2 /* pngstruct.h - header file for PNG reference library
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4 * Copyright (c) 1998-2013 Glenn Randers-Pehrson
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5 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
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6 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
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8 * Last changed in libpng 1.6.1 [March 28, 2013]
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10 * This code is released under the libpng license.
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11 * For conditions of distribution and use, see the disclaimer
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12 * and license in png.h
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15 /* The structure that holds the information to read and write PNG files.
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16 * The only people who need to care about what is inside of this are the
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17 * people who will be modifying the library for their own special needs.
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18 * It should NOT be accessed directly by an application.
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23 /* zlib.h defines the structure z_stream, an instance of which is included
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24 * in this structure and is required for decompressing the LZ compressed
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25 * data in PNG files.
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28 /* We must ensure that zlib uses 'const' in declarations. */
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31 #include "../../fx_zlib/include/fx_zlib.h"
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33 /* zlib.h sometimes #defines const to nothing, undo this. */
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37 /* zlib.h has mediocre z_const use before 1.2.6, this stuff is for compatibility
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38 * with older builds.
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40 #if ZLIB_VERNUM < 0x1260
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41 # define PNGZ_MSG_CAST(s) png_constcast(char*,s)
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42 # define PNGZ_INPUT_CAST(b) png_constcast(png_bytep,b)
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44 # define PNGZ_MSG_CAST(s) (s)
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45 # define PNGZ_INPUT_CAST(b) (b)
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48 /* zlib.h declares a magic type 'uInt' that limits the amount of data that zlib
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49 * can handle at once. This type need be no larger than 16 bits (so maximum of
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50 * 65535), this define allows us to discover how big it is, but limited by the
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51 * maximuum for png_size_t. The value can be overriden in a library build
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52 * (pngusr.h, or set it in CPPFLAGS) and it works to set it to a considerably
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53 * lower value (e.g. 255 works). A lower value may help memory usage (slightly)
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54 * and may even improve performance on some systems (and degrade it on others.)
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57 # define ZLIB_IO_MAX ((uInt)-1)
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60 #ifdef PNG_WRITE_SUPPORTED
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61 /* The type of a compression buffer list used by the write code. */
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62 typedef struct png_compression_buffer
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64 struct png_compression_buffer *next;
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65 png_byte output[1]; /* actually zbuf_size */
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66 } png_compression_buffer, *png_compression_bufferp;
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68 #define PNG_COMPRESSION_BUFFER_SIZE(pp)\
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69 (offsetof(png_compression_buffer, output) + (pp)->zbuffer_size)
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72 /* Colorspace support; structures used in png_struct, png_info and in internal
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73 * functions to hold and communicate information about the color space.
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75 * PNG_COLORSPACE_SUPPORTED is only required if the application will perform
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76 * colorspace corrections, otherwise all the colorspace information can be
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77 * skipped and the size of libpng can be reduced (significantly) by compiling
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78 * out the colorspace support.
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80 #ifdef PNG_COLORSPACE_SUPPORTED
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81 /* The chromaticities of the red, green and blue colorants and the chromaticity
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82 * of the corresponding white point (i.e. of rgb(1.0,1.0,1.0)).
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84 typedef struct png_xy
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86 png_fixed_point redx, redy;
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87 png_fixed_point greenx, greeny;
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88 png_fixed_point bluex, bluey;
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89 png_fixed_point whitex, whitey;
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92 /* The same data as above but encoded as CIE XYZ values. When this data comes
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93 * from chromaticities the sum of the Y values is assumed to be 1.0
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95 typedef struct png_XYZ
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97 png_fixed_point red_X, red_Y, red_Z;
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98 png_fixed_point green_X, green_Y, green_Z;
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99 png_fixed_point blue_X, blue_Y, blue_Z;
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101 #endif /* COLORSPACE */
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103 #if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
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104 /* A colorspace is all the above plus, potentially, profile information,
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105 * however at present libpng does not use the profile internally so it is only
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106 * stored in the png_info struct (if iCCP is supported.) The rendering intent
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107 * is retained here and is checked.
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109 * The file gamma encoding information is also stored here and gamma correction
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110 * is done by libpng, whereas color correction must currently be done by the
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113 typedef struct png_colorspace
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115 #ifdef PNG_GAMMA_SUPPORTED
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116 png_fixed_point gamma; /* File gamma */
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119 #ifdef PNG_COLORSPACE_SUPPORTED
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120 png_xy end_points_xy; /* End points as chromaticities */
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121 png_XYZ end_points_XYZ; /* End points as CIE XYZ colorant values */
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122 png_uint_16 rendering_intent; /* Rendering intent of a profile */
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125 /* Flags are always defined to simplify the code. */
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126 png_uint_16 flags; /* As defined below */
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127 } png_colorspace, * PNG_RESTRICT png_colorspacerp;
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129 typedef const png_colorspace * PNG_RESTRICT png_const_colorspacerp;
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131 /* General flags for the 'flags' field */
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132 #define PNG_COLORSPACE_HAVE_GAMMA 0x0001
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133 #define PNG_COLORSPACE_HAVE_ENDPOINTS 0x0002
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134 #define PNG_COLORSPACE_HAVE_INTENT 0x0004
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135 #define PNG_COLORSPACE_FROM_gAMA 0x0008
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136 #define PNG_COLORSPACE_FROM_cHRM 0x0010
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137 #define PNG_COLORSPACE_FROM_sRGB 0x0020
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138 #define PNG_COLORSPACE_ENDPOINTS_MATCH_sRGB 0x0040
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139 #define PNG_COLORSPACE_MATCHES_sRGB 0x0080 /* exact match on profile */
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140 #define PNG_COLORSPACE_INVALID 0x8000
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141 #define PNG_COLORSPACE_CANCEL(flags) (0xffff ^ (flags))
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142 #endif /* COLORSPACE || GAMMA */
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144 struct png_struct_def
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146 #ifdef PNG_SETJMP_SUPPORTED
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147 jmp_buf jmp_buf_local; /* New name in 1.6.0 for jmp_buf in png_struct */
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148 png_longjmp_ptr longjmp_fn;/* setjmp non-local goto function. */
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149 jmp_buf *jmp_buf_ptr; /* passed to longjmp_fn */
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150 size_t jmp_buf_size; /* size of the above, if allocated */
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152 png_error_ptr error_fn; /* function for printing errors and aborting */
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153 #ifdef PNG_WARNINGS_SUPPORTED
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154 png_error_ptr warning_fn; /* function for printing warnings */
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156 png_voidp error_ptr; /* user supplied struct for error functions */
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157 png_rw_ptr write_data_fn; /* function for writing output data */
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158 png_rw_ptr read_data_fn; /* function for reading input data */
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159 png_voidp io_ptr; /* ptr to application struct for I/O functions */
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161 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
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162 png_user_transform_ptr read_user_transform_fn; /* user read transform */
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165 #ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED
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166 png_user_transform_ptr write_user_transform_fn; /* user write transform */
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169 /* These were added in libpng-1.0.2 */
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170 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
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171 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
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172 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
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173 png_voidp user_transform_ptr; /* user supplied struct for user transform */
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174 png_byte user_transform_depth; /* bit depth of user transformed pixels */
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175 png_byte user_transform_channels; /* channels in user transformed pixels */
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179 png_uint_32 mode; /* tells us where we are in the PNG file */
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180 png_uint_32 flags; /* flags indicating various things to libpng */
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181 png_uint_32 transformations; /* which transformations to perform */
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183 png_uint_32 zowner; /* ID (chunk type) of zstream owner, 0 if none */
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184 z_stream zstream; /* decompression structure */
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186 #ifdef PNG_WRITE_SUPPORTED
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187 png_compression_bufferp zbuffer_list; /* Created on demand during write */
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188 uInt zbuffer_size; /* size of the actual buffer */
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190 int zlib_level; /* holds zlib compression level */
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191 int zlib_method; /* holds zlib compression method */
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192 int zlib_window_bits; /* holds zlib compression window bits */
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193 int zlib_mem_level; /* holds zlib compression memory level */
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194 int zlib_strategy; /* holds zlib compression strategy */
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196 /* Added at libpng 1.5.4 */
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197 #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
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198 int zlib_text_level; /* holds zlib compression level */
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199 int zlib_text_method; /* holds zlib compression method */
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200 int zlib_text_window_bits; /* holds zlib compression window bits */
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201 int zlib_text_mem_level; /* holds zlib compression memory level */
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202 int zlib_text_strategy; /* holds zlib compression strategy */
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204 /* End of material added at libpng 1.5.4 */
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205 /* Added at libpng 1.6.0 */
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206 #ifdef PNG_WRITE_SUPPORTED
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207 int zlib_set_level; /* Actual values set into the zstream on write */
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208 int zlib_set_method;
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209 int zlib_set_window_bits;
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210 int zlib_set_mem_level;
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211 int zlib_set_strategy;
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214 png_uint_32 width; /* width of image in pixels */
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215 png_uint_32 height; /* height of image in pixels */
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216 png_uint_32 num_rows; /* number of rows in current pass */
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217 png_uint_32 usr_width; /* width of row at start of write */
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218 png_size_t rowbytes; /* size of row in bytes */
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219 png_uint_32 iwidth; /* width of current interlaced row in pixels */
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220 png_uint_32 row_number; /* current row in interlace pass */
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221 png_uint_32 chunk_name; /* PNG_CHUNK() id of current chunk */
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222 png_bytep prev_row; /* buffer to save previous (unfiltered) row.
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223 * This is a pointer into big_prev_row
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225 png_bytep row_buf; /* buffer to save current (unfiltered) row.
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226 * This is a pointer into big_row_buf
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228 #ifdef PNG_WRITE_SUPPORTED
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229 png_bytep sub_row; /* buffer to save "sub" row when filtering */
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230 png_bytep up_row; /* buffer to save "up" row when filtering */
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231 png_bytep avg_row; /* buffer to save "avg" row when filtering */
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232 png_bytep paeth_row; /* buffer to save "Paeth" row when filtering */
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234 png_size_t info_rowbytes; /* Added in 1.5.4: cache of updated row bytes */
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236 png_uint_32 idat_size; /* current IDAT size for read */
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237 png_uint_32 crc; /* current chunk CRC value */
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238 png_colorp palette; /* palette from the input file */
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239 png_uint_16 num_palette; /* number of color entries in palette */
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241 /* Added at libpng-1.5.10 */
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242 #ifdef PNG_CHECK_FOR_INVALID_INDEX_SUPPORTED
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243 int num_palette_max; /* maximum palette index found in IDAT */
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246 png_uint_16 num_trans; /* number of transparency values */
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247 png_byte compression; /* file compression type (always 0) */
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248 png_byte filter; /* file filter type (always 0) */
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249 png_byte interlaced; /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */
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250 png_byte pass; /* current interlace pass (0 - 6) */
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251 png_byte do_filter; /* row filter flags (see PNG_FILTER_ below ) */
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252 png_byte color_type; /* color type of file */
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253 png_byte bit_depth; /* bit depth of file */
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254 png_byte usr_bit_depth; /* bit depth of users row: write only */
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255 png_byte pixel_depth; /* number of bits per pixel */
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256 png_byte channels; /* number of channels in file */
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257 #ifdef PNG_WRITE_SUPPORTED
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258 png_byte usr_channels; /* channels at start of write: write only */
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260 png_byte sig_bytes; /* magic bytes read/written from start of file */
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261 png_byte maximum_pixel_depth;
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262 /* pixel depth used for the row buffers */
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263 png_byte transformed_pixel_depth;
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264 /* pixel depth after read/write transforms */
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265 #if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED)
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266 png_uint_16 filler; /* filler bytes for pixel expansion */
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269 #if defined(PNG_bKGD_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
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270 defined(PNG_READ_ALPHA_MODE_SUPPORTED)
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271 png_byte background_gamma_type;
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272 png_fixed_point background_gamma;
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273 png_color_16 background; /* background color in screen gamma space */
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274 #ifdef PNG_READ_GAMMA_SUPPORTED
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275 png_color_16 background_1; /* background normalized to gamma 1.0 */
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277 #endif /* PNG_bKGD_SUPPORTED */
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279 #ifdef PNG_WRITE_FLUSH_SUPPORTED
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280 png_flush_ptr output_flush_fn; /* Function for flushing output */
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281 png_uint_32 flush_dist; /* how many rows apart to flush, 0 - no flush */
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282 png_uint_32 flush_rows; /* number of rows written since last flush */
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285 #ifdef PNG_READ_GAMMA_SUPPORTED
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286 int gamma_shift; /* number of "insignificant" bits in 16-bit gamma */
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287 png_fixed_point screen_gamma; /* screen gamma value (display_exponent) */
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289 png_bytep gamma_table; /* gamma table for 8-bit depth files */
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290 png_uint_16pp gamma_16_table; /* gamma table for 16-bit depth files */
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291 #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
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292 defined(PNG_READ_ALPHA_MODE_SUPPORTED) || \
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293 defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
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294 png_bytep gamma_from_1; /* converts from 1.0 to screen */
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295 png_bytep gamma_to_1; /* converts from file to 1.0 */
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296 png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */
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297 png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */
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298 #endif /* READ_BACKGROUND || READ_ALPHA_MODE || RGB_TO_GRAY */
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301 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_sBIT_SUPPORTED)
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302 png_color_8 sig_bit; /* significant bits in each available channel */
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305 #if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED)
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306 png_color_8 shift; /* shift for significant bit tranformation */
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309 #if defined(PNG_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) \
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310 || defined(PNG_READ_EXPAND_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
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311 png_bytep trans_alpha; /* alpha values for paletted files */
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312 png_color_16 trans_color; /* transparent color for non-paletted files */
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315 png_read_status_ptr read_row_fn; /* called after each row is decoded */
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316 png_write_status_ptr write_row_fn; /* called after each row is encoded */
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317 #ifdef PNG_PROGRESSIVE_READ_SUPPORTED
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318 png_progressive_info_ptr info_fn; /* called after header data fully read */
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319 png_progressive_row_ptr row_fn; /* called after a prog. row is decoded */
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320 png_progressive_end_ptr end_fn; /* called after image is complete */
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321 png_bytep save_buffer_ptr; /* current location in save_buffer */
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322 png_bytep save_buffer; /* buffer for previously read data */
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323 png_bytep current_buffer_ptr; /* current location in current_buffer */
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324 png_bytep current_buffer; /* buffer for recently used data */
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325 png_uint_32 push_length; /* size of current input chunk */
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326 png_uint_32 skip_length; /* bytes to skip in input data */
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327 png_size_t save_buffer_size; /* amount of data now in save_buffer */
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328 png_size_t save_buffer_max; /* total size of save_buffer */
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329 png_size_t buffer_size; /* total amount of available input data */
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330 png_size_t current_buffer_size; /* amount of data now in current_buffer */
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331 int process_mode; /* what push library is currently doing */
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332 int cur_palette; /* current push library palette index */
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334 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
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336 #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
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337 /* For the Borland special 64K segment handler */
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338 png_bytepp offset_table_ptr;
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339 png_bytep offset_table;
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340 png_uint_16 offset_table_number;
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341 png_uint_16 offset_table_count;
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342 png_uint_16 offset_table_count_free;
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345 #ifdef PNG_READ_QUANTIZE_SUPPORTED
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346 png_bytep palette_lookup; /* lookup table for quantizing */
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347 png_bytep quantize_index; /* index translation for palette files */
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350 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
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351 png_byte heuristic_method; /* heuristic for row filter selection */
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352 png_byte num_prev_filters; /* number of weights for previous rows */
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353 png_bytep prev_filters; /* filter type(s) of previous row(s) */
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354 png_uint_16p filter_weights; /* weight(s) for previous line(s) */
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355 png_uint_16p inv_filter_weights; /* 1/weight(s) for previous line(s) */
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356 png_uint_16p filter_costs; /* relative filter calculation cost */
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357 png_uint_16p inv_filter_costs; /* 1/relative filter calculation cost */
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361 #ifdef PNG_SET_OPTION_SUPPORTED
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362 png_byte options; /* On/off state (up to 4 options) */
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365 #if PNG_LIBPNG_VER < 10700
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366 /* To do: remove this from libpng-1.7 */
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367 #ifdef PNG_TIME_RFC1123_SUPPORTED
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368 char time_buffer[29]; /* String to hold RFC 1123 time text */
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372 /* New members added in libpng-1.0.6 */
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374 png_uint_32 free_me; /* flags items libpng is responsible for freeing */
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376 #ifdef PNG_USER_CHUNKS_SUPPORTED
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377 png_voidp user_chunk_ptr;
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378 #ifdef PNG_READ_USER_CHUNKS_SUPPORTED
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379 png_user_chunk_ptr read_user_chunk_fn; /* user read chunk handler */
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383 #ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
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384 int unknown_default; /* As PNG_HANDLE_* */
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385 unsigned int num_chunk_list; /* Number of entries in the list */
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386 png_bytep chunk_list; /* List of png_byte[5]; the textual chunk name
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387 * followed by a PNG_HANDLE_* byte */
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390 /* New members added in libpng-1.0.3 */
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391 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
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392 png_byte rgb_to_gray_status;
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393 /* Added in libpng 1.5.5 to record setting of coefficients: */
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394 png_byte rgb_to_gray_coefficients_set;
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395 /* These were changed from png_byte in libpng-1.0.6 */
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396 png_uint_16 rgb_to_gray_red_coeff;
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397 png_uint_16 rgb_to_gray_green_coeff;
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398 /* deleted in 1.5.5: rgb_to_gray_blue_coeff; */
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401 /* New member added in libpng-1.0.4 (renamed in 1.0.9) */
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402 #if defined(PNG_MNG_FEATURES_SUPPORTED)
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403 /* Changed from png_byte to png_uint_32 at version 1.2.0 */
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404 png_uint_32 mng_features_permitted;
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407 /* New member added in libpng-1.0.9, ifdef'ed out in 1.0.12, enabled in 1.2.0 */
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408 #ifdef PNG_MNG_FEATURES_SUPPORTED
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409 png_byte filter_type;
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412 /* New members added in libpng-1.2.0 */
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414 /* New members added in libpng-1.0.2 but first enabled by default in 1.2.0 */
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415 #ifdef PNG_USER_MEM_SUPPORTED
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416 png_voidp mem_ptr; /* user supplied struct for mem functions */
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417 png_malloc_ptr malloc_fn; /* function for allocating memory */
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418 png_free_ptr free_fn; /* function for freeing memory */
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421 /* New member added in libpng-1.0.13 and 1.2.0 */
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422 png_bytep big_row_buf; /* buffer to save current (unfiltered) row */
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424 #ifdef PNG_READ_QUANTIZE_SUPPORTED
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425 /* The following three members were added at version 1.0.14 and 1.2.4 */
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426 png_bytep quantize_sort; /* working sort array */
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427 png_bytep index_to_palette; /* where the original index currently is
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429 png_bytep palette_to_index; /* which original index points to this
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433 /* New members added in libpng-1.0.16 and 1.2.6 */
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434 png_byte compression_type;
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436 #ifdef PNG_USER_LIMITS_SUPPORTED
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437 png_uint_32 user_width_max;
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438 png_uint_32 user_height_max;
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440 /* Added in libpng-1.4.0: Total number of sPLT, text, and unknown
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441 * chunks that can be stored (0 means unlimited).
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443 png_uint_32 user_chunk_cache_max;
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445 /* Total memory that a zTXt, sPLT, iTXt, iCCP, or unknown chunk
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446 * can occupy when decompressed. 0 means unlimited.
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448 png_alloc_size_t user_chunk_malloc_max;
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451 /* New member added in libpng-1.0.25 and 1.2.17 */
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452 #ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
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453 /* Temporary storage for unknown chunk that the library doesn't recognize,
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454 * used while reading the chunk.
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456 png_unknown_chunk unknown_chunk;
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459 /* New member added in libpng-1.2.26 */
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460 png_size_t old_big_row_buf_size;
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462 #ifdef PNG_READ_SUPPORTED
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463 /* New member added in libpng-1.2.30 */
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464 png_bytep read_buffer; /* buffer for reading chunk data */
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465 png_alloc_size_t read_buffer_size; /* current size of the buffer */
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467 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
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468 uInt IDAT_read_size; /* limit on read buffer size for IDAT */
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471 #ifdef PNG_IO_STATE_SUPPORTED
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472 /* New member added in libpng-1.4.0 */
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473 png_uint_32 io_state;
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476 /* New member added in libpng-1.5.6 */
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477 png_bytep big_prev_row;
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479 /* New member added in libpng-1.5.7 */
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480 void (*read_filter[PNG_FILTER_VALUE_LAST-1])(png_row_infop row_info,
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481 png_bytep row, png_const_bytep prev_row);
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483 #ifdef PNG_READ_SUPPORTED
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484 #if defined(PNG_COLORSPACE_SUPPORTED) || defined(PNG_GAMMA_SUPPORTED)
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485 png_colorspace colorspace;
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489 #endif /* PNGSTRUCT_H */
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