| |
| /* pngread.c - read a PNG file |
| * |
| * Last changed in libpng 1.4.21 [August 24, 2017] |
| * Copyright (c) 1998-2002,2004,2006-2014,2017 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 |
| * |
| * This file contains routines that an application calls directly to |
| * read a PNG file or stream. |
| */ |
| |
| #define PNG_NO_PEDANTIC_WARNINGS |
| #include "png.h" |
| #ifdef PNG_READ_SUPPORTED |
| #include "pngpriv.h" |
| |
| |
| /* Create a PNG structure for reading, and allocate any memory needed. */ |
| png_structp PNGAPI |
| png_create_read_struct(png_const_charp user_png_ver, png_voidp error_ptr, |
| png_error_ptr error_fn, png_error_ptr warn_fn) |
| { |
| |
| #ifdef PNG_USER_MEM_SUPPORTED |
| return (png_create_read_struct_2(user_png_ver, error_ptr, error_fn, |
| warn_fn, NULL, NULL, NULL)); |
| } |
| |
| /* Alternate create PNG structure for reading, and allocate any memory |
| * needed. |
| */ |
| png_structp PNGAPI |
| png_create_read_struct_2(png_const_charp user_png_ver, png_voidp error_ptr, |
| png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr, |
| png_malloc_ptr malloc_fn, png_free_ptr free_fn) |
| { |
| #endif /* PNG_USER_MEM_SUPPORTED */ |
| |
| #ifdef PNG_SETJMP_SUPPORTED |
| volatile |
| #endif |
| png_structp png_ptr; |
| volatile int png_cleanup_needed = 0; |
| |
| #ifdef PNG_SETJMP_SUPPORTED |
| #ifdef USE_FAR_KEYWORD |
| jmp_buf jmpbuf; |
| #endif |
| #endif |
| |
| png_debug(1, "in png_create_read_struct"); |
| |
| #ifdef PNG_USER_MEM_SUPPORTED |
| png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG, |
| malloc_fn, mem_ptr); |
| #else |
| png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG); |
| #endif |
| if (png_ptr == NULL) |
| return (NULL); |
| |
| /* Added at libpng-1.2.6 */ |
| #ifdef PNG_USER_LIMITS_SUPPORTED |
| png_ptr->user_width_max = PNG_USER_WIDTH_MAX; |
| png_ptr->user_height_max = PNG_USER_HEIGHT_MAX; |
| |
| /* Added at libpng-1.2.43 and 1.4.0 */ |
| png_ptr->user_chunk_cache_max = PNG_USER_CHUNK_CACHE_MAX; |
| |
| /* Added at libpng-1.4.1 */ |
| png_ptr->user_chunk_malloc_max = PNG_USER_CHUNK_MALLOC_MAX; |
| #endif |
| |
| #ifdef PNG_SETJMP_SUPPORTED |
| /* Applications that neglect to set up their own setjmp() and then |
| encounter a png_error() will longjmp here. Since the jmpbuf is |
| then meaningless we abort instead of returning. */ |
| #ifdef USE_FAR_KEYWORD |
| if (setjmp(jmpbuf)) |
| #else |
| if (setjmp(png_jmpbuf(png_ptr))) /* Sets longjmp to match setjmp */ |
| #endif |
| PNG_ABORT(); |
| #ifdef USE_FAR_KEYWORD |
| png_memcpy(png_jmpbuf(png_ptr), jmpbuf, png_sizeof(jmp_buf)); |
| #endif |
| #endif /* PNG_SETJMP_SUPPORTED */ |
| |
| #ifdef PNG_USER_MEM_SUPPORTED |
| png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn); |
| #endif |
| |
| png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn); |
| |
| if (user_png_ver != NULL) |
| { |
| int i = -1; |
| int found_dots = 0; |
| |
| do |
| { |
| i++; |
| if (user_png_ver[i] != PNG_LIBPNG_VER_STRING[i]) |
| png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH; |
| if (user_png_ver[i] == '.') |
| found_dots++; |
| } while (found_dots < 2 && user_png_ver[i] != 0 && |
| PNG_LIBPNG_VER_STRING[i] != 0); |
| } |
| else |
| png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH; |
| |
| |
| if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH) |
| { |
| /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so |
| * we must recompile any applications that use any older library version. |
| * For versions after libpng 1.0, we will be compatible, so we need |
| * only check the first digit. |
| */ |
| if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] || |
| (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) || |
| (user_png_ver[0] == '0' && user_png_ver[2] < '9')) |
| { |
| #ifdef PNG_STDIO_SUPPORTED |
| char msg[80]; |
| if (user_png_ver) |
| { |
| png_snprintf(msg, 80, |
| "Application was compiled with png.h from libpng-%.20s", |
| user_png_ver); |
| png_warning(png_ptr, msg); |
| } |
| png_snprintf(msg, 80, |
| "Application is running with png.c from libpng-%.20s", |
| png_libpng_ver); |
| png_warning(png_ptr, msg); |
| #endif |
| #ifdef PNG_ERROR_NUMBERS_SUPPORTED |
| png_ptr->flags = 0; |
| #endif |
| png_warning(png_ptr, |
| "Incompatible libpng version in application and library"); |
| |
| png_cleanup_needed = 1; |
| } |
| } |
| |
| if (!png_cleanup_needed) |
| { |
| /* Initialize zbuf - compression buffer */ |
| png_ptr->zbuf_size = PNG_ZBUF_SIZE; |
| png_ptr->zbuf = (png_bytep)png_malloc_warn(png_ptr, |
| png_ptr->zbuf_size); |
| if (png_ptr->zbuf == NULL) |
| png_cleanup_needed = 1; |
| } |
| png_ptr->zstream.zalloc = png_zalloc; |
| png_ptr->zstream.zfree = png_zfree; |
| png_ptr->zstream.opaque = (voidpf)png_ptr; |
| |
| if (!png_cleanup_needed) |
| { |
| switch (inflateInit(&png_ptr->zstream)) |
| { |
| case Z_OK: /* Do nothing */ break; |
| case Z_MEM_ERROR: |
| case Z_STREAM_ERROR: png_warning(png_ptr, "zlib memory error"); |
| png_cleanup_needed = 1; break; |
| case Z_VERSION_ERROR: png_warning(png_ptr, "zlib version error"); |
| png_cleanup_needed = 1; break; |
| default: png_warning(png_ptr, "Unknown zlib error"); |
| png_cleanup_needed = 1; |
| } |
| } |
| |
| if (png_cleanup_needed) |
| { |
| /* 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); |
| } |
| |
| png_ptr->zstream.next_out = png_ptr->zbuf; |
| png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; |
| |
| png_set_read_fn(png_ptr, NULL, NULL); |
| |
| |
| return (png_ptr); |
| } |
| |
| |
| #ifdef PNG_SEQUENTIAL_READ_SUPPORTED |
| /* Read the information before the actual image data. This has been |
| * changed in v0.90 to allow reading a file that already has the magic |
| * bytes read from the stream. You can tell libpng how many bytes have |
| * been read from the beginning of the stream (up to the maximum of 8) |
| * via png_set_sig_bytes(), and we will only check the remaining bytes |
| * here. The application can then have access to the signature bytes we |
| * read if it is determined that this isn't a valid PNG file. |
| */ |
| void PNGAPI |
| png_read_info(png_structp png_ptr, png_infop info_ptr) |
| { |
| png_debug(1, "in png_read_info"); |
| |
| if (png_ptr == NULL || info_ptr == NULL) |
| return; |
| |
| /* Read and check the PNG file signature. */ |
| png_read_sig(png_ptr, info_ptr); |
| |
| for (;;) |
| { |
| PNG_IHDR; |
| PNG_IDAT; |
| PNG_IEND; |
| PNG_PLTE; |
| #ifdef PNG_READ_bKGD_SUPPORTED |
| PNG_bKGD; |
| #endif |
| #ifdef PNG_READ_cHRM_SUPPORTED |
| PNG_cHRM; |
| #endif |
| #ifdef PNG_READ_gAMA_SUPPORTED |
| PNG_gAMA; |
| #endif |
| #ifdef PNG_READ_hIST_SUPPORTED |
| PNG_hIST; |
| #endif |
| #ifdef PNG_READ_iCCP_SUPPORTED |
| PNG_iCCP; |
| #endif |
| #ifdef PNG_READ_iTXt_SUPPORTED |
| PNG_iTXt; |
| #endif |
| #ifdef PNG_READ_oFFs_SUPPORTED |
| PNG_oFFs; |
| #endif |
| #ifdef PNG_READ_pCAL_SUPPORTED |
| PNG_pCAL; |
| #endif |
| #ifdef PNG_READ_pHYs_SUPPORTED |
| PNG_pHYs; |
| #endif |
| #ifdef PNG_READ_sBIT_SUPPORTED |
| PNG_sBIT; |
| #endif |
| #ifdef PNG_READ_sCAL_SUPPORTED |
| PNG_sCAL; |
| #endif |
| #ifdef PNG_READ_sPLT_SUPPORTED |
| PNG_sPLT; |
| #endif |
| #ifdef PNG_READ_sRGB_SUPPORTED |
| PNG_sRGB; |
| #endif |
| #ifdef PNG_READ_tEXt_SUPPORTED |
| PNG_tEXt; |
| #endif |
| #ifdef PNG_READ_tIME_SUPPORTED |
| PNG_tIME; |
| #endif |
| #ifdef PNG_READ_tRNS_SUPPORTED |
| PNG_tRNS; |
| #endif |
| #ifdef PNG_READ_zTXt_SUPPORTED |
| PNG_zTXt; |
| #endif |
| png_uint_32 length = png_read_chunk_header(png_ptr); |
| PNG_CONST png_bytep chunk_name = png_ptr->chunk_name; |
| |
| /* This should be a binary subdivision search or a hash for |
| * matching the chunk name rather than a linear search. |
| */ |
| if (!png_memcmp(chunk_name, png_IDAT, 4)) |
| if (png_ptr->mode & PNG_AFTER_IDAT) |
| png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT; |
| |
| if (!png_memcmp(chunk_name, png_IHDR, 4)) |
| png_handle_IHDR(png_ptr, info_ptr, length); |
| else if (!png_memcmp(chunk_name, png_IEND, 4)) |
| png_handle_IEND(png_ptr, info_ptr, length); |
| #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED |
| else if (png_handle_as_unknown(png_ptr, chunk_name)) |
| { |
| if (!png_memcmp(chunk_name, png_IDAT, 4)) |
| png_ptr->mode |= PNG_HAVE_IDAT; |
| png_handle_unknown(png_ptr, info_ptr, length); |
| if (!png_memcmp(chunk_name, png_PLTE, 4)) |
| png_ptr->mode |= PNG_HAVE_PLTE; |
| else if (!png_memcmp(chunk_name, png_IDAT, 4)) |
| { |
| if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
| png_error(png_ptr, "Missing IHDR before IDAT"); |
| else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && |
| !(png_ptr->mode & PNG_HAVE_PLTE)) |
| png_error(png_ptr, "Missing PLTE before IDAT"); |
| break; |
| } |
| } |
| #endif |
| else if (!png_memcmp(chunk_name, png_PLTE, 4)) |
| png_handle_PLTE(png_ptr, info_ptr, length); |
| else if (!png_memcmp(chunk_name, png_IDAT, 4)) |
| { |
| if (!(png_ptr->mode & PNG_HAVE_IHDR)) |
| png_error(png_ptr, "Missing IHDR before IDAT"); |
| else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && |
| !(png_ptr->mode & PNG_HAVE_PLTE)) |
| png_error(png_ptr, "Missing PLTE before IDAT"); |
| |
| png_ptr->idat_size = length; |
| png_ptr->mode |= PNG_HAVE_IDAT; |
| break; |
| } |
| #ifdef PNG_READ_bKGD_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_bKGD, 4)) |
| png_handle_bKGD(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_cHRM_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_cHRM, 4)) |
| png_handle_cHRM(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_gAMA_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_gAMA, 4)) |
| png_handle_gAMA(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_hIST_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_hIST, 4)) |
| png_handle_hIST(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_oFFs_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_oFFs, 4)) |
| png_handle_oFFs(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_pCAL_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_pCAL, 4)) |
| png_handle_pCAL(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_sCAL_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_sCAL, 4)) |
| png_handle_sCAL(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_pHYs_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_pHYs, 4)) |
| png_handle_pHYs(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_sBIT_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_sBIT, 4)) |
| png_handle_sBIT(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_sRGB_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_sRGB, 4)) |
| png_handle_sRGB(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_iCCP_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_iCCP, 4)) |
| png_handle_iCCP(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_sPLT_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_sPLT, 4)) |
| png_handle_sPLT(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_tEXt_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_tEXt, 4)) |
| png_handle_tEXt(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_tIME_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_tIME, 4)) |
| png_handle_tIME(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_tRNS_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_tRNS, 4)) |
| png_handle_tRNS(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_zTXt_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_zTXt, 4)) |
| png_handle_zTXt(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_iTXt_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_iTXt, 4)) |
| png_handle_iTXt(png_ptr, info_ptr, length); |
| #endif |
| else |
| png_handle_unknown(png_ptr, info_ptr, length); |
| } |
| } |
| #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */ |
| |
| /* Optional call to update the users info_ptr structure */ |
| void PNGAPI |
| png_read_update_info(png_structp png_ptr, png_infop info_ptr) |
| { |
| png_debug(1, "in png_read_update_info"); |
| |
| if (png_ptr == NULL) |
| return; |
| if (!(png_ptr->flags & PNG_FLAG_ROW_INIT)) |
| png_read_start_row(png_ptr); |
| else |
| png_warning(png_ptr, |
| "Ignoring extra png_read_update_info() call; row buffer not reallocated"); |
| |
| png_read_transform_info(png_ptr, info_ptr); |
| } |
| |
| #ifdef PNG_SEQUENTIAL_READ_SUPPORTED |
| /* Initialize palette, background, etc, after transformations |
| * are set, but before any reading takes place. This allows |
| * the user to obtain a gamma-corrected palette, for example. |
| * If the user doesn't call this, we will do it ourselves. |
| */ |
| void PNGAPI |
| png_start_read_image(png_structp png_ptr) |
| { |
| png_debug(1, "in png_start_read_image"); |
| |
| if (png_ptr == NULL) |
| return; |
| if (!(png_ptr->flags & PNG_FLAG_ROW_INIT)) |
| png_read_start_row(png_ptr); |
| } |
| #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */ |
| |
| #ifdef PNG_SEQUENTIAL_READ_SUPPORTED |
| void PNGAPI |
| png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row) |
| { |
| PNG_IDAT; |
| #ifdef PNG_READ_INTERLACING_SUPPORTED |
| PNG_CONST int png_pass_dsp_mask[7] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, |
| 0xff}; |
| PNG_CONST int png_pass_mask[7] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff}; |
| int ret; |
| #endif |
| |
| if (png_ptr == NULL) |
| return; |
| |
| png_debug2(1, "in png_read_row (row %lu, pass %d)", |
| (unsigned long) png_ptr->row_number, png_ptr->pass); |
| |
| if (!(png_ptr->flags & PNG_FLAG_ROW_INIT)) |
| png_read_start_row(png_ptr); |
| if (png_ptr->row_number == 0 && png_ptr->pass == 0) |
| { |
| /* 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_READ_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_READ_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_READ_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_READ_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_READ_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_READ_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_READ_SWAP_SUPPORTED is not defined"); |
| #endif |
| } |
| |
| #ifdef PNG_READ_INTERLACING_SUPPORTED |
| /* If interlaced and we do not need a new row, combine row and return */ |
| if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE)) |
| { |
| switch (png_ptr->pass) |
| { |
| case 0: |
| if (png_ptr->row_number & 0x07) |
| { |
| if (dsp_row != NULL) |
| png_combine_row(png_ptr, dsp_row, |
| png_pass_dsp_mask[png_ptr->pass]); |
| png_read_finish_row(png_ptr); |
| return; |
| } |
| break; |
| |
| case 1: |
| if ((png_ptr->row_number & 0x07) || png_ptr->width < 5) |
| { |
| if (dsp_row != NULL) |
| png_combine_row(png_ptr, dsp_row, |
| png_pass_dsp_mask[png_ptr->pass]); |
| png_read_finish_row(png_ptr); |
| return; |
| } |
| break; |
| |
| case 2: |
| if ((png_ptr->row_number & 0x07) != 4) |
| { |
| if (dsp_row != NULL && (png_ptr->row_number & 4)) |
| png_combine_row(png_ptr, dsp_row, |
| png_pass_dsp_mask[png_ptr->pass]); |
| png_read_finish_row(png_ptr); |
| return; |
| } |
| break; |
| |
| case 3: |
| if ((png_ptr->row_number & 3) || png_ptr->width < 3) |
| { |
| if (dsp_row != NULL) |
| png_combine_row(png_ptr, dsp_row, |
| png_pass_dsp_mask[png_ptr->pass]); |
| png_read_finish_row(png_ptr); |
| return; |
| } |
| break; |
| |
| case 4: |
| if ((png_ptr->row_number & 3) != 2) |
| { |
| if (dsp_row != NULL && (png_ptr->row_number & 2)) |
| png_combine_row(png_ptr, dsp_row, |
| png_pass_dsp_mask[png_ptr->pass]); |
| png_read_finish_row(png_ptr); |
| return; |
| } |
| break; |
| |
| case 5: |
| if ((png_ptr->row_number & 1) || png_ptr->width < 2) |
| { |
| if (dsp_row != NULL) |
| png_combine_row(png_ptr, dsp_row, |
| png_pass_dsp_mask[png_ptr->pass]); |
| png_read_finish_row(png_ptr); |
| return; |
| } |
| break; |
| |
| default: |
| case 6: |
| if (!(png_ptr->row_number & 1)) |
| { |
| png_read_finish_row(png_ptr); |
| return; |
| } |
| break; |
| } |
| } |
| #endif |
| |
| if (!(png_ptr->mode & PNG_HAVE_IDAT)) |
| png_error(png_ptr, "Invalid attempt to read row data"); |
| |
| png_ptr->zstream.next_out = png_ptr->row_buf; |
| png_ptr->zstream.avail_out = |
| (uInt)(PNG_ROWBYTES(png_ptr->pixel_depth, |
| png_ptr->iwidth) + 1); |
| do |
| { |
| if (!(png_ptr->zstream.avail_in)) |
| { |
| while (!png_ptr->idat_size) |
| { |
| png_crc_finish(png_ptr, 0); |
| |
| png_ptr->idat_size = png_read_chunk_header(png_ptr); |
| if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) |
| png_error(png_ptr, "Not enough image data"); |
| } |
| png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size; |
| png_ptr->zstream.next_in = png_ptr->zbuf; |
| if (png_ptr->zbuf_size > png_ptr->idat_size) |
| png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size; |
| png_crc_read(png_ptr, png_ptr->zbuf, |
| (png_size_t)png_ptr->zstream.avail_in); |
| png_ptr->idat_size -= png_ptr->zstream.avail_in; |
| } |
| ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); |
| if (ret == Z_STREAM_END) |
| { |
| if (png_ptr->zstream.avail_out || png_ptr->zstream.avail_in || |
| png_ptr->idat_size) |
| png_benign_error(png_ptr, "Extra compressed data"); |
| png_ptr->mode |= PNG_AFTER_IDAT; |
| png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; |
| break; |
| } |
| if (ret != Z_OK) |
| png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg : |
| "Decompression error"); |
| |
| } while (png_ptr->zstream.avail_out); |
| |
| png_ptr->row_info.color_type = png_ptr->color_type; |
| png_ptr->row_info.width = png_ptr->iwidth; |
| png_ptr->row_info.channels = png_ptr->channels; |
| png_ptr->row_info.bit_depth = png_ptr->bit_depth; |
| png_ptr->row_info.pixel_depth = png_ptr->pixel_depth; |
| png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth, |
| png_ptr->row_info.width); |
| |
| if (png_ptr->row_buf[0]) |
| png_read_filter_row(png_ptr, &(png_ptr->row_info), |
| png_ptr->row_buf + 1, png_ptr->prev_row + 1, |
| (int)(png_ptr->row_buf[0])); |
| |
| png_memcpy(png_ptr->prev_row, png_ptr->row_buf, png_ptr->rowbytes + 1); |
| |
| #ifdef PNG_MNG_FEATURES_SUPPORTED |
| if ((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) && |
| (png_ptr->filter_type == PNG_INTRAPIXEL_DIFFERENCING)) |
| { |
| /* Intrapixel differencing */ |
| png_do_read_intrapixel(&(png_ptr->row_info), png_ptr->row_buf + 1); |
| } |
| #endif |
| |
| |
| if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA)) |
| png_do_read_transformations(png_ptr); |
| |
| #ifdef PNG_READ_INTERLACING_SUPPORTED |
| /* Blow up interlaced rows to full size */ |
| if (png_ptr->interlaced && |
| (png_ptr->transformations & PNG_INTERLACE)) |
| { |
| if (png_ptr->pass < 6) |
| /* Old interface (pre-1.0.9): |
| * png_do_read_interlace(&(png_ptr->row_info), |
| * png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations); |
| */ |
| png_do_read_interlace(png_ptr); |
| |
| if (dsp_row != NULL) |
| png_combine_row(png_ptr, dsp_row, |
| png_pass_dsp_mask[png_ptr->pass]); |
| if (row != NULL) |
| png_combine_row(png_ptr, row, |
| png_pass_mask[png_ptr->pass]); |
| } |
| else |
| #endif |
| { |
| if (row != NULL) |
| png_combine_row(png_ptr, row, 0xff); |
| if (dsp_row != NULL) |
| png_combine_row(png_ptr, dsp_row, 0xff); |
| } |
| png_read_finish_row(png_ptr); |
| |
| if (png_ptr->read_row_fn != NULL) |
| (*(png_ptr->read_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass); |
| } |
| #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */ |
| |
| #ifdef PNG_SEQUENTIAL_READ_SUPPORTED |
| /* Read one or more rows of image data. If the image is interlaced, |
| * and png_set_interlace_handling() has been called, the rows need to |
| * contain the contents of the rows from the previous pass. If the |
| * image has alpha or transparency, and png_handle_alpha()[*] has been |
| * called, the rows contents must be initialized to the contents of the |
| * screen. |
| * |
| * "row" holds the actual image, and pixels are placed in it |
| * as they arrive. If the image is displayed after each pass, it will |
| * appear to "sparkle" in. "display_row" can be used to display a |
| * "chunky" progressive image, with finer detail added as it becomes |
| * available. If you do not want this "chunky" display, you may pass |
| * NULL for display_row. If you do not want the sparkle display, and |
| * you have not called png_handle_alpha(), you may pass NULL for rows. |
| * If you have called png_handle_alpha(), and the image has either an |
| * alpha channel or a transparency chunk, you must provide a buffer for |
| * rows. In this case, you do not have to provide a display_row buffer |
| * also, but you may. If the image is not interlaced, or if you have |
| * not called png_set_interlace_handling(), the display_row buffer will |
| * be ignored, so pass NULL to it. |
| * |
| * [*] png_handle_alpha() does not exist yet, as of this version of libpng |
| */ |
| |
| void PNGAPI |
| png_read_rows(png_structp png_ptr, png_bytepp row, |
| png_bytepp display_row, png_uint_32 num_rows) |
| { |
| png_uint_32 i; |
| png_bytepp rp; |
| png_bytepp dp; |
| |
| png_debug(1, "in png_read_rows"); |
| |
| if (png_ptr == NULL) |
| return; |
| rp = row; |
| dp = display_row; |
| if (rp != NULL && dp != NULL) |
| for (i = 0; i < num_rows; i++) |
| { |
| png_bytep rptr = *rp++; |
| png_bytep dptr = *dp++; |
| |
| png_read_row(png_ptr, rptr, dptr); |
| } |
| else if (rp != NULL) |
| for (i = 0; i < num_rows; i++) |
| { |
| png_bytep rptr = *rp; |
| png_read_row(png_ptr, rptr, NULL); |
| rp++; |
| } |
| else if (dp != NULL) |
| for (i = 0; i < num_rows; i++) |
| { |
| png_bytep dptr = *dp; |
| png_read_row(png_ptr, NULL, dptr); |
| dp++; |
| } |
| } |
| #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */ |
| |
| #ifdef PNG_SEQUENTIAL_READ_SUPPORTED |
| /* Read the entire image. If the image has an alpha channel or a tRNS |
| * chunk, and you have called png_handle_alpha()[*], you will need to |
| * initialize the image to the current image that PNG will be overlaying. |
| * We set the num_rows again here, in case it was incorrectly set in |
| * png_read_start_row() by a call to png_read_update_info() or |
| * png_start_read_image() if png_set_interlace_handling() wasn't called |
| * prior to either of these functions like it should have been. You can |
| * only call this function once. If you desire to have an image for |
| * each pass of a interlaced image, use png_read_rows() instead. |
| * |
| * [*] png_handle_alpha() does not exist yet, as of this version of libpng |
| */ |
| void PNGAPI |
| png_read_image(png_structp png_ptr, png_bytepp image) |
| { |
| png_uint_32 i, image_height; |
| int pass, j; |
| png_bytepp rp; |
| |
| png_debug(1, "in png_read_image"); |
| |
| if (png_ptr == NULL) |
| return; |
| |
| #ifdef PNG_READ_INTERLACING_SUPPORTED |
| pass = png_set_interlace_handling(png_ptr); |
| #else |
| if (png_ptr->interlaced) |
| png_error(png_ptr, |
| "Cannot read interlaced image -- interlace handler disabled"); |
| pass = 1; |
| #endif |
| |
| |
| image_height=png_ptr->height; |
| png_ptr->num_rows = image_height; /* Make sure this is set correctly */ |
| |
| for (j = 0; j < pass; j++) |
| { |
| rp = image; |
| for (i = 0; i < image_height; i++) |
| { |
| png_read_row(png_ptr, *rp, NULL); |
| rp++; |
| } |
| } |
| } |
| #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */ |
| |
| #ifdef PNG_SEQUENTIAL_READ_SUPPORTED |
| /* Read the end of the PNG file. Will not read past the end of the |
| * file, will verify the end is accurate, and will read any comments |
| * or time information at the end of the file, if info is not NULL. |
| */ |
| void PNGAPI |
| png_read_end(png_structp png_ptr, png_infop info_ptr) |
| { |
| png_debug(1, "in png_read_end"); |
| |
| if (png_ptr == NULL) |
| return; |
| png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */ |
| |
| do |
| { |
| PNG_IHDR; |
| PNG_IDAT; |
| PNG_IEND; |
| PNG_PLTE; |
| #ifdef PNG_READ_bKGD_SUPPORTED |
| PNG_bKGD; |
| #endif |
| #ifdef PNG_READ_cHRM_SUPPORTED |
| PNG_cHRM; |
| #endif |
| #ifdef PNG_READ_gAMA_SUPPORTED |
| PNG_gAMA; |
| #endif |
| #ifdef PNG_READ_hIST_SUPPORTED |
| PNG_hIST; |
| #endif |
| #ifdef PNG_READ_iCCP_SUPPORTED |
| PNG_iCCP; |
| #endif |
| #ifdef PNG_READ_iTXt_SUPPORTED |
| PNG_iTXt; |
| #endif |
| #ifdef PNG_READ_oFFs_SUPPORTED |
| PNG_oFFs; |
| #endif |
| #ifdef PNG_READ_pCAL_SUPPORTED |
| PNG_pCAL; |
| #endif |
| #ifdef PNG_READ_pHYs_SUPPORTED |
| PNG_pHYs; |
| #endif |
| #ifdef PNG_READ_sBIT_SUPPORTED |
| PNG_sBIT; |
| #endif |
| #ifdef PNG_READ_sCAL_SUPPORTED |
| PNG_sCAL; |
| #endif |
| #ifdef PNG_READ_sPLT_SUPPORTED |
| PNG_sPLT; |
| #endif |
| #ifdef PNG_READ_sRGB_SUPPORTED |
| PNG_sRGB; |
| #endif |
| #ifdef PNG_READ_tEXt_SUPPORTED |
| PNG_tEXt; |
| #endif |
| #ifdef PNG_READ_tIME_SUPPORTED |
| PNG_tIME; |
| #endif |
| #ifdef PNG_READ_tRNS_SUPPORTED |
| PNG_tRNS; |
| #endif |
| #ifdef PNG_READ_zTXt_SUPPORTED |
| PNG_zTXt; |
| #endif |
| png_uint_32 length = png_read_chunk_header(png_ptr); |
| PNG_CONST png_bytep chunk_name = png_ptr->chunk_name; |
| |
| if (!png_memcmp(chunk_name, png_IHDR, 4)) |
| png_handle_IHDR(png_ptr, info_ptr, length); |
| else if (!png_memcmp(chunk_name, png_IEND, 4)) |
| png_handle_IEND(png_ptr, info_ptr, length); |
| #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED |
| else if (png_handle_as_unknown(png_ptr, chunk_name)) |
| { |
| if (!png_memcmp(chunk_name, png_IDAT, 4)) |
| { |
| if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT)) |
| png_benign_error(png_ptr, "Too many IDATs found"); |
| } |
| png_handle_unknown(png_ptr, info_ptr, length); |
| if (!png_memcmp(chunk_name, png_PLTE, 4)) |
| png_ptr->mode |= PNG_HAVE_PLTE; |
| } |
| #endif |
| else if (!png_memcmp(chunk_name, png_IDAT, 4)) |
| { |
| /* Zero length IDATs are legal after the last IDAT has been |
| * read, but not after other chunks have been read. |
| */ |
| if ((length > 0) || (png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT)) |
| png_benign_error(png_ptr, "Too many IDATs found"); |
| png_crc_finish(png_ptr, length); |
| } |
| else if (!png_memcmp(chunk_name, png_PLTE, 4)) |
| png_handle_PLTE(png_ptr, info_ptr, length); |
| #ifdef PNG_READ_bKGD_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_bKGD, 4)) |
| png_handle_bKGD(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_cHRM_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_cHRM, 4)) |
| png_handle_cHRM(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_gAMA_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_gAMA, 4)) |
| png_handle_gAMA(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_hIST_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_hIST, 4)) |
| png_handle_hIST(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_oFFs_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_oFFs, 4)) |
| png_handle_oFFs(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_pCAL_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_pCAL, 4)) |
| png_handle_pCAL(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_sCAL_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_sCAL, 4)) |
| png_handle_sCAL(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_pHYs_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_pHYs, 4)) |
| png_handle_pHYs(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_sBIT_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_sBIT, 4)) |
| png_handle_sBIT(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_sRGB_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_sRGB, 4)) |
| png_handle_sRGB(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_iCCP_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_iCCP, 4)) |
| png_handle_iCCP(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_sPLT_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_sPLT, 4)) |
| png_handle_sPLT(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_tEXt_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_tEXt, 4)) |
| png_handle_tEXt(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_tIME_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_tIME, 4)) |
| png_handle_tIME(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_tRNS_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_tRNS, 4)) |
| png_handle_tRNS(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_zTXt_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_zTXt, 4)) |
| png_handle_zTXt(png_ptr, info_ptr, length); |
| #endif |
| #ifdef PNG_READ_iTXt_SUPPORTED |
| else if (!png_memcmp(chunk_name, png_iTXt, 4)) |
| png_handle_iTXt(png_ptr, info_ptr, length); |
| #endif |
| else |
| png_handle_unknown(png_ptr, info_ptr, length); |
| } while (!(png_ptr->mode & PNG_HAVE_IEND)); |
| } |
| #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */ |
| |
| /* Free all memory used by the read */ |
| void PNGAPI |
| png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr, |
| png_infopp end_info_ptr_ptr) |
| { |
| png_structp png_ptr = NULL; |
| png_infop info_ptr = NULL, end_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_read_struct"); |
| |
| if (png_ptr_ptr != NULL) |
| png_ptr = *png_ptr_ptr; |
| if (png_ptr == NULL) |
| return; |
| |
| #ifdef PNG_USER_MEM_SUPPORTED |
| free_fn = png_ptr->free_fn; |
| mem_ptr = png_ptr->mem_ptr; |
| #endif |
| |
| if (info_ptr_ptr != NULL) |
| info_ptr = *info_ptr_ptr; |
| |
| if (end_info_ptr_ptr != NULL) |
| end_info_ptr = *end_info_ptr_ptr; |
| |
| png_read_destroy(png_ptr, info_ptr, end_info_ptr); |
| |
| if (info_ptr != NULL) |
| { |
| #ifdef PNG_TEXT_SUPPORTED |
| png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, -1); |
| #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 (end_info_ptr != NULL) |
| { |
| #ifdef PNG_READ_TEXT_SUPPORTED |
| png_free_data(png_ptr, end_info_ptr, PNG_FREE_TEXT, -1); |
| #endif |
| #ifdef PNG_USER_MEM_SUPPORTED |
| png_destroy_struct_2((png_voidp)end_info_ptr, (png_free_ptr)free_fn, |
| (png_voidp)mem_ptr); |
| #else |
| png_destroy_struct((png_voidp)end_info_ptr); |
| #endif |
| *end_info_ptr_ptr = NULL; |
| } |
| |
| if (png_ptr != 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 |
| *png_ptr_ptr = NULL; |
| } |
| } |
| |
| /* Free all memory used by the read (old method) */ |
| void /* PRIVATE */ |
| png_read_destroy(png_structp png_ptr, png_infop info_ptr, |
| png_infop end_info_ptr) |
| { |
| #ifdef PNG_SETJMP_SUPPORTED |
| jmp_buf tmp_jmp; |
| #endif |
| png_error_ptr error_fn; |
| png_error_ptr warning_fn; |
| png_voidp error_ptr; |
| #ifdef PNG_USER_MEM_SUPPORTED |
| png_free_ptr free_fn; |
| #endif |
| |
| png_debug(1, "in png_read_destroy"); |
| |
| if (info_ptr != NULL) |
| png_info_destroy(png_ptr, info_ptr); |
| |
| if (end_info_ptr != NULL) |
| png_info_destroy(png_ptr, end_info_ptr); |
| |
| png_free(png_ptr, png_ptr->zbuf); |
| png_free(png_ptr, png_ptr->big_row_buf); |
| png_free(png_ptr, png_ptr->prev_row); |
| png_free(png_ptr, png_ptr->chunkdata); |
| #ifdef PNG_READ_QUANTIZE_SUPPORTED |
| png_free(png_ptr, png_ptr->palette_lookup); |
| png_free(png_ptr, png_ptr->quantize_index); |
| #endif |
| #ifdef PNG_READ_GAMMA_SUPPORTED |
| png_free(png_ptr, png_ptr->gamma_table); |
| #endif |
| #ifdef PNG_READ_BACKGROUND_SUPPORTED |
| png_free(png_ptr, png_ptr->gamma_from_1); |
| png_free(png_ptr, png_ptr->gamma_to_1); |
| #endif |
| if (png_ptr->free_me & PNG_FREE_PLTE) |
| png_zfree(png_ptr, png_ptr->palette); |
| png_ptr->free_me &= ~PNG_FREE_PLTE; |
| #if defined(PNG_tRNS_SUPPORTED) || \ |
| defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) |
| if (png_ptr->free_me & PNG_FREE_TRNS) |
| png_free(png_ptr, png_ptr->trans_alpha); |
| png_ptr->free_me &= ~PNG_FREE_TRNS; |
| #endif |
| #ifdef PNG_READ_hIST_SUPPORTED |
| if (png_ptr->free_me & PNG_FREE_HIST) |
| png_free(png_ptr, png_ptr->hist); |
| png_ptr->free_me &= ~PNG_FREE_HIST; |
| #endif |
| #ifdef PNG_READ_GAMMA_SUPPORTED |
| if (png_ptr->gamma_16_table != NULL) |
| { |
| int i; |
| int istop = (1 << (8 - png_ptr->gamma_shift)); |
| for (i = 0; i < istop; i++) |
| { |
| png_free(png_ptr, png_ptr->gamma_16_table[i]); |
| } |
| png_free(png_ptr, png_ptr->gamma_16_table); |
| } |
| #ifdef PNG_READ_BACKGROUND_SUPPORTED |
| if (png_ptr->gamma_16_from_1 != NULL) |
| { |
| int i; |
| int istop = (1 << (8 - png_ptr->gamma_shift)); |
| for (i = 0; i < istop; i++) |
| { |
| png_free(png_ptr, png_ptr->gamma_16_from_1[i]); |
| } |
| png_free(png_ptr, png_ptr->gamma_16_from_1); |
| } |
| if (png_ptr->gamma_16_to_1 != NULL) |
| { |
| int i; |
| int istop = (1 << (8 - png_ptr->gamma_shift)); |
| for (i = 0; i < istop; i++) |
| { |
| png_free(png_ptr, png_ptr->gamma_16_to_1[i]); |
| } |
| png_free(png_ptr, png_ptr->gamma_16_to_1); |
| } |
| #endif |
| #endif |
| #ifdef PNG_TIME_RFC1123_SUPPORTED |
| png_free(png_ptr, png_ptr->time_buffer); |
| #endif |
| |
| inflateEnd(&png_ptr->zstream); |
| #ifdef PNG_PROGRESSIVE_READ_SUPPORTED |
| png_free(png_ptr, png_ptr->save_buffer); |
| #endif |
| |
| /* Save the important info out of the png_struct, in case it is |
| * being used again. |
| */ |
| #ifdef PNG_SETJMP_SUPPORTED |
| png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof(jmp_buf)); |
| #endif |
| |
| error_fn = png_ptr->error_fn; |
| warning_fn = png_ptr->warning_fn; |
| error_ptr = png_ptr->error_ptr; |
| #ifdef PNG_USER_MEM_SUPPORTED |
| free_fn = png_ptr->free_fn; |
| #endif |
| |
| png_memset(png_ptr, 0, png_sizeof(png_struct)); |
| |
| png_ptr->error_fn = error_fn; |
| png_ptr->warning_fn = warning_fn; |
| png_ptr->error_ptr = error_ptr; |
| #ifdef PNG_USER_MEM_SUPPORTED |
| png_ptr->free_fn = free_fn; |
| #endif |
| |
| #ifdef PNG_SETJMP_SUPPORTED |
| png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof(jmp_buf)); |
| #endif |
| |
| } |
| |
| void PNGAPI |
| png_set_read_status_fn(png_structp png_ptr, png_read_status_ptr read_row_fn) |
| { |
| if (png_ptr == NULL) |
| return; |
| png_ptr->read_row_fn = read_row_fn; |
| } |
| |
| |
| #ifdef PNG_SEQUENTIAL_READ_SUPPORTED |
| #ifdef PNG_INFO_IMAGE_SUPPORTED |
| void PNGAPI |
| png_read_png(png_structp png_ptr, png_infop info_ptr, |
| int transforms, |
| voidp params) |
| { |
| int row; |
| |
| if (png_ptr == NULL) |
| return; |
| |
| /* png_read_info() gives us all of the information from the |
| * PNG file before the first IDAT (image data chunk). |
| */ |
| png_read_info(png_ptr, info_ptr); |
| if (info_ptr->height > PNG_UINT_32_MAX/png_sizeof(png_bytep)) |
| png_error(png_ptr, "Image is too high to process with png_read_png()"); |
| |
| /* -------------- image transformations start here ------------------- */ |
| |
| #ifdef PNG_READ_16_TO_8_SUPPORTED |
| /* Tell libpng to strip 16 bit/color files down to 8 bits per color. |
| */ |
| if (transforms & PNG_TRANSFORM_STRIP_16) |
| png_set_strip_16(png_ptr); |
| #endif |
| |
| #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED |
| /* Strip alpha bytes from the input data without combining with |
| * the background (not recommended). |
| */ |
| if (transforms & PNG_TRANSFORM_STRIP_ALPHA) |
| png_set_strip_alpha(png_ptr); |
| #endif |
| |
| #if defined(PNG_READ_PACK_SUPPORTED) && !defined(PNG_READ_EXPAND_SUPPORTED) |
| /* Extract multiple pixels with bit depths of 1, 2, or 4 from a single |
| * byte into separate bytes (useful for paletted and grayscale images). |
| */ |
| if (transforms & PNG_TRANSFORM_PACKING) |
| png_set_packing(png_ptr); |
| #endif |
| |
| #ifdef PNG_READ_PACKSWAP_SUPPORTED |
| /* Change the order of packed pixels to least significant bit first |
| * (not useful if you are using png_set_packing). |
| */ |
| if (transforms & PNG_TRANSFORM_PACKSWAP) |
| png_set_packswap(png_ptr); |
| #endif |
| |
| #ifdef PNG_READ_EXPAND_SUPPORTED |
| /* Expand paletted colors into true RGB triplets |
| * Expand grayscale images to full 8 bits from 1, 2, or 4 bits/pixel |
| * Expand paletted or RGB images with transparency to full alpha |
| * channels so the data will be available as RGBA quartets. |
| */ |
| if (transforms & PNG_TRANSFORM_EXPAND) |
| if ((png_ptr->bit_depth < 8) || |
| (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) || |
| (info_ptr->valid & PNG_INFO_tRNS)) |
| png_set_expand(png_ptr); |
| #endif |
| |
| /* We don't handle background color or gamma transformation or quantizing. |
| */ |
| |
| #ifdef PNG_READ_INVERT_SUPPORTED |
| /* Invert monochrome files to have 0 as white and 1 as black |
| */ |
| if (transforms & PNG_TRANSFORM_INVERT_MONO) |
| png_set_invert_mono(png_ptr); |
| #endif |
| |
| #ifdef PNG_READ_SHIFT_SUPPORTED |
| /* If you want to shift the pixel values from the range [0,255] or |
| * [0,65535] to the original [0,7] or [0,31], or whatever range the |
| * colors were originally in: |
| */ |
| if ((transforms & PNG_TRANSFORM_SHIFT) && (info_ptr->valid & PNG_INFO_sBIT)) |
| png_set_shift(png_ptr, &info_ptr->sig_bit); |
| #endif |
| |
| #ifdef PNG_READ_BGR_SUPPORTED |
| /* Flip the RGB pixels to BGR (or RGBA to BGRA) |
| */ |
| if (transforms & PNG_TRANSFORM_BGR) |
| png_set_bgr(png_ptr); |
| #endif |
| |
| #ifdef PNG_READ_SWAP_ALPHA_SUPPORTED |
| /* Swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) |
| */ |
| if (transforms & PNG_TRANSFORM_SWAP_ALPHA) |
| png_set_swap_alpha(png_ptr); |
| #endif |
| |
| #ifdef PNG_READ_SWAP_SUPPORTED |
| /* Swap bytes of 16 bit files to least significant byte first |
| */ |
| if (transforms & PNG_TRANSFORM_SWAP_ENDIAN) |
| png_set_swap(png_ptr); |
| #endif |
| |
| /* Added at libpng-1.2.41 */ |
| #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED |
| /* Invert the alpha channel from opacity to transparency |
| */ |
| if (transforms & PNG_TRANSFORM_INVERT_ALPHA) |
| png_set_invert_alpha(png_ptr); |
| #endif |
| |
| /* Added at libpng-1.2.41 */ |
| #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED |
| /* Expand grayscale image to RGB |
| */ |
| if (transforms & PNG_TRANSFORM_GRAY_TO_RGB) |
| png_set_gray_to_rgb(png_ptr); |
| #endif |
| |
| /* We don't handle adding filler bytes */ |
| |
| /* Optional call to gamma correct and add the background to the palette |
| * and update info structure. REQUIRED if you are expecting libpng to |
| * update the palette for you (i.e., you selected such a transform above). |
| */ |
| png_read_update_info(png_ptr, info_ptr); |
| |
| /* -------------- image transformations end here ------------------- */ |
| |
| png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0); |
| if (info_ptr->row_pointers == NULL) |
| { |
| png_uint_32 iptr; |
| |
| info_ptr->row_pointers = (png_bytepp)png_malloc(png_ptr, |
| info_ptr->height * png_sizeof(png_bytep)); |
| for (iptr=0; iptr<info_ptr->height; iptr++) |
| info_ptr->row_pointers[iptr] = NULL; |
| |
| info_ptr->free_me |= PNG_FREE_ROWS; |
| |
| for (row = 0; row < (int)info_ptr->height; row++) |
| info_ptr->row_pointers[row] = (png_bytep)png_malloc(png_ptr, |
| png_get_rowbytes(png_ptr, info_ptr)); |
| } |
| |
| png_read_image(png_ptr, info_ptr->row_pointers); |
| info_ptr->valid |= PNG_INFO_IDAT; |
| |
| /* Read rest of file, and get additional chunks in info_ptr - REQUIRED */ |
| png_read_end(png_ptr, info_ptr); |
| |
| PNG_UNUSED(transforms) /* Quiet compiler warnings */ |
| PNG_UNUSED(params) |
| |
| } |
| #endif /* PNG_INFO_IMAGE_SUPPORTED */ |
| #endif /* PNG_SEQUENTIAL_READ_SUPPORTED */ |
| #endif /* PNG_READ_SUPPORTED */ |