4 * This file was part of the Independent JPEG Group's software:
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5 * Copyright (C) 1991-1998, Thomas G. Lane.
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6 * Modified 2002-2009 by Guido Vollbeding.
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7 * libjpeg-turbo Modifications:
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8 * Copyright (C) 2009-2011, 2013-2014, 2016, D. R. Commander.
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9 * Copyright (C) 2015, Google, Inc.
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10 * For conditions of distribution and use, see the accompanying README.ijg
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13 * This file defines the application interface for the JPEG library.
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14 * Most applications using the library need only include this file,
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15 * and perhaps jerror.h if they want to know the exact error codes.
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22 * First we include the configuration files that record how this
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23 * installation of the JPEG library is set up. jconfig.h can be
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24 * generated automatically for many systems. jmorecfg.h contains
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25 * manual configuration options that most people need not worry about.
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28 #ifndef JCONFIG_INCLUDED /* in case jinclude.h already did */
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29 #include "jconfig.h" /* widely used configuration options */
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31 #include "jmorecfg.h" /* seldom changed options */
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35 #ifndef DONT_USE_EXTERN_C
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41 /* Various constants determining the sizes of things.
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42 * All of these are specified by the JPEG standard, so don't change them
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43 * if you want to be compatible.
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46 #define DCTSIZE 8 /* The basic DCT block is 8x8 samples */
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47 #define DCTSIZE2 64 /* DCTSIZE squared; # of elements in a block */
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48 #define NUM_QUANT_TBLS 4 /* Quantization tables are numbered 0..3 */
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49 #define NUM_HUFF_TBLS 4 /* Huffman tables are numbered 0..3 */
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50 #define NUM_ARITH_TBLS 16 /* Arith-coding tables are numbered 0..15 */
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51 #define MAX_COMPS_IN_SCAN 4 /* JPEG limit on # of components in one scan */
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52 #define MAX_SAMP_FACTOR 4 /* JPEG limit on sampling factors */
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53 /* Unfortunately, some bozo at Adobe saw no reason to be bound by the standard;
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54 * the PostScript DCT filter can emit files with many more than 10 blocks/MCU.
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55 * If you happen to run across such a file, you can up D_MAX_BLOCKS_IN_MCU
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56 * to handle it. We even let you do this from the jconfig.h file. However,
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57 * we strongly discourage changing C_MAX_BLOCKS_IN_MCU; just because Adobe
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58 * sometimes emits noncompliant files doesn't mean you should too.
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60 #define C_MAX_BLOCKS_IN_MCU 10 /* compressor's limit on blocks per MCU */
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61 #ifndef D_MAX_BLOCKS_IN_MCU
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62 #define D_MAX_BLOCKS_IN_MCU 10 /* decompressor's limit on blocks per MCU */
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66 /* Data structures for images (arrays of samples and of DCT coefficients).
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69 typedef JSAMPLE *JSAMPROW; /* ptr to one image row of pixel samples. */
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70 typedef JSAMPROW *JSAMPARRAY; /* ptr to some rows (a 2-D sample array) */
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71 typedef JSAMPARRAY *JSAMPIMAGE; /* a 3-D sample array: top index is color */
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73 typedef JCOEF JBLOCK[DCTSIZE2]; /* one block of coefficients */
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74 typedef JBLOCK *JBLOCKROW; /* pointer to one row of coefficient blocks */
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75 typedef JBLOCKROW *JBLOCKARRAY; /* a 2-D array of coefficient blocks */
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76 typedef JBLOCKARRAY *JBLOCKIMAGE; /* a 3-D array of coefficient blocks */
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78 typedef JCOEF *JCOEFPTR; /* useful in a couple of places */
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81 /* Types for JPEG compression parameters and working tables. */
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84 /* DCT coefficient quantization tables. */
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87 /* This array gives the coefficient quantizers in natural array order
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88 * (not the zigzag order in which they are stored in a JPEG DQT marker).
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89 * CAUTION: IJG versions prior to v6a kept this array in zigzag order.
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91 UINT16 quantval[DCTSIZE2]; /* quantization step for each coefficient */
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92 /* This field is used only during compression. It's initialized FALSE when
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93 * the table is created, and set TRUE when it's been output to the file.
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94 * You could suppress output of a table by setting this to TRUE.
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95 * (See jpeg_suppress_tables for an example.)
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97 boolean sent_table; /* TRUE when table has been output */
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101 /* Huffman coding tables. */
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104 /* These two fields directly represent the contents of a JPEG DHT marker */
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105 UINT8 bits[17]; /* bits[k] = # of symbols with codes of */
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106 /* length k bits; bits[0] is unused */
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107 UINT8 huffval[256]; /* The symbols, in order of incr code length */
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108 /* This field is used only during compression. It's initialized FALSE when
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109 * the table is created, and set TRUE when it's been output to the file.
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110 * You could suppress output of a table by setting this to TRUE.
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111 * (See jpeg_suppress_tables for an example.)
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113 boolean sent_table; /* TRUE when table has been output */
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117 /* Basic info about one component (color channel). */
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120 /* These values are fixed over the whole image. */
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121 /* For compression, they must be supplied by parameter setup; */
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122 /* for decompression, they are read from the SOF marker. */
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123 int component_id; /* identifier for this component (0..255) */
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124 int component_index; /* its index in SOF or cinfo->comp_info[] */
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125 int h_samp_factor; /* horizontal sampling factor (1..4) */
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126 int v_samp_factor; /* vertical sampling factor (1..4) */
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127 int quant_tbl_no; /* quantization table selector (0..3) */
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128 /* These values may vary between scans. */
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129 /* For compression, they must be supplied by parameter setup; */
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130 /* for decompression, they are read from the SOS marker. */
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131 /* The decompressor output side may not use these variables. */
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132 int dc_tbl_no; /* DC entropy table selector (0..3) */
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133 int ac_tbl_no; /* AC entropy table selector (0..3) */
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135 /* Remaining fields should be treated as private by applications. */
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137 /* These values are computed during compression or decompression startup: */
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138 /* Component's size in DCT blocks.
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139 * Any dummy blocks added to complete an MCU are not counted; therefore
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140 * these values do not depend on whether a scan is interleaved or not.
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142 JDIMENSION width_in_blocks;
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143 JDIMENSION height_in_blocks;
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144 /* Size of a DCT block in samples. Always DCTSIZE for compression.
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145 * For decompression this is the size of the output from one DCT block,
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146 * reflecting any scaling we choose to apply during the IDCT step.
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147 * Values from 1 to 16 are supported.
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148 * Note that different components may receive different IDCT scalings.
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150 #if JPEG_LIB_VERSION >= 70
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151 int DCT_h_scaled_size;
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152 int DCT_v_scaled_size;
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154 int DCT_scaled_size;
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156 /* The downsampled dimensions are the component's actual, unpadded number
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157 * of samples at the main buffer (preprocessing/compression interface), thus
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158 * downsampled_width = ceil(image_width * Hi/Hmax)
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159 * and similarly for height. For decompression, IDCT scaling is included, so
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160 * downsampled_width = ceil(image_width * Hi/Hmax * DCT_[h_]scaled_size/DCTSIZE)
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162 JDIMENSION downsampled_width; /* actual width in samples */
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163 JDIMENSION downsampled_height; /* actual height in samples */
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164 /* This flag is used only for decompression. In cases where some of the
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165 * components will be ignored (eg grayscale output from YCbCr image),
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166 * we can skip most computations for the unused components.
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168 boolean component_needed; /* do we need the value of this component? */
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170 /* These values are computed before starting a scan of the component. */
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171 /* The decompressor output side may not use these variables. */
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172 int MCU_width; /* number of blocks per MCU, horizontally */
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173 int MCU_height; /* number of blocks per MCU, vertically */
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174 int MCU_blocks; /* MCU_width * MCU_height */
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175 int MCU_sample_width; /* MCU width in samples, MCU_width*DCT_[h_]scaled_size */
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176 int last_col_width; /* # of non-dummy blocks across in last MCU */
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177 int last_row_height; /* # of non-dummy blocks down in last MCU */
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179 /* Saved quantization table for component; NULL if none yet saved.
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180 * See jdinput.c comments about the need for this information.
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181 * This field is currently used only for decompression.
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183 JQUANT_TBL *quant_table;
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185 /* Private per-component storage for DCT or IDCT subsystem. */
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187 } jpeg_component_info;
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190 /* The script for encoding a multiple-scan file is an array of these: */
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193 int comps_in_scan; /* number of components encoded in this scan */
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194 int component_index[MAX_COMPS_IN_SCAN]; /* their SOF/comp_info[] indexes */
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195 int Ss, Se; /* progressive JPEG spectral selection parms */
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196 int Ah, Al; /* progressive JPEG successive approx. parms */
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199 /* The decompressor can save APPn and COM markers in a list of these: */
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201 typedef struct jpeg_marker_struct *jpeg_saved_marker_ptr;
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203 struct jpeg_marker_struct {
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204 jpeg_saved_marker_ptr next; /* next in list, or NULL */
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205 UINT8 marker; /* marker code: JPEG_COM, or JPEG_APP0+n */
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206 unsigned int original_length; /* # bytes of data in the file */
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207 unsigned int data_length; /* # bytes of data saved at data[] */
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208 JOCTET *data; /* the data contained in the marker */
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209 /* the marker length word is not counted in data_length or original_length */
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212 /* Known color spaces. */
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214 #define JCS_EXTENSIONS 1
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215 #define JCS_ALPHA_EXTENSIONS 1
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218 JCS_UNKNOWN, /* error/unspecified */
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219 JCS_GRAYSCALE, /* monochrome */
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220 JCS_RGB, /* red/green/blue as specified by the RGB_RED,
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221 RGB_GREEN, RGB_BLUE, and RGB_PIXELSIZE macros */
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222 JCS_YCbCr, /* Y/Cb/Cr (also known as YUV) */
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223 JCS_CMYK, /* C/M/Y/K */
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224 JCS_YCCK, /* Y/Cb/Cr/K */
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225 JCS_EXT_RGB, /* red/green/blue */
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226 JCS_EXT_RGBX, /* red/green/blue/x */
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227 JCS_EXT_BGR, /* blue/green/red */
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228 JCS_EXT_BGRX, /* blue/green/red/x */
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229 JCS_EXT_XBGR, /* x/blue/green/red */
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230 JCS_EXT_XRGB, /* x/red/green/blue */
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231 /* When out_color_space it set to JCS_EXT_RGBX, JCS_EXT_BGRX, JCS_EXT_XBGR,
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232 or JCS_EXT_XRGB during decompression, the X byte is undefined, and in
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233 order to ensure the best performance, libjpeg-turbo can set that byte to
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234 whatever value it wishes. Use the following colorspace constants to
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235 ensure that the X byte is set to 0xFF, so that it can be interpreted as an
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236 opaque alpha channel. */
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237 JCS_EXT_RGBA, /* red/green/blue/alpha */
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238 JCS_EXT_BGRA, /* blue/green/red/alpha */
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239 JCS_EXT_ABGR, /* alpha/blue/green/red */
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240 JCS_EXT_ARGB, /* alpha/red/green/blue */
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241 JCS_RGB565 /* 5-bit red/6-bit green/5-bit blue */
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244 /* DCT/IDCT algorithm options. */
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247 JDCT_ISLOW, /* slow but accurate integer algorithm */
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248 JDCT_IFAST, /* faster, less accurate integer method */
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249 JDCT_FLOAT /* floating-point: accurate, fast on fast HW */
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252 #ifndef JDCT_DEFAULT /* may be overridden in jconfig.h */
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253 #define JDCT_DEFAULT JDCT_ISLOW
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255 #ifndef JDCT_FASTEST /* may be overridden in jconfig.h */
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256 #define JDCT_FASTEST JDCT_IFAST
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259 /* Dithering options for decompression. */
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262 JDITHER_NONE, /* no dithering */
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263 JDITHER_ORDERED, /* simple ordered dither */
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264 JDITHER_FS /* Floyd-Steinberg error diffusion dither */
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268 /* Common fields between JPEG compression and decompression master structs. */
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270 #define jpeg_common_fields \
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271 struct jpeg_error_mgr *err; /* Error handler module */\
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272 struct jpeg_memory_mgr *mem; /* Memory manager module */\
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273 struct jpeg_progress_mgr *progress; /* Progress monitor, or NULL if none */\
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274 void *client_data; /* Available for use by application */\
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275 boolean is_decompressor; /* So common code can tell which is which */\
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276 int global_state /* For checking call sequence validity */
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278 /* Routines that are to be used by both halves of the library are declared
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279 * to receive a pointer to this structure. There are no actual instances of
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280 * jpeg_common_struct, only of jpeg_compress_struct and jpeg_decompress_struct.
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282 struct jpeg_common_struct {
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283 jpeg_common_fields; /* Fields common to both master struct types */
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284 /* Additional fields follow in an actual jpeg_compress_struct or
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285 * jpeg_decompress_struct. All three structs must agree on these
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286 * initial fields! (This would be a lot cleaner in C++.)
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290 typedef struct jpeg_common_struct *j_common_ptr;
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291 typedef struct jpeg_compress_struct *j_compress_ptr;
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292 typedef struct jpeg_decompress_struct *j_decompress_ptr;
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295 /* Master record for a compression instance */
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297 struct jpeg_compress_struct {
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298 jpeg_common_fields; /* Fields shared with jpeg_decompress_struct */
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300 /* Destination for compressed data */
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301 struct jpeg_destination_mgr *dest;
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303 /* Description of source image --- these fields must be filled in by
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304 * outer application before starting compression. in_color_space must
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305 * be correct before you can even call jpeg_set_defaults().
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308 JDIMENSION image_width; /* input image width */
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309 JDIMENSION image_height; /* input image height */
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310 int input_components; /* # of color components in input image */
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311 J_COLOR_SPACE in_color_space; /* colorspace of input image */
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313 double input_gamma; /* image gamma of input image */
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315 /* Compression parameters --- these fields must be set before calling
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316 * jpeg_start_compress(). We recommend calling jpeg_set_defaults() to
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317 * initialize everything to reasonable defaults, then changing anything
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318 * the application specifically wants to change. That way you won't get
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319 * burnt when new parameters are added. Also note that there are several
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320 * helper routines to simplify changing parameters.
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323 #if JPEG_LIB_VERSION >= 70
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324 unsigned int scale_num, scale_denom; /* fraction by which to scale image */
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326 JDIMENSION jpeg_width; /* scaled JPEG image width */
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327 JDIMENSION jpeg_height; /* scaled JPEG image height */
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328 /* Dimensions of actual JPEG image that will be written to file,
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329 * derived from input dimensions by scaling factors above.
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330 * These fields are computed by jpeg_start_compress().
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331 * You can also use jpeg_calc_jpeg_dimensions() to determine these values
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332 * in advance of calling jpeg_start_compress().
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336 int data_precision; /* bits of precision in image data */
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338 int num_components; /* # of color components in JPEG image */
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339 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
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341 jpeg_component_info *comp_info;
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342 /* comp_info[i] describes component that appears i'th in SOF */
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344 JQUANT_TBL *quant_tbl_ptrs[NUM_QUANT_TBLS];
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345 #if JPEG_LIB_VERSION >= 70
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346 int q_scale_factor[NUM_QUANT_TBLS];
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348 /* ptrs to coefficient quantization tables, or NULL if not defined,
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349 * and corresponding scale factors (percentage, initialized 100).
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352 JHUFF_TBL *dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
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353 JHUFF_TBL *ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
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354 /* ptrs to Huffman coding tables, or NULL if not defined */
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356 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
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357 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
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358 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
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360 int num_scans; /* # of entries in scan_info array */
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361 const jpeg_scan_info *scan_info; /* script for multi-scan file, or NULL */
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362 /* The default value of scan_info is NULL, which causes a single-scan
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363 * sequential JPEG file to be emitted. To create a multi-scan file,
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364 * set num_scans and scan_info to point to an array of scan definitions.
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367 boolean raw_data_in; /* TRUE=caller supplies downsampled data */
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368 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */
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369 boolean optimize_coding; /* TRUE=optimize entropy encoding parms */
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370 boolean CCIR601_sampling; /* TRUE=first samples are cosited */
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371 #if JPEG_LIB_VERSION >= 70
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372 boolean do_fancy_downsampling; /* TRUE=apply fancy downsampling */
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374 int smoothing_factor; /* 1..100, or 0 for no input smoothing */
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375 J_DCT_METHOD dct_method; /* DCT algorithm selector */
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377 /* The restart interval can be specified in absolute MCUs by setting
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378 * restart_interval, or in MCU rows by setting restart_in_rows
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379 * (in which case the correct restart_interval will be figured
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382 unsigned int restart_interval; /* MCUs per restart, or 0 for no restart */
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383 int restart_in_rows; /* if > 0, MCU rows per restart interval */
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385 /* Parameters controlling emission of special markers. */
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387 boolean write_JFIF_header; /* should a JFIF marker be written? */
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388 UINT8 JFIF_major_version; /* What to write for the JFIF version number */
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389 UINT8 JFIF_minor_version;
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390 /* These three values are not used by the JPEG code, merely copied */
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391 /* into the JFIF APP0 marker. density_unit can be 0 for unknown, */
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392 /* 1 for dots/inch, or 2 for dots/cm. Note that the pixel aspect */
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393 /* ratio is defined by X_density/Y_density even when density_unit=0. */
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394 UINT8 density_unit; /* JFIF code for pixel size units */
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395 UINT16 X_density; /* Horizontal pixel density */
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396 UINT16 Y_density; /* Vertical pixel density */
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397 boolean write_Adobe_marker; /* should an Adobe marker be written? */
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399 /* State variable: index of next scanline to be written to
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400 * jpeg_write_scanlines(). Application may use this to control its
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401 * processing loop, e.g., "while (next_scanline < image_height)".
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404 JDIMENSION next_scanline; /* 0 .. image_height-1 */
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406 /* Remaining fields are known throughout compressor, but generally
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407 * should not be touched by a surrounding application.
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411 * These fields are computed during compression startup
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413 boolean progressive_mode; /* TRUE if scan script uses progressive mode */
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414 int max_h_samp_factor; /* largest h_samp_factor */
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415 int max_v_samp_factor; /* largest v_samp_factor */
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417 #if JPEG_LIB_VERSION >= 70
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418 int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */
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419 int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */
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422 JDIMENSION total_iMCU_rows; /* # of iMCU rows to be input to coef ctlr */
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423 /* The coefficient controller receives data in units of MCU rows as defined
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424 * for fully interleaved scans (whether the JPEG file is interleaved or not).
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425 * There are v_samp_factor * DCTSIZE sample rows of each component in an
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426 * "iMCU" (interleaved MCU) row.
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430 * These fields are valid during any one scan.
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431 * They describe the components and MCUs actually appearing in the scan.
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433 int comps_in_scan; /* # of JPEG components in this scan */
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434 jpeg_component_info *cur_comp_info[MAX_COMPS_IN_SCAN];
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435 /* *cur_comp_info[i] describes component that appears i'th in SOS */
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437 JDIMENSION MCUs_per_row; /* # of MCUs across the image */
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438 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */
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440 int blocks_in_MCU; /* # of DCT blocks per MCU */
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441 int MCU_membership[C_MAX_BLOCKS_IN_MCU];
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442 /* MCU_membership[i] is index in cur_comp_info of component owning */
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443 /* i'th block in an MCU */
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445 int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */
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447 #if JPEG_LIB_VERSION >= 80
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448 int block_size; /* the basic DCT block size: 1..16 */
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449 const int *natural_order; /* natural-order position array */
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450 int lim_Se; /* min( Se, DCTSIZE2-1 ) */
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454 * Links to compression subobjects (methods and private variables of modules)
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456 struct jpeg_comp_master *master;
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457 struct jpeg_c_main_controller *main;
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458 struct jpeg_c_prep_controller *prep;
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459 struct jpeg_c_coef_controller *coef;
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460 struct jpeg_marker_writer *marker;
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461 struct jpeg_color_converter *cconvert;
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462 struct jpeg_downsampler *downsample;
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463 struct jpeg_forward_dct *fdct;
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464 struct jpeg_entropy_encoder *entropy;
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465 jpeg_scan_info *script_space; /* workspace for jpeg_simple_progression */
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466 int script_space_size;
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470 /* Master record for a decompression instance */
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472 struct jpeg_decompress_struct {
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473 jpeg_common_fields; /* Fields shared with jpeg_compress_struct */
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475 /* Source of compressed data */
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476 struct jpeg_source_mgr *src;
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478 /* Basic description of image --- filled in by jpeg_read_header(). */
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479 /* Application may inspect these values to decide how to process image. */
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481 JDIMENSION image_width; /* nominal image width (from SOF marker) */
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482 JDIMENSION image_height; /* nominal image height */
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483 int num_components; /* # of color components in JPEG image */
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484 J_COLOR_SPACE jpeg_color_space; /* colorspace of JPEG image */
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486 /* Decompression processing parameters --- these fields must be set before
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487 * calling jpeg_start_decompress(). Note that jpeg_read_header() initializes
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488 * them to default values.
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491 J_COLOR_SPACE out_color_space; /* colorspace for output */
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493 unsigned int scale_num, scale_denom; /* fraction by which to scale image */
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495 double output_gamma; /* image gamma wanted in output */
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497 boolean buffered_image; /* TRUE=multiple output passes */
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498 boolean raw_data_out; /* TRUE=downsampled data wanted */
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500 J_DCT_METHOD dct_method; /* IDCT algorithm selector */
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501 boolean do_fancy_upsampling; /* TRUE=apply fancy upsampling */
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502 boolean do_block_smoothing; /* TRUE=apply interblock smoothing */
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504 boolean quantize_colors; /* TRUE=colormapped output wanted */
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505 /* the following are ignored if not quantize_colors: */
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506 J_DITHER_MODE dither_mode; /* type of color dithering to use */
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507 boolean two_pass_quantize; /* TRUE=use two-pass color quantization */
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508 int desired_number_of_colors; /* max # colors to use in created colormap */
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509 /* these are significant only in buffered-image mode: */
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510 boolean enable_1pass_quant; /* enable future use of 1-pass quantizer */
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511 boolean enable_external_quant;/* enable future use of external colormap */
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512 boolean enable_2pass_quant; /* enable future use of 2-pass quantizer */
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514 /* Description of actual output image that will be returned to application.
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515 * These fields are computed by jpeg_start_decompress().
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516 * You can also use jpeg_calc_output_dimensions() to determine these values
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517 * in advance of calling jpeg_start_decompress().
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520 JDIMENSION output_width; /* scaled image width */
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521 JDIMENSION output_height; /* scaled image height */
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522 int out_color_components; /* # of color components in out_color_space */
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523 int output_components; /* # of color components returned */
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524 /* output_components is 1 (a colormap index) when quantizing colors;
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525 * otherwise it equals out_color_components.
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527 int rec_outbuf_height; /* min recommended height of scanline buffer */
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528 /* If the buffer passed to jpeg_read_scanlines() is less than this many rows
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529 * high, space and time will be wasted due to unnecessary data copying.
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530 * Usually rec_outbuf_height will be 1 or 2, at most 4.
\r
533 /* When quantizing colors, the output colormap is described by these fields.
\r
534 * The application can supply a colormap by setting colormap non-NULL before
\r
535 * calling jpeg_start_decompress; otherwise a colormap is created during
\r
536 * jpeg_start_decompress or jpeg_start_output.
\r
537 * The map has out_color_components rows and actual_number_of_colors columns.
\r
539 int actual_number_of_colors; /* number of entries in use */
\r
540 JSAMPARRAY colormap; /* The color map as a 2-D pixel array */
\r
542 /* State variables: these variables indicate the progress of decompression.
\r
543 * The application may examine these but must not modify them.
\r
546 /* Row index of next scanline to be read from jpeg_read_scanlines().
\r
547 * Application may use this to control its processing loop, e.g.,
\r
548 * "while (output_scanline < output_height)".
\r
550 JDIMENSION output_scanline; /* 0 .. output_height-1 */
\r
552 /* Current input scan number and number of iMCU rows completed in scan.
\r
553 * These indicate the progress of the decompressor input side.
\r
555 int input_scan_number; /* Number of SOS markers seen so far */
\r
556 JDIMENSION input_iMCU_row; /* Number of iMCU rows completed */
\r
558 /* The "output scan number" is the notional scan being displayed by the
\r
559 * output side. The decompressor will not allow output scan/row number
\r
560 * to get ahead of input scan/row, but it can fall arbitrarily far behind.
\r
562 int output_scan_number; /* Nominal scan number being displayed */
\r
563 JDIMENSION output_iMCU_row; /* Number of iMCU rows read */
\r
565 /* Current progression status. coef_bits[c][i] indicates the precision
\r
566 * with which component c's DCT coefficient i (in zigzag order) is known.
\r
567 * It is -1 when no data has yet been received, otherwise it is the point
\r
568 * transform (shift) value for the most recent scan of the coefficient
\r
569 * (thus, 0 at completion of the progression).
\r
570 * This pointer is NULL when reading a non-progressive file.
\r
572 int (*coef_bits)[DCTSIZE2]; /* -1 or current Al value for each coef */
\r
574 /* Internal JPEG parameters --- the application usually need not look at
\r
575 * these fields. Note that the decompressor output side may not use
\r
576 * any parameters that can change between scans.
\r
579 /* Quantization and Huffman tables are carried forward across input
\r
580 * datastreams when processing abbreviated JPEG datastreams.
\r
583 JQUANT_TBL *quant_tbl_ptrs[NUM_QUANT_TBLS];
\r
584 /* ptrs to coefficient quantization tables, or NULL if not defined */
\r
586 JHUFF_TBL *dc_huff_tbl_ptrs[NUM_HUFF_TBLS];
\r
587 JHUFF_TBL *ac_huff_tbl_ptrs[NUM_HUFF_TBLS];
\r
588 /* ptrs to Huffman coding tables, or NULL if not defined */
\r
590 /* These parameters are never carried across datastreams, since they
\r
591 * are given in SOF/SOS markers or defined to be reset by SOI.
\r
594 int data_precision; /* bits of precision in image data */
\r
596 jpeg_component_info *comp_info;
\r
597 /* comp_info[i] describes component that appears i'th in SOF */
\r
599 #if JPEG_LIB_VERSION >= 80
\r
600 boolean is_baseline; /* TRUE if Baseline SOF0 encountered */
\r
602 boolean progressive_mode; /* TRUE if SOFn specifies progressive mode */
\r
603 boolean arith_code; /* TRUE=arithmetic coding, FALSE=Huffman */
\r
605 UINT8 arith_dc_L[NUM_ARITH_TBLS]; /* L values for DC arith-coding tables */
\r
606 UINT8 arith_dc_U[NUM_ARITH_TBLS]; /* U values for DC arith-coding tables */
\r
607 UINT8 arith_ac_K[NUM_ARITH_TBLS]; /* Kx values for AC arith-coding tables */
\r
609 unsigned int restart_interval; /* MCUs per restart interval, or 0 for no restart */
\r
611 /* These fields record data obtained from optional markers recognized by
\r
612 * the JPEG library.
\r
614 boolean saw_JFIF_marker; /* TRUE iff a JFIF APP0 marker was found */
\r
615 /* Data copied from JFIF marker; only valid if saw_JFIF_marker is TRUE: */
\r
616 UINT8 JFIF_major_version; /* JFIF version number */
\r
617 UINT8 JFIF_minor_version;
\r
618 UINT8 density_unit; /* JFIF code for pixel size units */
\r
619 UINT16 X_density; /* Horizontal pixel density */
\r
620 UINT16 Y_density; /* Vertical pixel density */
\r
621 boolean saw_Adobe_marker; /* TRUE iff an Adobe APP14 marker was found */
\r
622 UINT8 Adobe_transform; /* Color transform code from Adobe marker */
\r
624 boolean CCIR601_sampling; /* TRUE=first samples are cosited */
\r
626 /* Aside from the specific data retained from APPn markers known to the
\r
627 * library, the uninterpreted contents of any or all APPn and COM markers
\r
628 * can be saved in a list for examination by the application.
\r
630 jpeg_saved_marker_ptr marker_list; /* Head of list of saved markers */
\r
632 /* Remaining fields are known throughout decompressor, but generally
\r
633 * should not be touched by a surrounding application.
\r
637 * These fields are computed during decompression startup
\r
639 int max_h_samp_factor; /* largest h_samp_factor */
\r
640 int max_v_samp_factor; /* largest v_samp_factor */
\r
642 #if JPEG_LIB_VERSION >= 70
\r
643 int min_DCT_h_scaled_size; /* smallest DCT_h_scaled_size of any component */
\r
644 int min_DCT_v_scaled_size; /* smallest DCT_v_scaled_size of any component */
\r
646 int min_DCT_scaled_size; /* smallest DCT_scaled_size of any component */
\r
649 JDIMENSION total_iMCU_rows; /* # of iMCU rows in image */
\r
650 /* The coefficient controller's input and output progress is measured in
\r
651 * units of "iMCU" (interleaved MCU) rows. These are the same as MCU rows
\r
652 * in fully interleaved JPEG scans, but are used whether the scan is
\r
653 * interleaved or not. We define an iMCU row as v_samp_factor DCT block
\r
654 * rows of each component. Therefore, the IDCT output contains
\r
655 * v_samp_factor*DCT_[v_]scaled_size sample rows of a component per iMCU row.
\r
658 JSAMPLE *sample_range_limit; /* table for fast range-limiting */
\r
661 * These fields are valid during any one scan.
\r
662 * They describe the components and MCUs actually appearing in the scan.
\r
663 * Note that the decompressor output side must not use these fields.
\r
665 int comps_in_scan; /* # of JPEG components in this scan */
\r
666 jpeg_component_info *cur_comp_info[MAX_COMPS_IN_SCAN];
\r
667 /* *cur_comp_info[i] describes component that appears i'th in SOS */
\r
669 JDIMENSION MCUs_per_row; /* # of MCUs across the image */
\r
670 JDIMENSION MCU_rows_in_scan; /* # of MCU rows in the image */
\r
672 int blocks_in_MCU; /* # of DCT blocks per MCU */
\r
673 int MCU_membership[D_MAX_BLOCKS_IN_MCU];
\r
674 /* MCU_membership[i] is index in cur_comp_info of component owning */
\r
675 /* i'th block in an MCU */
\r
677 int Ss, Se, Ah, Al; /* progressive JPEG parameters for scan */
\r
679 #if JPEG_LIB_VERSION >= 80
\r
680 /* These fields are derived from Se of first SOS marker.
\r
682 int block_size; /* the basic DCT block size: 1..16 */
\r
683 const int *natural_order; /* natural-order position array for entropy decode */
\r
684 int lim_Se; /* min( Se, DCTSIZE2-1 ) for entropy decode */
\r
687 /* This field is shared between entropy decoder and marker parser.
\r
688 * It is either zero or the code of a JPEG marker that has been
\r
689 * read from the data source, but has not yet been processed.
\r
694 * Links to decompression subobjects (methods, private variables of modules)
\r
696 struct jpeg_decomp_master *master;
\r
697 struct jpeg_d_main_controller *main;
\r
698 struct jpeg_d_coef_controller *coef;
\r
699 struct jpeg_d_post_controller *post;
\r
700 struct jpeg_input_controller *inputctl;
\r
701 struct jpeg_marker_reader *marker;
\r
702 struct jpeg_entropy_decoder *entropy;
\r
703 struct jpeg_inverse_dct *idct;
\r
704 struct jpeg_upsampler *upsample;
\r
705 struct jpeg_color_deconverter *cconvert;
\r
706 struct jpeg_color_quantizer *cquantize;
\r
710 /* "Object" declarations for JPEG modules that may be supplied or called
\r
711 * directly by the surrounding application.
\r
712 * As with all objects in the JPEG library, these structs only define the
\r
713 * publicly visible methods and state variables of a module. Additional
\r
714 * private fields may exist after the public ones.
\r
718 /* Error handler object */
\r
720 struct jpeg_error_mgr {
\r
721 /* Error exit handler: does not return to caller */
\r
722 void (*error_exit) (j_common_ptr cinfo);
\r
723 /* Conditionally emit a trace or warning message */
\r
724 void (*emit_message) (j_common_ptr cinfo, int msg_level);
\r
725 /* Routine that actually outputs a trace or error message */
\r
726 void (*output_message) (j_common_ptr cinfo);
\r
727 /* Format a message string for the most recent JPEG error or message */
\r
728 void (*format_message) (j_common_ptr cinfo, char *buffer);
\r
729 #define JMSG_LENGTH_MAX 200 /* recommended size of format_message buffer */
\r
730 /* Reset error state variables at start of a new image */
\r
731 void (*reset_error_mgr) (j_common_ptr cinfo);
\r
733 /* The message ID code and any parameters are saved here.
\r
734 * A message can have one string parameter or up to 8 int parameters.
\r
737 #define JMSG_STR_PARM_MAX 80
\r
740 char s[JMSG_STR_PARM_MAX];
\r
743 /* Standard state variables for error facility */
\r
745 int trace_level; /* max msg_level that will be displayed */
\r
747 /* For recoverable corrupt-data errors, we emit a warning message,
\r
748 * but keep going unless emit_message chooses to abort. emit_message
\r
749 * should count warnings in num_warnings. The surrounding application
\r
750 * can check for bad data by seeing if num_warnings is nonzero at the
\r
751 * end of processing.
\r
753 long num_warnings; /* number of corrupt-data warnings */
\r
755 /* These fields point to the table(s) of error message strings.
\r
756 * An application can change the table pointer to switch to a different
\r
757 * message list (typically, to change the language in which errors are
\r
758 * reported). Some applications may wish to add additional error codes
\r
759 * that will be handled by the JPEG library error mechanism; the second
\r
760 * table pointer is used for this purpose.
\r
762 * First table includes all errors generated by JPEG library itself.
\r
763 * Error code 0 is reserved for a "no such error string" message.
\r
765 const char * const *jpeg_message_table; /* Library errors */
\r
766 int last_jpeg_message; /* Table contains strings 0..last_jpeg_message */
\r
767 /* Second table can be added by application (see cjpeg/djpeg for example).
\r
768 * It contains strings numbered first_addon_message..last_addon_message.
\r
770 const char * const *addon_message_table; /* Non-library errors */
\r
771 int first_addon_message; /* code for first string in addon table */
\r
772 int last_addon_message; /* code for last string in addon table */
\r
776 /* Progress monitor object */
\r
778 struct jpeg_progress_mgr {
\r
779 void (*progress_monitor) (j_common_ptr cinfo);
\r
781 long pass_counter; /* work units completed in this pass */
\r
782 long pass_limit; /* total number of work units in this pass */
\r
783 int completed_passes; /* passes completed so far */
\r
784 int total_passes; /* total number of passes expected */
\r
788 /* Data destination object for compression */
\r
790 struct jpeg_destination_mgr {
\r
791 JOCTET *next_output_byte; /* => next byte to write in buffer */
\r
792 size_t free_in_buffer; /* # of byte spaces remaining in buffer */
\r
794 void (*init_destination) (j_compress_ptr cinfo);
\r
795 boolean (*empty_output_buffer) (j_compress_ptr cinfo);
\r
796 void (*term_destination) (j_compress_ptr cinfo);
\r
800 /* Data source object for decompression */
\r
802 struct jpeg_source_mgr {
\r
803 const JOCTET *next_input_byte; /* => next byte to read from buffer */
\r
804 size_t bytes_in_buffer; /* # of bytes remaining in buffer */
\r
806 void (*init_source) (j_decompress_ptr cinfo);
\r
807 boolean (*fill_input_buffer) (j_decompress_ptr cinfo);
\r
808 void (*skip_input_data) (j_decompress_ptr cinfo, long num_bytes);
\r
809 boolean (*resync_to_restart) (j_decompress_ptr cinfo, int desired);
\r
810 void (*term_source) (j_decompress_ptr cinfo);
\r
814 /* Memory manager object.
\r
815 * Allocates "small" objects (a few K total), "large" objects (tens of K),
\r
816 * and "really big" objects (virtual arrays with backing store if needed).
\r
817 * The memory manager does not allow individual objects to be freed; rather,
\r
818 * each created object is assigned to a pool, and whole pools can be freed
\r
819 * at once. This is faster and more convenient than remembering exactly what
\r
820 * to free, especially where malloc()/free() are not too speedy.
\r
821 * NB: alloc routines never return NULL. They exit to error_exit if not
\r
825 #define JPOOL_PERMANENT 0 /* lasts until master record is destroyed */
\r
826 #define JPOOL_IMAGE 1 /* lasts until done with image/datastream */
\r
827 #define JPOOL_NUMPOOLS 2
\r
829 typedef struct jvirt_sarray_control *jvirt_sarray_ptr;
\r
830 typedef struct jvirt_barray_control *jvirt_barray_ptr;
\r
833 struct jpeg_memory_mgr {
\r
834 /* Method pointers */
\r
835 void *(*alloc_small) (j_common_ptr cinfo, int pool_id, size_t sizeofobject);
\r
836 void *(*alloc_large) (j_common_ptr cinfo, int pool_id,
\r
837 size_t sizeofobject);
\r
838 JSAMPARRAY (*alloc_sarray) (j_common_ptr cinfo, int pool_id,
\r
839 JDIMENSION samplesperrow, JDIMENSION numrows);
\r
840 JBLOCKARRAY (*alloc_barray) (j_common_ptr cinfo, int pool_id,
\r
841 JDIMENSION blocksperrow, JDIMENSION numrows);
\r
842 jvirt_sarray_ptr (*request_virt_sarray) (j_common_ptr cinfo, int pool_id,
\r
844 JDIMENSION samplesperrow,
\r
845 JDIMENSION numrows,
\r
846 JDIMENSION maxaccess);
\r
847 jvirt_barray_ptr (*request_virt_barray) (j_common_ptr cinfo, int pool_id,
\r
849 JDIMENSION blocksperrow,
\r
850 JDIMENSION numrows,
\r
851 JDIMENSION maxaccess);
\r
852 void (*realize_virt_arrays) (j_common_ptr cinfo);
\r
853 JSAMPARRAY (*access_virt_sarray) (j_common_ptr cinfo, jvirt_sarray_ptr ptr,
\r
854 JDIMENSION start_row, JDIMENSION num_rows,
\r
856 JBLOCKARRAY (*access_virt_barray) (j_common_ptr cinfo, jvirt_barray_ptr ptr,
\r
857 JDIMENSION start_row, JDIMENSION num_rows,
\r
859 void (*free_pool) (j_common_ptr cinfo, int pool_id);
\r
860 void (*self_destruct) (j_common_ptr cinfo);
\r
862 /* Limit on memory allocation for this JPEG object. (Note that this is
\r
863 * merely advisory, not a guaranteed maximum; it only affects the space
\r
864 * used for virtual-array buffers.) May be changed by outer application
\r
865 * after creating the JPEG object.
\r
867 long max_memory_to_use;
\r
869 /* Maximum allocation request accepted by alloc_large. */
\r
870 long max_alloc_chunk;
\r
874 /* Routine signature for application-supplied marker processing methods.
\r
875 * Need not pass marker code since it is stored in cinfo->unread_marker.
\r
877 typedef boolean (*jpeg_marker_parser_method) (j_decompress_ptr cinfo);
\r
880 /* Originally, this macro was used as a way of defining function prototypes
\r
881 * for both modern compilers as well as older compilers that did not support
\r
882 * prototype parameters. libjpeg-turbo has never supported these older,
\r
883 * non-ANSI compilers, but the macro is still included because there is some
\r
884 * software out there that uses it.
\r
887 #define JPP(arglist) arglist
\r
890 /* Default error-management setup */
\r
891 EXTERN(struct jpeg_error_mgr *) jpeg_std_error (struct jpeg_error_mgr *err);
\r
893 /* Initialization of JPEG compression objects.
\r
894 * jpeg_create_compress() and jpeg_create_decompress() are the exported
\r
895 * names that applications should call. These expand to calls on
\r
896 * jpeg_CreateCompress and jpeg_CreateDecompress with additional information
\r
897 * passed for version mismatch checking.
\r
898 * NB: you must set up the error-manager BEFORE calling jpeg_create_xxx.
\r
900 #define jpeg_create_compress(cinfo) \
\r
901 jpeg_CreateCompress((cinfo), JPEG_LIB_VERSION, \
\r
902 (size_t) sizeof(struct jpeg_compress_struct))
\r
903 #define jpeg_create_decompress(cinfo) \
\r
904 jpeg_CreateDecompress((cinfo), JPEG_LIB_VERSION, \
\r
905 (size_t) sizeof(struct jpeg_decompress_struct))
\r
906 EXTERN(void) jpeg_CreateCompress (j_compress_ptr cinfo, int version,
\r
907 size_t structsize);
\r
908 EXTERN(void) jpeg_CreateDecompress (j_decompress_ptr cinfo, int version,
\r
909 size_t structsize);
\r
910 /* Destruction of JPEG compression objects */
\r
911 EXTERN(void) jpeg_destroy_compress (j_compress_ptr cinfo);
\r
912 EXTERN(void) jpeg_destroy_decompress (j_decompress_ptr cinfo);
\r
914 /* Standard data source and destination managers: stdio streams. */
\r
915 /* Caller is responsible for opening the file before and closing after. */
\r
919 size_t(*ReadBufferCallback)(long, char*, int);
\r
922 EXTERN(void) jpeg_stdio_dest (j_compress_ptr cinfo, FILE *outfile);
\r
923 EXTERN(void) jpeg_stdio_src (j_decompress_ptr cinfo, void *infile);
\r
925 #if JPEG_LIB_VERSION >= 80 || defined(MEM_SRCDST_SUPPORTED)
\r
926 /* Data source and destination managers: memory buffers. */
\r
927 EXTERN(void) jpeg_mem_dest (j_compress_ptr cinfo, unsigned char **outbuffer,
\r
928 unsigned long *outsize);
\r
929 EXTERN(void) jpeg_mem_src (j_decompress_ptr cinfo,
\r
930 const unsigned char *inbuffer,
\r
931 unsigned long insize);
\r
934 /* Default parameter setup for compression */
\r
935 EXTERN(void) jpeg_set_defaults (j_compress_ptr cinfo);
\r
936 /* Compression parameter setup aids */
\r
937 EXTERN(void) jpeg_set_colorspace (j_compress_ptr cinfo,
\r
938 J_COLOR_SPACE colorspace);
\r
939 EXTERN(void) jpeg_default_colorspace (j_compress_ptr cinfo);
\r
940 EXTERN(void) jpeg_set_quality (j_compress_ptr cinfo, int quality,
\r
941 boolean force_baseline);
\r
942 EXTERN(void) jpeg_set_linear_quality (j_compress_ptr cinfo, int scale_factor,
\r
943 boolean force_baseline);
\r
944 #if JPEG_LIB_VERSION >= 70
\r
945 EXTERN(void) jpeg_default_qtables (j_compress_ptr cinfo,
\r
946 boolean force_baseline);
\r
948 EXTERN(void) jpeg_add_quant_table (j_compress_ptr cinfo, int which_tbl,
\r
949 const unsigned int *basic_table,
\r
950 int scale_factor, boolean force_baseline);
\r
951 EXTERN(int) jpeg_quality_scaling (int quality);
\r
952 EXTERN(void) jpeg_simple_progression (j_compress_ptr cinfo);
\r
953 EXTERN(void) jpeg_suppress_tables (j_compress_ptr cinfo, boolean suppress);
\r
954 EXTERN(JQUANT_TBL *) jpeg_alloc_quant_table (j_common_ptr cinfo);
\r
955 EXTERN(JHUFF_TBL *) jpeg_alloc_huff_table (j_common_ptr cinfo);
\r
957 /* Main entry points for compression */
\r
958 EXTERN(void) jpeg_start_compress (j_compress_ptr cinfo,
\r
959 boolean write_all_tables);
\r
960 EXTERN(JDIMENSION) jpeg_write_scanlines (j_compress_ptr cinfo,
\r
961 JSAMPARRAY scanlines,
\r
962 JDIMENSION num_lines);
\r
963 EXTERN(void) jpeg_finish_compress (j_compress_ptr cinfo);
\r
965 #if JPEG_LIB_VERSION >= 70
\r
966 /* Precalculate JPEG dimensions for current compression parameters. */
\r
967 EXTERN(void) jpeg_calc_jpeg_dimensions (j_compress_ptr cinfo);
\r
970 /* Replaces jpeg_write_scanlines when writing raw downsampled data. */
\r
971 EXTERN(JDIMENSION) jpeg_write_raw_data (j_compress_ptr cinfo, JSAMPIMAGE data,
\r
972 JDIMENSION num_lines);
\r
974 /* Write a special marker. See libjpeg.txt concerning safe usage. */
\r
975 EXTERN(void) jpeg_write_marker (j_compress_ptr cinfo, int marker,
\r
976 const JOCTET *dataptr, unsigned int datalen);
\r
977 /* Same, but piecemeal. */
\r
978 EXTERN(void) jpeg_write_m_header (j_compress_ptr cinfo, int marker,
\r
979 unsigned int datalen);
\r
980 EXTERN(void) jpeg_write_m_byte (j_compress_ptr cinfo, int val);
\r
982 /* Alternate compression function: just write an abbreviated table file */
\r
983 EXTERN(void) jpeg_write_tables (j_compress_ptr cinfo);
\r
985 /* Decompression startup: read start of JPEG datastream to see what's there */
\r
986 EXTERN(int) jpeg_read_header (j_decompress_ptr cinfo, boolean require_image);
\r
987 /* Return value is one of: */
\r
988 #define JPEG_SUSPENDED 0 /* Suspended due to lack of input data */
\r
989 #define JPEG_HEADER_OK 1 /* Found valid image datastream */
\r
990 #define JPEG_HEADER_TABLES_ONLY 2 /* Found valid table-specs-only datastream */
\r
991 /* If you pass require_image = TRUE (normal case), you need not check for
\r
992 * a TABLES_ONLY return code; an abbreviated file will cause an error exit.
\r
993 * JPEG_SUSPENDED is only possible if you use a data source module that can
\r
994 * give a suspension return (the stdio source module doesn't).
\r
997 /* Main entry points for decompression */
\r
998 EXTERN(boolean) jpeg_start_decompress (j_decompress_ptr cinfo);
\r
999 EXTERN(JDIMENSION) jpeg_read_scanlines (j_decompress_ptr cinfo,
\r
1000 JSAMPARRAY scanlines,
\r
1001 JDIMENSION max_lines);
\r
1002 EXTERN(JDIMENSION) jpeg_skip_scanlines (j_decompress_ptr cinfo,
\r
1003 JDIMENSION num_lines);
\r
1004 EXTERN(void) jpeg_crop_scanline (j_decompress_ptr cinfo, JDIMENSION *xoffset,
\r
1005 JDIMENSION *width);
\r
1006 EXTERN(boolean) jpeg_finish_decompress (j_decompress_ptr cinfo);
\r
1008 /* Replaces jpeg_read_scanlines when reading raw downsampled data. */
\r
1009 EXTERN(JDIMENSION) jpeg_read_raw_data (j_decompress_ptr cinfo, JSAMPIMAGE data,
\r
1010 JDIMENSION max_lines);
\r
1012 /* Additional entry points for buffered-image mode. */
\r
1013 EXTERN(boolean) jpeg_has_multiple_scans (j_decompress_ptr cinfo);
\r
1014 EXTERN(boolean) jpeg_start_output (j_decompress_ptr cinfo, int scan_number);
\r
1015 EXTERN(boolean) jpeg_finish_output (j_decompress_ptr cinfo);
\r
1016 EXTERN(boolean) jpeg_input_complete (j_decompress_ptr cinfo);
\r
1017 EXTERN(void) jpeg_new_colormap (j_decompress_ptr cinfo);
\r
1018 EXTERN(int) jpeg_consume_input (j_decompress_ptr cinfo);
\r
1019 /* Return value is one of: */
\r
1020 /* #define JPEG_SUSPENDED 0 Suspended due to lack of input data */
\r
1021 #define JPEG_REACHED_SOS 1 /* Reached start of new scan */
\r
1022 #define JPEG_REACHED_EOI 2 /* Reached end of image */
\r
1023 #define JPEG_ROW_COMPLETED 3 /* Completed one iMCU row */
\r
1024 #define JPEG_SCAN_COMPLETED 4 /* Completed last iMCU row of a scan */
\r
1026 /* Precalculate output dimensions for current decompression parameters. */
\r
1027 #if JPEG_LIB_VERSION >= 80
\r
1028 EXTERN(void) jpeg_core_output_dimensions (j_decompress_ptr cinfo);
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1030 EXTERN(void) jpeg_calc_output_dimensions (j_decompress_ptr cinfo);
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1032 /* Control saving of COM and APPn markers into marker_list. */
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1033 EXTERN(void) jpeg_save_markers (j_decompress_ptr cinfo, int marker_code,
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1034 unsigned int length_limit);
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1036 /* Install a special processing method for COM or APPn markers. */
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1037 EXTERN(void) jpeg_set_marker_processor (j_decompress_ptr cinfo,
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1039 jpeg_marker_parser_method routine);
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1041 /* Read or write raw DCT coefficients --- useful for lossless transcoding. */
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1042 EXTERN(jvirt_barray_ptr *) jpeg_read_coefficients (j_decompress_ptr cinfo);
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1043 EXTERN(void) jpeg_write_coefficients (j_compress_ptr cinfo,
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1044 jvirt_barray_ptr *coef_arrays);
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1045 EXTERN(void) jpeg_copy_critical_parameters (j_decompress_ptr srcinfo,
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1046 j_compress_ptr dstinfo);
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1048 /* If you choose to abort compression or decompression before completing
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1049 * jpeg_finish_(de)compress, then you need to clean up to release memory,
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1050 * temporary files, etc. You can just call jpeg_destroy_(de)compress
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1051 * if you're done with the JPEG object, but if you want to clean it up and
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1052 * reuse it, call this:
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1054 EXTERN(void) jpeg_abort_compress (j_compress_ptr cinfo);
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1055 EXTERN(void) jpeg_abort_decompress (j_decompress_ptr cinfo);
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1057 /* Generic versions of jpeg_abort and jpeg_destroy that work on either
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1058 * flavor of JPEG object. These may be more convenient in some places.
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1060 EXTERN(void) jpeg_abort (j_common_ptr cinfo);
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1061 EXTERN(void) jpeg_destroy (j_common_ptr cinfo);
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1063 /* Default restart-marker-resync procedure for use by data source modules */
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1064 EXTERN(boolean) jpeg_resync_to_restart (j_decompress_ptr cinfo, int desired);
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1067 /* These marker codes are exported since applications and data source modules
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1068 * are likely to want to use them.
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1071 #define JPEG_RST0 0xD0 /* RST0 marker code */
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1072 #define JPEG_EOI 0xD9 /* EOI marker code */
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1073 #define JPEG_APP0 0xE0 /* APP0 marker code */
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1074 #define JPEG_COM 0xFE /* COM marker code */
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1077 /* If we have a brain-damaged compiler that emits warnings (or worse, errors)
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1078 * for structure definitions that are never filled in, keep it quiet by
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1079 * supplying dummy definitions for the various substructures.
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1082 #ifdef INCOMPLETE_TYPES_BROKEN
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1083 #ifndef JPEG_INTERNALS /* will be defined in jpegint.h */
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1084 struct jvirt_sarray_control { long dummy; };
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1085 struct jvirt_barray_control { long dummy; };
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1086 struct jpeg_comp_master { long dummy; };
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1087 struct jpeg_c_main_controller { long dummy; };
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1088 struct jpeg_c_prep_controller { long dummy; };
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1089 struct jpeg_c_coef_controller { long dummy; };
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1090 struct jpeg_marker_writer { long dummy; };
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1091 struct jpeg_color_converter { long dummy; };
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1092 struct jpeg_downsampler { long dummy; };
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1093 struct jpeg_forward_dct { long dummy; };
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1094 struct jpeg_entropy_encoder { long dummy; };
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1095 struct jpeg_decomp_master { long dummy; };
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1096 struct jpeg_d_main_controller { long dummy; };
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1097 struct jpeg_d_coef_controller { long dummy; };
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1098 struct jpeg_d_post_controller { long dummy; };
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1099 struct jpeg_input_controller { long dummy; };
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1100 struct jpeg_marker_reader { long dummy; };
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1101 struct jpeg_entropy_decoder { long dummy; };
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1102 struct jpeg_inverse_dct { long dummy; };
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1103 struct jpeg_upsampler { long dummy; };
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1104 struct jpeg_color_deconverter { long dummy; };
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1105 struct jpeg_color_quantizer { long dummy; };
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1106 #endif /* JPEG_INTERNALS */
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1107 #endif /* INCOMPLETE_TYPES_BROKEN */
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1111 * The JPEG library modules define JPEG_INTERNALS before including this file.
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1112 * The internal structure declarations are read only when that is true.
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1113 * Applications using the library should not include jpegint.h, but may wish
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1114 * to include jerror.h.
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1117 #ifdef JPEG_INTERNALS
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1118 #include "jpegint.h" /* fetch private declarations */
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1119 #include "jerror.h" /* fetch error codes too */
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1122 #ifdef __cplusplus
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1123 #ifndef DONT_USE_EXTERN_C
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1128 #endif /* JPEGLIB_H */
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