
png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
(png_voidp)mem_ptr);
#else
png_destroy_struct((png_voidp)png_ptr);
#endif
*png_ptr_ptr = NULL;
}
}
/* Free any memory used in png_ptr struct (old method) */
void /* PRIVATE */
png_write_destroy(png_structp png_ptr)
{
#ifdef PNG_SETJMP_SUPPORTED
jmp_buf tmp_jmp; /* save jump buffer */
#endif
png_error_ptr error_fn;
png_error_ptr warning_fn;
png_voidp error_ptr;
#ifdef PNG_USER_MEM_SUPPORTED
png_free_ptr free_fn;
#endif
png_debug(1, "in png_write_destroy\n");
/* free any memory zlib uses */
deflateEnd(&png_ptr->zstream);
/* free our memory. png_free checks NULL for us. */
png_free(png_ptr, png_ptr->zbuf);
png_free(png_ptr, png_ptr->row_buf);
#ifndef PNG_NO_WRITE_FILTERING
png_free(png_ptr, png_ptr->prev_row);
png_free(png_ptr, png_ptr->sub_row);
png_free(png_ptr, png_ptr->up_row);
png_free(png_ptr, png_ptr->avg_row);
png_free(png_ptr, png_ptr->paeth_row);
#endif
#if defined(PNG_TIME_RFC1123_SUPPORTED)
png_free(png_ptr, png_ptr->time_buffer);
#endif
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
png_free(png_ptr, png_ptr->prev_filters);
png_free(png_ptr, png_ptr->filter_weights);
png_free(png_ptr, png_ptr->inv_filter_weights);
png_free(png_ptr, png_ptr->filter_costs);
png_free(png_ptr, png_ptr->inv_filter_costs);
#endif
#ifdef PNG_SETJMP_SUPPORTED
/* reset structure */
png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof (jmp_buf));
#endif
error_fn = png_ptr->error_fn;
warning_fn = png_ptr->warning_fn;
error_ptr = png_ptr->error_ptr;
#ifdef PNG_USER_MEM_SUPPORTED
free_fn = png_ptr->free_fn;
#endif
png_memset(png_ptr, 0, png_sizeof (png_struct));
png_ptr->error_fn = error_fn;
png_ptr->warning_fn = warning_fn;
png_ptr->error_ptr = error_ptr;
#ifdef PNG_USER_MEM_SUPPORTED
png_ptr->free_fn = free_fn;
#endif
#ifdef PNG_SETJMP_SUPPORTED
png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof (jmp_buf));
#endif
}
/* Allow the application to select one or more row filters to use. */
void PNGAPI
png_set_filter(png_structp png_ptr, int method, int filters)
{
png_debug(1, "in png_set_filter\n");
if (png_ptr == NULL)
return;
#if defined(PNG_MNG_FEATURES_SUPPORTED)
if((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
(method == PNG_INTRAPIXEL_DIFFERENCING))
method = PNG_FILTER_TYPE_BASE;
#endif
if (method == PNG_FILTER_TYPE_BASE)
{
switch (filters & (PNG_ALL_FILTERS | 0x07))
{
#ifndef PNG_NO_WRITE_FILTER
case 5:
case 6:
case 7: png_warning(png_ptr, "Unknown row filter for method 0");
#endif /* PNG_NO_WRITE_FILTER */
case PNG_FILTER_VALUE_NONE:
png_ptr->do_filter=PNG_FILTER_NONE; break;
#ifndef PNG_NO_WRITE_FILTER
case PNG_FILTER_VALUE_SUB:
png_ptr->do_filter=PNG_FILTER_SUB; break;
case PNG_FILTER_VALUE_UP:
png_ptr->do_filter=PNG_FILTER_UP; break;
case PNG_FILTER_VALUE_AVG:
png_ptr->do_filter=PNG_FILTER_AVG; break;
case PNG_FILTER_VALUE_PAETH:
png_ptr->do_filter=PNG_FILTER_PAETH; break;
default: png_ptr->do_filter = (png_byte)filters; break;
#else
default: png_warning(png_ptr, "Unknown row filter for method 0");
#endif /* PNG_NO_WRITE_FILTER */
}
/* If we have allocated the row_buf, this means we have already started
* with the image and we should have allocated all of the filter buffers
* that have been selected. If prev_row isn't already allocated, then
* it is too late to start using the filters that need it, since we
* will be missing the data in the previous row. If an application
* wants to start and stop using particular filters during compression,
* it should start out with all of the filters, and then add and
* remove them after the start of compression.
*/
if (png_ptr->row_buf != NULL)
{
#ifndef PNG_NO_WRITE_FILTER
if ((png_ptr->do_filter & PNG_FILTER_SUB) && png_ptr->sub_row == NULL)
{
png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
(png_ptr->rowbytes + 1));
png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
}
if ((png_ptr->do_filter & PNG_FILTER_UP) && png_ptr->up_row == NULL)
{
if (png_ptr->prev_row == NULL)
{
png_warning(png_ptr, "Can't add Up filter after starting");
png_ptr->do_filter &= ~PNG_FILTER_UP;
}
else
{
png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
(png_ptr->rowbytes + 1));
png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
}
}
if ((png_ptr->do_filter & PNG_FILTER_AVG) && png_ptr->avg_row == NULL)
{
if (png_ptr->prev_row == NULL)
{
png_warning(png_ptr, "Can't add Average filter after starting");
png_ptr->do_filter &= ~PNG_FILTER_AVG;
}
else
{
png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
(png_ptr->rowbytes + 1));
png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
}
}
if ((png_ptr->do_filter & PNG_FILTER_PAETH) &&
png_ptr->paeth_row == NULL)
{
if (png_ptr->prev_row == NULL)
{
png_warning(png_ptr, "Can't add Paeth filter after starting");
png_ptr->do_filter &= (png_byte)(~PNG_FILTER_PAETH);
}
else
{
png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
(png_ptr->rowbytes + 1));
png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
}
}
if (png_ptr->do_filter == PNG_NO_FILTERS)
#endif /* PNG_NO_WRITE_FILTER */
png_ptr->do_filter = PNG_FILTER_NONE;
}
}
else
png_error(png_ptr, "Unknown custom filter method");
}
/* This allows us to influence the way in which libpng chooses the "best"
* filter for the current scanline. While the "minimum-sum-of-absolute-
* differences metric is relatively fast and effective, there is some
* question as to whether it can be improved upon by trying to keep the
* filtered data going to zlib more consistent, hopefully resulting in
* better compression.
*/
#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) /* GRR 970116 */
void PNGAPI
png_set_filter_heuristics(png_structp png_ptr, int heuristic_method,
int num_weights, png_doublep filter_weights,
png_doublep filter_costs)
{
int i;
png_debug(1, "in png_set_filter_heuristics\n");
if (png_ptr == NULL)
return;
if (heuristic_method >= PNG_FILTER_HEURISTIC_LAST)
{
png_warning(png_ptr, "Unknown filter heuristic method");
return;
}
if (heuristic_method == PNG_FILTER_HEURISTIC_DEFAULT)
{
heuristic_method = PNG_FILTER_HEURISTIC_UNWEIGHTED;
}
if (num_weights < 0 || filter_weights == NULL ||
heuristic_method == PNG_FILTER_HEURISTIC_UNWEIGHTED)
{
num_weights = 0;
}
png_ptr->num_prev_filters = (png_byte)num_weights;
png_ptr->heuristic_method = (png_byte)heuristic_method;
if (num_weights > 0)
{
if (png_ptr->prev_filters == NULL)
{
png_ptr->prev_filters = (png_bytep)png_malloc(png_ptr,
(png_uint_32)(png_sizeof(png_byte) * num_weights));
/* To make sure that the weighting starts out fairly */
for (i = 0; i < num_weights; i++)
{
png_ptr->prev_filters[i] = 255;
}
}
if (png_ptr->filter_weights == NULL)
{
png_ptr->filter_weights = (png_uint_16p)png_malloc(png_ptr,
(png_uint_32)(png_sizeof(png_uint_16) * num_weights));
png_ptr->inv_filter_weights = (png_uint_16p)png_malloc(png_ptr,
(png_uint_32)(png_sizeof(png_uint_16) * num_weights));
for (i = 0; i < num_weights; i++)
{
png_ptr->inv_filter_weights[i] =
png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
}
}
for (i = 0; i < num_weights; i++)
{
if (filter_weights[i] < 0.0)
{
png_ptr->inv_filter_weights[i] =
png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR;
}
else
{
png_ptr->inv_filter_weights[i] =
(png_uint_16)((double)PNG_WEIGHT_FACTOR*filter_weights[i]+0.5);
png_ptr->filter_weights[i] =
(png_uint_16)((double)PNG_WEIGHT_FACTOR/filter_weights[i]+0.5);
}
}
}
/* If, in the future, there are other filter methods, this would
* need to be based on png_ptr->filter.
*/
if (png_ptr->filter_costs == NULL)
{
png_ptr->filter_costs = (png_uint_16p)png_malloc(png_ptr,
(png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
png_ptr->inv_filter_costs = (png_uint_16p)png_malloc(png_ptr,
(png_uint_32)(png_sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST));
for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
{
png_ptr->inv_filter_costs[i] =
png_ptr->filter_costs[i] = PNG_COST_FACTOR;
}
}
/* Here is where we set the relative costs of the different filters. We
* should take the desired compression level into account when setting
* the costs, so that Paeth, for instance, has a high relative cost at low
* compression levels, while it has a lower relative cost at higher
* compression settings. The filter types are in order of increasing
* relative cost, so it would be possible to do this with an algorithm.
*/
for (i = 0; i < PNG_FILTER_VALUE_LAST; i++)
{
if (filter_costs == NULL || filter_costs[i] < 0.0)
{
png_ptr->inv_filter_costs[i] =
png_ptr->filter_costs[i] = PNG_COST_FACTOR;
}
else if (filter_costs[i] >= 1.0)
{
png_ptr->inv_filter_costs[i] =
(png_uint_16)((double)PNG_COST_FACTOR / filter_costs[i] + 0.5);
png_ptr->filter_costs[i] =
(png_uint_16)((double)PNG_COST_FACTOR * filter_costs[i] + 0.5);
}
}
}
#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */
void PNGAPI
png_set_compression_level(png_structp png_ptr, int level)
{
png_debug(1, "in png_set_compression_level\n");
if (png_ptr == NULL)
return;
png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_LEVEL;
png_ptr->zlib_level = level;
}
void PNGAPI
png_set_compression_mem_level(png_structp png_ptr, int mem_level)
{
png_debug(1, "in png_set_compression_mem_level\n");
if (png_ptr == NULL)
return;
png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL;
png_ptr->zlib_mem_level = mem_level;
}
void PNGAPI
png_set_compression_strategy(png_structp png_ptr, int strategy)
{
png_debug(1, "in png_set_compression_strategy\n");
if (png_ptr == NULL)
return;
png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY;
png_ptr->zlib_strategy = strategy;
}
void PNGAPI
png_set_compression_window_bits(png_structp png_ptr, int window_bits)
{
if (png_ptr == NULL)
return;
if (window_bits > 15)
png_warning(png_ptr, "Only compression windows <= 32k supported by PNG");
else if (window_bits < 8)
png_warning(png_ptr, "Only compression windows >= 256 supported by PNG");
#ifndef WBITS_8_OK
/* avoid libpng bug with 256-byte windows */
if (window_bits == 8)
{
png_warning(png_ptr, "Compression window is being reset to 512");
window_bits=9;
}
#endif
png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS;
png_ptr->zlib_window_bits = window_bits;
}
void PNGAPI
png_set_compression_method(png_structp png_ptr, int method)
{
png_debug(1, "in png_set_compression_method\n");
if (png_ptr == NULL)
return;
if (method != 8)
png_warning(png_ptr, "Only compression method 8 is supported by PNG");
png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_METHOD;
png_ptr->zlib_method = method;
}
void PNGAPI
png_set_write_status_fn(png_structp png_ptr, png_write_status_ptr write_row_fn)
{
if (png_ptr == NULL)
return;
png_ptr->write_row_fn = write_row_fn;
}
#if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
void PNGAPI
png_set_write_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
write_user_transform_fn)
{
png_debug(1, "in png_set_write_user_transform_fn\n");
if (png_ptr == NULL)
return;
png_ptr->transformations |= PNG_USER_TRANSFORM;
png_ptr->write_user_transform_fn = write_user_transform_fn;
}
#endif
#if defined(PNG_INFO_IMAGE_SUPPORTED)
void PNGAPI
png_write_png(png_structp png_ptr, png_infop info_ptr,
int transforms, voidp params)
{
if (png_ptr == NULL || info_ptr == NULL)
return;
#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
/* invert the alpha channel from opacity to transparency */
if (transforms & PNG_TRANSFORM_INVERT_ALPHA)
png_set_invert_alpha(png_ptr);
#endif
/* Write the file header information. */
png_write_info(png_ptr, info_ptr);
/* ------ these transformations don't touch the info structure ------- */
#if defined(PNG_WRITE_INVERT_SUPPORTED)
/* invert monochrome pixels */
if (transforms & PNG_TRANSFORM_INVERT_MONO)
png_set_invert_mono(png_ptr);
#endif
#if defined(PNG_WRITE_SHIFT_SUPPORTED)
/* Shift the pixels up to a legal bit depth and fill in
* as appropriate to correctly scale the image.
*/
if ((transforms & PNG_TRANSFORM_SHIFT)
&& (info_ptr->valid & PNG_INFO_sBIT))
png_set_shift(png_ptr, &info_ptr->sig_bit);
#endif
#if defined(PNG_WRITE_PACK_SUPPORTED)
/* pack pixels into bytes */
if (transforms & PNG_TRANSFORM_PACKING)
png_set_packing(png_ptr);
#endif
#if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
/* swap location of alpha bytes from ARGB to RGBA */
if (transforms & PNG_TRANSFORM_SWAP_ALPHA)
png_set_swap_alpha(png_ptr);
#endif
#if defined(PNG_WRITE_FILLER_SUPPORTED)
/* Get rid of filler (OR ALPHA) bytes, pack XRGB/RGBX/ARGB/RGBA into
* RGB (4 channels -> 3 channels). The second parameter is not used.
*/
if (transforms & PNG_TRANSFORM_STRIP_FILLER)
png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE);
#endif
#if defined(PNG_WRITE_BGR_SUPPORTED)
/* flip BGR pixels to RGB */
if (transforms & PNG_TRANSFORM_BGR)
png_set_bgr(png_ptr);
#endif
#if defined(PNG_WRITE_SWAP_SUPPORTED)
/* swap bytes of 16-bit files to most significant byte first */
if (transforms & PNG_TRANSFORM_SWAP_ENDIAN)
png_set_swap(png_ptr);
#endif
#if defined(PNG_WRITE_PACKSWAP_SUPPORTED)
/* swap bits of 1, 2, 4 bit packed pixel formats */
if (transforms & PNG_TRANSFORM_PACKSWAP)
png_set_packswap(png_ptr);
#endif
/* ----------------------- end of transformations ------------------- */
/* write the bits */
if (info_ptr->valid & PNG_INFO_IDAT)
png_write_image(png_ptr, info_ptr->row_pointers);
/* It is REQUIRED to call this to finish writing the rest of the file */
png_write_end(png_ptr, info_ptr);
transforms = transforms; /* quiet compiler warnings */
params = params;
}
#endif
#endif /* PNG_WRITE_SUPPORTED */
Reference in New Issue View Git Blame Copy Permalink