/* pngwrite.c - general routines to write a PNG file * * Last changed in libpng 1.6.2 [April 25, 2013] * Copyright (c) 1998-2013 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.) * * This code is released under the libpng license. * For conditions of distribution and use, see the disclaimer * and license in png.h */ #include "pngpriv.h" #if defined(PNG_SIMPLIFIED_WRITE_SUPPORTED) && defined(PNG_STDIO_SUPPORTED) # include <errno.h> #endif #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) { 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) { /* 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 /* PNG_WRITE_UNKNOWN_CHUNKS_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_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)) { /* 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)) { 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, #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 and * 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_GAMMA_SUPPORTED # ifdef PNG_WRITE_gAMA_SUPPORTED if (!(info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) && (info_ptr->colorspace.flags & PNG_COLORSPACE_FROM_gAMA) && (info_ptr->valid & PNG_INFO_gAMA)) png_write_gAMA_fixed(png_ptr, info_ptr->colorspace.gamma); # endif #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) && (info_ptr->valid & PNG_INFO_iCCP)) { # ifdef PNG_WRITE_sRGB_SUPPORTED if (info_ptr->valid & PNG_INFO_sRGB) 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) && (info_ptr->valid & PNG_INFO_sRGB)) 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); #endif #ifdef PNG_COLORSPACE_SUPPORTED # ifdef PNG_WRITE_cHRM_SUPPORTED if (!(info_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) && (info_ptr->colorspace.flags & PNG_COLORSPACE_FROM_cHRM) && (info_ptr->valid & PNG_INFO_cHRM)) png_write_cHRM_fixed(png_ptr, &info_ptr->colorspace.end_points_xy); # endif #endif #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED 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_structrp png_ptr, png_const_inforp info_ptr) { #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED) int i; #endif png_debug(1, "in png_write_info"); 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"); #ifdef PNG_WRITE_tRNS_SUPPORTED if (info_ptr->valid & PNG_INFO_tRNS) { #ifdef 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_alpha[j] = (png_byte)(255 - info_ptr->trans_alpha[j]); } #endif png_write_tRNS(png_ptr, info_ptr->trans_alpha, &(info_ptr->trans_color), info_ptr->num_trans, info_ptr->color_type); } #endif #ifdef PNG_WRITE_bKGD_SUPPORTED if (info_ptr->valid & PNG_INFO_bKGD) 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) 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) 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) 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) 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) 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) { png_write_tIME(png_ptr, &(info_ptr->mod_time)); png_ptr->mode |= PNG_WROTE_tIME; } #endif /* tIME */ #ifdef 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 /* sPLT */ #ifdef 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", i, info_ptr->text[i].compression); /* An internationalized chunk? */ if (info_ptr->text[i].compression > 0) { #ifdef 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) { #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); #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) { #ifdef PNG_WRITE_tEXt_SUPPORTED /* Write uncompressed chunk */ png_write_tEXt(png_ptr, info_ptr->text[i].key, info_ptr->text[i].text, 0); /* Mark this chunk as written */ info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR; #else /* Can't get here */ png_warning(png_ptr, "Unable to write uncompressed text"); #endif } } #endif /* tEXt */ #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED write_unknown_chunks(png_ptr, info_ptr, PNG_HAVE_PLTE); #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_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)) png_error(png_ptr, "No IDATs written into file"); #ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED if (png_ptr->num_palette_max > png_ptr->num_palette) png_benign_error(png_ptr, "Wrote palette index exceeding num_palette"); #endif /* See if user wants us to write information chunks */ if (info_ptr != NULL) { #ifdef PNG_WRITE_TEXT_SUPPORTED int i; /* local index variable */ #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)) png_write_tIME(png_ptr, &(info_ptr->mod_time)); #endif #ifdef 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", i, info_ptr->text[i].compression); /* An internationalized chunk? */ if (info_ptr->text[i].compression > 0) { #ifdef 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) { #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); #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) { #ifdef 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 #ifdef PNG_WRITE_UNKNOWN_CHUNKS_SUPPORTED write_unknown_chunks(png_ptr, info_ptr, PNG_AFTER_IDAT); #endif } png_ptr->mode |= PNG_AFTER_IDAT; /* 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 * experiences a problem, please try building libpng with * PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED defined, and report the event to * png-mng-implement at lists.sf.net . */ #ifdef PNG_WRITE_FLUSH_SUPPORTED # ifdef PNG_WRITE_FLUSH_AFTER_IEND_SUPPORTED png_flush(png_ptr); # endif #endif } #ifdef PNG_CONVERT_tIME_SUPPORTED void PNGAPI png_convert_from_struct_tm(png_timep ptime, PNG_CONST struct tm * ttime) { png_debug(1, "in png_convert_from_struct_tm"); 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"); tbuf = gmtime(&ttime); png_convert_from_struct_tm(ptime, tbuf); } #endif /* Initialize png_ptr structure, and allocate any memory needed */ 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) { #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) { png_structrp png_ptr = png_create_png_struct(user_png_ver, error_ptr, error_fn, warn_fn, mem_ptr, malloc_fn, free_fn); #endif /* PNG_USER_MEM_SUPPORTED */ 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; /* 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 /* PNG_WRITE_COMPRESSED_TEXT_SUPPORTED */ /* 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 png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN; /* In stable builds only warn if an application error can be completely * handled. */ #endif /* App warnings are warnings in release (or release candidate) builds but * are errors during development. */ #if PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC png_ptr->flags |= PNG_FLAG_APP_WARNINGS_WARN; #endif /* 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); } return png_ptr; } /* 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_structrp 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"); 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_structrp 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"); #ifdef PNG_WRITE_INTERLACING_SUPPORTED /* Initialize 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_structrp png_ptr, png_const_bytep row) { /* 1.5.6: moved from png_struct to be a local structure: */ png_row_info row_info; if (png_ptr == NULL) return; png_debug2(1, "in png_write_row (row %u, pass %d)", 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); } #ifdef 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; default: /* error: ignore it */ break; } } #endif /* Set up row info for transformations */ row_info.color_type = png_ptr->color_type; row_info.width = png_ptr->usr_width; row_info.channels = png_ptr->usr_channels; row_info.bit_depth = png_ptr->usr_bit_depth; row_info.pixel_depth = (png_byte)(row_info.bit_depth * row_info.channels); row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width); png_debug1(3, "row_info->color_type = %d", row_info.color_type); png_debug1(3, "row_info->width = %u", row_info.width); png_debug1(3, "row_info->channels = %d", row_info.channels); png_debug1(3, "row_info->bit_depth = %d", row_info.bit_depth); png_debug1(3, "row_info->pixel_depth = %d", row_info.pixel_depth); png_debug1(3, "row_info->rowbytes = %lu", (unsigned long)row_info.rowbytes); /* Copy user's row into buffer, leaving room for filter byte. */ 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_do_write_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass); /* This should always get caught above, but still ... */ if (!(row_info.width)) { png_write_finish_row(png_ptr); return; } } #endif #ifdef PNG_WRITE_TRANSFORMS_SUPPORTED /* Handle other transformations */ if (png_ptr->transformations) png_do_write_transformations(png_ptr, &row_info); #endif /* At this point the row_info pixel depth must match the 'transformed' depth, * which is also the output depth. */ if (row_info.pixel_depth != png_ptr->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 /* 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(&row_info, png_ptr->row_buf + 1); } #endif /* Added at libpng-1.5.10 */ #ifdef PNG_WRITE_CHECK_FOR_INVALID_INDEX_SUPPORTED /* Check for out-of-range palette index */ if (row_info.color_type == PNG_COLOR_TYPE_PALETTE && png_ptr->num_palette_max >= 0) png_do_check_palette_indexes(png_ptr, &row_info); #endif /* Find a filter if necessary, filter the row and write it out. */ png_write_find_filter(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); } #ifdef PNG_WRITE_FLUSH_SUPPORTED /* Set the automatic flush interval or 0 to turn flushing off */ void PNGAPI png_set_flush(png_structrp png_ptr, int nrows) { png_debug(1, "in png_set_flush"); 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_structrp png_ptr) { png_debug(1, "in png_write_flush"); if (png_ptr == NULL) return; /* We have already written out all of the data */ if (png_ptr->row_number >= png_ptr->num_rows) return; png_compress_IDAT(png_ptr, NULL, 0, Z_SYNC_FLUSH); png_ptr->flush_rows = 0; png_flush(png_ptr); } #endif /* PNG_WRITE_FLUSH_SUPPORTED */ #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED static void png_reset_filter_heuristics(png_structrp png_ptr);/* forward decl */ #endif /* Free any memory used in png_ptr struct without freeing the struct itself. */ static void png_write_destroy(png_structrp png_ptr) { png_debug(1, "in png_write_destroy"); /* Free any memory zlib uses */ if (png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) deflateEnd(&png_ptr->zstream); /* Free our memory. png_free checks NULL for us. */ png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list); png_free(png_ptr, png_ptr->row_buf); #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); #endif #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* Use this to save a little code space, it doesn't free the filter_costs */ png_reset_filter_heuristics(png_ptr); png_free(png_ptr, png_ptr->filter_costs); png_free(png_ptr, png_ptr->inv_filter_costs); #endif #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED png_free(png_ptr, png_ptr->chunk_list); #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. */ } /* 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"); if (png_ptr_ptr != NULL) { png_structrp png_ptr = *png_ptr_ptr; 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_structrp png_ptr, int method, int filters) { png_debug(1, "in png_set_filter"); if (png_ptr == NULL) return; #ifdef 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)) { #ifdef PNG_WRITE_FILTER_SUPPORTED case 5: case 6: case 7: png_app_error(png_ptr, "Unknown row filter for method 0"); /* FALL THROUGH */ #endif /* PNG_WRITE_FILTER_SUPPORTED */ case PNG_FILTER_VALUE_NONE: png_ptr->do_filter = PNG_FILTER_NONE; break; #ifdef PNG_WRITE_FILTER_SUPPORTED 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_app_error(png_ptr, "Unknown row filter for method 0"); #endif /* 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. */ if (png_ptr->row_buf != NULL) { #ifdef PNG_WRITE_FILTER_SUPPORTED 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_byte)(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_byte)(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_WRITE_FILTER_SUPPORTED */ 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. */ #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* GRR 970116 */ /* Convenience reset API. */ static void png_reset_filter_heuristics(png_structrp png_ptr) { /* Clear out any old values in the 'weights' - this must be done because if * the app calls set_filter_heuristics multiple times with different * 'num_weights' values we would otherwise potentially have wrong sized * arrays. */ png_ptr->num_prev_filters = 0; png_ptr->heuristic_method = PNG_FILTER_HEURISTIC_UNWEIGHTED; if (png_ptr->prev_filters != NULL) { png_bytep old = png_ptr->prev_filters; png_ptr->prev_filters = NULL; png_free(png_ptr, old); } if (png_ptr->filter_weights != NULL) { png_uint_16p old = png_ptr->filter_weights; png_ptr->filter_weights = NULL; png_free(png_ptr, old); } if (png_ptr->inv_filter_weights != NULL) { png_uint_16p old = png_ptr->inv_filter_weights; png_ptr->inv_filter_weights = NULL; png_free(png_ptr, old); } /* Leave the filter_costs - this array is fixed size. */ } static int png_init_filter_heuristics(png_structrp png_ptr, int heuristic_method, int num_weights) { if (png_ptr == NULL) return 0; /* Clear out the arrays */ png_reset_filter_heuristics(png_ptr); /* Check arguments; the 'reset' function makes the correct settings for the * unweighted case, but we must handle the weight case by initializing the * arrays for the caller. */ if (heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) { int i; if (num_weights > 0) { png_ptr->prev_filters = (png_bytep)png_malloc(png_ptr, (png_uint_32)((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; } png_ptr->filter_weights = (png_uint_16p)png_malloc(png_ptr, (png_uint_32)((sizeof (png_uint_16)) * num_weights)); png_ptr->inv_filter_weights = (png_uint_16p)png_malloc(png_ptr, (png_uint_32)((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; } /* Safe to set this now */ png_ptr->num_prev_filters = (png_byte)num_weights; } /* 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)((sizeof (png_uint_16)) * PNG_FILTER_VALUE_LAST)); png_ptr->inv_filter_costs = (png_uint_16p)png_malloc(png_ptr, (png_uint_32)((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; } /* All the arrays are inited, safe to set this: */ png_ptr->heuristic_method = PNG_FILTER_HEURISTIC_WEIGHTED; /* Return the 'ok' code. */ return 1; } else if (heuristic_method == PNG_FILTER_HEURISTIC_DEFAULT || heuristic_method == PNG_FILTER_HEURISTIC_UNWEIGHTED) { return 1; } else { png_warning(png_ptr, "Unknown filter heuristic method"); return 0; } } /* Provide floating and fixed point APIs */ #ifdef PNG_FLOATING_POINT_SUPPORTED void PNGAPI png_set_filter_heuristics(png_structrp png_ptr, int heuristic_method, int num_weights, png_const_doublep filter_weights, png_const_doublep filter_costs) { png_debug(1, "in png_set_filter_heuristics"); /* The internal API allocates all the arrays and ensures that the elements of * those arrays are set to the default value. */ if (!png_init_filter_heuristics(png_ptr, heuristic_method, num_weights)) return; /* If using the weighted method copy in the weights. */ if (heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) { int i; 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)(PNG_WEIGHT_FACTOR*filter_weights[i]+.5); png_ptr->filter_weights[i] = (png_uint_16)(PNG_WEIGHT_FACTOR/filter_weights[i]+.5); } } /* 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[i] >= 1.0) { png_ptr->inv_filter_costs[i] = (png_uint_16)(PNG_COST_FACTOR / filter_costs[i] + .5); png_ptr->filter_costs[i] = (png_uint_16)(PNG_COST_FACTOR * filter_costs[i] + .5); } } } #endif /* FLOATING_POINT */ #ifdef PNG_FIXED_POINT_SUPPORTED void PNGAPI 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) { png_debug(1, "in png_set_filter_heuristics_fixed"); /* The internal API allocates all the arrays and ensures that the elements of * those arrays are set to the default value. */ if (!png_init_filter_heuristics(png_ptr, heuristic_method, num_weights)) return; /* If using the weighted method copy in the weights. */ if (heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) { int i; for (i = 0; i < num_weights; i++) { if (filter_weights[i] <= 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) ((PNG_WEIGHT_FACTOR*filter_weights[i]+PNG_FP_HALF)/PNG_FP_1); png_ptr->filter_weights[i] = (png_uint_16)((PNG_WEIGHT_FACTOR* PNG_FP_1+(filter_weights[i]/2))/filter_weights[i]); } } /* 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[i] >= PNG_FP_1) { png_uint_32 tmp; /* Use a 32 bit unsigned temporary here because otherwise the * intermediate value will be a 32 bit *signed* integer (ANSI rules) * and this will get the wrong answer on division. */ tmp = PNG_COST_FACTOR*PNG_FP_1 + (filter_costs[i]/2); tmp /= filter_costs[i]; png_ptr->inv_filter_costs[i] = (png_uint_16)tmp; tmp = PNG_COST_FACTOR * filter_costs[i] + PNG_FP_HALF; tmp /= PNG_FP_1; png_ptr->filter_costs[i] = (png_uint_16)tmp; } } } #endif /* FIXED_POINT */ #endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */ void PNGAPI 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->zlib_level = level; } void PNGAPI 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->zlib_mem_level = mem_level; } void PNGAPI 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; } /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a * smaller value of window_bits if it can do so safely. */ void PNGAPI 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 which 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; } png_ptr->zlib_window_bits = window_bits; } void PNGAPI 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->zlib_method = 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_structrp png_ptr, int level) { png_debug(1, "in png_set_text_compression_level"); if (png_ptr == NULL) return; png_ptr->zlib_text_level = level; } void PNGAPI 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->zlib_text_mem_level = mem_level; } void PNGAPI 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->zlib_text_strategy = strategy; } /* If PNG_WRITE_OPTIMIZE_CMF_SUPPORTED is defined, libpng will use a * smaller value of window_bits if it can do so safely. */ void PNGAPI 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"); window_bits = 8; } png_ptr->zlib_text_window_bits = window_bits; } void PNGAPI png_set_text_compression_method(png_structrp png_ptr, int method) { png_debug(1, "in png_set_text_compression_method"); if (png_ptr == NULL) return; if (method != 8) png_warning(png_ptr, "Only compression method 8 is supported by PNG"); png_ptr->zlib_text_method = method; } #endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */ /* end of API added to libpng-1.5.4 */ void PNGAPI png_set_write_status_fn(png_structrp png_ptr, png_write_status_ptr write_row_fn) { if (png_ptr == NULL) return; png_ptr->write_row_fn = write_row_fn; } #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED void PNGAPI 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"); if (png_ptr == NULL) return; png_ptr->transformations |= PNG_USER_TRANSFORM; png_ptr->write_user_transform_fn = write_user_transform_fn; } #endif #ifdef PNG_INFO_IMAGE_SUPPORTED void PNGAPI png_write_png(png_structrp png_ptr, png_inforp info_ptr, int transforms, voidp params) { if (png_ptr == NULL || info_ptr == NULL) 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) png_set_invert_mono(png_ptr); #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); #endif #ifdef PNG_WRITE_PACK_SUPPORTED /* Pack pixels into bytes */ if (transforms & PNG_TRANSFORM_PACKING) png_set_packing(png_ptr); #endif #ifdef 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 #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); else if (transforms & PNG_TRANSFORM_STRIP_FILLER_BEFORE) png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE); #endif #ifdef PNG_WRITE_BGR_SUPPORTED /* Flip BGR pixels to RGB */ if (transforms & PNG_TRANSFORM_BGR) png_set_bgr(png_ptr); #endif #ifdef 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 #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); #endif #ifdef 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 /* ----------------------- 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); PNG_UNUSED(transforms) /* Quiet compiler warnings */ PNG_UNUSED(params) } #endif #ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED #ifdef PNG_STDIO_SUPPORTED /* currently required for png_image_write_* */ /* 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; } 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) ? 3 : 1; int aindex = 0; png_uint_32 y = image->height; if (image->format & PNG_FORMAT_FLAG_ALPHA) { if (image->format & PNG_FORMAT_FLAG_AFIRST) { aindex = -1; ++input_row; /* To point to the first component */ ++output_row; } else aindex = channels; } 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) ? 3 : 1; if (image->format & PNG_FORMAT_FLAG_ALPHA) { png_bytep row_end; int aindex; if (image->format & PNG_FORMAT_FLAG_AFIRST) { aindex = -1; ++input_row; /* To point to the first component */ ++output_row; } else 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); # ifdef PNG_FORMAT_BGR_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) ? 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) { png_const_uint_16p entry = png_voidcast(png_const_uint_16p, cmap); entry += i * channels; if (channels & 1) /* 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; int colormap = (format & PNG_FORMAT_FLAG_COLORMAP) != 0; int linear = !colormap && (format & PNG_FORMAT_FLAG_LINEAR) != 0; /* input */ int alpha = !colormap && (format & PNG_FORMAT_FLAG_ALPHA) != 0; int write_16bit = linear && !colormap && !display->convert_to_8bit; # 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. */ if (display->row_stride == 0) display->row_stride = PNG_IMAGE_ROW_STRIDE(*image); /* Set the required transforms then write the rows in the correct order. */ if (format & PNG_FORMAT_FLAG_COLORMAP) { 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) { /* 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)) 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)) 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) { PNG_CONST png_uint_16 le = 0x0001; if (*(png_const_bytep)&le) png_set_swap(png_ptr); } # ifdef PNG_SIMPLIFIED_WRITE_BGR_SUPPORTED if (format & PNG_FORMAT_FLAG_BGR) { if (!colormap && (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) { if (!colormap && (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 && 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) 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. */ png_set_compression_level(png_ptr, 3); } /* 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 && alpha) || (!colormap && display->convert_to_8bit)) { 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) 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) 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; } 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) { if (png_image_write_init(image)) { 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) { FILE *fp = fopen(file_name, "wb"); if (fp != NULL) { if (png_image_write_to_stdio(image, fp, convert_to_8bit, buffer, row_stride, colormap)) { 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 /* PNG_STDIO_SUPPORTED */ #endif /* SIMPLIFIED_WRITE */ #endif /* PNG_WRITE_SUPPORTED */