ref: 5622b0bbd878dbc34045cc6fd37cffa64461eabe
dir: /sys/src/cmd/gs/libpng/pngread.c/
/* pngread.c - read a PNG file * * libpng 1.2.8 - December 3, 2004 * For conditions of distribution and use, see copyright notice in png.h * Copyright (c) 1998-2004 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 file contains routines that an application calls directly to * read a PNG file or stream. */ #define PNG_INTERNAL #include "png.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, png_voidp_NULL, png_malloc_ptr_NULL, png_free_ptr_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 */ png_structp png_ptr; #ifdef PNG_SETJMP_SUPPORTED #ifdef USE_FAR_KEYWORD jmp_buf jmpbuf; #endif #endif int i; png_debug(1, "in png_create_read_struct\n"); #ifdef PNG_USER_MEM_SUPPORTED png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG, (png_malloc_ptr)malloc_fn, (png_voidp)mem_ptr); #else png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG); #endif if (png_ptr == NULL) return (NULL); #if !defined(PNG_1_0_X) #ifdef PNG_ASSEMBLER_CODE_SUPPORTED png_init_mmx_flags(png_ptr); /* 1.2.0 addition */ #endif #endif /* PNG_1_0_X */ /* added at libpng-1.2.6 */ #ifdef PNG_SET_USER_LIMITS_SUPPORTED png_ptr->user_width_max=PNG_USER_WIDTH_MAX; png_ptr->user_height_max=PNG_USER_HEIGHT_MAX; #endif #ifdef PNG_SETJMP_SUPPORTED #ifdef USE_FAR_KEYWORD if (setjmp(jmpbuf)) #else if (setjmp(png_ptr->jmpbuf)) #endif { png_free(png_ptr, png_ptr->zbuf); png_ptr->zbuf=NULL; #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); } #ifdef USE_FAR_KEYWORD png_memcpy(png_ptr->jmpbuf,jmpbuf,png_sizeof(jmp_buf)); #endif #endif #ifdef PNG_USER_MEM_SUPPORTED png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn); #endif png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn); i=0; do { if(user_png_ver[i] != png_libpng_ver[i]) png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH; } while (png_libpng_ver[i++]); if (png_ptr->flags & PNG_FLAG_LIBRARY_MISMATCH) { /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so * we must recompile any applications that use any older library version. * For versions after libpng 1.0, we will be compatible, so we need * only check the first digit. */ if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] || (user_png_ver[0] == '1' && user_png_ver[2] != png_libpng_ver[2]) || (user_png_ver[0] == '0' && user_png_ver[2] < '9')) { #if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE) char msg[80]; if (user_png_ver) { sprintf(msg, "Application was compiled with png.h from libpng-%.20s", user_png_ver); png_warning(png_ptr, msg); } sprintf(msg, "Application is running with png.c from libpng-%.20s", png_libpng_ver); png_warning(png_ptr, msg); #endif #ifdef PNG_ERROR_NUMBERS_SUPPORTED png_ptr->flags=0; #endif png_error(png_ptr, "Incompatible libpng version in application and library"); } } /* initialize zbuf - compression buffer */ png_ptr->zbuf_size = PNG_ZBUF_SIZE; png_ptr->zbuf = (png_bytep)png_malloc(png_ptr, (png_uint_32)png_ptr->zbuf_size); png_ptr->zstream.zalloc = png_zalloc; png_ptr->zstream.zfree = png_zfree; png_ptr->zstream.opaque = (voidpf)png_ptr; switch (inflateInit(&png_ptr->zstream)) { case Z_OK: /* Do nothing */ break; case Z_MEM_ERROR: case Z_STREAM_ERROR: png_error(png_ptr, "zlib memory error"); break; case Z_VERSION_ERROR: png_error(png_ptr, "zlib version error"); break; default: png_error(png_ptr, "Unknown zlib error"); } png_ptr->zstream.next_out = png_ptr->zbuf; png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; png_set_read_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL); #ifdef PNG_SETJMP_SUPPORTED /* Applications that neglect to set up their own setjmp() and then encounter a png_error() will longjmp here. Since the jmpbuf is then meaningless we abort instead of returning. */ #ifdef USE_FAR_KEYWORD if (setjmp(jmpbuf)) PNG_ABORT(); png_memcpy(png_ptr->jmpbuf,jmpbuf,png_sizeof(jmp_buf)); #else if (setjmp(png_ptr->jmpbuf)) PNG_ABORT(); #endif #endif return (png_ptr); } /* Initialize PNG structure for reading, and allocate any memory needed. This interface is deprecated in favour of the png_create_read_struct(), and it will eventually disappear. */ #if defined(PNG_1_0_X) || defined (PNG_1_2_X) #undef png_read_init void PNGAPI png_read_init(png_structp png_ptr) { /* We only come here via pre-1.0.7-compiled applications */ png_read_init_2(png_ptr, "1.0.6 or earlier", 0, 0); } #endif void PNGAPI png_read_init_2(png_structp png_ptr, png_const_charp user_png_ver, png_size_t png_struct_size, png_size_t png_info_size) { /* We only come here via pre-1.0.12-compiled applications */ #if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE) if(png_sizeof(png_struct) > png_struct_size || png_sizeof(png_info) > png_info_size) { char msg[80]; png_ptr->warning_fn=NULL; if (user_png_ver) { sprintf(msg, "Application was compiled with png.h from libpng-%.20s", user_png_ver); png_warning(png_ptr, msg); } sprintf(msg, "Application is running with png.c from libpng-%.20s", png_libpng_ver); png_warning(png_ptr, msg); } #endif if(png_sizeof(png_struct) > png_struct_size) { png_ptr->error_fn=NULL; #ifdef PNG_ERROR_NUMBERS_SUPPORTED png_ptr->flags=0; #endif png_error(png_ptr, "The png struct allocated by the application for reading is too small."); } if(png_sizeof(png_info) > png_info_size) { png_ptr->error_fn=NULL; #ifdef PNG_ERROR_NUMBERS_SUPPORTED png_ptr->flags=0; #endif png_error(png_ptr, "The info struct allocated by application for reading is too small."); } png_read_init_3(&png_ptr, user_png_ver, png_struct_size); } void PNGAPI png_read_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver, png_size_t png_struct_size) { #ifdef PNG_SETJMP_SUPPORTED jmp_buf tmp_jmp; /* to save current jump buffer */ #endif int i=0; png_structp png_ptr=*ptr_ptr; do { if(user_png_ver[i] != png_libpng_ver[i]) { #ifdef PNG_LEGACY_SUPPORTED png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH; #else png_ptr->warning_fn=NULL; png_warning(png_ptr, "Application uses deprecated png_read_init() and should be recompiled."); break; #endif } } while (png_libpng_ver[i++]); png_debug(1, "in png_read_init_3\n"); #ifdef PNG_SETJMP_SUPPORTED /* save jump buffer and error functions */ png_memcpy(tmp_jmp, png_ptr->jmpbuf, png_sizeof (jmp_buf)); #endif if(png_sizeof(png_struct) > png_struct_size) { png_destroy_struct(png_ptr); *ptr_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG); png_ptr = *ptr_ptr; } /* reset all variables to 0 */ png_memset(png_ptr, 0, png_sizeof (png_struct)); #ifdef PNG_SETJMP_SUPPORTED /* restore jump buffer */ png_memcpy(png_ptr->jmpbuf, tmp_jmp, png_sizeof (jmp_buf)); #endif /* added at libpng-1.2.6 */ #ifdef PNG_SET_USER_LIMITS_SUPPORTED png_ptr->user_width_max=PNG_USER_WIDTH_MAX; png_ptr->user_height_max=PNG_USER_HEIGHT_MAX; #endif /* initialize zbuf - compression buffer */ png_ptr->zbuf_size = PNG_ZBUF_SIZE; png_ptr->zbuf = (png_bytep)png_malloc(png_ptr, (png_uint_32)png_ptr->zbuf_size); png_ptr->zstream.zalloc = png_zalloc; png_ptr->zstream.zfree = png_zfree; png_ptr->zstream.opaque = (voidpf)png_ptr; switch (inflateInit(&png_ptr->zstream)) { case Z_OK: /* Do nothing */ break; case Z_MEM_ERROR: case Z_STREAM_ERROR: png_error(png_ptr, "zlib memory"); break; case Z_VERSION_ERROR: png_error(png_ptr, "zlib version"); break; default: png_error(png_ptr, "Unknown zlib error"); } png_ptr->zstream.next_out = png_ptr->zbuf; png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; png_set_read_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL); } #ifndef PNG_NO_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\n"); /* If we haven't checked all of the PNG signature bytes, do so now. */ if (png_ptr->sig_bytes < 8) { png_size_t num_checked = png_ptr->sig_bytes, num_to_check = 8 - num_checked; png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check); png_ptr->sig_bytes = 8; if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check)) { if (num_checked < 4 && png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4)) png_error(png_ptr, "Not a PNG file"); else png_error(png_ptr, "PNG file corrupted by ASCII conversion"); } if (num_checked < 3) png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE; } for(;;) { #ifdef PNG_USE_LOCAL_ARRAYS PNG_IHDR; PNG_IDAT; PNG_IEND; PNG_PLTE; #if defined(PNG_READ_bKGD_SUPPORTED) PNG_bKGD; #endif #if defined(PNG_READ_cHRM_SUPPORTED) PNG_cHRM; #endif #if defined(PNG_READ_gAMA_SUPPORTED) PNG_gAMA; #endif #if defined(PNG_READ_hIST_SUPPORTED) PNG_hIST; #endif #if defined(PNG_READ_iCCP_SUPPORTED) PNG_iCCP; #endif #if defined(PNG_READ_iTXt_SUPPORTED) PNG_iTXt; #endif #if defined(PNG_READ_oFFs_SUPPORTED) PNG_oFFs; #endif #if defined(PNG_READ_pCAL_SUPPORTED) PNG_pCAL; #endif #if defined(PNG_READ_pHYs_SUPPORTED) PNG_pHYs; #endif #if defined(PNG_READ_sBIT_SUPPORTED) PNG_sBIT; #endif #if defined(PNG_READ_sCAL_SUPPORTED) PNG_sCAL; #endif #if defined(PNG_READ_sPLT_SUPPORTED) PNG_sPLT; #endif #if defined(PNG_READ_sRGB_SUPPORTED) PNG_sRGB; #endif #if defined(PNG_READ_tEXt_SUPPORTED) PNG_tEXt; #endif #if defined(PNG_READ_tIME_SUPPORTED) PNG_tIME; #endif #if defined(PNG_READ_tRNS_SUPPORTED) PNG_tRNS; #endif #if defined(PNG_READ_zTXt_SUPPORTED) PNG_zTXt; #endif #endif /* PNG_USE_LOCAL_ARRAYS */ png_byte chunk_length[4]; png_uint_32 length; png_read_data(png_ptr, chunk_length, 4); length = png_get_uint_31(png_ptr,chunk_length); png_reset_crc(png_ptr); png_crc_read(png_ptr, png_ptr->chunk_name, 4); png_debug2(0, "Reading %s chunk, length=%lu.\n", png_ptr->chunk_name, length); /* This should be a binary subdivision search or a hash for * matching the chunk name rather than a linear search. */ if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4)) png_handle_IHDR(png_ptr, info_ptr, length); else if (!png_memcmp(png_ptr->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, png_ptr->chunk_name)) { if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) png_ptr->mode |= PNG_HAVE_IDAT; png_handle_unknown(png_ptr, info_ptr, length); if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4)) png_ptr->mode |= PNG_HAVE_PLTE; else if (!png_memcmp(png_ptr->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(png_ptr->chunk_name, png_PLTE, 4)) png_handle_PLTE(png_ptr, info_ptr, length); else if (!png_memcmp(png_ptr->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; } #if defined(PNG_READ_bKGD_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4)) png_handle_bKGD(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_cHRM_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4)) png_handle_cHRM(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_gAMA_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4)) png_handle_gAMA(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_hIST_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4)) png_handle_hIST(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_oFFs_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4)) png_handle_oFFs(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_pCAL_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4)) png_handle_pCAL(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_sCAL_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4)) png_handle_sCAL(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_pHYs_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4)) png_handle_pHYs(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_sBIT_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4)) png_handle_sBIT(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_sRGB_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4)) png_handle_sRGB(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_iCCP_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4)) png_handle_iCCP(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_sPLT_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4)) png_handle_sPLT(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_tEXt_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4)) png_handle_tEXt(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_tIME_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4)) png_handle_tIME(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_tRNS_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4)) png_handle_tRNS(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_zTXt_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4)) png_handle_zTXt(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_iTXt_SUPPORTED) else if (!png_memcmp(png_ptr->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_NO_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\n"); 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); } #ifndef PNG_NO_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\n"); if (!(png_ptr->flags & PNG_FLAG_ROW_INIT)) png_read_start_row(png_ptr); } #endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */ #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED void PNGAPI png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row) { #ifdef PNG_USE_LOCAL_ARRAYS PNG_IDAT; const int png_pass_dsp_mask[7] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff}; const int png_pass_mask[7] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff}; #endif int ret; png_debug2(1, "in png_read_row (row %lu, pass %d)\n", 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 } #if defined(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; 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_ptr->irowbytes; do { if (!(png_ptr->zstream.avail_in)) { while (!png_ptr->idat_size) { png_byte chunk_length[4]; png_crc_finish(png_ptr, 0); png_read_data(png_ptr, chunk_length, 4); png_ptr->idat_size = png_get_uint_31(png_ptr,chunk_length); png_reset_crc(png_ptr); png_crc_read(png_ptr, png_ptr->chunk_name, 4); 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_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_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf, png_ptr->rowbytes + 1); #if defined(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); #if defined(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_NO_SEQUENTIAL_READ_SUPPORTED */ #ifndef PNG_NO_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 libpng version 1.2.8 */ 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\n"); 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, png_bytep_NULL); rp++; } else if(dp != NULL) for (i = 0; i < num_rows; i++) { png_bytep dptr = *dp; png_read_row(png_ptr, png_bytep_NULL, dptr); dp++; } } #endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */ #ifndef PNG_NO_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 libpng version 1.2.8 */ 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\n"); #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, png_bytep_NULL); rp++; } } } #endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */ #ifndef PNG_NO_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_byte chunk_length[4]; png_uint_32 length; png_debug(1, "in png_read_end\n"); png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */ do { #ifdef PNG_USE_LOCAL_ARRAYS PNG_IHDR; PNG_IDAT; PNG_IEND; PNG_PLTE; #if defined(PNG_READ_bKGD_SUPPORTED) PNG_bKGD; #endif #if defined(PNG_READ_cHRM_SUPPORTED) PNG_cHRM; #endif #if defined(PNG_READ_gAMA_SUPPORTED) PNG_gAMA; #endif #if defined(PNG_READ_hIST_SUPPORTED) PNG_hIST; #endif #if defined(PNG_READ_iCCP_SUPPORTED) PNG_iCCP; #endif #if defined(PNG_READ_iTXt_SUPPORTED) PNG_iTXt; #endif #if defined(PNG_READ_oFFs_SUPPORTED) PNG_oFFs; #endif #if defined(PNG_READ_pCAL_SUPPORTED) PNG_pCAL; #endif #if defined(PNG_READ_pHYs_SUPPORTED) PNG_pHYs; #endif #if defined(PNG_READ_sBIT_SUPPORTED) PNG_sBIT; #endif #if defined(PNG_READ_sCAL_SUPPORTED) PNG_sCAL; #endif #if defined(PNG_READ_sPLT_SUPPORTED) PNG_sPLT; #endif #if defined(PNG_READ_sRGB_SUPPORTED) PNG_sRGB; #endif #if defined(PNG_READ_tEXt_SUPPORTED) PNG_tEXt; #endif #if defined(PNG_READ_tIME_SUPPORTED) PNG_tIME; #endif #if defined(PNG_READ_tRNS_SUPPORTED) PNG_tRNS; #endif #if defined(PNG_READ_zTXt_SUPPORTED) PNG_zTXt; #endif #endif /* PNG_USE_LOCAL_ARRAYS */ png_read_data(png_ptr, chunk_length, 4); length = png_get_uint_31(png_ptr,chunk_length); png_reset_crc(png_ptr); png_crc_read(png_ptr, png_ptr->chunk_name, 4); png_debug1(0, "Reading %s chunk.\n", png_ptr->chunk_name); if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4)) png_handle_IHDR(png_ptr, info_ptr, length); else if (!png_memcmp(png_ptr->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, png_ptr->chunk_name)) { if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) { if (length > 0 || png_ptr->mode & PNG_AFTER_IDAT) png_error(png_ptr, "Too many IDAT's found"); } else png_ptr->mode |= PNG_AFTER_IDAT; png_handle_unknown(png_ptr, info_ptr, length); if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4)) png_ptr->mode |= PNG_HAVE_PLTE; } #endif else if (!png_memcmp(png_ptr->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_AFTER_IDAT) png_error(png_ptr, "Too many IDAT's found"); png_crc_finish(png_ptr, length); } else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4)) png_handle_PLTE(png_ptr, info_ptr, length); #if defined(PNG_READ_bKGD_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4)) png_handle_bKGD(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_cHRM_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4)) png_handle_cHRM(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_gAMA_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4)) png_handle_gAMA(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_hIST_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4)) png_handle_hIST(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_oFFs_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4)) png_handle_oFFs(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_pCAL_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4)) png_handle_pCAL(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_sCAL_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4)) png_handle_sCAL(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_pHYs_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4)) png_handle_pHYs(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_sBIT_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4)) png_handle_sBIT(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_sRGB_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4)) png_handle_sRGB(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_iCCP_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4)) png_handle_iCCP(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_sPLT_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4)) png_handle_sPLT(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_tEXt_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4)) png_handle_tEXt(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_tIME_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4)) png_handle_tIME(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_tRNS_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4)) png_handle_tRNS(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_zTXt_SUPPORTED) else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4)) png_handle_zTXt(png_ptr, info_ptr, length); #endif #if defined(PNG_READ_iTXt_SUPPORTED) else if (!png_memcmp(png_ptr->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_NO_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; png_voidp mem_ptr; #endif png_debug(1, "in png_destroy_read_struct\n"); if (png_ptr_ptr != NULL) png_ptr = *png_ptr_ptr; if (info_ptr_ptr != NULL) info_ptr = *info_ptr_ptr; if (end_info_ptr_ptr != NULL) end_info_ptr = *end_info_ptr_ptr; #ifdef PNG_USER_MEM_SUPPORTED free_fn = png_ptr->free_fn; mem_ptr = png_ptr->mem_ptr; #endif png_read_destroy(png_ptr, info_ptr, end_info_ptr); if (info_ptr != NULL) { #if defined(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) { #if defined(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\n"); 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); #if defined(PNG_READ_DITHER_SUPPORTED) png_free(png_ptr, png_ptr->palette_lookup); png_free(png_ptr, png_ptr->dither_index); #endif #if defined(PNG_READ_GAMMA_SUPPORTED) png_free(png_ptr, png_ptr->gamma_table); #endif #if defined(PNG_READ_BACKGROUND_SUPPORTED) png_free(png_ptr, png_ptr->gamma_from_1); png_free(png_ptr, png_ptr->gamma_to_1); #endif #ifdef PNG_FREE_ME_SUPPORTED if (png_ptr->free_me & PNG_FREE_PLTE) png_zfree(png_ptr, png_ptr->palette); png_ptr->free_me &= ~PNG_FREE_PLTE; #else if (png_ptr->flags & PNG_FLAG_FREE_PLTE) png_zfree(png_ptr, png_ptr->palette); png_ptr->flags &= ~PNG_FLAG_FREE_PLTE; #endif #if defined(PNG_tRNS_SUPPORTED) || \ defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) #ifdef PNG_FREE_ME_SUPPORTED if (png_ptr->free_me & PNG_FREE_TRNS) png_free(png_ptr, png_ptr->trans); png_ptr->free_me &= ~PNG_FREE_TRNS; #else if (png_ptr->flags & PNG_FLAG_FREE_TRNS) png_free(png_ptr, png_ptr->trans); png_ptr->flags &= ~PNG_FLAG_FREE_TRNS; #endif #endif #if defined(PNG_READ_hIST_SUPPORTED) #ifdef PNG_FREE_ME_SUPPORTED if (png_ptr->free_me & PNG_FREE_HIST) png_free(png_ptr, png_ptr->hist); png_ptr->free_me &= ~PNG_FREE_HIST; #else if (png_ptr->flags & PNG_FLAG_FREE_HIST) png_free(png_ptr, png_ptr->hist); png_ptr->flags &= ~PNG_FLAG_FREE_HIST; #endif #endif #if defined(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); } #if defined(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 #if defined(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 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED #ifdef PNG_TEXT_SUPPORTED png_free(png_ptr, png_ptr->current_text); #endif /* PNG_TEXT_SUPPORTED */ #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ /* 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) { png_ptr->read_row_fn = read_row_fn; } #ifndef PNG_NO_SEQUENTIAL_READ_SUPPORTED #if defined(PNG_INFO_IMAGE_SUPPORTED) void PNGAPI png_read_png(png_structp png_ptr, png_infop info_ptr, int transforms, voidp params) { int row; #if defined(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 /* 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 ------------------- */ #if defined(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 #if defined(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 #if defined(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 #if defined(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) || (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))) png_set_expand(png_ptr); #endif /* We don't handle background color or gamma transformation or dithering. */ #if defined(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 #if defined(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) && png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT)) { png_color_8p sig_bit; png_get_sBIT(png_ptr, info_ptr, &sig_bit); png_set_shift(png_ptr, sig_bit); } #endif #if defined(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 #if defined(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 #if defined(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 /* 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 ------------------- */ #ifdef PNG_FREE_ME_SUPPORTED png_free_data(png_ptr, info_ptr, PNG_FREE_ROWS, 0); #endif if(info_ptr->row_pointers == NULL) { info_ptr->row_pointers = (png_bytepp)png_malloc(png_ptr, info_ptr->height * png_sizeof(png_bytep)); #ifdef PNG_FREE_ME_SUPPORTED info_ptr->free_me |= PNG_FREE_ROWS; #endif 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); if(transforms == 0 || params == NULL) /* quiet compiler warnings */ return; } #endif #endif /* PNG_NO_SEQUENTIAL_READ_SUPPORTED */