diff options
Diffstat (limited to 'drivers/png/pngwrite.c')
| -rw-r--r-- | drivers/png/pngwrite.c | 1949 |
1 files changed, 1440 insertions, 509 deletions
diff --git a/drivers/png/pngwrite.c b/drivers/png/pngwrite.c index 776c23603a..181a899438 100644 --- a/drivers/png/pngwrite.c +++ b/drivers/png/pngwrite.c @@ -1,7 +1,7 @@ /* pngwrite.c - general routines to write a PNG file * - * Last changed in libpng 1.5.23 [July 23, 2015] + * Last changed in libpng 1.6.19 [November 12, 2015] * Copyright (c) 1998-2002,2004,2006-2015 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.) @@ -12,9 +12,65 @@ */ #include "pngpriv.h" +#ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED +# include <errno.h> +#endif /* SIMPLIFIED_WRITE_STDIO */ #ifdef PNG_WRITE_SUPPORTED +#ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED +/* Write out all the unknown chunks for the current given location */ +static void +write_unknown_chunks(png_structrp png_ptr, png_const_inforp info_ptr, + unsigned int where) +{ + if (info_ptr->unknown_chunks_num != 0) + { + png_const_unknown_chunkp up; + + png_debug(5, "writing extra chunks"); + + for (up = info_ptr->unknown_chunks; + up < info_ptr->unknown_chunks + info_ptr->unknown_chunks_num; + ++up) + if ((up->location & where) != 0) + { + /* If per-chunk unknown chunk handling is enabled use it, otherwise + * just write the chunks the application has set. + */ +#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED + int keep = png_handle_as_unknown(png_ptr, up->name); + + /* NOTE: this code is radically different from the read side in the + * matter of handling an ancillary unknown chunk. In the read side + * the default behavior is to discard it, in the code below the default + * behavior is to write it. Critical chunks are, however, only + * written if explicitly listed or if the default is set to write all + * unknown chunks. + * + * The default handling is also slightly weird - it is not possible to + * stop the writing of all unsafe-to-copy chunks! + * + * TODO: REVIEW: this would seem to be a bug. + */ + if (keep != PNG_HANDLE_CHUNK_NEVER && + ((up->name[3] & 0x20) /* safe-to-copy overrides everything */ || + keep == PNG_HANDLE_CHUNK_ALWAYS || + (keep == PNG_HANDLE_CHUNK_AS_DEFAULT && + png_ptr->unknown_default == PNG_HANDLE_CHUNK_ALWAYS))) +#endif + { + /* TODO: review, what is wrong with a zero length unknown chunk? */ + 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 /* WRITE_UNKNOWN_CHUNKS */ + /* 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 @@ -25,21 +81,21 @@ * them in png_write_end(), and compressing them. */ void PNGAPI -png_write_info_before_PLTE(png_structp png_ptr, png_infop info_ptr) +png_write_info_before_PLTE(png_structrp png_ptr, png_const_inforp info_ptr) { png_debug(1, "in png_write_info_before_PLTE"); if (png_ptr == NULL || info_ptr == NULL) return; - if (!(png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE)) + if ((png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE) == 0) { /* Write PNG signature */ png_write_sig(png_ptr); #ifdef PNG_MNG_FEATURES_SUPPORTED - if ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) && \ - (png_ptr->mng_features_permitted)) + if ((png_ptr->mode & PNG_HAVE_PNG_SIGNATURE) != 0 && \ + png_ptr->mng_features_permitted != 0) { png_warning(png_ptr, "MNG features are not allowed in a PNG datastream"); @@ -49,79 +105,91 @@ png_write_info_before_PLTE(png_structp png_ptr, png_infop info_ptr) /* 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, + info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type, + info_ptr->filter_type, #ifdef 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. + * + * 1.6.0: COLORSPACE support controls the writing of these chunks too, and + * the chunks will be written if the WRITE routine is there and + * information * is available in the COLORSPACE. (See + * png_colorspace_sync_info in png.c for where the valid flags get set.) + * + * Under certain circumstances the colorspace can be invalidated without + * syncing the info_struct 'valid' flags; this happens if libpng detects + * an error and calls png_error while the color space is being set, yet + * the application continues writing the PNG. So check the 'invalid' + * flag here too. */ -#ifdef PNG_WRITE_gAMA_SUPPORTED - if (info_ptr->valid & PNG_INFO_gAMA) - png_write_gAMA_fixed(png_ptr, info_ptr->gamma); -#endif -#ifdef PNG_WRITE_sRGB_SUPPORTED - if (info_ptr->valid & PNG_INFO_sRGB) - png_write_sRGB(png_ptr, (int)info_ptr->srgb_intent); +#ifdef PNG_GAMMA_SUPPORTED +# ifdef PNG_WRITE_gAMA_SUPPORTED + if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 && + (info_ptr->colorspace.flags & PNG_COLORSPACE_FROM_gAMA) != 0 && + (info_ptr->valid & PNG_INFO_gAMA) != 0) + png_write_gAMA_fixed(png_ptr, info_ptr->colorspace.gamma); +# endif #endif -#ifdef PNG_WRITE_iCCP_SUPPORTED - if (info_ptr->valid & PNG_INFO_iCCP) - png_write_iCCP(png_ptr, info_ptr->iccp_name, PNG_COMPRESSION_TYPE_BASE, - (png_charp)info_ptr->iccp_profile, (int)info_ptr->iccp_proflen); -#endif +#ifdef PNG_COLORSPACE_SUPPORTED + /* Write only one of sRGB or an ICC profile. If a profile was supplied + * and it matches one of the known sRGB ones issue a warning. + */ +# ifdef PNG_WRITE_iCCP_SUPPORTED + if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 && + (info_ptr->valid & PNG_INFO_iCCP) != 0) + { +# ifdef PNG_WRITE_sRGB_SUPPORTED + if ((info_ptr->valid & PNG_INFO_sRGB) != 0) + png_app_warning(png_ptr, + "profile matches sRGB but writing iCCP instead"); +# endif + + png_write_iCCP(png_ptr, info_ptr->iccp_name, + info_ptr->iccp_profile); + } +# ifdef PNG_WRITE_sRGB_SUPPORTED + else +# endif +# endif + +# ifdef PNG_WRITE_sRGB_SUPPORTED + if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 && + (info_ptr->valid & PNG_INFO_sRGB) != 0) + png_write_sRGB(png_ptr, info_ptr->colorspace.rendering_intent); +# endif /* WRITE_sRGB */ +#endif /* COLORSPACE */ + #ifdef PNG_WRITE_sBIT_SUPPORTED - if (info_ptr->valid & PNG_INFO_sBIT) - png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type); + if ((info_ptr->valid & PNG_INFO_sBIT) != 0) + png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type); #endif -#ifdef PNG_WRITE_cHRM_SUPPORTED - if (info_ptr->valid & PNG_INFO_cHRM) - png_write_cHRM_fixed(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); + +#ifdef PNG_COLORSPACE_SUPPORTED +# ifdef PNG_WRITE_cHRM_SUPPORTED + if ((info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) == 0 && + (info_ptr->colorspace.flags & PNG_COLORSPACE_FROM_cHRM) != 0 && + (info_ptr->valid & PNG_INFO_cHRM) != 0) + png_write_cHRM_fixed(png_ptr, &info_ptr->colorspace.end_points_xy); +# endif #endif #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED - if (info_ptr->unknown_chunks_num) - { - png_unknown_chunk *up; - - png_debug(5, "writing extra chunks"); - - 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->location & PNG_AFTER_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); - } - } - } + write_unknown_chunks(png_ptr, info_ptr, PNG_HAVE_IHDR); #endif + png_ptr->mode |= PNG_WROTE_INFO_BEFORE_PLTE; } } void PNGAPI -png_write_info(png_structp png_ptr, png_infop info_ptr) +png_write_info(png_structrp png_ptr, png_const_inforp info_ptr) { #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED) int i; @@ -134,7 +202,7 @@ png_write_info(png_structp png_ptr, png_infop info_ptr) png_write_info_before_PLTE(png_ptr, info_ptr); - if (info_ptr->valid & PNG_INFO_PLTE) + if ((info_ptr->valid & PNG_INFO_PLTE) != 0) png_write_PLTE(png_ptr, info_ptr->palette, (png_uint_32)info_ptr->num_palette); @@ -142,15 +210,20 @@ png_write_info(png_structp png_ptr, png_infop info_ptr) png_error(png_ptr, "Valid palette required for paletted images"); #ifdef PNG_WRITE_tRNS_SUPPORTED - if (info_ptr->valid & PNG_INFO_tRNS) + if ((info_ptr->valid & PNG_INFO_tRNS) !=0) { #ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED /* Invert the alpha channel (in tRNS) */ - if ((png_ptr->transformations & PNG_INVERT_ALPHA) && + if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0 && info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) { - int j; - for (j = 0; j<(int)info_ptr->num_trans; j++) + int j, jend; + + jend = info_ptr->num_trans; + if (jend > PNG_MAX_PALETTE_LENGTH) + jend = PNG_MAX_PALETTE_LENGTH; + + for (j = 0; j<jend; ++j) info_ptr->trans_alpha[j] = (png_byte)(255 - info_ptr->trans_alpha[j]); } @@ -160,42 +233,42 @@ png_write_info(png_structp png_ptr, png_infop info_ptr) } #endif #ifdef PNG_WRITE_bKGD_SUPPORTED - if (info_ptr->valid & PNG_INFO_bKGD) + if ((info_ptr->valid & PNG_INFO_bKGD) != 0) png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type); #endif #ifdef PNG_WRITE_hIST_SUPPORTED - if (info_ptr->valid & PNG_INFO_hIST) + if ((info_ptr->valid & PNG_INFO_hIST) != 0) png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette); #endif #ifdef PNG_WRITE_oFFs_SUPPORTED - if (info_ptr->valid & PNG_INFO_oFFs) + if ((info_ptr->valid & PNG_INFO_oFFs) != 0) png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset, info_ptr->offset_unit_type); #endif #ifdef PNG_WRITE_pCAL_SUPPORTED - if (info_ptr->valid & PNG_INFO_pCAL) + if ((info_ptr->valid & PNG_INFO_pCAL) != 0) 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 #ifdef PNG_WRITE_sCAL_SUPPORTED - if (info_ptr->valid & PNG_INFO_sCAL) + if ((info_ptr->valid & PNG_INFO_sCAL) != 0) png_write_sCAL_s(png_ptr, (int)info_ptr->scal_unit, info_ptr->scal_s_width, info_ptr->scal_s_height); #endif /* sCAL */ #ifdef PNG_WRITE_pHYs_SUPPORTED - if (info_ptr->valid & PNG_INFO_pHYs) + if ((info_ptr->valid & PNG_INFO_pHYs) != 0) png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit, info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type); #endif /* pHYs */ #ifdef PNG_WRITE_tIME_SUPPORTED - if (info_ptr->valid & PNG_INFO_tIME) + if ((info_ptr->valid & PNG_INFO_tIME) != 0) { png_write_tIME(png_ptr, &(info_ptr->mod_time)); png_ptr->mode |= PNG_WROTE_tIME; @@ -203,7 +276,7 @@ png_write_info(png_structp png_ptr, png_infop info_ptr) #endif /* tIME */ #ifdef PNG_WRITE_sPLT_SUPPORTED - if (info_ptr->valid & PNG_INFO_sPLT) + if ((info_ptr->valid & PNG_INFO_sPLT) != 0) for (i = 0; i < (int)info_ptr->splt_palettes_num; i++) png_write_sPLT(png_ptr, info_ptr->splt_palettes + i); #endif /* sPLT */ @@ -241,8 +314,7 @@ png_write_info(png_structp png_ptr, png_infop info_ptr) #ifdef 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); + info_ptr->text[i].text, info_ptr->text[i].compression); /* Mark this chunk as written */ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR; #else @@ -268,29 +340,7 @@ png_write_info(png_structp png_ptr, png_infop info_ptr) #endif /* tEXt */ #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED - if (info_ptr->unknown_chunks_num) - { - png_unknown_chunk *up; - - png_debug(5, "writing extra chunks"); - - 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->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); - } - } - } + write_unknown_chunks(png_ptr, info_ptr, PNG_HAVE_PLTE); #endif } @@ -300,14 +350,14 @@ png_write_info(png_structp png_ptr, png_infop info_ptr) * comments, I suggest writing them here, and compressing them. */ void PNGAPI -png_write_end(png_structp png_ptr, png_infop info_ptr) +png_write_end(png_structrp png_ptr, png_inforp info_ptr) { png_debug(1, "in png_write_end"); if (png_ptr == NULL) return; - if (!(png_ptr->mode & PNG_HAVE_IDAT)) + if ((png_ptr->mode & PNG_HAVE_IDAT) == 0) png_error(png_ptr, "No IDATs written into file"); #ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED @@ -323,8 +373,8 @@ png_write_end(png_structp png_ptr, png_infop info_ptr) #endif #ifdef 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)) + if ((info_ptr->valid & PNG_INFO_tIME) != 0 && + (png_ptr->mode & PNG_WROTE_tIME) == 0) png_write_tIME(png_ptr, &(info_ptr->mod_time)); #endif @@ -346,7 +396,10 @@ png_write_end(png_structp png_ptr, png_infop info_ptr) info_ptr->text[i].lang_key, info_ptr->text[i].text); /* Mark this chunk as written */ - info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR; + if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE) + info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR; + else + info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR; #else png_warning(png_ptr, "Unable to write international text"); #endif @@ -357,8 +410,7 @@ png_write_end(png_structp png_ptr, png_infop info_ptr) #ifdef 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); + info_ptr->text[i].text, info_ptr->text[i].compression); /* Mark this chunk as written */ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR; #else @@ -381,27 +433,7 @@ png_write_end(png_structp png_ptr, png_infop info_ptr) } #endif #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED - if (info_ptr->unknown_chunks_num) - { - png_unknown_chunk *up; - - png_debug(5, "writing extra chunks"); - - 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); - } - } - } + write_unknown_chunks(png_ptr, info_ptr, PNG_AFTER_IDAT); #endif } @@ -409,6 +441,7 @@ png_write_end(png_structp png_ptr, png_infop info_ptr) /* Write end of PNG file */ png_write_IEND(png_ptr); + /* This flush, added in libpng-1.0.8, removed from libpng-1.0.9beta03, * and restored again in libpng-1.2.30, may cause some applications that * do not set png_ptr->output_flush_fn to crash. If your application @@ -425,7 +458,7 @@ png_write_end(png_structp png_ptr, png_infop info_ptr) #ifdef PNG_CONVERT_tIME_SUPPORTED void PNGAPI -png_convert_from_struct_tm(png_timep ptime, PNG_CONST struct tm FAR * ttime) +png_convert_from_struct_tm(png_timep ptime, PNG_CONST struct tm * ttime) { png_debug(1, "in png_convert_from_struct_tm"); @@ -454,96 +487,75 @@ PNG_FUNCTION(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),PNG_ALLOCATED) { -#ifdef PNG_USER_MEM_SUPPORTED - return (png_create_write_struct_2(user_png_ver, error_ptr, error_fn, - warn_fn, NULL, NULL, NULL)); +#ifndef PNG_USER_MEM_SUPPORTED + png_structrp png_ptr = png_create_png_struct(user_png_ver, error_ptr, + error_fn, warn_fn, NULL, NULL, NULL); +#else + return png_create_write_struct_2(user_png_ver, error_ptr, error_fn, + warn_fn, NULL, NULL, NULL); } +/* Alternate initialize png_ptr structure, and allocate any memory needed */ PNG_FUNCTION(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),PNG_ALLOCATED) { -#endif /* PNG_USER_MEM_SUPPORTED */ - volatile int png_cleanup_needed = 0; -#ifdef PNG_SETJMP_SUPPORTED - volatile -#endif - png_structp png_ptr; -#ifdef PNG_SETJMP_SUPPORTED -#ifdef USE_FAR_KEYWORD - jmp_buf tmp_jmpbuf; -#endif -#endif - - png_debug(1, "in png_create_write_struct"); - -#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); + png_structrp png_ptr = png_create_png_struct(user_png_ver, error_ptr, + error_fn, warn_fn, mem_ptr, malloc_fn, free_fn); +#endif /* USER_MEM */ + if (png_ptr != NULL) + { + /* Set the zlib control values to defaults; they can be overridden by the + * application after the struct has been created. + */ + png_ptr->zbuffer_size = PNG_ZBUF_SIZE; - /* 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; + /* The 'zlib_strategy' setting is irrelevant because png_default_claim in + * pngwutil.c defaults it according to whether or not filters will be + * used, and ignores this setting. + */ + png_ptr->zlib_strategy = PNG_Z_DEFAULT_STRATEGY; + png_ptr->zlib_level = PNG_Z_DEFAULT_COMPRESSION; + png_ptr->zlib_mem_level = 8; + png_ptr->zlib_window_bits = 15; + png_ptr->zlib_method = 8; + +#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED + png_ptr->zlib_text_strategy = PNG_TEXT_Z_DEFAULT_STRATEGY; + png_ptr->zlib_text_level = PNG_TEXT_Z_DEFAULT_COMPRESSION; + png_ptr->zlib_text_mem_level = 8; + png_ptr->zlib_text_window_bits = 15; + png_ptr->zlib_text_method = 8; +#endif /* WRITE_COMPRESSED_TEXT */ + + /* This is a highly dubious configuration option; by default it is off, + * but it may be appropriate for private builds that are testing + * extensions not conformant to the current specification, or of + * applications that must not fail to write at all costs! + */ +#ifdef PNG_BENIGN_WRITE_ERRORS_SUPPORTED + /* In stable builds only warn if an application error can be completely + * handled. + */ + png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN; #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(tmp_jmpbuf)) - png_memcpy(png_jmpbuf(png_ptr), tmp_jmpbuf, png_sizeof(jmp_buf)); - PNG_ABORT(); -#else - if (setjmp(png_jmpbuf(png_ptr))) /* sets longjmp to match setjmp */ - PNG_ABORT(); -#endif + /* App warnings are warnings in release (or release candidate) builds but + * are errors during development. + */ +#if PNG_RELEASE_BUILD + png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN; #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 (!png_user_version_check(png_ptr, user_png_ver)) - png_cleanup_needed = 1; - - /* Initialize zbuf - compression buffer */ - png_ptr->zbuf_size = PNG_ZBUF_SIZE; - - if (png_cleanup_needed == 0) - { - png_ptr->zbuf = (png_bytep)png_malloc_warn(png_ptr, - png_ptr->zbuf_size); - if (png_ptr->zbuf == NULL) - png_cleanup_needed = 1; - } - - if (png_cleanup_needed != 0) - { - /* Clean up PNG structure and deallocate any memory. */ - png_free(png_ptr, png_ptr->zbuf); - png_ptr->zbuf = NULL; -#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 - return (NULL); + /* TODO: delay this, it can be done in png_init_io() (if the app doesn't + * do it itself) avoiding setting the default function if it is not + * required. + */ + png_set_write_fn(png_ptr, NULL, NULL, NULL); } - png_set_write_fn(png_ptr, NULL, NULL, NULL); - - return (png_ptr); + return png_ptr; } @@ -553,7 +565,7 @@ png_create_write_struct_2,(png_const_charp user_png_ver, png_voidp error_ptr, * "write" the image seven times. */ void PNGAPI -png_write_rows(png_structp png_ptr, png_bytepp row, +png_write_rows(png_structrp png_ptr, png_bytepp row, png_uint_32 num_rows) { png_uint_32 i; /* row counter */ @@ -575,7 +587,7 @@ png_write_rows(png_structp png_ptr, png_bytepp row, * if you are writing an interlaced image. */ void PNGAPI -png_write_image(png_structp png_ptr, png_bytepp image) +png_write_image(png_structrp png_ptr, png_bytepp image) { png_uint_32 i; /* row index */ int pass, num_pass; /* pass variables */ @@ -605,9 +617,74 @@ png_write_image(png_structp png_ptr, png_bytepp image) } } +#ifdef PNG_MNG_FEATURES_SUPPORTED +/* Performs intrapixel differencing */ +static void +png_do_write_intrapixel(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_write_intrapixel"); + + if ((row_info->color_type & PNG_COLOR_MASK_COLOR) != 0) + { + int bytes_per_pixel; + png_uint_32 row_width = row_info->width; + if (row_info->bit_depth == 8) + { + png_bytep rp; + png_uint_32 i; + + if (row_info->color_type == PNG_COLOR_TYPE_RGB) + bytes_per_pixel = 3; + + else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + bytes_per_pixel = 4; + + else + return; + + for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) + { + *(rp) = (png_byte)(*rp - *(rp + 1)); + *(rp + 2) = (png_byte)(*(rp + 2) - *(rp + 1)); + } + } + +#ifdef PNG_WRITE_16BIT_SUPPORTED + else if (row_info->bit_depth == 16) + { + png_bytep rp; + png_uint_32 i; + + if (row_info->color_type == PNG_COLOR_TYPE_RGB) + bytes_per_pixel = 6; + + else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + bytes_per_pixel = 8; + + else + return; + + for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) + { + png_uint_32 s0 = (*(rp ) << 8) | *(rp + 1); + png_uint_32 s1 = (*(rp + 2) << 8) | *(rp + 3); + png_uint_32 s2 = (*(rp + 4) << 8) | *(rp + 5); + png_uint_32 red = (png_uint_32)((s0 - s1) & 0xffffL); + png_uint_32 blue = (png_uint_32)((s2 - s1) & 0xffffL); + *(rp ) = (png_byte)(red >> 8); + *(rp + 1) = (png_byte)red; + *(rp + 4) = (png_byte)(blue >> 8); + *(rp + 5) = (png_byte)blue; + } + } +#endif /* WRITE_16BIT */ + } +} +#endif /* MNG_FEATURES */ + /* Called by user to write a row of image data */ void PNGAPI -png_write_row(png_structp png_ptr, png_const_bytep row) +png_write_row(png_structrp png_ptr, png_const_bytep row) { /* 1.5.6: moved from png_struct to be a local structure: */ png_row_info row_info; @@ -622,44 +699,44 @@ png_write_row(png_structp png_ptr, png_const_bytep row) 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)) + if ((png_ptr->mode & PNG_WROTE_INFO_BEFORE_PLTE) == 0) 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) + if ((png_ptr->transformations & PNG_INVERT_MONO) != 0) 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) + if ((png_ptr->transformations & PNG_FILLER) != 0) 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) + if ((png_ptr->transformations & PNG_PACKSWAP) != 0) 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) + if ((png_ptr->transformations & PNG_PACK) != 0) 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) + if ((png_ptr->transformations & PNG_SHIFT) != 0) 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) + if ((png_ptr->transformations & PNG_BGR) != 0) 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) + if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0) png_warning(png_ptr, "PNG_WRITE_SWAP_SUPPORTED is not defined"); #endif @@ -668,12 +745,13 @@ png_write_row(png_structp png_ptr, png_const_bytep row) #ifdef PNG_WRITE_INTERLACING_SUPPORTED /* If interlaced and not interested in row, return */ - if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE)) + if (png_ptr->interlaced != 0 && + (png_ptr->transformations & PNG_INTERLACE) != 0) { switch (png_ptr->pass) { case 0: - if (png_ptr->row_number & 0x07) + if ((png_ptr->row_number & 0x07) != 0) { png_write_finish_row(png_ptr); return; @@ -681,7 +759,7 @@ png_write_row(png_structp png_ptr, png_const_bytep row) break; case 1: - if ((png_ptr->row_number & 0x07) || png_ptr->width < 5) + if ((png_ptr->row_number & 0x07) != 0 || png_ptr->width < 5) { png_write_finish_row(png_ptr); return; @@ -697,7 +775,7 @@ png_write_row(png_structp png_ptr, png_const_bytep row) break; case 3: - if ((png_ptr->row_number & 0x03) || png_ptr->width < 3) + if ((png_ptr->row_number & 0x03) != 0 || png_ptr->width < 3) { png_write_finish_row(png_ptr); return; @@ -713,7 +791,7 @@ png_write_row(png_structp png_ptr, png_const_bytep row) break; case 5: - if ((png_ptr->row_number & 0x01) || png_ptr->width < 2) + if ((png_ptr->row_number & 0x01) != 0 || png_ptr->width < 2) { png_write_finish_row(png_ptr); return; @@ -721,7 +799,7 @@ png_write_row(png_structp png_ptr, png_const_bytep row) break; case 6: - if (!(png_ptr->row_number & 0x01)) + if ((png_ptr->row_number & 0x01) == 0) { png_write_finish_row(png_ptr); return; @@ -750,12 +828,12 @@ png_write_row(png_structp png_ptr, png_const_bytep row) png_debug1(3, "row_info->rowbytes = %lu", (unsigned long)row_info.rowbytes); /* Copy user's row into buffer, leaving room for filter byte. */ - png_memcpy(png_ptr->row_buf + 1, row, row_info.rowbytes); + memcpy(png_ptr->row_buf + 1, row, row_info.rowbytes); #ifdef PNG_WRITE_INTERLACING_SUPPORTED /* Handle interlacing */ if (png_ptr->interlaced && png_ptr->pass < 6 && - (png_ptr->transformations & PNG_INTERLACE)) + (png_ptr->transformations & PNG_INTERLACE) != 0) { png_do_write_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass); /* This should always get caught above, but still ... */ @@ -769,7 +847,7 @@ png_write_row(png_structp png_ptr, png_const_bytep row) #ifdef PNG_WRITE_TRANSFORMS_SUPPORTED /* Handle other transformations */ - if (png_ptr->transformations) + if (png_ptr->transformations != 0) png_do_write_transformations(png_ptr, &row_info); #endif @@ -777,7 +855,7 @@ png_write_row(png_structp png_ptr, png_const_bytep row) * which is also the output depth. */ if (row_info.pixel_depth != png_ptr->pixel_depth || - row_info.pixel_depth != png_ptr->transformed_pixel_depth) + row_info.pixel_depth != png_ptr->transformed_pixel_depth) png_error(png_ptr, "internal write transform logic error"); #ifdef PNG_MNG_FEATURES_SUPPORTED @@ -790,7 +868,7 @@ png_write_row(png_structp png_ptr, png_const_bytep row) * 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) && + if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 && (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING)) { /* Intrapixel differencing */ @@ -816,7 +894,7 @@ png_write_row(png_structp png_ptr, png_const_bytep row) #ifdef 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_set_flush(png_structrp png_ptr, int nrows) { png_debug(1, "in png_set_flush"); @@ -828,10 +906,8 @@ png_set_flush(png_structp png_ptr, int nrows) /* Flush the current output buffers now */ void PNGAPI -png_write_flush(png_structp png_ptr) +png_write_flush(png_structrp png_ptr) { - int wrote_IDAT; - png_debug(1, "in png_write_flush"); if (png_ptr == NULL) @@ -841,175 +917,76 @@ png_write_flush(png_structp png_ptr) 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) == 0) - { - /* Write the IDAT and reset the zlib output buffer */ - png_write_IDAT(png_ptr, png_ptr->zbuf, 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_compress_IDAT(png_ptr, NULL, 0, Z_SYNC_FLUSH); png_ptr->flush_rows = 0; png_flush(png_ptr); } -#endif /* PNG_WRITE_FLUSH_SUPPORTED */ +#endif /* WRITE_FLUSH */ -/* Free all memory used by the write */ -void PNGAPI -png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr) +/* Free any memory used in png_ptr struct without freeing the struct itself. */ +static void +png_write_destroy(png_structrp png_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"); - - if (png_ptr_ptr != NULL) - png_ptr = *png_ptr_ptr; - -#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); - -#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED - if (png_ptr->num_chunk_list) - { - png_free(png_ptr, png_ptr->chunk_list); - 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; -#ifdef PNG_WARNINGS_SUPPORTED - png_error_ptr warning_fn; -#endif - png_voidp error_ptr; -#ifdef PNG_USER_MEM_SUPPORTED - png_free_ptr free_fn; -#endif - png_debug(1, "in png_write_destroy"); /* Free any memory zlib uses */ - if (png_ptr->zlib_state != PNG_ZLIB_UNINITIALIZED) + if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0) deflateEnd(&png_ptr->zstream); /* Free our memory. png_free checks NULL for us. */ - png_free(png_ptr, png_ptr->zbuf); + png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list); png_free(png_ptr, png_ptr->row_buf); + png_ptr->row_buf = NULL; #ifdef PNG_WRITE_FILTER_SUPPORTED 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); + png_free(png_ptr, png_ptr->try_row); + png_free(png_ptr, png_ptr->tst_row); + png_ptr->prev_row = NULL; + png_ptr->try_row = NULL; + png_ptr->tst_row = NULL; #endif -#ifdef PNG_SETJMP_SUPPORTED - /* Reset structure */ - png_memcpy(tmp_jmp, png_ptr->longjmp_buffer, png_sizeof(jmp_buf)); +#ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED + png_free(png_ptr, png_ptr->chunk_list); + png_ptr->chunk_list = NULL; #endif - error_fn = png_ptr->error_fn; -#ifdef PNG_WARNINGS_SUPPORTED - warning_fn = png_ptr->warning_fn; -#endif - error_ptr = png_ptr->error_ptr; -#ifdef PNG_USER_MEM_SUPPORTED - free_fn = png_ptr->free_fn; -#endif + /* The error handling and memory handling information is left intact at this + * point: the jmp_buf may still have to be freed. See png_destroy_png_struct + * for how this happens. + */ +} - png_memset(png_ptr, 0, png_sizeof(png_struct)); +/* Free all memory used by the write. + * In libpng 1.6.0 this API changed quietly to no longer accept a NULL value for + * *png_ptr_ptr. Prior to 1.6.0 it would accept such a value and it would free + * the passed in info_structs but it would quietly fail to free any of the data + * inside them. In 1.6.0 it quietly does nothing (it has to be quiet because it + * has no png_ptr.) + */ +void PNGAPI +png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr) +{ + png_debug(1, "in png_destroy_write_struct"); - png_ptr->error_fn = error_fn; -#ifdef PNG_WARNINGS_SUPPORTED - png_ptr->warning_fn = warning_fn; -#endif - png_ptr->error_ptr = error_ptr; -#ifdef PNG_USER_MEM_SUPPORTED - png_ptr->free_fn = free_fn; -#endif + if (png_ptr_ptr != NULL) + { + png_structrp png_ptr = *png_ptr_ptr; -#ifdef PNG_SETJMP_SUPPORTED - png_memcpy(png_ptr->longjmp_buffer, tmp_jmp, png_sizeof(jmp_buf)); -#endif + if (png_ptr != NULL) /* added in libpng 1.6.0 */ + { + png_destroy_info_struct(png_ptr, info_ptr_ptr); + + *png_ptr_ptr = NULL; + png_write_destroy(png_ptr); + png_destroy_png_struct(png_ptr); + } + } } /* 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_set_filter(png_structrp png_ptr, int method, int filters) { png_debug(1, "in png_set_filter"); @@ -1017,7 +994,7 @@ png_set_filter(png_structp png_ptr, int method, int filters) return; #ifdef PNG_MNG_FEATURES_SUPPORTED - if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) && + if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 && (method == PNG_INTRAPIXEL_DIFFERENCING)) method = PNG_FILTER_TYPE_BASE; @@ -1029,9 +1006,9 @@ png_set_filter(png_structp png_ptr, int method, int filters) #ifdef PNG_WRITE_FILTER_SUPPORTED case 5: case 6: - case 7: png_warning(png_ptr, "Unknown row filter for method 0"); - /* FALL THROUGH */ -#endif /* PNG_WRITE_FILTER_SUPPORTED */ + case 7: png_app_error(png_ptr, "Unknown row filter for method 0"); + /* FALL THROUGH */ +#endif /* WRITE_FILTER */ case PNG_FILTER_VALUE_NONE: png_ptr->do_filter = PNG_FILTER_NONE; break; @@ -1052,102 +1029,93 @@ png_set_filter(png_structp png_ptr, int method, int filters) png_ptr->do_filter = (png_byte)filters; break; #else default: - png_warning(png_ptr, "Unknown row filter for method 0"); -#endif /* PNG_WRITE_FILTER_SUPPORTED */ + png_app_error(png_ptr, "Unknown row filter for method 0"); +#endif /* WRITE_FILTER */ } +#ifdef PNG_WRITE_FILTER_SUPPORTED /* 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. + * it should start out with all of the filters, and then remove them + * or add them back after the start of compression. + * + * NOTE: this is a nasty constraint on the code, because it means that the + * prev_row buffer must be maintained even if there are currently no + * 'prev_row' requiring filters active. */ if (png_ptr->row_buf != NULL) { - png_ptr->do_filter = PNG_FILTER_NONE; -#ifdef PNG_WRITE_FILTER_SUPPORTED - if ((png_ptr->do_filter & PNG_FILTER_SUB) && png_ptr->sub_row == NULL) + int num_filters; + png_alloc_size_t buf_size; + + /* Repeat the checks in png_write_start_row; 1 pixel high or wide + * images cannot benefit from certain filters. If this isn't done here + * the check below will fire on 1 pixel high images. + */ + if (png_ptr->height == 1) + filters &= ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH); + + if (png_ptr->width == 1) + filters &= ~(PNG_FILTER_SUB|PNG_FILTER_AVG|PNG_FILTER_PAETH); + + if ((filters & (PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH)) != 0 + && png_ptr->prev_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; + /* This is the error case, however it is benign - the previous row + * is not available so the filter can't be used. Just warn here. + */ + png_app_warning(png_ptr, + "png_set_filter: UP/AVG/PAETH cannot be added after start"); + filters &= ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH); } - 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_byte)(png_ptr->do_filter & - ~PNG_FILTER_UP); - } + num_filters = 0; - 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 (filters & PNG_FILTER_SUB) + num_filters++; - 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_byte)(png_ptr->do_filter & - ~PNG_FILTER_AVG); - } + if (filters & PNG_FILTER_UP) + num_filters++; - 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 (filters & PNG_FILTER_AVG) + num_filters++; - 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); - } + if (filters & PNG_FILTER_PAETH) + num_filters++; - else - { - png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr, - (png_ptr->rowbytes + 1)); - png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH; - } - } + /* Allocate needed row buffers if they have not already been + * allocated. + */ + buf_size = PNG_ROWBYTES(png_ptr->usr_channels * png_ptr->usr_bit_depth, + png_ptr->width) + 1; + + if (png_ptr->try_row == NULL) + png_ptr->try_row = png_voidcast(png_bytep, + png_malloc(png_ptr, buf_size)); - if (png_ptr->do_filter == PNG_NO_FILTERS) - png_ptr->do_filter = PNG_FILTER_NONE; -#endif /* PNG_WRITE_FILTER_SUPPORTED */ + if (num_filters > 1) + { + if (png_ptr->tst_row == NULL) + png_ptr->tst_row = png_voidcast(png_bytep, + png_malloc(png_ptr, buf_size)); + } } + png_ptr->do_filter = (png_byte)filters; +#endif } 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. - */ #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* DEPRECATED */ /* Provide floating and fixed point APIs */ #ifdef PNG_FLOATING_POINT_SUPPORTED void PNGAPI -png_set_filter_heuristics(png_structp png_ptr, int heuristic_method, +png_set_filter_heuristics(png_structrp png_ptr, int heuristic_method, int num_weights, png_const_doublep filter_weights, png_const_doublep filter_costs) { @@ -1161,7 +1129,7 @@ png_set_filter_heuristics(png_structp png_ptr, int heuristic_method, #ifdef PNG_FIXED_POINT_SUPPORTED void PNGAPI -png_set_filter_heuristics_fixed(png_structp png_ptr, int heuristic_method, +png_set_filter_heuristics_fixed(png_structrp png_ptr, int heuristic_method, int num_weights, png_const_fixed_point_p filter_weights, png_const_fixed_point_p filter_costs) { @@ -1176,37 +1144,37 @@ png_set_filter_heuristics_fixed(png_structp png_ptr, int heuristic_method, #ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED void PNGAPI -png_set_compression_level(png_structp png_ptr, int level) +png_set_compression_level(png_structrp png_ptr, int level) { png_debug(1, "in png_set_compression_level"); 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_set_compression_mem_level(png_structrp png_ptr, int mem_level) { png_debug(1, "in png_set_compression_mem_level"); 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_set_compression_strategy(png_structrp png_ptr, int strategy) { png_debug(1, "in png_set_compression_strategy"); if (png_ptr == NULL) return; + /* The flag setting here prevents the libpng dynamic selection of strategy. + */ png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY; png_ptr->zlib_strategy = strategy; } @@ -1215,42 +1183,46 @@ png_set_compression_strategy(png_structp png_ptr, int strategy) * smaller value of window_bits if it can do so safely. */ void PNGAPI -png_set_compression_window_bits(png_structp png_ptr, int window_bits) +png_set_compression_window_bits(png_structrp png_ptr, int window_bits) { if (png_ptr == NULL) return; + /* Prior to 1.6.0 this would warn but then set the window_bits value. This + * meant that negative window bits values could be selected that would cause + * libpng to write a non-standard PNG file with raw deflate or gzip + * compressed IDAT or ancillary chunks. Such files can be read and there is + * no warning on read, so this seems like a very bad idea. + */ if (window_bits > 15) + { png_warning(png_ptr, "Only compression windows <= 32k supported by PNG"); + window_bits = 15; + } else if (window_bits < 8) + { png_warning(png_ptr, "Only compression windows >= 256 supported by PNG"); + window_bits = 8; + } -#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_set_compression_method(png_structrp png_ptr, int method) { png_debug(1, "in png_set_compression_method"); if (png_ptr == NULL) return; + /* This would produce an invalid PNG file if it worked, but it doesn't and + * deflate will fault it, so it is harmless to just warn here. + */ 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; } #endif /* WRITE_CUSTOMIZE_COMPRESSION */ @@ -1258,38 +1230,35 @@ png_set_compression_method(png_structp png_ptr, int method) /* The following were added to libpng-1.5.4 */ #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED void PNGAPI -png_set_text_compression_level(png_structp png_ptr, int level) +png_set_text_compression_level(png_structrp png_ptr, int level) { png_debug(1, "in png_set_text_compression_level"); if (png_ptr == NULL) return; - png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_LEVEL; png_ptr->zlib_text_level = level; } void PNGAPI -png_set_text_compression_mem_level(png_structp png_ptr, int mem_level) +png_set_text_compression_mem_level(png_structrp png_ptr, int mem_level) { png_debug(1, "in png_set_text_compression_mem_level"); if (png_ptr == NULL) return; - png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_MEM_LEVEL; png_ptr->zlib_text_mem_level = mem_level; } void PNGAPI -png_set_text_compression_strategy(png_structp png_ptr, int strategy) +png_set_text_compression_strategy(png_structrp png_ptr, int strategy) { png_debug(1, "in png_set_text_compression_strategy"); if (png_ptr == NULL) return; - png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_STRATEGY; png_ptr->zlib_text_strategy = strategy; } @@ -1297,32 +1266,28 @@ png_set_text_compression_strategy(png_structp png_ptr, int strategy) * smaller value of window_bits if it can do so safely. */ void PNGAPI -png_set_text_compression_window_bits(png_structp png_ptr, int window_bits) +png_set_text_compression_window_bits(png_structrp 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"); + window_bits = 15; + } 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, "Text compression window is being reset to 512"); - window_bits = 9; + png_warning(png_ptr, "Only compression windows >= 256 supported by PNG"); + window_bits = 8; } -#endif - png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_WINDOW_BITS; png_ptr->zlib_text_window_bits = window_bits; } void PNGAPI -png_set_text_compression_method(png_structp png_ptr, int method) +png_set_text_compression_method(png_structrp png_ptr, int method) { png_debug(1, "in png_set_text_compression_method"); @@ -1332,14 +1297,13 @@ png_set_text_compression_method(png_structp png_ptr, int method) if (method != 8) png_warning(png_ptr, "Only compression method 8 is supported by PNG"); - png_ptr->flags |= PNG_FLAG_ZTXT_CUSTOM_METHOD; png_ptr->zlib_text_method = method; } -#endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */ +#endif /* WRITE_CUSTOMIZE_ZTXT_COMPRESSION */ /* end of API added to libpng-1.5.4 */ void PNGAPI -png_set_write_status_fn(png_structp png_ptr, png_write_status_ptr write_row_fn) +png_set_write_status_fn(png_structrp png_ptr, png_write_status_ptr write_row_fn) { if (png_ptr == NULL) return; @@ -1349,7 +1313,7 @@ png_set_write_status_fn(png_structp png_ptr, png_write_status_ptr write_row_fn) #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED void PNGAPI -png_set_write_user_transform_fn(png_structp png_ptr, png_user_transform_ptr +png_set_write_user_transform_fn(png_structrp png_ptr, png_user_transform_ptr write_user_transform_fn) { png_debug(1, "in png_set_write_user_transform_fn"); @@ -1365,88 +1329,1055 @@ png_set_write_user_transform_fn(png_structp png_ptr, png_user_transform_ptr #ifdef PNG_INFO_IMAGE_SUPPORTED void PNGAPI -png_write_png(png_structp png_ptr, png_infop info_ptr, +png_write_png(png_structrp png_ptr, png_inforp info_ptr, int transforms, voidp params) { if (png_ptr == NULL || info_ptr == NULL) return; + if ((info_ptr->valid & PNG_INFO_IDAT) == 0) + { + png_app_error(png_ptr, "no rows for png_write_image to write"); + return; + } + /* Write the file header information. */ png_write_info(png_ptr, info_ptr); /* ------ these transformations don't touch the info structure ------- */ -#ifdef PNG_WRITE_INVERT_SUPPORTED /* Invert monochrome pixels */ - if (transforms & PNG_TRANSFORM_INVERT_MONO) + if ((transforms & PNG_TRANSFORM_INVERT_MONO) != 0) +#ifdef PNG_WRITE_INVERT_SUPPORTED png_set_invert_mono(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_MONO not supported"); #endif -#ifdef 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); + if ((transforms & PNG_TRANSFORM_SHIFT) != 0) +#ifdef PNG_WRITE_SHIFT_SUPPORTED + if ((info_ptr->valid & PNG_INFO_sBIT) != 0) + png_set_shift(png_ptr, &info_ptr->sig_bit); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_SHIFT not supported"); #endif -#ifdef PNG_WRITE_PACK_SUPPORTED /* Pack pixels into bytes */ - if (transforms & PNG_TRANSFORM_PACKING) - png_set_packing(png_ptr); + if ((transforms & PNG_TRANSFORM_PACKING) != 0) +#ifdef PNG_WRITE_PACK_SUPPORTED + png_set_packing(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_PACKING not supported"); #endif -#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED /* Swap location of alpha bytes from ARGB to RGBA */ - if (transforms & PNG_TRANSFORM_SWAP_ALPHA) + if ((transforms & PNG_TRANSFORM_SWAP_ALPHA) != 0) +#ifdef PNG_WRITE_SWAP_ALPHA_SUPPORTED png_set_swap_alpha(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ALPHA not supported"); #endif + /* Remove a filler (X) from XRGB/RGBX/AG/GA into to convert it into + * RGB, note that the code expects the input color type to be G or RGB; no + * alpha channel. + */ + if ((transforms & (PNG_TRANSFORM_STRIP_FILLER_AFTER| + PNG_TRANSFORM_STRIP_FILLER_BEFORE)) != 0) + { #ifdef PNG_WRITE_FILLER_SUPPORTED - /* Pack XRGB/RGBX/ARGB/RGBA into RGB (4 channels -> 3 channels) */ - if (transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER) - png_set_filler(png_ptr, 0, PNG_FILLER_AFTER); + if ((transforms & PNG_TRANSFORM_STRIP_FILLER_AFTER) != 0) + { + if ((transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE) != 0) + png_app_error(png_ptr, + "PNG_TRANSFORM_STRIP_FILLER: BEFORE+AFTER not supported"); - else if (transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE) - png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE); + /* Continue if ignored - this is the pre-1.6.10 behavior */ + png_set_filler(png_ptr, 0, PNG_FILLER_AFTER); + } + + else if ((transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE) != 0) + png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_STRIP_FILLER not supported"); #endif + } -#ifdef PNG_WRITE_BGR_SUPPORTED /* Flip BGR pixels to RGB */ - if (transforms & PNG_TRANSFORM_BGR) + if ((transforms & PNG_TRANSFORM_BGR) != 0) +#ifdef PNG_WRITE_BGR_SUPPORTED png_set_bgr(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_BGR not supported"); #endif -#ifdef PNG_WRITE_SWAP_SUPPORTED /* Swap bytes of 16-bit files to most significant byte first */ - if (transforms & PNG_TRANSFORM_SWAP_ENDIAN) + if ((transforms & PNG_TRANSFORM_SWAP_ENDIAN) != 0) +#ifdef PNG_WRITE_SWAP_SUPPORTED png_set_swap(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_SWAP_ENDIAN not supported"); #endif + /* Swap bits of 1-bit, 2-bit, 4-bit packed pixel formats */ + if ((transforms & PNG_TRANSFORM_PACKSWAP) != 0) #ifdef PNG_WRITE_PACKSWAP_SUPPORTED - /* Swap bits of 1, 2, 4 bit packed pixel formats */ - if (transforms & PNG_TRANSFORM_PACKSWAP) png_set_packswap(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_PACKSWAP not supported"); #endif -#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED /* Invert the alpha channel from opacity to transparency */ - if (transforms & PNG_TRANSFORM_INVERT_ALPHA) + if ((transforms & PNG_TRANSFORM_INVERT_ALPHA) != 0) +#ifdef PNG_WRITE_INVERT_ALPHA_SUPPORTED png_set_invert_alpha(png_ptr); +#else + png_app_error(png_ptr, "PNG_TRANSFORM_INVERT_ALPHA not supported"); #endif /* ----------------------- end of transformations ------------------- */ /* Write the bits */ - if (info_ptr->valid & PNG_INFO_IDAT) - png_write_image(png_ptr, info_ptr->row_pointers); + 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); - PNG_UNUSED(transforms) /* Quiet compiler warnings */ PNG_UNUSED(params) } #endif -#endif /* PNG_WRITE_SUPPORTED */ + + +#ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED +/* Initialize the write structure - general purpose utility. */ +static int +png_image_write_init(png_imagep image) +{ + png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, image, + png_safe_error, png_safe_warning); + + if (png_ptr != NULL) + { + png_infop info_ptr = png_create_info_struct(png_ptr); + + if (info_ptr != NULL) + { + png_controlp control = png_voidcast(png_controlp, + png_malloc_warn(png_ptr, (sizeof *control))); + + if (control != NULL) + { + memset(control, 0, (sizeof *control)); + + control->png_ptr = png_ptr; + control->info_ptr = info_ptr; + control->for_write = 1; + + image->opaque = control; + return 1; + } + + /* Error clean up */ + png_destroy_info_struct(png_ptr, &info_ptr); + } + + png_destroy_write_struct(&png_ptr, NULL); + } + + return png_image_error(image, "png_image_write_: out of memory"); +} + +/* Arguments to png_image_write_main: */ +typedef struct +{ + /* Arguments: */ + png_imagep image; + png_const_voidp buffer; + png_int_32 row_stride; + png_const_voidp colormap; + int convert_to_8bit; + /* Local variables: */ + png_const_voidp first_row; + ptrdiff_t row_bytes; + png_voidp local_row; + /* Byte count for memory writing */ + png_bytep memory; + png_alloc_size_t memory_bytes; /* not used for STDIO */ + png_alloc_size_t output_bytes; /* running total */ +} png_image_write_control; + +/* Write png_uint_16 input to a 16-bit PNG; the png_ptr has already been set to + * do any necessary byte swapping. The component order is defined by the + * png_image format value. + */ +static int +png_write_image_16bit(png_voidp argument) +{ + png_image_write_control *display = png_voidcast(png_image_write_control*, + argument); + png_imagep image = display->image; + png_structrp png_ptr = image->opaque->png_ptr; + + png_const_uint_16p input_row = png_voidcast(png_const_uint_16p, + display->first_row); + png_uint_16p output_row = png_voidcast(png_uint_16p, display->local_row); + png_uint_16p row_end; + const int channels = (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ? 3 : 1; + int aindex = 0; + png_uint_32 y = image->height; + + if ((image->format & PNG_FORMAT_FLAG_ALPHA) != 0) + { +# ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED + if ((image->format & PNG_FORMAT_FLAG_AFIRST) != 0) + { + aindex = -1; + ++input_row; /* To point to the first component */ + ++output_row; + } + else + aindex = channels; +# else + aindex = channels; +# endif + } + + else + png_error(png_ptr, "png_write_image: internal call error"); + + /* Work out the output row end and count over this, note that the increment + * above to 'row' means that row_end can actually be beyond the end of the + * row; this is correct. + */ + row_end = output_row + image->width * (channels+1); + + while (y-- > 0) + { + png_const_uint_16p in_ptr = input_row; + png_uint_16p out_ptr = output_row; + + while (out_ptr < row_end) + { + const png_uint_16 alpha = in_ptr[aindex]; + png_uint_32 reciprocal = 0; + int c; + + out_ptr[aindex] = alpha; + + /* Calculate a reciprocal. The correct calculation is simply + * component/alpha*65535 << 15. (I.e. 15 bits of precision); this + * allows correct rounding by adding .5 before the shift. 'reciprocal' + * is only initialized when required. + */ + if (alpha > 0 && alpha < 65535) + reciprocal = ((0xffff<<15)+(alpha>>1))/alpha; + + c = channels; + do /* always at least one channel */ + { + png_uint_16 component = *in_ptr++; + + /* The following gives 65535 for an alpha of 0, which is fine, + * otherwise if 0/0 is represented as some other value there is more + * likely to be a discontinuity which will probably damage + * compression when moving from a fully transparent area to a + * nearly transparent one. (The assumption here is that opaque + * areas tend not to be 0 intensity.) + */ + if (component >= alpha) + component = 65535; + + /* component<alpha, so component/alpha is less than one and + * component*reciprocal is less than 2^31. + */ + else if (component > 0 && alpha < 65535) + { + png_uint_32 calc = component * reciprocal; + calc += 16384; /* round to nearest */ + component = (png_uint_16)(calc >> 15); + } + + *out_ptr++ = component; + } + while (--c > 0); + + /* Skip to next component (skip the intervening alpha channel) */ + ++in_ptr; + ++out_ptr; + } + + png_write_row(png_ptr, png_voidcast(png_const_bytep, display->local_row)); + input_row += display->row_bytes/(sizeof (png_uint_16)); + } + + return 1; +} + +/* Given 16-bit input (1 to 4 channels) write 8-bit output. If an alpha channel + * is present it must be removed from the components, the components are then + * written in sRGB encoding. No components are added or removed. + * + * Calculate an alpha reciprocal to reverse pre-multiplication. As above the + * calculation can be done to 15 bits of accuracy; however, the output needs to + * be scaled in the range 0..255*65535, so include that scaling here. + */ +# define UNP_RECIPROCAL(alpha) ((((0xffff*0xff)<<7)+(alpha>>1))/alpha) + +static png_byte +png_unpremultiply(png_uint_32 component, png_uint_32 alpha, + png_uint_32 reciprocal/*from the above macro*/) +{ + /* The following gives 1.0 for an alpha of 0, which is fine, otherwise if 0/0 + * is represented as some other value there is more likely to be a + * discontinuity which will probably damage compression when moving from a + * fully transparent area to a nearly transparent one. (The assumption here + * is that opaque areas tend not to be 0 intensity.) + * + * There is a rounding problem here; if alpha is less than 128 it will end up + * as 0 when scaled to 8 bits. To avoid introducing spurious colors into the + * output change for this too. + */ + if (component >= alpha || alpha < 128) + return 255; + + /* component<alpha, so component/alpha is less than one and + * component*reciprocal is less than 2^31. + */ + else if (component > 0) + { + /* The test is that alpha/257 (rounded) is less than 255, the first value + * that becomes 255 is 65407. + * NOTE: this must agree with the PNG_DIV257 macro (which must, therefore, + * be exact!) [Could also test reciprocal != 0] + */ + if (alpha < 65407) + { + component *= reciprocal; + component += 64; /* round to nearest */ + component >>= 7; + } + + else + component *= 255; + + /* Convert the component to sRGB. */ + return (png_byte)PNG_sRGB_FROM_LINEAR(component); + } + + else + return 0; +} + +static int +png_write_image_8bit(png_voidp argument) +{ + png_image_write_control *display = png_voidcast(png_image_write_control*, + argument); + png_imagep image = display->image; + png_structrp png_ptr = image->opaque->png_ptr; + + png_const_uint_16p input_row = png_voidcast(png_const_uint_16p, + display->first_row); + png_bytep output_row = png_voidcast(png_bytep, display->local_row); + png_uint_32 y = image->height; + const int channels = (image->format & PNG_FORMAT_FLAG_COLOR) != 0 ? 3 : 1; + + if ((image->format & PNG_FORMAT_FLAG_ALPHA) != 0) + { + png_bytep row_end; + int aindex; + +# ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED + if ((image->format & PNG_FORMAT_FLAG_AFIRST) != 0) + { + aindex = -1; + ++input_row; /* To point to the first component */ + ++output_row; + } + + else +# endif + aindex = channels; + + /* Use row_end in place of a loop counter: */ + row_end = output_row + image->width * (channels+1); + + while (y-- > 0) + { + png_const_uint_16p in_ptr = input_row; + png_bytep out_ptr = output_row; + + while (out_ptr < row_end) + { + png_uint_16 alpha = in_ptr[aindex]; + png_byte alphabyte = (png_byte)PNG_DIV257(alpha); + png_uint_32 reciprocal = 0; + int c; + + /* Scale and write the alpha channel. */ + out_ptr[aindex] = alphabyte; + + if (alphabyte > 0 && alphabyte < 255) + reciprocal = UNP_RECIPROCAL(alpha); + + c = channels; + do /* always at least one channel */ + *out_ptr++ = png_unpremultiply(*in_ptr++, alpha, reciprocal); + while (--c > 0); + + /* Skip to next component (skip the intervening alpha channel) */ + ++in_ptr; + ++out_ptr; + } /* while out_ptr < row_end */ + + png_write_row(png_ptr, png_voidcast(png_const_bytep, + display->local_row)); + input_row += display->row_bytes/(sizeof (png_uint_16)); + } /* while y */ + } + + else + { + /* No alpha channel, so the row_end really is the end of the row and it + * is sufficient to loop over the components one by one. + */ + png_bytep row_end = output_row + image->width * channels; + + while (y-- > 0) + { + png_const_uint_16p in_ptr = input_row; + png_bytep out_ptr = output_row; + + while (out_ptr < row_end) + { + png_uint_32 component = *in_ptr++; + + component *= 255; + *out_ptr++ = (png_byte)PNG_sRGB_FROM_LINEAR(component); + } + + png_write_row(png_ptr, output_row); + input_row += display->row_bytes/(sizeof (png_uint_16)); + } + } + + return 1; +} + +static void +png_image_set_PLTE(png_image_write_control *display) +{ + const png_imagep image = display->image; + const void *cmap = display->colormap; + const int entries = image->colormap_entries > 256 ? 256 : + (int)image->colormap_entries; + + /* NOTE: the caller must check for cmap != NULL and entries != 0 */ + const png_uint_32 format = image->format; + const int channels = PNG_IMAGE_SAMPLE_CHANNELS(format); + +# if defined(PNG_FORMAT_BGR_SUPPORTED) &&\ + defined(PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED) + const int afirst = (format & PNG_FORMAT_FLAG_AFIRST) != 0 && + (format & PNG_FORMAT_FLAG_ALPHA) != 0; +# else +# define afirst 0 +# endif + +# ifdef PNG_FORMAT_BGR_SUPPORTED + const int bgr = (format & PNG_FORMAT_FLAG_BGR) != 0 ? 2 : 0; +# else +# define bgr 0 +# endif + + int i, num_trans; + png_color palette[256]; + png_byte tRNS[256]; + + memset(tRNS, 255, (sizeof tRNS)); + memset(palette, 0, (sizeof palette)); + + for (i=num_trans=0; i<entries; ++i) + { + /* This gets automatically converted to sRGB with reversal of the + * pre-multiplication if the color-map has an alpha channel. + */ + if ((format & PNG_FORMAT_FLAG_LINEAR) != 0) + { + png_const_uint_16p entry = png_voidcast(png_const_uint_16p, cmap); + + entry += i * channels; + + if ((channels & 1) != 0) /* no alpha */ + { + if (channels >= 3) /* RGB */ + { + palette[i].blue = (png_byte)PNG_sRGB_FROM_LINEAR(255 * + entry[(2 ^ bgr)]); + palette[i].green = (png_byte)PNG_sRGB_FROM_LINEAR(255 * + entry[1]); + palette[i].red = (png_byte)PNG_sRGB_FROM_LINEAR(255 * + entry[bgr]); + } + + else /* Gray */ + palette[i].blue = palette[i].red = palette[i].green = + (png_byte)PNG_sRGB_FROM_LINEAR(255 * *entry); + } + + else /* alpha */ + { + png_uint_16 alpha = entry[afirst ? 0 : channels-1]; + png_byte alphabyte = (png_byte)PNG_DIV257(alpha); + png_uint_32 reciprocal = 0; + + /* Calculate a reciprocal, as in the png_write_image_8bit code above + * this is designed to produce a value scaled to 255*65535 when + * divided by 128 (i.e. asr 7). + */ + if (alphabyte > 0 && alphabyte < 255) + reciprocal = (((0xffff*0xff)<<7)+(alpha>>1))/alpha; + + tRNS[i] = alphabyte; + if (alphabyte < 255) + num_trans = i+1; + + if (channels >= 3) /* RGB */ + { + palette[i].blue = png_unpremultiply(entry[afirst + (2 ^ bgr)], + alpha, reciprocal); + palette[i].green = png_unpremultiply(entry[afirst + 1], alpha, + reciprocal); + palette[i].red = png_unpremultiply(entry[afirst + bgr], alpha, + reciprocal); + } + + else /* gray */ + palette[i].blue = palette[i].red = palette[i].green = + png_unpremultiply(entry[afirst], alpha, reciprocal); + } + } + + else /* Color-map has sRGB values */ + { + png_const_bytep entry = png_voidcast(png_const_bytep, cmap); + + entry += i * channels; + + switch (channels) + { + case 4: + tRNS[i] = entry[afirst ? 0 : 3]; + if (tRNS[i] < 255) + num_trans = i+1; + /* FALL THROUGH */ + case 3: + palette[i].blue = entry[afirst + (2 ^ bgr)]; + palette[i].green = entry[afirst + 1]; + palette[i].red = entry[afirst + bgr]; + break; + + case 2: + tRNS[i] = entry[1 ^ afirst]; + if (tRNS[i] < 255) + num_trans = i+1; + /* FALL THROUGH */ + case 1: + palette[i].blue = palette[i].red = palette[i].green = + entry[afirst]; + break; + + default: + break; + } + } + } + +# ifdef afirst +# undef afirst +# endif +# ifdef bgr +# undef bgr +# endif + + png_set_PLTE(image->opaque->png_ptr, image->opaque->info_ptr, palette, + entries); + + if (num_trans > 0) + png_set_tRNS(image->opaque->png_ptr, image->opaque->info_ptr, tRNS, + num_trans, NULL); + + image->colormap_entries = entries; +} + +static int +png_image_write_main(png_voidp argument) +{ + png_image_write_control *display = png_voidcast(png_image_write_control*, + argument); + png_imagep image = display->image; + png_structrp png_ptr = image->opaque->png_ptr; + png_inforp info_ptr = image->opaque->info_ptr; + png_uint_32 format = image->format; + + /* The following four ints are actually booleans */ + int colormap = (format & PNG_FORMAT_FLAG_COLORMAP); + int linear = !colormap && (format & PNG_FORMAT_FLAG_LINEAR); /* input */ + int alpha = !colormap && (format & PNG_FORMAT_FLAG_ALPHA); + int write_16bit = linear && !colormap && (display->convert_to_8bit == 0); + +# ifdef PNG_BENIGN_ERRORS_SUPPORTED + /* Make sure we error out on any bad situation */ + png_set_benign_errors(png_ptr, 0/*error*/); +# endif + + /* Default the 'row_stride' parameter if required, also check the row stride + * and total image size to ensure that they are within the system limits. + */ + { + const unsigned int channels = PNG_IMAGE_PIXEL_CHANNELS(image->format); + + if (image->width <= 0x7FFFFFFFU/channels) /* no overflow */ + { + png_uint_32 check; + const png_uint_32 png_row_stride = image->width * channels; + + if (display->row_stride == 0) + display->row_stride = (png_int_32)/*SAFE*/png_row_stride; + + if (display->row_stride < 0) + check = -display->row_stride; + + else + check = display->row_stride; + + if (check >= png_row_stride) + { + /* Now check for overflow of the image buffer calculation; this + * limits the whole image size to 32 bits for API compatibility with + * the current, 32-bit, PNG_IMAGE_BUFFER_SIZE macro. + */ + if (image->height > 0xFFFFFFFF/png_row_stride) + png_error(image->opaque->png_ptr, "memory image too large"); + } + + else + png_error(image->opaque->png_ptr, "supplied row stride too small"); + } + + else + png_error(image->opaque->png_ptr, "image row stride too large"); + } + + /* Set the required transforms then write the rows in the correct order. */ + if ((format & PNG_FORMAT_FLAG_COLORMAP) != 0) + { + if (display->colormap != NULL && image->colormap_entries > 0) + { + png_uint_32 entries = image->colormap_entries; + + png_set_IHDR(png_ptr, info_ptr, image->width, image->height, + entries > 16 ? 8 : (entries > 4 ? 4 : (entries > 2 ? 2 : 1)), + PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE, + PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); + + png_image_set_PLTE(display); + } + + else + png_error(image->opaque->png_ptr, + "no color-map for color-mapped image"); + } + + else + png_set_IHDR(png_ptr, info_ptr, image->width, image->height, + write_16bit ? 16 : 8, + ((format & PNG_FORMAT_FLAG_COLOR) ? PNG_COLOR_MASK_COLOR : 0) + + ((format & PNG_FORMAT_FLAG_ALPHA) ? PNG_COLOR_MASK_ALPHA : 0), + PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); + + /* Counter-intuitively the data transformations must be called *after* + * png_write_info, not before as in the read code, but the 'set' functions + * must still be called before. Just set the color space information, never + * write an interlaced image. + */ + + if (write_16bit != 0) + { + /* The gamma here is 1.0 (linear) and the cHRM chunk matches sRGB. */ + png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_LINEAR); + + if ((image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB) == 0) + png_set_cHRM_fixed(png_ptr, info_ptr, + /* color x y */ + /* white */ 31270, 32900, + /* red */ 64000, 33000, + /* green */ 30000, 60000, + /* blue */ 15000, 6000 + ); + } + + else if ((image->flags & PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB) == 0) + png_set_sRGB(png_ptr, info_ptr, PNG_sRGB_INTENT_PERCEPTUAL); + + /* Else writing an 8-bit file and the *colors* aren't sRGB, but the 8-bit + * space must still be gamma encoded. + */ + else + png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_sRGB_INVERSE); + + /* Write the file header. */ + png_write_info(png_ptr, info_ptr); + + /* Now set up the data transformations (*after* the header is written), + * remove the handled transformations from the 'format' flags for checking. + * + * First check for a little endian system if writing 16-bit files. + */ + if (write_16bit != 0) + { + PNG_CONST png_uint_16 le = 0x0001; + + if ((*(png_const_bytep) & le) != 0) + png_set_swap(png_ptr); + } + +# ifdef PNG_SIMPLIFIED_WRITE_BGR_SUPPORTED + if ((format & PNG_FORMAT_FLAG_BGR) != 0) + { + if (colormap == 0 && (format & PNG_FORMAT_FLAG_COLOR) != 0) + png_set_bgr(png_ptr); + format &= ~PNG_FORMAT_FLAG_BGR; + } +# endif + +# ifdef PNG_SIMPLIFIED_WRITE_AFIRST_SUPPORTED + if ((format & PNG_FORMAT_FLAG_AFIRST) != 0) + { + if (colormap == 0 && (format & PNG_FORMAT_FLAG_ALPHA) != 0) + png_set_swap_alpha(png_ptr); + format &= ~PNG_FORMAT_FLAG_AFIRST; + } +# endif + + /* If there are 16 or fewer color-map entries we wrote a lower bit depth + * above, but the application data is still byte packed. + */ + if (colormap != 0 && image->colormap_entries <= 16) + png_set_packing(png_ptr); + + /* That should have handled all (both) the transforms. */ + if ((format & ~(png_uint_32)(PNG_FORMAT_FLAG_COLOR | PNG_FORMAT_FLAG_LINEAR | + PNG_FORMAT_FLAG_ALPHA | PNG_FORMAT_FLAG_COLORMAP)) != 0) + png_error(png_ptr, "png_write_image: unsupported transformation"); + + { + png_const_bytep row = png_voidcast(png_const_bytep, display->buffer); + ptrdiff_t row_bytes = display->row_stride; + + if (linear != 0) + row_bytes *= (sizeof (png_uint_16)); + + if (row_bytes < 0) + row += (image->height-1) * (-row_bytes); + + display->first_row = row; + display->row_bytes = row_bytes; + } + + /* Apply 'fast' options if the flag is set. */ + if ((image->flags & PNG_IMAGE_FLAG_FAST) != 0) + { + png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, PNG_NO_FILTERS); + /* NOTE: determined by experiment using pngstest, this reflects some + * balance between the time to write the image once and the time to read + * it about 50 times. The speed-up in pngstest was about 10-20% of the + * total (user) time on a heavily loaded system. + */ +# ifdef PNG_WRITE_CUSTOMIZE_COMPRESSION_SUPPORTED + png_set_compression_level(png_ptr, 3); +# endif + } + + /* Check for the cases that currently require a pre-transform on the row + * before it is written. This only applies when the input is 16-bit and + * either there is an alpha channel or it is converted to 8-bit. + */ + if ((linear != 0 && alpha != 0 ) || + (colormap == 0 && display->convert_to_8bit != 0)) + { + png_bytep row = png_voidcast(png_bytep, png_malloc(png_ptr, + png_get_rowbytes(png_ptr, info_ptr))); + int result; + + display->local_row = row; + if (write_16bit != 0) + result = png_safe_execute(image, png_write_image_16bit, display); + else + result = png_safe_execute(image, png_write_image_8bit, display); + display->local_row = NULL; + + png_free(png_ptr, row); + + /* Skip the 'write_end' on error: */ + if (result == 0) + return 0; + } + + /* Otherwise this is the case where the input is in a format currently + * supported by the rest of the libpng write code; call it directly. + */ + else + { + png_const_bytep row = png_voidcast(png_const_bytep, display->first_row); + ptrdiff_t row_bytes = display->row_bytes; + png_uint_32 y = image->height; + + while (y-- > 0) + { + png_write_row(png_ptr, row); + row += row_bytes; + } + } + + png_write_end(png_ptr, info_ptr); + return 1; +} + + +static void (PNGCBAPI +image_memory_write)(png_structp png_ptr, png_bytep/*const*/ data, + png_size_t size) +{ + png_image_write_control *display = png_voidcast(png_image_write_control*, + png_ptr->io_ptr/*backdoor: png_get_io_ptr(png_ptr)*/); + const png_alloc_size_t ob = display->output_bytes; + + /* Check for overflow; this should never happen: */ + if (size <= ((png_alloc_size_t)-1) - ob) + { + /* I don't think libpng ever does this, but just in case: */ + if (size > 0) + { + if (display->memory_bytes >= ob+size) /* writing */ + memcpy(display->memory+ob, data, size); + + /* Always update the size: */ + display->output_bytes = ob+size; + } + } + + else + png_error(png_ptr, "png_image_write_to_memory: PNG too big"); +} + +static void (PNGCBAPI +image_memory_flush)(png_structp png_ptr) +{ + PNG_UNUSED(png_ptr) +} + +static int +png_image_write_memory(png_voidp argument) +{ + png_image_write_control *display = png_voidcast(png_image_write_control*, + argument); + + /* The rest of the memory-specific init and write_main in an error protected + * environment. This case needs to use callbacks for the write operations + * since libpng has no built in support for writing to memory. + */ + png_set_write_fn(display->image->opaque->png_ptr, display/*io_ptr*/, + image_memory_write, image_memory_flush); + + return png_image_write_main(display); +} + +int PNGAPI +png_image_write_to_memory(png_imagep image, void *memory, + png_alloc_size_t * PNG_RESTRICT memory_bytes, int convert_to_8bit, + const void *buffer, png_int_32 row_stride, const void *colormap) +{ + /* Write the image to the given buffer, or count the bytes if it is NULL */ + if (image != NULL && image->version == PNG_IMAGE_VERSION) + { + if (memory_bytes != NULL && buffer != NULL) + { + /* This is to give the caller an easier error detection in the NULL + * case and guard against uninitialized variable problems: + */ + if (memory == NULL) + *memory_bytes = 0; + + if (png_image_write_init(image) != 0) + { + png_image_write_control display; + int result; + + memset(&display, 0, (sizeof display)); + display.image = image; + display.buffer = buffer; + display.row_stride = row_stride; + display.colormap = colormap; + display.convert_to_8bit = convert_to_8bit; + display.memory = png_voidcast(png_bytep, memory); + display.memory_bytes = *memory_bytes; + display.output_bytes = 0; + + result = png_safe_execute(image, png_image_write_memory, &display); + png_image_free(image); + + /* write_memory returns true even if we ran out of buffer. */ + if (result) + { + /* On out-of-buffer this function returns '0' but still updates + * memory_bytes: + */ + if (memory != NULL && display.output_bytes > *memory_bytes) + result = 0; + + *memory_bytes = display.output_bytes; + } + + return result; + } + + else + return 0; + } + + else + return png_image_error(image, + "png_image_write_to_memory: invalid argument"); + } + + else if (image != NULL) + return png_image_error(image, + "png_image_write_to_memory: incorrect PNG_IMAGE_VERSION"); + + else + return 0; +} + +#ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED +int PNGAPI +png_image_write_to_stdio(png_imagep image, FILE *file, int convert_to_8bit, + const void *buffer, png_int_32 row_stride, const void *colormap) +{ + /* Write the image to the given (FILE*). */ + if (image != NULL && image->version == PNG_IMAGE_VERSION) + { + if (file != NULL && buffer != NULL) + { + if (png_image_write_init(image) != 0) + { + png_image_write_control display; + int result; + + /* This is slightly evil, but png_init_io doesn't do anything other + * than this and we haven't changed the standard IO functions so + * this saves a 'safe' function. + */ + image->opaque->png_ptr->io_ptr = file; + + memset(&display, 0, (sizeof display)); + display.image = image; + display.buffer = buffer; + display.row_stride = row_stride; + display.colormap = colormap; + display.convert_to_8bit = convert_to_8bit; + + result = png_safe_execute(image, png_image_write_main, &display); + png_image_free(image); + return result; + } + + else + return 0; + } + + else + return png_image_error(image, + "png_image_write_to_stdio: invalid argument"); + } + + else if (image != NULL) + return png_image_error(image, + "png_image_write_to_stdio: incorrect PNG_IMAGE_VERSION"); + + else + return 0; +} + +int PNGAPI +png_image_write_to_file(png_imagep image, const char *file_name, + int convert_to_8bit, const void *buffer, png_int_32 row_stride, + const void *colormap) +{ + /* Write the image to the named file. */ + if (image != NULL && image->version == PNG_IMAGE_VERSION) + { + if (file_name != NULL && buffer != NULL) + { + FILE *fp = fopen(file_name, "wb"); + + if (fp != NULL) + { + if (png_image_write_to_stdio(image, fp, convert_to_8bit, buffer, + row_stride, colormap) != 0) + { + int error; /* from fflush/fclose */ + + /* Make sure the file is flushed correctly. */ + if (fflush(fp) == 0 && ferror(fp) == 0) + { + if (fclose(fp) == 0) + return 1; + + error = errno; /* from fclose */ + } + + else + { + error = errno; /* from fflush or ferror */ + (void)fclose(fp); + } + + (void)remove(file_name); + /* The image has already been cleaned up; this is just used to + * set the error (because the original write succeeded). + */ + return png_image_error(image, strerror(error)); + } + + else + { + /* Clean up: just the opened file. */ + (void)fclose(fp); + (void)remove(file_name); + return 0; + } + } + + else + return png_image_error(image, strerror(errno)); + } + + else + return png_image_error(image, + "png_image_write_to_file: invalid argument"); + } + + else if (image != NULL) + return png_image_error(image, + "png_image_write_to_file: incorrect PNG_IMAGE_VERSION"); + + else + return 0; +} +#endif /* SIMPLIFIED_WRITE_STDIO */ +#endif /* SIMPLIFIED_WRITE */ +#endif /* WRITE */ |