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2296
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1
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2 /* pngwutil.c - utilities to write a PNG file
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3 *
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4 * Last changed in libpng 1.6.2 [April 25, 2013]
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5 * Copyright (c) 1998-2013 Glenn Randers-Pehrson
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6 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
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7 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
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8 *
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9 * This code is released under the libpng license.
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10 * For conditions of distribution and use, see the disclaimer
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11 * and license in png.h
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12 */
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13
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14 #include "pngpriv.h"
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15
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16 #ifdef PNG_WRITE_SUPPORTED
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17
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18 #ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED
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19 /* Place a 32-bit number into a buffer in PNG byte order. We work
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20 * with unsigned numbers for convenience, although one supported
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21 * ancillary chunk uses signed (two's complement) numbers.
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22 */
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23 void PNGAPI
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24 png_save_uint_32(png_bytep buf, png_uint_32 i)
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25 {
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26 buf[0] = (png_byte)((i >> 24) & 0xff);
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27 buf[1] = (png_byte)((i >> 16) & 0xff);
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28 buf[2] = (png_byte)((i >> 8) & 0xff);
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29 buf[3] = (png_byte)(i & 0xff);
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30 }
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31
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32 /* Place a 16-bit number into a buffer in PNG byte order.
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33 * The parameter is declared unsigned int, not png_uint_16,
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34 * just to avoid potential problems on pre-ANSI C compilers.
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35 */
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36 void PNGAPI
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37 png_save_uint_16(png_bytep buf, unsigned int i)
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38 {
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39 buf[0] = (png_byte)((i >> 8) & 0xff);
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40 buf[1] = (png_byte)(i & 0xff);
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41 }
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42 #endif
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43
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44 /* Simple function to write the signature. If we have already written
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45 * the magic bytes of the signature, or more likely, the PNG stream is
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46 * being embedded into another stream and doesn't need its own signature,
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47 * we should call png_set_sig_bytes() to tell libpng how many of the
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48 * bytes have already been written.
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49 */
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50 void PNGAPI
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51 png_write_sig(png_structrp png_ptr)
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52 {
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53 png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
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54
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55 #ifdef PNG_IO_STATE_SUPPORTED
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56 /* Inform the I/O callback that the signature is being written */
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57 png_ptr->io_state = PNG_IO_WRITING | PNG_IO_SIGNATURE;
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58 #endif
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59
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60 /* Write the rest of the 8 byte signature */
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61 png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes],
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62 (png_size_t)(8 - png_ptr->sig_bytes));
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63
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64 if (png_ptr->sig_bytes < 3)
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65 png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
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66 }
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67
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68 /* Write the start of a PNG chunk. The type is the chunk type.
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69 * The total_length is the sum of the lengths of all the data you will be
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70 * passing in png_write_chunk_data().
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71 */
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72 static void
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73 png_write_chunk_header(png_structrp png_ptr, png_uint_32 chunk_name,
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74 png_uint_32 length)
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75 {
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76 png_byte buf[8];
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77
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78 #if defined(PNG_DEBUG) && (PNG_DEBUG > 0)
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79 PNG_CSTRING_FROM_CHUNK(buf, chunk_name);
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80 png_debug2(0, "Writing %s chunk, length = %lu", buf, (unsigned long)length);
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81 #endif
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82
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83 if (png_ptr == NULL)
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84 return;
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85
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86 #ifdef PNG_IO_STATE_SUPPORTED
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87 /* Inform the I/O callback that the chunk header is being written.
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88 * PNG_IO_CHUNK_HDR requires a single I/O call.
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89 */
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90 png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_HDR;
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91 #endif
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92
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93 /* Write the length and the chunk name */
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94 png_save_uint_32(buf, length);
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95 png_save_uint_32(buf + 4, chunk_name);
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96 png_write_data(png_ptr, buf, 8);
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97
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98 /* Put the chunk name into png_ptr->chunk_name */
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99 png_ptr->chunk_name = chunk_name;
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100
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101 /* Reset the crc and run it over the chunk name */
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102 png_reset_crc(png_ptr);
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103
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104 png_calculate_crc(png_ptr, buf + 4, 4);
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105
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106 #ifdef PNG_IO_STATE_SUPPORTED
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107 /* Inform the I/O callback that chunk data will (possibly) be written.
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108 * PNG_IO_CHUNK_DATA does NOT require a specific number of I/O calls.
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109 */
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110 png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_DATA;
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111 #endif
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112 }
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113
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114 void PNGAPI
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115 png_write_chunk_start(png_structrp png_ptr, png_const_bytep chunk_string,
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116 png_uint_32 length)
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117 {
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118 png_write_chunk_header(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), length);
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119 }
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120
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121 /* Write the data of a PNG chunk started with png_write_chunk_header().
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122 * Note that multiple calls to this function are allowed, and that the
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123 * sum of the lengths from these calls *must* add up to the total_length
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124 * given to png_write_chunk_header().
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125 */
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126 void PNGAPI
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127 png_write_chunk_data(png_structrp png_ptr, png_const_bytep data,
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128 png_size_t length)
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129 {
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130 /* Write the data, and run the CRC over it */
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131 if (png_ptr == NULL)
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132 return;
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133
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134 if (data != NULL && length > 0)
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135 {
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136 png_write_data(png_ptr, data, length);
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137
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138 /* Update the CRC after writing the data,
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139 * in case that the user I/O routine alters it.
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140 */
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141 png_calculate_crc(png_ptr, data, length);
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142 }
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143 }
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144
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145 /* Finish a chunk started with png_write_chunk_header(). */
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146 void PNGAPI
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147 png_write_chunk_end(png_structrp png_ptr)
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148 {
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149 png_byte buf[4];
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150
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151 if (png_ptr == NULL) return;
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152
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153 #ifdef PNG_IO_STATE_SUPPORTED
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154 /* Inform the I/O callback that the chunk CRC is being written.
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155 * PNG_IO_CHUNK_CRC requires a single I/O function call.
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156 */
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157 png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_CRC;
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158 #endif
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159
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160 /* Write the crc in a single operation */
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161 png_save_uint_32(buf, png_ptr->crc);
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162
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163 png_write_data(png_ptr, buf, (png_size_t)4);
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164 }
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165
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166 /* Write a PNG chunk all at once. The type is an array of ASCII characters
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167 * representing the chunk name. The array must be at least 4 bytes in
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168 * length, and does not need to be null terminated. To be safe, pass the
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169 * pre-defined chunk names here, and if you need a new one, define it
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170 * where the others are defined. The length is the length of the data.
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171 * All the data must be present. If that is not possible, use the
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172 * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end()
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173 * functions instead.
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174 */
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175 static void
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176 png_write_complete_chunk(png_structrp png_ptr, png_uint_32 chunk_name,
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177 png_const_bytep data, png_size_t length)
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178 {
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179 if (png_ptr == NULL)
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180 return;
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181
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182 /* On 64 bit architectures 'length' may not fit in a png_uint_32. */
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183 if (length > PNG_UINT_31_MAX)
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184 png_error(png_ptr, "length exceeds PNG maxima");
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185
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186 png_write_chunk_header(png_ptr, chunk_name, (png_uint_32)length);
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187 png_write_chunk_data(png_ptr, data, length);
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188 png_write_chunk_end(png_ptr);
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189 }
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190
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191 /* This is the API that calls the internal function above. */
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192 void PNGAPI
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193 png_write_chunk(png_structrp png_ptr, png_const_bytep chunk_string,
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194 png_const_bytep data, png_size_t length)
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195 {
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196 png_write_complete_chunk(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), data,
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197 length);
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198 }
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199
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200 /* This is used below to find the size of an image to pass to png_deflate_claim,
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201 * so it only needs to be accurate if the size is less than 16384 bytes (the
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202 * point at which a lower LZ window size can be used.)
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203 */
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204 static png_alloc_size_t
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205 png_image_size(png_structrp png_ptr)
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206 {
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207 /* Only return sizes up to the maximum of a png_uint_32, do this by limiting
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208 * the width and height used to 15 bits.
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209 */
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210 png_uint_32 h = png_ptr->height;
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211
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212 if (png_ptr->rowbytes < 32768 && h < 32768)
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213 {
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214 if (png_ptr->interlaced)
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215 {
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216 /* Interlacing makes the image larger because of the replication of
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217 * both the filter byte and the padding to a byte boundary.
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218 */
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219 png_uint_32 w = png_ptr->width;
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220 unsigned int pd = png_ptr->pixel_depth;
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221 png_alloc_size_t cb_base;
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222 int pass;
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223
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224 for (cb_base=0, pass=0; pass<=6; ++pass)
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225 {
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226 png_uint_32 pw = PNG_PASS_COLS(w, pass);
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227
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228 if (pw > 0)
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229 cb_base += (PNG_ROWBYTES(pd, pw)+1) * PNG_PASS_ROWS(h, pass);
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230 }
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231
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232 return cb_base;
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233 }
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234
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235 else
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236 return (png_ptr->rowbytes+1) * h;
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237 }
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238
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239 else
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240 return 0xffffffffU;
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241 }
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242
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243 #ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
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244 /* This is the code to hack the first two bytes of the deflate stream (the
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245 * deflate header) to correct the windowBits value to match the actual data
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246 * size. Note that the second argument is the *uncompressed* size but the
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247 * first argument is the *compressed* data (and it must be deflate
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248 * compressed.)
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249 */
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250 static void
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251 optimize_cmf(png_bytep data, png_alloc_size_t data_size)
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252 {
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253 /* Optimize the CMF field in the zlib stream. The resultant zlib stream is
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254 * still compliant to the stream specification.
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255 */
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256 if (data_size <= 16384) /* else windowBits must be 15 */
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257 {
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258 unsigned int z_cmf = data[0]; /* zlib compression method and flags */
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259
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260 if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70)
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261 {
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262 unsigned int z_cinfo;
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263 unsigned int half_z_window_size;
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264
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265 z_cinfo = z_cmf >> 4;
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266 half_z_window_size = 1U << (z_cinfo + 7);
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267
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268 if (data_size <= half_z_window_size) /* else no change */
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269 {
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270 unsigned int tmp;
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271
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272 do
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273 {
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274 half_z_window_size >>= 1;
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275 --z_cinfo;
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276 }
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277 while (z_cinfo > 0 && data_size <= half_z_window_size);
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278
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279 z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4);
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280
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281 data[0] = (png_byte)z_cmf;
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282 tmp = data[1] & 0xe0;
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283 tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f;
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284 data[1] = (png_byte)tmp;
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285 }
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286 }
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287 }
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288 }
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289 #else
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290 # define optimize_cmf(dp,dl) ((void)0)
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291 #endif /* PNG_WRITE_OPTIMIZE_CMF_SUPPORTED */
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292
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293 /* Initialize the compressor for the appropriate type of compression. */
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294 static int
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295 png_deflate_claim(png_structrp png_ptr, png_uint_32 owner,
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296 png_alloc_size_t data_size)
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297 {
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298 if (png_ptr->zowner != 0)
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299 {
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300 char msg[64];
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301
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302 PNG_STRING_FROM_CHUNK(msg, owner);
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303 msg[4] = ':';
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304 msg[5] = ' ';
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305 PNG_STRING_FROM_CHUNK(msg+6, png_ptr->zowner);
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306 /* So the message that results is "<chunk> using zstream"; this is an
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307 * internal error, but is very useful for debugging. i18n requirements
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308 * are minimal.
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309 */
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310 (void)png_safecat(msg, (sizeof msg), 10, " using zstream");
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311 # if PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC
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312 png_warning(png_ptr, msg);
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313
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314 /* Attempt sane error recovery */
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315 if (png_ptr->zowner == png_IDAT) /* don't steal from IDAT */
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316 {
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317 png_ptr->zstream.msg = PNGZ_MSG_CAST("in use by IDAT");
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318 return Z_STREAM_ERROR;
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319 }
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320
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321 png_ptr->zowner = 0;
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322 # else
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323 png_error(png_ptr, msg);
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324 # endif
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325 }
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326
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327 {
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328 int level = png_ptr->zlib_level;
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329 int method = png_ptr->zlib_method;
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330 int windowBits = png_ptr->zlib_window_bits;
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331 int memLevel = png_ptr->zlib_mem_level;
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332 int strategy; /* set below */
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333 int ret; /* zlib return code */
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334
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335 if (owner == png_IDAT)
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336 {
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337 if (png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY)
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338 strategy = png_ptr->zlib_strategy;
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339
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340 else if (png_ptr->do_filter != PNG_FILTER_NONE)
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341 strategy = PNG_Z_DEFAULT_STRATEGY;
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342
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343 else
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344 strategy = PNG_Z_DEFAULT_NOFILTER_STRATEGY;
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345 }
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346
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347 else
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348 {
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349 # ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
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350 level = png_ptr->zlib_text_level;
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351 method = png_ptr->zlib_text_method;
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352 windowBits = png_ptr->zlib_text_window_bits;
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353 memLevel = png_ptr->zlib_text_mem_level;
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354 strategy = png_ptr->zlib_text_strategy;
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355 # else
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356 /* If customization is not supported the values all come from the
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357 * IDAT values except for the strategy, which is fixed to the
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358 * default. (This is the pre-1.6.0 behavior too, although it was
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359 * implemented in a very different way.)
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360 */
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361 strategy = Z_DEFAULT_STRATEGY;
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362 # endif
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363 }
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364
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365 /* Adjust 'windowBits' down if larger than 'data_size'; to stop this
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366 * happening just pass 32768 as the data_size parameter. Notice that zlib
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367 * requires an extra 262 bytes in the window in addition to the data to be
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368 * able to see the whole of the data, so if data_size+262 takes us to the
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369 * next windowBits size we need to fix up the value later. (Because even
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370 * though deflate needs the extra window, inflate does not!)
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371 */
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372 if (data_size <= 16384)
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373 {
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374 /* IMPLEMENTATION NOTE: this 'half_window_size' stuff is only here to
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375 * work round a Microsoft Visual C misbehavior which, contrary to C-90,
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376 * widens the result of the following shift to 64-bits if (and,
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377 * apparently, only if) it is used in a test.
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378 */
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379 unsigned int half_window_size = 1U << (windowBits-1);
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380
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381 while (data_size + 262 <= half_window_size)
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382 {
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383 half_window_size >>= 1;
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384 --windowBits;
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385 }
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386 }
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387
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388 /* Check against the previous initialized values, if any. */
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389 if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) &&
|
|
|
390 (png_ptr->zlib_set_level != level ||
|
|
|
391 png_ptr->zlib_set_method != method ||
|
|
|
392 png_ptr->zlib_set_window_bits != windowBits ||
|
|
|
393 png_ptr->zlib_set_mem_level != memLevel ||
|
|
|
394 png_ptr->zlib_set_strategy != strategy))
|
|
|
395 {
|
|
|
396 if (deflateEnd(&png_ptr->zstream) != Z_OK)
|
|
|
397 png_warning(png_ptr, "deflateEnd failed (ignored)");
|
|
|
398
|
|
|
399 png_ptr->flags &= ~PNG_FLAG_ZSTREAM_INITIALIZED;
|
|
|
400 }
|
|
|
401
|
|
|
402 /* For safety clear out the input and output pointers (currently zlib
|
|
|
403 * doesn't use them on Init, but it might in the future).
|
|
|
404 */
|
|
|
405 png_ptr->zstream.next_in = NULL;
|
|
|
406 png_ptr->zstream.avail_in = 0;
|
|
|
407 png_ptr->zstream.next_out = NULL;
|
|
|
408 png_ptr->zstream.avail_out = 0;
|
|
|
409
|
|
|
410 /* Now initialize if required, setting the new parameters, otherwise just
|
|
|
411 * to a simple reset to the previous parameters.
|
|
|
412 */
|
|
|
413 if (png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED)
|
|
|
414 ret = deflateReset(&png_ptr->zstream);
|
|
|
415
|
|
|
416 else
|
|
|
417 {
|
|
|
418 ret = deflateInit2(&png_ptr->zstream, level, method, windowBits,
|
|
|
419 memLevel, strategy);
|
|
|
420
|
|
|
421 if (ret == Z_OK)
|
|
|
422 png_ptr->flags |= PNG_FLAG_ZSTREAM_INITIALIZED;
|
|
|
423 }
|
|
|
424
|
|
|
425 /* The return code is from either deflateReset or deflateInit2; they have
|
|
|
426 * pretty much the same set of error codes.
|
|
|
427 */
|
|
|
428 if (ret == Z_OK)
|
|
|
429 png_ptr->zowner = owner;
|
|
|
430
|
|
|
431 else
|
|
|
432 png_zstream_error(png_ptr, ret);
|
|
|
433
|
|
|
434 return ret;
|
|
|
435 }
|
|
|
436 }
|
|
|
437
|
|
|
438 /* Clean up (or trim) a linked list of compression buffers. */
|
|
|
439 void /* PRIVATE */
|
|
|
440 png_free_buffer_list(png_structrp png_ptr, png_compression_bufferp *listp)
|
|
|
441 {
|
|
|
442 png_compression_bufferp list = *listp;
|
|
|
443
|
|
|
444 if (list != NULL)
|
|
|
445 {
|
|
|
446 *listp = NULL;
|
|
|
447
|
|
|
448 do
|
|
|
449 {
|
|
|
450 png_compression_bufferp next = list->next;
|
|
|
451
|
|
|
452 png_free(png_ptr, list);
|
|
|
453 list = next;
|
|
|
454 }
|
|
|
455 while (list != NULL);
|
|
|
456 }
|
|
|
457 }
|
|
|
458
|
|
|
459 #ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
|
|
|
460 /* This pair of functions encapsulates the operation of (a) compressing a
|
|
|
461 * text string, and (b) issuing it later as a series of chunk data writes.
|
|
|
462 * The compression_state structure is shared context for these functions
|
|
|
463 * set up by the caller to allow access to the relevant local variables.
|
|
|
464 *
|
|
|
465 * compression_buffer (new in 1.6.0) is just a linked list of zbuffer_size
|
|
|
466 * temporary buffers. From 1.6.0 it is retained in png_struct so that it will
|
|
|
467 * be correctly freed in the event of a write error (previous implementations
|
|
|
468 * just leaked memory.)
|
|
|
469 */
|
|
|
470 typedef struct
|
|
|
471 {
|
|
|
472 png_const_bytep input; /* The uncompressed input data */
|
|
|
473 png_alloc_size_t input_len; /* Its length */
|
|
|
474 png_uint_32 output_len; /* Final compressed length */
|
|
|
475 png_byte output[1024]; /* First block of output */
|
|
|
476 } compression_state;
|
|
|
477
|
|
|
478 static void
|
|
|
479 png_text_compress_init(compression_state *comp, png_const_bytep input,
|
|
|
480 png_alloc_size_t input_len)
|
|
|
481 {
|
|
|
482 comp->input = input;
|
|
|
483 comp->input_len = input_len;
|
|
|
484 comp->output_len = 0;
|
|
|
485 }
|
|
|
486
|
|
|
487 /* Compress the data in the compression state input */
|
|
|
488 static int
|
|
|
489 png_text_compress(png_structrp png_ptr, png_uint_32 chunk_name,
|
|
|
490 compression_state *comp, png_uint_32 prefix_len)
|
|
|
491 {
|
|
|
492 int ret;
|
|
|
493
|
|
|
494 /* To find the length of the output it is necessary to first compress the
|
|
|
495 * input, the result is buffered rather than using the two-pass algorithm
|
|
|
496 * that is used on the inflate side; deflate is assumed to be slower and a
|
|
|
497 * PNG writer is assumed to have more memory available than a PNG reader.
|
|
|
498 *
|
|
|
499 * IMPLEMENTATION NOTE: the zlib API deflateBound() can be used to find an
|
|
|
500 * upper limit on the output size, but it is always bigger than the input
|
|
|
501 * size so it is likely to be more efficient to use this linked-list
|
|
|
502 * approach.
|
|
|
503 */
|
|
|
504 ret = png_deflate_claim(png_ptr, chunk_name, comp->input_len);
|
|
|
505
|
|
|
506 if (ret != Z_OK)
|
|
|
507 return ret;
|
|
|
508
|
|
|
509 /* Set up the compression buffers, we need a loop here to avoid overflowing a
|
|
|
510 * uInt. Use ZLIB_IO_MAX to limit the input. The output is always limited
|
|
|
511 * by the output buffer size, so there is no need to check that. Since this
|
|
|
512 * is ANSI-C we know that an 'int', hence a uInt, is always at least 16 bits
|
|
|
513 * in size.
|
|
|
514 */
|
|
|
515 {
|
|
|
516 png_compression_bufferp *end = &png_ptr->zbuffer_list;
|
|
|
517 png_alloc_size_t input_len = comp->input_len; /* may be zero! */
|
|
|
518 png_uint_32 output_len;
|
|
|
519
|
|
|
520 /* zlib updates these for us: */
|
|
|
521 png_ptr->zstream.next_in = PNGZ_INPUT_CAST(comp->input);
|
|
|
522 png_ptr->zstream.avail_in = 0; /* Set below */
|
|
|
523 png_ptr->zstream.next_out = comp->output;
|
|
|
524 png_ptr->zstream.avail_out = (sizeof comp->output);
|
|
|
525
|
|
|
526 output_len = png_ptr->zstream.avail_out;
|
|
|
527
|
|
|
528 do
|
|
|
529 {
|
|
|
530 uInt avail_in = ZLIB_IO_MAX;
|
|
|
531
|
|
|
532 if (avail_in > input_len)
|
|
|
533 avail_in = (uInt)input_len;
|
|
|
534
|
|
|
535 input_len -= avail_in;
|
|
|
536
|
|
|
537 png_ptr->zstream.avail_in = avail_in;
|
|
|
538
|
|
|
539 if (png_ptr->zstream.avail_out == 0)
|
|
|
540 {
|
|
|
541 png_compression_buffer *next;
|
|
|
542
|
|
|
543 /* Chunk data is limited to 2^31 bytes in length, so the prefix
|
|
|
544 * length must be counted here.
|
|
|
545 */
|
|
|
546 if (output_len + prefix_len > PNG_UINT_31_MAX)
|
|
|
547 {
|
|
|
548 ret = Z_MEM_ERROR;
|
|
|
549 break;
|
|
|
550 }
|
|
|
551
|
|
|
552 /* Need a new (malloc'ed) buffer, but there may be one present
|
|
|
553 * already.
|
|
|
554 */
|
|
|
555 next = *end;
|
|
|
556 if (next == NULL)
|
|
|
557 {
|
|
|
558 next = png_voidcast(png_compression_bufferp, png_malloc_base
|
|
|
559 (png_ptr, PNG_COMPRESSION_BUFFER_SIZE(png_ptr)));
|
|
|
560
|
|
|
561 if (next == NULL)
|
|
|
562 {
|
|
|
563 ret = Z_MEM_ERROR;
|
|
|
564 break;
|
|
|
565 }
|
|
|
566
|
|
|
567 /* Link in this buffer (so that it will be freed later) */
|
|
|
568 next->next = NULL;
|
|
|
569 *end = next;
|
|
|
570 }
|
|
|
571
|
|
|
572 png_ptr->zstream.next_out = next->output;
|
|
|
573 png_ptr->zstream.avail_out = png_ptr->zbuffer_size;
|
|
|
574 output_len += png_ptr->zstream.avail_out;
|
|
|
575
|
|
|
576 /* Move 'end' to the next buffer pointer. */
|
|
|
577 end = &next->next;
|
|
|
578 }
|
|
|
579
|
|
|
580 /* Compress the data */
|
|
|
581 ret = deflate(&png_ptr->zstream,
|
|
|
582 input_len > 0 ? Z_NO_FLUSH : Z_FINISH);
|
|
|
583
|
|
|
584 /* Claw back input data that was not consumed (because avail_in is
|
|
|
585 * reset above every time round the loop).
|
|
|
586 */
|
|
|
587 input_len += png_ptr->zstream.avail_in;
|
|
|
588 png_ptr->zstream.avail_in = 0; /* safety */
|
|
|
589 }
|
|
|
590 while (ret == Z_OK);
|
|
|
591
|
|
|
592 /* There may be some space left in the last output buffer, this needs to
|
|
|
593 * be subtracted from output_len.
|
|
|
594 */
|
|
|
595 output_len -= png_ptr->zstream.avail_out;
|
|
|
596 png_ptr->zstream.avail_out = 0; /* safety */
|
|
|
597 comp->output_len = output_len;
|
|
|
598
|
|
|
599 /* Now double check the output length, put in a custom message if it is
|
|
|
600 * too long. Otherwise ensure the z_stream::msg pointer is set to
|
|
|
601 * something.
|
|
|
602 */
|
|
|
603 if (output_len + prefix_len >= PNG_UINT_31_MAX)
|
|
|
604 {
|
|
|
605 png_ptr->zstream.msg = PNGZ_MSG_CAST("compressed data too long");
|
|
|
606 ret = Z_MEM_ERROR;
|
|
|
607 }
|
|
|
608
|
|
|
609 else
|
|
|
610 png_zstream_error(png_ptr, ret);
|
|
|
611
|
|
|
612 /* Reset zlib for another zTXt/iTXt or image data */
|
|
|
613 png_ptr->zowner = 0;
|
|
|
614
|
|
|
615 /* The only success case is Z_STREAM_END, input_len must be 0, if not this
|
|
|
616 * is an internal error.
|
|
|
617 */
|
|
|
618 if (ret == Z_STREAM_END && input_len == 0)
|
|
|
619 {
|
|
|
620 /* Fix up the deflate header, if required */
|
|
|
621 optimize_cmf(comp->output, comp->input_len);
|
|
|
622
|
|
|
623 /* But Z_OK is returned, not Z_STREAM_END; this allows the claim
|
|
|
624 * function above to return Z_STREAM_END on an error (though it never
|
|
|
625 * does in the current versions of zlib.)
|
|
|
626 */
|
|
|
627 return Z_OK;
|
|
|
628 }
|
|
|
629
|
|
|
630 else
|
|
|
631 return ret;
|
|
|
632 }
|
|
|
633 }
|
|
|
634
|
|
|
635 /* Ship the compressed text out via chunk writes */
|
|
|
636 static void
|
|
|
637 png_write_compressed_data_out(png_structrp png_ptr, compression_state *comp)
|
|
|
638 {
|
|
|
639 png_uint_32 output_len = comp->output_len;
|
|
|
640 png_const_bytep output = comp->output;
|
|
|
641 png_uint_32 avail = (sizeof comp->output);
|
|
|
642 png_compression_buffer *next = png_ptr->zbuffer_list;
|
|
|
643
|
|
|
644 for (;;)
|
|
|
645 {
|
|
|
646 if (avail > output_len)
|
|
|
647 avail = output_len;
|
|
|
648
|
|
|
649 png_write_chunk_data(png_ptr, output, avail);
|
|
|
650
|
|
|
651 output_len -= avail;
|
|
|
652
|
|
|
653 if (output_len == 0 || next == NULL)
|
|
|
654 break;
|
|
|
655
|
|
|
656 avail = png_ptr->zbuffer_size;
|
|
|
657 output = next->output;
|
|
|
658 next = next->next;
|
|
|
659 }
|
|
|
660
|
|
|
661 /* This is an internal error; 'next' must have been NULL! */
|
|
|
662 if (output_len > 0)
|
|
|
663 png_error(png_ptr, "error writing ancillary chunked compressed data");
|
|
|
664 }
|
|
|
665 #endif /* PNG_WRITE_COMPRESSED_TEXT_SUPPORTED */
|
|
|
666
|
|
|
667 #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \
|
|
|
668 defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED)
|
|
|
669 /* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification,
|
|
|
670 * and if invalid, correct the keyword rather than discarding the entire
|
|
|
671 * chunk. The PNG 1.0 specification requires keywords 1-79 characters in
|
|
|
672 * length, forbids leading or trailing whitespace, multiple internal spaces,
|
|
|
673 * and the non-break space (0x80) from ISO 8859-1. Returns keyword length.
|
|
|
674 *
|
|
|
675 * The 'new_key' buffer must be 80 characters in size (for the keyword plus a
|
|
|
676 * trailing '\0'). If this routine returns 0 then there was no keyword, or a
|
|
|
677 * valid one could not be generated, and the caller must png_error.
|
|
|
678 */
|
|
|
679 static png_uint_32
|
|
|
680 png_check_keyword(png_structrp png_ptr, png_const_charp key, png_bytep new_key)
|
|
|
681 {
|
|
|
682 png_const_charp orig_key = key;
|
|
|
683 png_uint_32 key_len = 0;
|
|
|
684 int bad_character = 0;
|
|
|
685 int space = 1;
|
|
|
686
|
|
|
687 png_debug(1, "in png_check_keyword");
|
|
|
688
|
|
|
689 if (key == NULL)
|
|
|
690 {
|
|
|
691 *new_key = 0;
|
|
|
692 return 0;
|
|
|
693 }
|
|
|
694
|
|
|
695 while (*key && key_len < 79)
|
|
|
696 {
|
|
|
697 png_byte ch = (png_byte)(0xff & *key++);
|
|
|
698
|
|
|
699 if ((ch > 32 && ch <= 126) || (ch >= 161 /*&& ch <= 255*/))
|
|
|
700 *new_key++ = ch, ++key_len, space = 0;
|
|
|
701
|
|
|
702 else if (!space)
|
|
|
703 {
|
|
|
704 /* A space or an invalid character when one wasn't seen immediately
|
|
|
705 * before; output just a space.
|
|
|
706 */
|
|
|
707 *new_key++ = 32, ++key_len, space = 1;
|
|
|
708
|
|
|
709 /* If the character was not a space then it is invalid. */
|
|
|
710 if (ch != 32)
|
|
|
711 bad_character = ch;
|
|
|
712 }
|
|
|
713
|
|
|
714 else if (!bad_character)
|
|
|
715 bad_character = ch; /* just skip it, record the first error */
|
|
|
716 }
|
|
|
717
|
|
|
718 if (key_len > 0 && space) /* trailing space */
|
|
|
719 {
|
|
|
720 --key_len, --new_key;
|
|
|
721 if (!bad_character)
|
|
|
722 bad_character = 32;
|
|
|
723 }
|
|
|
724
|
|
|
725 /* Terminate the keyword */
|
|
|
726 *new_key = 0;
|
|
|
727
|
|
|
728 if (key_len == 0)
|
|
|
729 return 0;
|
|
|
730
|
|
|
731 /* Try to only output one warning per keyword: */
|
|
|
732 if (*key) /* keyword too long */
|
|
|
733 png_warning(png_ptr, "keyword truncated");
|
|
|
734
|
|
|
735 else if (bad_character)
|
|
|
736 {
|
|
|
737 PNG_WARNING_PARAMETERS(p)
|
|
|
738
|
|
|
739 png_warning_parameter(p, 1, orig_key);
|
|
|
740 png_warning_parameter_signed(p, 2, PNG_NUMBER_FORMAT_02x, bad_character);
|
|
|
741
|
|
|
742 png_formatted_warning(png_ptr, p, "keyword \"@1\": bad character '0x@2'");
|
|
|
743 }
|
|
|
744
|
|
|
745 return key_len;
|
|
|
746 }
|
|
|
747 #endif
|
|
|
748
|
|
|
749 /* Write the IHDR chunk, and update the png_struct with the necessary
|
|
|
750 * information. Note that the rest of this code depends upon this
|
|
|
751 * information being correct.
|
|
|
752 */
|
|
|
753 void /* PRIVATE */
|
|
|
754 png_write_IHDR(png_structrp png_ptr, png_uint_32 width, png_uint_32 height,
|
|
|
755 int bit_depth, int color_type, int compression_type, int filter_type,
|
|
|
756 int interlace_type)
|
|
|
757 {
|
|
|
758 png_byte buf[13]; /* Buffer to store the IHDR info */
|
|
|
759
|
|
|
760 png_debug(1, "in png_write_IHDR");
|
|
|
761
|
|
|
762 /* Check that we have valid input data from the application info */
|
|
|
763 switch (color_type)
|
|
|
764 {
|
|
|
765 case PNG_COLOR_TYPE_GRAY:
|
|
|
766 switch (bit_depth)
|
|
|
767 {
|
|
|
768 case 1:
|
|
|
769 case 2:
|
|
|
770 case 4:
|
|
|
771 case 8:
|
|
|
772 #ifdef PNG_WRITE_16BIT_SUPPORTED
|
|
|
773 case 16:
|
|
|
774 #endif
|
|
|
775 png_ptr->channels = 1; break;
|
|
|
776
|
|
|
777 default:
|
|
|
778 png_error(png_ptr,
|
|
|
779 "Invalid bit depth for grayscale image");
|
|
|
780 }
|
|
|
781 break;
|
|
|
782
|
|
|
783 case PNG_COLOR_TYPE_RGB:
|
|
|
784 #ifdef PNG_WRITE_16BIT_SUPPORTED
|
|
|
785 if (bit_depth != 8 && bit_depth != 16)
|
|
|
786 #else
|
|
|
787 if (bit_depth != 8)
|
|
|
788 #endif
|
|
|
789 png_error(png_ptr, "Invalid bit depth for RGB image");
|
|
|
790
|
|
|
791 png_ptr->channels = 3;
|
|
|
792 break;
|
|
|
793
|
|
|
794 case PNG_COLOR_TYPE_PALETTE:
|
|
|
795 switch (bit_depth)
|
|
|
796 {
|
|
|
797 case 1:
|
|
|
798 case 2:
|
|
|
799 case 4:
|
|
|
800 case 8:
|
|
|
801 png_ptr->channels = 1;
|
|
|
802 break;
|
|
|
803
|
|
|
804 default:
|
|
|
805 png_error(png_ptr, "Invalid bit depth for paletted image");
|
|
|
806 }
|
|
|
807 break;
|
|
|
808
|
|
|
809 case PNG_COLOR_TYPE_GRAY_ALPHA:
|
|
|
810 if (bit_depth != 8 && bit_depth != 16)
|
|
|
811 png_error(png_ptr, "Invalid bit depth for grayscale+alpha image");
|
|
|
812
|
|
|
813 png_ptr->channels = 2;
|
|
|
814 break;
|
|
|
815
|
|
|
816 case PNG_COLOR_TYPE_RGB_ALPHA:
|
|
|
817 #ifdef PNG_WRITE_16BIT_SUPPORTED
|
|
|
818 if (bit_depth != 8 && bit_depth != 16)
|
|
|
819 #else
|
|
|
820 if (bit_depth != 8)
|
|
|
821 #endif
|
|
|
822 png_error(png_ptr, "Invalid bit depth for RGBA image");
|
|
|
823
|
|
|
824 png_ptr->channels = 4;
|
|
|
825 break;
|
|
|
826
|
|
|
827 default:
|
|
|
828 png_error(png_ptr, "Invalid image color type specified");
|
|
|
829 }
|
|
|
830
|
|
|
831 if (compression_type != PNG_COMPRESSION_TYPE_BASE)
|
|
|
832 {
|
|
|
833 png_warning(png_ptr, "Invalid compression type specified");
|
|
|
834 compression_type = PNG_COMPRESSION_TYPE_BASE;
|
|
|
835 }
|
|
|
836
|
|
|
837 /* Write filter_method 64 (intrapixel differencing) only if
|
|
|
838 * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
|
|
|
839 * 2. Libpng did not write a PNG signature (this filter_method is only
|
|
|
840 * used in PNG datastreams that are embedded in MNG datastreams) and
|
|
|
841 * 3. The application called png_permit_mng_features with a mask that
|
|
|
842 * included PNG_FLAG_MNG_FILTER_64 and
|
|
|
843 * 4. The filter_method is 64 and
|
|
|
844 * 5. The color_type is RGB or RGBA
|
|
|
845 */
|
|
|
846 if (
|
|
|
847 #ifdef PNG_MNG_FEATURES_SUPPORTED
|
|
|
848 !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
|
|
|
849 ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) == 0) &&
|
|
|
850 (color_type == PNG_COLOR_TYPE_RGB ||
|
|
|
851 color_type == PNG_COLOR_TYPE_RGB_ALPHA) &&
|
|
|
852 (filter_type == PNG_INTRAPIXEL_DIFFERENCING)) &&
|
|
|
853 #endif
|
|
|
854 filter_type != PNG_FILTER_TYPE_BASE)
|
|
|
855 {
|
|
|
856 png_warning(png_ptr, "Invalid filter type specified");
|
|
|
857 filter_type = PNG_FILTER_TYPE_BASE;
|
|
|
858 }
|
|
|
859
|
|
|
860 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
|
|
|
861 if (interlace_type != PNG_INTERLACE_NONE &&
|
|
|
862 interlace_type != PNG_INTERLACE_ADAM7)
|
|
|
863 {
|
|
|
864 png_warning(png_ptr, "Invalid interlace type specified");
|
|
|
865 interlace_type = PNG_INTERLACE_ADAM7;
|
|
|
866 }
|
|
|
867 #else
|
|
|
868 interlace_type=PNG_INTERLACE_NONE;
|
|
|
869 #endif
|
|
|
870
|
|
|
871 /* Save the relevent information */
|
|
|
872 png_ptr->bit_depth = (png_byte)bit_depth;
|
|
|
873 png_ptr->color_type = (png_byte)color_type;
|
|
|
874 png_ptr->interlaced = (png_byte)interlace_type;
|
|
|
875 #ifdef PNG_MNG_FEATURES_SUPPORTED
|
|
|
876 png_ptr->filter_type = (png_byte)filter_type;
|
|
|
877 #endif
|
|
|
878 png_ptr->compression_type = (png_byte)compression_type;
|
|
|
879 png_ptr->width = width;
|
|
|
880 png_ptr->height = height;
|
|
|
881
|
|
|
882 png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels);
|
|
|
883 png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width);
|
|
|
884 /* Set the usr info, so any transformations can modify it */
|
|
|
885 png_ptr->usr_width = png_ptr->width;
|
|
|
886 png_ptr->usr_bit_depth = png_ptr->bit_depth;
|
|
|
887 png_ptr->usr_channels = png_ptr->channels;
|
|
|
888
|
|
|
889 /* Pack the header information into the buffer */
|
|
|
890 png_save_uint_32(buf, width);
|
|
|
891 png_save_uint_32(buf + 4, height);
|
|
|
892 buf[8] = (png_byte)bit_depth;
|
|
|
893 buf[9] = (png_byte)color_type;
|
|
|
894 buf[10] = (png_byte)compression_type;
|
|
|
895 buf[11] = (png_byte)filter_type;
|
|
|
896 buf[12] = (png_byte)interlace_type;
|
|
|
897
|
|
|
898 /* Write the chunk */
|
|
|
899 png_write_complete_chunk(png_ptr, png_IHDR, buf, (png_size_t)13);
|
|
|
900
|
|
|
901 if (!(png_ptr->do_filter))
|
|
|
902 {
|
|
|
903 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||
|
|
|
904 png_ptr->bit_depth < 8)
|
|
|
905 png_ptr->do_filter = PNG_FILTER_NONE;
|
|
|
906
|
|
|
907 else
|
|
|
908 png_ptr->do_filter = PNG_ALL_FILTERS;
|
|
|
909 }
|
|
|
910
|
|
|
911 png_ptr->mode = PNG_HAVE_IHDR; /* not READY_FOR_ZTXT */
|
|
|
912 }
|
|
|
913
|
|
|
914 /* Write the palette. We are careful not to trust png_color to be in the
|
|
|
915 * correct order for PNG, so people can redefine it to any convenient
|
|
|
916 * structure.
|
|
|
917 */
|
|
|
918 void /* PRIVATE */
|
|
|
919 png_write_PLTE(png_structrp png_ptr, png_const_colorp palette,
|
|
|
920 png_uint_32 num_pal)
|
|
|
921 {
|
|
|
922 png_uint_32 i;
|
|
|
923 png_const_colorp pal_ptr;
|
|
|
924 png_byte buf[3];
|
|
|
925
|
|
|
926 png_debug(1, "in png_write_PLTE");
|
|
|
927
|
|
|
928 if ((
|
|
|
929 #ifdef PNG_MNG_FEATURES_SUPPORTED
|
|
|
930 !(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) &&
|
|
|
931 #endif
|
|
|
932 num_pal == 0) || num_pal > 256)
|
|
|
933 {
|
|
|
934 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
|
|
|
935 {
|
|
|
936 png_error(png_ptr, "Invalid number of colors in palette");
|
|
|
937 }
|
|
|
938
|
|
|
939 else
|
|
|
940 {
|
|
|
941 png_warning(png_ptr, "Invalid number of colors in palette");
|
|
|
942 return;
|
|
|
943 }
|
|
|
944 }
|
|
|
945
|
|
|
946 if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR))
|
|
|
947 {
|
|
|
948 png_warning(png_ptr,
|
|
|
949 "Ignoring request to write a PLTE chunk in grayscale PNG");
|
|
|
950
|
|
|
951 return;
|
|
|
952 }
|
|
|
953
|
|
|
954 png_ptr->num_palette = (png_uint_16)num_pal;
|
|
|
955 png_debug1(3, "num_palette = %d", png_ptr->num_palette);
|
|
|
956
|
|
|
957 png_write_chunk_header(png_ptr, png_PLTE, (png_uint_32)(num_pal * 3));
|
|
|
958 #ifdef PNG_POINTER_INDEXING_SUPPORTED
|
|
|
959
|
|
|
960 for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++)
|
|
|
961 {
|
|
|
962 buf[0] = pal_ptr->red;
|
|
|
963 buf[1] = pal_ptr->green;
|
|
|
964 buf[2] = pal_ptr->blue;
|
|
|
965 png_write_chunk_data(png_ptr, buf, (png_size_t)3);
|
|
|
966 }
|
|
|
967
|
|
|
968 #else
|
|
|
969 /* This is a little slower but some buggy compilers need to do this
|
|
|
970 * instead
|
|
|
971 */
|
|
|
972 pal_ptr=palette;
|
|
|
973
|
|
|
974 for (i = 0; i < num_pal; i++)
|
|
|
975 {
|
|
|
976 buf[0] = pal_ptr[i].red;
|
|
|
977 buf[1] = pal_ptr[i].green;
|
|
|
978 buf[2] = pal_ptr[i].blue;
|
|
|
979 png_write_chunk_data(png_ptr, buf, (png_size_t)3);
|
|
|
980 }
|
|
|
981
|
|
|
982 #endif
|
|
|
983 png_write_chunk_end(png_ptr);
|
|
|
984 png_ptr->mode |= PNG_HAVE_PLTE;
|
|
|
985 }
|
|
|
986
|
|
|
987 /* This is similar to png_text_compress, above, except that it does not require
|
|
|
988 * all of the data at once and, instead of buffering the compressed result,
|
|
|
989 * writes it as IDAT chunks. Unlike png_text_compress it *can* png_error out
|
|
|
990 * because it calls the write interface. As a result it does its own error
|
|
|
991 * reporting and does not return an error code. In the event of error it will
|
|
|
992 * just call png_error. The input data length may exceed 32-bits. The 'flush'
|
|
|
993 * parameter is exactly the same as that to deflate, with the following
|
|
|
994 * meanings:
|
|
|
995 *
|
|
|
996 * Z_NO_FLUSH: normal incremental output of compressed data
|
|
|
997 * Z_SYNC_FLUSH: do a SYNC_FLUSH, used by png_write_flush
|
|
|
998 * Z_FINISH: this is the end of the input, do a Z_FINISH and clean up
|
|
|
999 *
|
|
|
1000 * The routine manages the acquire and release of the png_ptr->zstream by
|
|
|
1001 * checking and (at the end) clearing png_ptr->zowner, it does some sanity
|
|
|
1002 * checks on the 'mode' flags while doing this.
|
|
|
1003 */
|
|
|
1004 void /* PRIVATE */
|
|
|
1005 png_compress_IDAT(png_structrp png_ptr, png_const_bytep input,
|
|
|
1006 png_alloc_size_t input_len, int flush)
|
|
|
1007 {
|
|
|
1008 if (png_ptr->zowner != png_IDAT)
|
|
|
1009 {
|
|
|
1010 /* First time. Ensure we have a temporary buffer for compression and
|
|
|
1011 * trim the buffer list if it has more than one entry to free memory.
|
|
|
1012 * If 'WRITE_COMPRESSED_TEXT' is not set the list will never have been
|
|
|
1013 * created at this point, but the check here is quick and safe.
|
|
|
1014 */
|
|
|
1015 if (png_ptr->zbuffer_list == NULL)
|
|
|
1016 {
|
|
|
1017 png_ptr->zbuffer_list = png_voidcast(png_compression_bufferp,
|
|
|
1018 png_malloc(png_ptr, PNG_COMPRESSION_BUFFER_SIZE(png_ptr)));
|
|
|
1019 png_ptr->zbuffer_list->next = NULL;
|
|
|
1020 }
|
|
|
1021
|
|
|
1022 else
|
|
|
1023 png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list->next);
|
|
|
1024
|
|
|
1025 /* It is a terminal error if we can't claim the zstream. */
|
|
|
1026 if (png_deflate_claim(png_ptr, png_IDAT, png_image_size(png_ptr)) != Z_OK)
|
|
|
1027 png_error(png_ptr, png_ptr->zstream.msg);
|
|
|
1028
|
|
|
1029 /* The output state is maintained in png_ptr->zstream, so it must be
|
|
|
1030 * initialized here after the claim.
|
|
|
1031 */
|
|
|
1032 png_ptr->zstream.next_out = png_ptr->zbuffer_list->output;
|
|
|
1033 png_ptr->zstream.avail_out = png_ptr->zbuffer_size;
|
|
|
1034 }
|
|
|
1035
|
|
|
1036 /* Now loop reading and writing until all the input is consumed or an error
|
|
|
1037 * terminates the operation. The _out values are maintained across calls to
|
|
|
1038 * this function, but the input must be reset each time.
|
|
|
1039 */
|
|
|
1040 png_ptr->zstream.next_in = PNGZ_INPUT_CAST(input);
|
|
|
1041 png_ptr->zstream.avail_in = 0; /* set below */
|
|
|
1042 for (;;)
|
|
|
1043 {
|
|
|
1044 int ret;
|
|
|
1045
|
|
|
1046 /* INPUT: from the row data */
|
|
|
1047 uInt avail = ZLIB_IO_MAX;
|
|
|
1048
|
|
|
1049 if (avail > input_len)
|
|
|
1050 avail = (uInt)input_len; /* safe because of the check */
|
|
|
1051
|
|
|
1052 png_ptr->zstream.avail_in = avail;
|
|
|
1053 input_len -= avail;
|
|
|
1054
|
|
|
1055 ret = deflate(&png_ptr->zstream, input_len > 0 ? Z_NO_FLUSH : flush);
|
|
|
1056
|
|
|
1057 /* Include as-yet unconsumed input */
|
|
|
1058 input_len += png_ptr->zstream.avail_in;
|
|
|
1059 png_ptr->zstream.avail_in = 0;
|
|
|
1060
|
|
|
1061 /* OUTPUT: write complete IDAT chunks when avail_out drops to zero, note
|
|
|
1062 * that these two zstream fields are preserved across the calls, therefore
|
|
|
1063 * there is no need to set these up on entry to the loop.
|
|
|
1064 */
|
|
|
1065 if (png_ptr->zstream.avail_out == 0)
|
|
|
1066 {
|
|
|
1067 png_bytep data = png_ptr->zbuffer_list->output;
|
|
|
1068 uInt size = png_ptr->zbuffer_size;
|
|
|
1069
|
|
|
1070 /* Write an IDAT containing the data then reset the buffer. The
|
|
|
1071 * first IDAT may need deflate header optimization.
|
|
|
1072 */
|
|
|
1073 # ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
|
|
|
1074 if (!(png_ptr->mode & PNG_HAVE_IDAT) &&
|
|
|
1075 png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE)
|
|
|
1076 optimize_cmf(data, png_image_size(png_ptr));
|
|
|
1077 # endif
|
|
|
1078
|
|
|
1079 png_write_complete_chunk(png_ptr, png_IDAT, data, size);
|
|
|
1080 png_ptr->mode |= PNG_HAVE_IDAT;
|
|
|
1081
|
|
|
1082 png_ptr->zstream.next_out = data;
|
|
|
1083 png_ptr->zstream.avail_out = size;
|
|
|
1084
|
|
|
1085 /* For SYNC_FLUSH or FINISH it is essential to keep calling zlib with
|
|
|
1086 * the same flush parameter until it has finished output, for NO_FLUSH
|
|
|
1087 * it doesn't matter.
|
|
|
1088 */
|
|
|
1089 if (ret == Z_OK && flush != Z_NO_FLUSH)
|
|
|
1090 continue;
|
|
|
1091 }
|
|
|
1092
|
|
|
1093 /* The order of these checks doesn't matter much; it just effect which
|
|
|
1094 * possible error might be detected if multiple things go wrong at once.
|
|
|
1095 */
|
|
|
1096 if (ret == Z_OK) /* most likely return code! */
|
|
|
1097 {
|
|
|
1098 /* If all the input has been consumed then just return. If Z_FINISH
|
|
|
1099 * was used as the flush parameter something has gone wrong if we get
|
|
|
1100 * here.
|
|
|
1101 */
|
|
|
1102 if (input_len == 0)
|
|
|
1103 {
|
|
|
1104 if (flush == Z_FINISH)
|
|
|
1105 png_error(png_ptr, "Z_OK on Z_FINISH with output space");
|
|
|
1106
|
|
|
1107 return;
|
|
|
1108 }
|
|
|
1109 }
|
|
|
1110
|
|
|
1111 else if (ret == Z_STREAM_END && flush == Z_FINISH)
|
|
|
1112 {
|
|
|
1113 /* This is the end of the IDAT data; any pending output must be
|
|
|
1114 * flushed. For small PNG files we may still be at the beginning.
|
|
|
1115 */
|
|
|
1116 png_bytep data = png_ptr->zbuffer_list->output;
|
|
|
1117 uInt size = png_ptr->zbuffer_size - png_ptr->zstream.avail_out;
|
|
|
1118
|
|
|
1119 # ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
|
|
|
1120 if (!(png_ptr->mode & PNG_HAVE_IDAT) &&
|
|
|
1121 png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE)
|
|
|
1122 optimize_cmf(data, png_image_size(png_ptr));
|
|
|
1123 # endif
|
|
|
1124
|
|
|
1125 png_write_complete_chunk(png_ptr, png_IDAT, data, size);
|
|
|
1126 png_ptr->zstream.avail_out = 0;
|
|
|
1127 png_ptr->zstream.next_out = NULL;
|
|
|
1128 png_ptr->mode |= PNG_HAVE_IDAT | PNG_AFTER_IDAT;
|
|
|
1129
|
|
|
1130 png_ptr->zowner = 0; /* Release the stream */
|
|
|
1131 return;
|
|
|
1132 }
|
|
|
1133
|
|
|
1134 else
|
|
|
1135 {
|
|
|
1136 /* This is an error condition. */
|
|
|
1137 png_zstream_error(png_ptr, ret);
|
|
|
1138 png_error(png_ptr, png_ptr->zstream.msg);
|
|
|
1139 }
|
|
|
1140 }
|
|
|
1141 }
|
|
|
1142
|
|
|
1143 /* Write an IEND chunk */
|
|
|
1144 void /* PRIVATE */
|
|
|
1145 png_write_IEND(png_structrp png_ptr)
|
|
|
1146 {
|
|
|
1147 png_debug(1, "in png_write_IEND");
|
|
|
1148
|
|
|
1149 png_write_complete_chunk(png_ptr, png_IEND, NULL, (png_size_t)0);
|
|
|
1150 png_ptr->mode |= PNG_HAVE_IEND;
|
|
|
1151 }
|
|
|
1152
|
|
|
1153 #ifdef PNG_WRITE_gAMA_SUPPORTED
|
|
|
1154 /* Write a gAMA chunk */
|
|
|
1155 void /* PRIVATE */
|
|
|
1156 png_write_gAMA_fixed(png_structrp png_ptr, png_fixed_point file_gamma)
|
|
|
1157 {
|
|
|
1158 png_byte buf[4];
|
|
|
1159
|
|
|
1160 png_debug(1, "in png_write_gAMA");
|
|
|
1161
|
|
|
1162 /* file_gamma is saved in 1/100,000ths */
|
|
|
1163 png_save_uint_32(buf, (png_uint_32)file_gamma);
|
|
|
1164 png_write_complete_chunk(png_ptr, png_gAMA, buf, (png_size_t)4);
|
|
|
1165 }
|
|
|
1166 #endif
|
|
|
1167
|
|
|
1168 #ifdef PNG_WRITE_sRGB_SUPPORTED
|
|
|
1169 /* Write a sRGB chunk */
|
|
|
1170 void /* PRIVATE */
|
|
|
1171 png_write_sRGB(png_structrp png_ptr, int srgb_intent)
|
|
|
1172 {
|
|
|
1173 png_byte buf[1];
|
|
|
1174
|
|
|
1175 png_debug(1, "in png_write_sRGB");
|
|
|
1176
|
|
|
1177 if (srgb_intent >= PNG_sRGB_INTENT_LAST)
|
|
|
1178 png_warning(png_ptr,
|
|
|
1179 "Invalid sRGB rendering intent specified");
|
|
|
1180
|
|
|
1181 buf[0]=(png_byte)srgb_intent;
|
|
|
1182 png_write_complete_chunk(png_ptr, png_sRGB, buf, (png_size_t)1);
|
|
|
1183 }
|
|
|
1184 #endif
|
|
|
1185
|
|
|
1186 #ifdef PNG_WRITE_iCCP_SUPPORTED
|
|
|
1187 /* Write an iCCP chunk */
|
|
|
1188 void /* PRIVATE */
|
|
|
1189 png_write_iCCP(png_structrp png_ptr, png_const_charp name,
|
|
|
1190 png_const_bytep profile)
|
|
|
1191 {
|
|
|
1192 png_uint_32 name_len;
|
|
|
1193 png_uint_32 profile_len;
|
|
|
1194 png_byte new_name[81]; /* 1 byte for the compression byte */
|
|
|
1195 compression_state comp;
|
|
|
1196
|
|
|
1197 png_debug(1, "in png_write_iCCP");
|
|
|
1198
|
|
|
1199 /* These are all internal problems: the profile should have been checked
|
|
|
1200 * before when it was stored.
|
|
|
1201 */
|
|
|
1202 if (profile == NULL)
|
|
|
1203 png_error(png_ptr, "No profile for iCCP chunk"); /* internal error */
|
|
|
1204
|
|
|
1205 profile_len = png_get_uint_32(profile);
|
|
|
1206
|
|
|
1207 if (profile_len < 132)
|
|
|
1208 png_error(png_ptr, "ICC profile too short");
|
|
|
1209
|
|
|
1210 if (profile_len & 0x03)
|
|
|
1211 png_error(png_ptr, "ICC profile length invalid (not a multiple of 4)");
|
|
|
1212
|
|
|
1213 {
|
|
|
1214 png_uint_32 embedded_profile_len = png_get_uint_32(profile);
|
|
|
1215
|
|
|
1216 if (profile_len != embedded_profile_len)
|
|
|
1217 png_error(png_ptr, "Profile length does not match profile");
|
|
|
1218 }
|
|
|
1219
|
|
|
1220 name_len = png_check_keyword(png_ptr, name, new_name);
|
|
|
1221
|
|
|
1222 if (name_len == 0)
|
|
|
1223 png_error(png_ptr, "iCCP: invalid keyword");
|
|
|
1224
|
|
|
1225 new_name[++name_len] = PNG_COMPRESSION_TYPE_BASE;
|
|
|
1226
|
|
|
1227 /* Make sure we include the NULL after the name and the compression type */
|
|
|
1228 ++name_len;
|
|
|
1229
|
|
|
1230 png_text_compress_init(&comp, profile, profile_len);
|
|
|
1231
|
|
|
1232 /* Allow for keyword terminator and compression byte */
|
|
|
1233 if (png_text_compress(png_ptr, png_iCCP, &comp, name_len) != Z_OK)
|
|
|
1234 png_error(png_ptr, png_ptr->zstream.msg);
|
|
|
1235
|
|
|
1236 png_write_chunk_header(png_ptr, png_iCCP, name_len + comp.output_len);
|
|
|
1237
|
|
|
1238 png_write_chunk_data(png_ptr, new_name, name_len);
|
|
|
1239
|
|
|
1240 png_write_compressed_data_out(png_ptr, &comp);
|
|
|
1241
|
|
|
1242 png_write_chunk_end(png_ptr);
|
|
|
1243 }
|
|
|
1244 #endif
|
|
|
1245
|
|
|
1246 #ifdef PNG_WRITE_sPLT_SUPPORTED
|
|
|
1247 /* Write a sPLT chunk */
|
|
|
1248 void /* PRIVATE */
|
|
|
1249 png_write_sPLT(png_structrp png_ptr, png_const_sPLT_tp spalette)
|
|
|
1250 {
|
|
|
1251 png_uint_32 name_len;
|
|
|
1252 png_byte new_name[80];
|
|
|
1253 png_byte entrybuf[10];
|
|
|
1254 png_size_t entry_size = (spalette->depth == 8 ? 6 : 10);
|
|
|
1255 png_size_t palette_size = entry_size * spalette->nentries;
|
|
|
1256 png_sPLT_entryp ep;
|
|
|
1257 #ifndef PNG_POINTER_INDEXING_SUPPORTED
|
|
|
1258 int i;
|
|
|
1259 #endif
|
|
|
1260
|
|
|
1261 png_debug(1, "in png_write_sPLT");
|
|
|
1262
|
|
|
1263 name_len = png_check_keyword(png_ptr, spalette->name, new_name);
|
|
|
1264
|
|
|
1265 if (name_len == 0)
|
|
|
1266 png_error(png_ptr, "sPLT: invalid keyword");
|
|
|
1267
|
|
|
1268 /* Make sure we include the NULL after the name */
|
|
|
1269 png_write_chunk_header(png_ptr, png_sPLT,
|
|
|
1270 (png_uint_32)(name_len + 2 + palette_size));
|
|
|
1271
|
|
|
1272 png_write_chunk_data(png_ptr, (png_bytep)new_name,
|
|
|
1273 (png_size_t)(name_len + 1));
|
|
|
1274
|
|
|
1275 png_write_chunk_data(png_ptr, &spalette->depth, (png_size_t)1);
|
|
|
1276
|
|
|
1277 /* Loop through each palette entry, writing appropriately */
|
|
|
1278 #ifdef PNG_POINTER_INDEXING_SUPPORTED
|
|
|
1279 for (ep = spalette->entries; ep<spalette->entries + spalette->nentries; ep++)
|
|
|
1280 {
|
|
|
1281 if (spalette->depth == 8)
|
|
|
1282 {
|
|
|
1283 entrybuf[0] = (png_byte)ep->red;
|
|
|
1284 entrybuf[1] = (png_byte)ep->green;
|
|
|
1285 entrybuf[2] = (png_byte)ep->blue;
|
|
|
1286 entrybuf[3] = (png_byte)ep->alpha;
|
|
|
1287 png_save_uint_16(entrybuf + 4, ep->frequency);
|
|
|
1288 }
|
|
|
1289
|
|
|
1290 else
|
|
|
1291 {
|
|
|
1292 png_save_uint_16(entrybuf + 0, ep->red);
|
|
|
1293 png_save_uint_16(entrybuf + 2, ep->green);
|
|
|
1294 png_save_uint_16(entrybuf + 4, ep->blue);
|
|
|
1295 png_save_uint_16(entrybuf + 6, ep->alpha);
|
|
|
1296 png_save_uint_16(entrybuf + 8, ep->frequency);
|
|
|
1297 }
|
|
|
1298
|
|
|
1299 png_write_chunk_data(png_ptr, entrybuf, entry_size);
|
|
|
1300 }
|
|
|
1301 #else
|
|
|
1302 ep=spalette->entries;
|
|
|
1303 for (i = 0; i>spalette->nentries; i++)
|
|
|
1304 {
|
|
|
1305 if (spalette->depth == 8)
|
|
|
1306 {
|
|
|
1307 entrybuf[0] = (png_byte)ep[i].red;
|
|
|
1308 entrybuf[1] = (png_byte)ep[i].green;
|
|
|
1309 entrybuf[2] = (png_byte)ep[i].blue;
|
|
|
1310 entrybuf[3] = (png_byte)ep[i].alpha;
|
|
|
1311 png_save_uint_16(entrybuf + 4, ep[i].frequency);
|
|
|
1312 }
|
|
|
1313
|
|
|
1314 else
|
|
|
1315 {
|
|
|
1316 png_save_uint_16(entrybuf + 0, ep[i].red);
|
|
|
1317 png_save_uint_16(entrybuf + 2, ep[i].green);
|
|
|
1318 png_save_uint_16(entrybuf + 4, ep[i].blue);
|
|
|
1319 png_save_uint_16(entrybuf + 6, ep[i].alpha);
|
|
|
1320 png_save_uint_16(entrybuf + 8, ep[i].frequency);
|
|
|
1321 }
|
|
|
1322
|
|
|
1323 png_write_chunk_data(png_ptr, entrybuf, entry_size);
|
|
|
1324 }
|
|
|
1325 #endif
|
|
|
1326
|
|
|
1327 png_write_chunk_end(png_ptr);
|
|
|
1328 }
|
|
|
1329 #endif
|
|
|
1330
|
|
|
1331 #ifdef PNG_WRITE_sBIT_SUPPORTED
|
|
|
1332 /* Write the sBIT chunk */
|
|
|
1333 void /* PRIVATE */
|
|
|
1334 png_write_sBIT(png_structrp png_ptr, png_const_color_8p sbit, int color_type)
|
|
|
1335 {
|
|
|
1336 png_byte buf[4];
|
|
|
1337 png_size_t size;
|
|
|
1338
|
|
|
1339 png_debug(1, "in png_write_sBIT");
|
|
|
1340
|
|
|
1341 /* Make sure we don't depend upon the order of PNG_COLOR_8 */
|
|
|
1342 if (color_type & PNG_COLOR_MASK_COLOR)
|
|
|
1343 {
|
|
|
1344 png_byte maxbits;
|
|
|
1345
|
|
|
1346 maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 :
|
|
|
1347 png_ptr->usr_bit_depth);
|
|
|
1348
|
|
|
1349 if (sbit->red == 0 || sbit->red > maxbits ||
|
|
|
1350 sbit->green == 0 || sbit->green > maxbits ||
|
|
|
1351 sbit->blue == 0 || sbit->blue > maxbits)
|
|
|
1352 {
|
|
|
1353 png_warning(png_ptr, "Invalid sBIT depth specified");
|
|
|
1354 return;
|
|
|
1355 }
|
|
|
1356
|
|
|
1357 buf[0] = sbit->red;
|
|
|
1358 buf[1] = sbit->green;
|
|
|
1359 buf[2] = sbit->blue;
|
|
|
1360 size = 3;
|
|
|
1361 }
|
|
|
1362
|
|
|
1363 else
|
|
|
1364 {
|
|
|
1365 if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth)
|
|
|
1366 {
|
|
|
1367 png_warning(png_ptr, "Invalid sBIT depth specified");
|
|
|
1368 return;
|
|
|
1369 }
|
|
|
1370
|
|
|
1371 buf[0] = sbit->gray;
|
|
|
1372 size = 1;
|
|
|
1373 }
|
|
|
1374
|
|
|
1375 if (color_type & PNG_COLOR_MASK_ALPHA)
|
|
|
1376 {
|
|
|
1377 if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth)
|
|
|
1378 {
|
|
|
1379 png_warning(png_ptr, "Invalid sBIT depth specified");
|
|
|
1380 return;
|
|
|
1381 }
|
|
|
1382
|
|
|
1383 buf[size++] = sbit->alpha;
|
|
|
1384 }
|
|
|
1385
|
|
|
1386 png_write_complete_chunk(png_ptr, png_sBIT, buf, size);
|
|
|
1387 }
|
|
|
1388 #endif
|
|
|
1389
|
|
|
1390 #ifdef PNG_WRITE_cHRM_SUPPORTED
|
|
|
1391 /* Write the cHRM chunk */
|
|
|
1392 void /* PRIVATE */
|
|
|
1393 png_write_cHRM_fixed(png_structrp png_ptr, const png_xy *xy)
|
|
|
1394 {
|
|
|
1395 png_byte buf[32];
|
|
|
1396
|
|
|
1397 png_debug(1, "in png_write_cHRM");
|
|
|
1398
|
|
|
1399 /* Each value is saved in 1/100,000ths */
|
|
|
1400 png_save_int_32(buf, xy->whitex);
|
|
|
1401 png_save_int_32(buf + 4, xy->whitey);
|
|
|
1402
|
|
|
1403 png_save_int_32(buf + 8, xy->redx);
|
|
|
1404 png_save_int_32(buf + 12, xy->redy);
|
|
|
1405
|
|
|
1406 png_save_int_32(buf + 16, xy->greenx);
|
|
|
1407 png_save_int_32(buf + 20, xy->greeny);
|
|
|
1408
|
|
|
1409 png_save_int_32(buf + 24, xy->bluex);
|
|
|
1410 png_save_int_32(buf + 28, xy->bluey);
|
|
|
1411
|
|
|
1412 png_write_complete_chunk(png_ptr, png_cHRM, buf, 32);
|
|
|
1413 }
|
|
|
1414 #endif
|
|
|
1415
|
|
|
1416 #ifdef PNG_WRITE_tRNS_SUPPORTED
|
|
|
1417 /* Write the tRNS chunk */
|
|
|
1418 void /* PRIVATE */
|
|
|
1419 png_write_tRNS(png_structrp png_ptr, png_const_bytep trans_alpha,
|
|
|
1420 png_const_color_16p tran, int num_trans, int color_type)
|
|
|
1421 {
|
|
|
1422 png_byte buf[6];
|
|
|
1423
|
|
|
1424 png_debug(1, "in png_write_tRNS");
|
|
|
1425
|
|
|
1426 if (color_type == PNG_COLOR_TYPE_PALETTE)
|
|
|
1427 {
|
|
|
1428 if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette)
|
|
|
1429 {
|
|
|
1430 png_app_warning(png_ptr,
|
|
|
1431 "Invalid number of transparent colors specified");
|
|
|
1432 return;
|
|
|
1433 }
|
|
|
1434
|
|
|
1435 /* Write the chunk out as it is */
|
|
|
1436 png_write_complete_chunk(png_ptr, png_tRNS, trans_alpha,
|
|
|
1437 (png_size_t)num_trans);
|
|
|
1438 }
|
|
|
1439
|
|
|
1440 else if (color_type == PNG_COLOR_TYPE_GRAY)
|
|
|
1441 {
|
|
|
1442 /* One 16 bit value */
|
|
|
1443 if (tran->gray >= (1 << png_ptr->bit_depth))
|
|
|
1444 {
|
|
|
1445 png_app_warning(png_ptr,
|
|
|
1446 "Ignoring attempt to write tRNS chunk out-of-range for bit_depth");
|
|
|
1447
|
|
|
1448 return;
|
|
|
1449 }
|
|
|
1450
|
|
|
1451 png_save_uint_16(buf, tran->gray);
|
|
|
1452 png_write_complete_chunk(png_ptr, png_tRNS, buf, (png_size_t)2);
|
|
|
1453 }
|
|
|
1454
|
|
|
1455 else if (color_type == PNG_COLOR_TYPE_RGB)
|
|
|
1456 {
|
|
|
1457 /* Three 16 bit values */
|
|
|
1458 png_save_uint_16(buf, tran->red);
|
|
|
1459 png_save_uint_16(buf + 2, tran->green);
|
|
|
1460 png_save_uint_16(buf + 4, tran->blue);
|
|
|
1461 #ifdef PNG_WRITE_16BIT_SUPPORTED
|
|
|
1462 if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
|
|
|
1463 #else
|
|
|
1464 if (buf[0] | buf[2] | buf[4])
|
|
|
1465 #endif
|
|
|
1466 {
|
|
|
1467 png_app_warning(png_ptr,
|
|
|
1468 "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8");
|
|
|
1469 return;
|
|
|
1470 }
|
|
|
1471
|
|
|
1472 png_write_complete_chunk(png_ptr, png_tRNS, buf, (png_size_t)6);
|
|
|
1473 }
|
|
|
1474
|
|
|
1475 else
|
|
|
1476 {
|
|
|
1477 png_app_warning(png_ptr, "Can't write tRNS with an alpha channel");
|
|
|
1478 }
|
|
|
1479 }
|
|
|
1480 #endif
|
|
|
1481
|
|
|
1482 #ifdef PNG_WRITE_bKGD_SUPPORTED
|
|
|
1483 /* Write the background chunk */
|
|
|
1484 void /* PRIVATE */
|
|
|
1485 png_write_bKGD(png_structrp png_ptr, png_const_color_16p back, int color_type)
|
|
|
1486 {
|
|
|
1487 png_byte buf[6];
|
|
|
1488
|
|
|
1489 png_debug(1, "in png_write_bKGD");
|
|
|
1490
|
|
|
1491 if (color_type == PNG_COLOR_TYPE_PALETTE)
|
|
|
1492 {
|
|
|
1493 if (
|
|
|
1494 #ifdef PNG_MNG_FEATURES_SUPPORTED
|
|
|
1495 (png_ptr->num_palette ||
|
|
|
1496 (!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE))) &&
|
|
|
1497 #endif
|
|
|
1498 back->index >= png_ptr->num_palette)
|
|
|
1499 {
|
|
|
1500 png_warning(png_ptr, "Invalid background palette index");
|
|
|
1501 return;
|
|
|
1502 }
|
|
|
1503
|
|
|
1504 buf[0] = back->index;
|
|
|
1505 png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)1);
|
|
|
1506 }
|
|
|
1507
|
|
|
1508 else if (color_type & PNG_COLOR_MASK_COLOR)
|
|
|
1509 {
|
|
|
1510 png_save_uint_16(buf, back->red);
|
|
|
1511 png_save_uint_16(buf + 2, back->green);
|
|
|
1512 png_save_uint_16(buf + 4, back->blue);
|
|
|
1513 #ifdef PNG_WRITE_16BIT_SUPPORTED
|
|
|
1514 if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]))
|
|
|
1515 #else
|
|
|
1516 if (buf[0] | buf[2] | buf[4])
|
|
|
1517 #endif
|
|
|
1518 {
|
|
|
1519 png_warning(png_ptr,
|
|
|
1520 "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8");
|
|
|
1521
|
|
|
1522 return;
|
|
|
1523 }
|
|
|
1524
|
|
|
1525 png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)6);
|
|
|
1526 }
|
|
|
1527
|
|
|
1528 else
|
|
|
1529 {
|
|
|
1530 if (back->gray >= (1 << png_ptr->bit_depth))
|
|
|
1531 {
|
|
|
1532 png_warning(png_ptr,
|
|
|
1533 "Ignoring attempt to write bKGD chunk out-of-range for bit_depth");
|
|
|
1534
|
|
|
1535 return;
|
|
|
1536 }
|
|
|
1537
|
|
|
1538 png_save_uint_16(buf, back->gray);
|
|
|
1539 png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)2);
|
|
|
1540 }
|
|
|
1541 }
|
|
|
1542 #endif
|
|
|
1543
|
|
|
1544 #ifdef PNG_WRITE_hIST_SUPPORTED
|
|
|
1545 /* Write the histogram */
|
|
|
1546 void /* PRIVATE */
|
|
|
1547 png_write_hIST(png_structrp png_ptr, png_const_uint_16p hist, int num_hist)
|
|
|
1548 {
|
|
|
1549 int i;
|
|
|
1550 png_byte buf[3];
|
|
|
1551
|
|
|
1552 png_debug(1, "in png_write_hIST");
|
|
|
1553
|
|
|
1554 if (num_hist > (int)png_ptr->num_palette)
|
|
|
1555 {
|
|
|
1556 png_debug2(3, "num_hist = %d, num_palette = %d", num_hist,
|
|
|
1557 png_ptr->num_palette);
|
|
|
1558
|
|
|
1559 png_warning(png_ptr, "Invalid number of histogram entries specified");
|
|
|
1560 return;
|
|
|
1561 }
|
|
|
1562
|
|
|
1563 png_write_chunk_header(png_ptr, png_hIST, (png_uint_32)(num_hist * 2));
|
|
|
1564
|
|
|
1565 for (i = 0; i < num_hist; i++)
|
|
|
1566 {
|
|
|
1567 png_save_uint_16(buf, hist[i]);
|
|
|
1568 png_write_chunk_data(png_ptr, buf, (png_size_t)2);
|
|
|
1569 }
|
|
|
1570
|
|
|
1571 png_write_chunk_end(png_ptr);
|
|
|
1572 }
|
|
|
1573 #endif
|
|
|
1574
|
|
|
1575 #ifdef PNG_WRITE_tEXt_SUPPORTED
|
|
|
1576 /* Write a tEXt chunk */
|
|
|
1577 void /* PRIVATE */
|
|
|
1578 png_write_tEXt(png_structrp png_ptr, png_const_charp key, png_const_charp text,
|
|
|
1579 png_size_t text_len)
|
|
|
1580 {
|
|
|
1581 png_uint_32 key_len;
|
|
|
1582 png_byte new_key[80];
|
|
|
1583
|
|
|
1584 png_debug(1, "in png_write_tEXt");
|
|
|
1585
|
|
|
1586 key_len = png_check_keyword(png_ptr, key, new_key);
|
|
|
1587
|
|
|
1588 if (key_len == 0)
|
|
|
1589 png_error(png_ptr, "tEXt: invalid keyword");
|
|
|
1590
|
|
|
1591 if (text == NULL || *text == '\0')
|
|
|
1592 text_len = 0;
|
|
|
1593
|
|
|
1594 else
|
|
|
1595 text_len = strlen(text);
|
|
|
1596
|
|
|
1597 if (text_len > PNG_UINT_31_MAX - (key_len+1))
|
|
|
1598 png_error(png_ptr, "tEXt: text too long");
|
|
|
1599
|
|
|
1600 /* Make sure we include the 0 after the key */
|
|
|
1601 png_write_chunk_header(png_ptr, png_tEXt,
|
|
|
1602 (png_uint_32)/*checked above*/(key_len + text_len + 1));
|
|
|
1603 /*
|
|
|
1604 * We leave it to the application to meet PNG-1.0 requirements on the
|
|
|
1605 * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
|
|
|
1606 * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them.
|
|
|
1607 * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
|
|
|
1608 */
|
|
|
1609 png_write_chunk_data(png_ptr, new_key, key_len + 1);
|
|
|
1610
|
|
|
1611 if (text_len)
|
|
|
1612 png_write_chunk_data(png_ptr, (png_const_bytep)text, text_len);
|
|
|
1613
|
|
|
1614 png_write_chunk_end(png_ptr);
|
|
|
1615 }
|
|
|
1616 #endif
|
|
|
1617
|
|
|
1618 #ifdef PNG_WRITE_zTXt_SUPPORTED
|
|
|
1619 /* Write a compressed text chunk */
|
|
|
1620 void /* PRIVATE */
|
|
|
1621 png_write_zTXt(png_structrp png_ptr, png_const_charp key, png_const_charp text,
|
|
|
1622 png_size_t text_len, int compression)
|
|
|
1623 {
|
|
|
1624 png_uint_32 key_len;
|
|
|
1625 png_byte new_key[81];
|
|
|
1626 compression_state comp;
|
|
|
1627
|
|
|
1628 png_debug(1, "in png_write_zTXt");
|
|
|
1629 PNG_UNUSED(text_len) /* Always use strlen */
|
|
|
1630
|
|
|
1631 if (compression == PNG_TEXT_COMPRESSION_NONE)
|
|
|
1632 {
|
|
|
1633 png_write_tEXt(png_ptr, key, text, 0);
|
|
|
1634 return;
|
|
|
1635 }
|
|
|
1636
|
|
|
1637 if (compression != PNG_TEXT_COMPRESSION_zTXt)
|
|
|
1638 png_error(png_ptr, "zTXt: invalid compression type");
|
|
|
1639
|
|
|
1640 key_len = png_check_keyword(png_ptr, key, new_key);
|
|
|
1641
|
|
|
1642 if (key_len == 0)
|
|
|
1643 png_error(png_ptr, "zTXt: invalid keyword");
|
|
|
1644
|
|
|
1645 /* Add the compression method and 1 for the keyword separator. */
|
|
|
1646 new_key[++key_len] = PNG_COMPRESSION_TYPE_BASE;
|
|
|
1647 ++key_len;
|
|
|
1648
|
|
|
1649 /* Compute the compressed data; do it now for the length */
|
|
|
1650 png_text_compress_init(&comp, (png_const_bytep)text,
|
|
|
1651 text == NULL ? 0 : strlen(text));
|
|
|
1652
|
|
|
1653 if (png_text_compress(png_ptr, png_zTXt, &comp, key_len) != Z_OK)
|
|
|
1654 png_error(png_ptr, png_ptr->zstream.msg);
|
|
|
1655
|
|
|
1656 /* Write start of chunk */
|
|
|
1657 png_write_chunk_header(png_ptr, png_zTXt, key_len + comp.output_len);
|
|
|
1658
|
|
|
1659 /* Write key */
|
|
|
1660 png_write_chunk_data(png_ptr, new_key, key_len);
|
|
|
1661
|
|
|
1662 /* Write the compressed data */
|
|
|
1663 png_write_compressed_data_out(png_ptr, &comp);
|
|
|
1664
|
|
|
1665 /* Close the chunk */
|
|
|
1666 png_write_chunk_end(png_ptr);
|
|
|
1667 }
|
|
|
1668 #endif
|
|
|
1669
|
|
|
1670 #ifdef PNG_WRITE_iTXt_SUPPORTED
|
|
|
1671 /* Write an iTXt chunk */
|
|
|
1672 void /* PRIVATE */
|
|
|
1673 png_write_iTXt(png_structrp png_ptr, int compression, png_const_charp key,
|
|
|
1674 png_const_charp lang, png_const_charp lang_key, png_const_charp text)
|
|
|
1675 {
|
|
|
1676 png_uint_32 key_len, prefix_len;
|
|
|
1677 png_size_t lang_len, lang_key_len;
|
|
|
1678 png_byte new_key[82];
|
|
|
1679 compression_state comp;
|
|
|
1680
|
|
|
1681 png_debug(1, "in png_write_iTXt");
|
|
|
1682
|
|
|
1683 key_len = png_check_keyword(png_ptr, key, new_key);
|
|
|
1684
|
|
|
1685 if (key_len == 0)
|
|
|
1686 png_error(png_ptr, "iTXt: invalid keyword");
|
|
|
1687
|
|
|
1688 /* Set the compression flag */
|
|
|
1689 switch (compression)
|
|
|
1690 {
|
|
|
1691 case PNG_ITXT_COMPRESSION_NONE:
|
|
|
1692 case PNG_TEXT_COMPRESSION_NONE:
|
|
|
1693 compression = new_key[++key_len] = 0; /* no compression */
|
|
|
1694 break;
|
|
|
1695
|
|
|
1696 case PNG_TEXT_COMPRESSION_zTXt:
|
|
|
1697 case PNG_ITXT_COMPRESSION_zTXt:
|
|
|
1698 compression = new_key[++key_len] = 1; /* compressed */
|
|
|
1699 break;
|
|
|
1700
|
|
|
1701 default:
|
|
|
1702 png_error(png_ptr, "iTXt: invalid compression");
|
|
|
1703 }
|
|
|
1704
|
|
|
1705 new_key[++key_len] = PNG_COMPRESSION_TYPE_BASE;
|
|
|
1706 ++key_len; /* for the keywod separator */
|
|
|
1707
|
|
|
1708 /* We leave it to the application to meet PNG-1.0 requirements on the
|
|
|
1709 * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
|
|
|
1710 * any non-Latin-1 characters except for NEWLINE. ISO PNG, however,
|
|
|
1711 * specifies that the text is UTF-8 and this really doesn't require any
|
|
|
1712 * checking.
|
|
|
1713 *
|
|
|
1714 * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
|
|
|
1715 *
|
|
|
1716 * TODO: validate the language tag correctly (see the spec.)
|
|
|
1717 */
|
|
|
1718 if (lang == NULL) lang = ""; /* empty language is valid */
|
|
|
1719 lang_len = strlen(lang)+1;
|
|
|
1720 if (lang_key == NULL) lang_key = ""; /* may be empty */
|
|
|
1721 lang_key_len = strlen(lang_key)+1;
|
|
|
1722 if (text == NULL) text = ""; /* may be empty */
|
|
|
1723
|
|
|
1724 prefix_len = key_len;
|
|
|
1725 if (lang_len > PNG_UINT_31_MAX-prefix_len)
|
|
|
1726 prefix_len = PNG_UINT_31_MAX;
|
|
|
1727 else
|
|
|
1728 prefix_len = (png_uint_32)(prefix_len + lang_len);
|
|
|
1729
|
|
|
1730 if (lang_key_len > PNG_UINT_31_MAX-prefix_len)
|
|
|
1731 prefix_len = PNG_UINT_31_MAX;
|
|
|
1732 else
|
|
|
1733 prefix_len = (png_uint_32)(prefix_len + lang_key_len);
|
|
|
1734
|
|
|
1735 png_text_compress_init(&comp, (png_const_bytep)text, strlen(text));
|
|
|
1736
|
|
|
1737 if (compression)
|
|
|
1738 {
|
|
|
1739 if (png_text_compress(png_ptr, png_iTXt, &comp, prefix_len) != Z_OK)
|
|
|
1740 png_error(png_ptr, png_ptr->zstream.msg);
|
|
|
1741 }
|
|
|
1742
|
|
|
1743 else
|
|
|
1744 {
|
|
|
1745 if (comp.input_len > PNG_UINT_31_MAX-prefix_len)
|
|
|
1746 png_error(png_ptr, "iTXt: uncompressed text too long");
|
|
|
1747
|
|
|
1748 /* So the string will fit in a chunk: */
|
|
|
1749 comp.output_len = (png_uint_32)/*SAFE*/comp.input_len;
|
|
|
1750 }
|
|
|
1751
|
|
|
1752 png_write_chunk_header(png_ptr, png_iTXt, comp.output_len + prefix_len);
|
|
|
1753
|
|
|
1754 png_write_chunk_data(png_ptr, new_key, key_len);
|
|
|
1755
|
|
|
1756 png_write_chunk_data(png_ptr, (png_const_bytep)lang, lang_len);
|
|
|
1757
|
|
|
1758 png_write_chunk_data(png_ptr, (png_const_bytep)lang_key, lang_key_len);
|
|
|
1759
|
|
|
1760 if (compression)
|
|
|
1761 png_write_compressed_data_out(png_ptr, &comp);
|
|
|
1762
|
|
|
1763 else
|
|
|
1764 png_write_chunk_data(png_ptr, (png_const_bytep)text, comp.input_len);
|
|
|
1765
|
|
|
1766 png_write_chunk_end(png_ptr);
|
|
|
1767 }
|
|
|
1768 #endif
|
|
|
1769
|
|
|
1770 #ifdef PNG_WRITE_oFFs_SUPPORTED
|
|
|
1771 /* Write the oFFs chunk */
|
|
|
1772 void /* PRIVATE */
|
|
|
1773 png_write_oFFs(png_structrp png_ptr, png_int_32 x_offset, png_int_32 y_offset,
|
|
|
1774 int unit_type)
|
|
|
1775 {
|
|
|
1776 png_byte buf[9];
|
|
|
1777
|
|
|
1778 png_debug(1, "in png_write_oFFs");
|
|
|
1779
|
|
|
1780 if (unit_type >= PNG_OFFSET_LAST)
|
|
|
1781 png_warning(png_ptr, "Unrecognized unit type for oFFs chunk");
|
|
|
1782
|
|
|
1783 png_save_int_32(buf, x_offset);
|
|
|
1784 png_save_int_32(buf + 4, y_offset);
|
|
|
1785 buf[8] = (png_byte)unit_type;
|
|
|
1786
|
|
|
1787 png_write_complete_chunk(png_ptr, png_oFFs, buf, (png_size_t)9);
|
|
|
1788 }
|
|
|
1789 #endif
|
|
|
1790 #ifdef PNG_WRITE_pCAL_SUPPORTED
|
|
|
1791 /* Write the pCAL chunk (described in the PNG extensions document) */
|
|
|
1792 void /* PRIVATE */
|
|
|
1793 png_write_pCAL(png_structrp png_ptr, png_charp purpose, png_int_32 X0,
|
|
|
1794 png_int_32 X1, int type, int nparams, png_const_charp units,
|
|
|
1795 png_charpp params)
|
|
|
1796 {
|
|
|
1797 png_uint_32 purpose_len;
|
|
|
1798 png_size_t units_len, total_len;
|
|
|
1799 png_size_tp params_len;
|
|
|
1800 png_byte buf[10];
|
|
|
1801 png_byte new_purpose[80];
|
|
|
1802 int i;
|
|
|
1803
|
|
|
1804 png_debug1(1, "in png_write_pCAL (%d parameters)", nparams);
|
|
|
1805
|
|
|
1806 if (type >= PNG_EQUATION_LAST)
|
|
|
1807 png_error(png_ptr, "Unrecognized equation type for pCAL chunk");
|
|
|
1808
|
|
|
1809 purpose_len = png_check_keyword(png_ptr, purpose, new_purpose);
|
|
|
1810
|
|
|
1811 if (purpose_len == 0)
|
|
|
1812 png_error(png_ptr, "pCAL: invalid keyword");
|
|
|
1813
|
|
|
1814 ++purpose_len; /* terminator */
|
|
|
1815
|
|
|
1816 png_debug1(3, "pCAL purpose length = %d", (int)purpose_len);
|
|
|
1817 units_len = strlen(units) + (nparams == 0 ? 0 : 1);
|
|
|
1818 png_debug1(3, "pCAL units length = %d", (int)units_len);
|
|
|
1819 total_len = purpose_len + units_len + 10;
|
|
|
1820
|
|
|
1821 params_len = (png_size_tp)png_malloc(png_ptr,
|
|
|
1822 (png_alloc_size_t)(nparams * (sizeof (png_size_t))));
|
|
|
1823
|
|
|
1824 /* Find the length of each parameter, making sure we don't count the
|
|
|
1825 * null terminator for the last parameter.
|
|
|
1826 */
|
|
|
1827 for (i = 0; i < nparams; i++)
|
|
|
1828 {
|
|
|
1829 params_len[i] = strlen(params[i]) + (i == nparams - 1 ? 0 : 1);
|
|
|
1830 png_debug2(3, "pCAL parameter %d length = %lu", i,
|
|
|
1831 (unsigned long)params_len[i]);
|
|
|
1832 total_len += params_len[i];
|
|
|
1833 }
|
|
|
1834
|
|
|
1835 png_debug1(3, "pCAL total length = %d", (int)total_len);
|
|
|
1836 png_write_chunk_header(png_ptr, png_pCAL, (png_uint_32)total_len);
|
|
|
1837 png_write_chunk_data(png_ptr, new_purpose, purpose_len);
|
|
|
1838 png_save_int_32(buf, X0);
|
|
|
1839 png_save_int_32(buf + 4, X1);
|
|
|
1840 buf[8] = (png_byte)type;
|
|
|
1841 buf[9] = (png_byte)nparams;
|
|
|
1842 png_write_chunk_data(png_ptr, buf, (png_size_t)10);
|
|
|
1843 png_write_chunk_data(png_ptr, (png_const_bytep)units, (png_size_t)units_len);
|
|
|
1844
|
|
|
1845 for (i = 0; i < nparams; i++)
|
|
|
1846 {
|
|
|
1847 png_write_chunk_data(png_ptr, (png_const_bytep)params[i], params_len[i]);
|
|
|
1848 }
|
|
|
1849
|
|
|
1850 png_free(png_ptr, params_len);
|
|
|
1851 png_write_chunk_end(png_ptr);
|
|
|
1852 }
|
|
|
1853 #endif
|
|
|
1854
|
|
|
1855 #ifdef PNG_WRITE_sCAL_SUPPORTED
|
|
|
1856 /* Write the sCAL chunk */
|
|
|
1857 void /* PRIVATE */
|
|
|
1858 png_write_sCAL_s(png_structrp png_ptr, int unit, png_const_charp width,
|
|
|
1859 png_const_charp height)
|
|
|
1860 {
|
|
|
1861 png_byte buf[64];
|
|
|
1862 png_size_t wlen, hlen, total_len;
|
|
|
1863
|
|
|
1864 png_debug(1, "in png_write_sCAL_s");
|
|
|
1865
|
|
|
1866 wlen = strlen(width);
|
|
|
1867 hlen = strlen(height);
|
|
|
1868 total_len = wlen + hlen + 2;
|
|
|
1869
|
|
|
1870 if (total_len > 64)
|
|
|
1871 {
|
|
|
1872 png_warning(png_ptr, "Can't write sCAL (buffer too small)");
|
|
|
1873 return;
|
|
|
1874 }
|
|
|
1875
|
|
|
1876 buf[0] = (png_byte)unit;
|
|
|
1877 memcpy(buf + 1, width, wlen + 1); /* Append the '\0' here */
|
|
|
1878 memcpy(buf + wlen + 2, height, hlen); /* Do NOT append the '\0' here */
|
|
|
1879
|
|
|
1880 png_debug1(3, "sCAL total length = %u", (unsigned int)total_len);
|
|
|
1881 png_write_complete_chunk(png_ptr, png_sCAL, buf, total_len);
|
|
|
1882 }
|
|
|
1883 #endif
|
|
|
1884
|
|
|
1885 #ifdef PNG_WRITE_pHYs_SUPPORTED
|
|
|
1886 /* Write the pHYs chunk */
|
|
|
1887 void /* PRIVATE */
|
|
|
1888 png_write_pHYs(png_structrp png_ptr, png_uint_32 x_pixels_per_unit,
|
|
|
1889 png_uint_32 y_pixels_per_unit,
|
|
|
1890 int unit_type)
|
|
|
1891 {
|
|
|
1892 png_byte buf[9];
|
|
|
1893
|
|
|
1894 png_debug(1, "in png_write_pHYs");
|
|
|
1895
|
|
|
1896 if (unit_type >= PNG_RESOLUTION_LAST)
|
|
|
1897 png_warning(png_ptr, "Unrecognized unit type for pHYs chunk");
|
|
|
1898
|
|
|
1899 png_save_uint_32(buf, x_pixels_per_unit);
|
|
|
1900 png_save_uint_32(buf + 4, y_pixels_per_unit);
|
|
|
1901 buf[8] = (png_byte)unit_type;
|
|
|
1902
|
|
|
1903 png_write_complete_chunk(png_ptr, png_pHYs, buf, (png_size_t)9);
|
|
|
1904 }
|
|
|
1905 #endif
|
|
|
1906
|
|
|
1907 #ifdef PNG_WRITE_tIME_SUPPORTED
|
|
|
1908 /* Write the tIME chunk. Use either png_convert_from_struct_tm()
|
|
|
1909 * or png_convert_from_time_t(), or fill in the structure yourself.
|
|
|
1910 */
|
|
|
1911 void /* PRIVATE */
|
|
|
1912 png_write_tIME(png_structrp png_ptr, png_const_timep mod_time)
|
|
|
1913 {
|
|
|
1914 png_byte buf[7];
|
|
|
1915
|
|
|
1916 png_debug(1, "in png_write_tIME");
|
|
|
1917
|
|
|
1918 if (mod_time->month > 12 || mod_time->month < 1 ||
|
|
|
1919 mod_time->day > 31 || mod_time->day < 1 ||
|
|
|
1920 mod_time->hour > 23 || mod_time->second > 60)
|
|
|
1921 {
|
|
|
1922 png_warning(png_ptr, "Invalid time specified for tIME chunk");
|
|
|
1923 return;
|
|
|
1924 }
|
|
|
1925
|
|
|
1926 png_save_uint_16(buf, mod_time->year);
|
|
|
1927 buf[2] = mod_time->month;
|
|
|
1928 buf[3] = mod_time->day;
|
|
|
1929 buf[4] = mod_time->hour;
|
|
|
1930 buf[5] = mod_time->minute;
|
|
|
1931 buf[6] = mod_time->second;
|
|
|
1932
|
|
|
1933 png_write_complete_chunk(png_ptr, png_tIME, buf, (png_size_t)7);
|
|
|
1934 }
|
|
|
1935 #endif
|
|
|
1936
|
|
|
1937 /* Initializes the row writing capability of libpng */
|
|
|
1938 void /* PRIVATE */
|
|
|
1939 png_write_start_row(png_structrp png_ptr)
|
|
|
1940 {
|
|
|
1941 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
|
|
|
1942 /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
|
|
|
1943
|
|
|
1944 /* Start of interlace block */
|
|
|
1945 static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
|
|
|
1946
|
|
|
1947 /* Offset to next interlace block */
|
|
|
1948 static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
|
|
|
1949
|
|
|
1950 /* Start of interlace block in the y direction */
|
|
|
1951 static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
|
|
|
1952
|
|
|
1953 /* Offset to next interlace block in the y direction */
|
|
|
1954 static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
|
|
|
1955 #endif
|
|
|
1956
|
|
|
1957 png_alloc_size_t buf_size;
|
|
|
1958 int usr_pixel_depth;
|
|
|
1959
|
|
|
1960 png_debug(1, "in png_write_start_row");
|
|
|
1961
|
|
|
1962 usr_pixel_depth = png_ptr->usr_channels * png_ptr->usr_bit_depth;
|
|
|
1963 buf_size = PNG_ROWBYTES(usr_pixel_depth, png_ptr->width) + 1;
|
|
|
1964
|
|
|
1965 /* 1.5.6: added to allow checking in the row write code. */
|
|
|
1966 png_ptr->transformed_pixel_depth = png_ptr->pixel_depth;
|
|
|
1967 png_ptr->maximum_pixel_depth = (png_byte)usr_pixel_depth;
|
|
|
1968
|
|
|
1969 /* Set up row buffer */
|
|
|
1970 png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, buf_size);
|
|
|
1971
|
|
|
1972 png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE;
|
|
|
1973
|
|
|
1974 #ifdef PNG_WRITE_FILTER_SUPPORTED
|
|
|
1975 /* Set up filtering buffer, if using this filter */
|
|
|
1976 if (png_ptr->do_filter & PNG_FILTER_SUB)
|
|
|
1977 {
|
|
|
1978 png_ptr->sub_row = (png_bytep)png_malloc(png_ptr, png_ptr->rowbytes + 1);
|
|
|
1979
|
|
|
1980 png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
|
|
|
1981 }
|
|
|
1982
|
|
|
1983 /* We only need to keep the previous row if we are using one of these. */
|
|
|
1984 if (png_ptr->do_filter & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH))
|
|
|
1985 {
|
|
|
1986 /* Set up previous row buffer */
|
|
|
1987 png_ptr->prev_row = (png_bytep)png_calloc(png_ptr, buf_size);
|
|
|
1988
|
|
|
1989 if (png_ptr->do_filter & PNG_FILTER_UP)
|
|
|
1990 {
|
|
|
1991 png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
|
|
|
1992 png_ptr->rowbytes + 1);
|
|
|
1993
|
|
|
1994 png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
|
|
|
1995 }
|
|
|
1996
|
|
|
1997 if (png_ptr->do_filter & PNG_FILTER_AVG)
|
|
|
1998 {
|
|
|
1999 png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
|
|
|
2000 png_ptr->rowbytes + 1);
|
|
|
2001
|
|
|
2002 png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
|
|
|
2003 }
|
|
|
2004
|
|
|
2005 if (png_ptr->do_filter & PNG_FILTER_PAETH)
|
|
|
2006 {
|
|
|
2007 png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
|
|
|
2008 png_ptr->rowbytes + 1);
|
|
|
2009
|
|
|
2010 png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
|
|
|
2011 }
|
|
|
2012 }
|
|
|
2013 #endif /* PNG_WRITE_FILTER_SUPPORTED */
|
|
|
2014
|
|
|
2015 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
|
|
|
2016 /* If interlaced, we need to set up width and height of pass */
|
|
|
2017 if (png_ptr->interlaced)
|
|
|
2018 {
|
|
|
2019 if (!(png_ptr->transformations & PNG_INTERLACE))
|
|
|
2020 {
|
|
|
2021 png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
|
|
|
2022 png_pass_ystart[0]) / png_pass_yinc[0];
|
|
|
2023
|
|
|
2024 png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 -
|
|
|
2025 png_pass_start[0]) / png_pass_inc[0];
|
|
|
2026 }
|
|
|
2027
|
|
|
2028 else
|
|
|
2029 {
|
|
|
2030 png_ptr->num_rows = png_ptr->height;
|
|
|
2031 png_ptr->usr_width = png_ptr->width;
|
|
|
2032 }
|
|
|
2033 }
|
|
|
2034
|
|
|
2035 else
|
|
|
2036 #endif
|
|
|
2037 {
|
|
|
2038 png_ptr->num_rows = png_ptr->height;
|
|
|
2039 png_ptr->usr_width = png_ptr->width;
|
|
|
2040 }
|
|
|
2041 }
|
|
|
2042
|
|
|
2043 /* Internal use only. Called when finished processing a row of data. */
|
|
|
2044 void /* PRIVATE */
|
|
|
2045 png_write_finish_row(png_structrp png_ptr)
|
|
|
2046 {
|
|
|
2047 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
|
|
|
2048 /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
|
|
|
2049
|
|
|
2050 /* Start of interlace block */
|
|
|
2051 static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
|
|
|
2052
|
|
|
2053 /* Offset to next interlace block */
|
|
|
2054 static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
|
|
|
2055
|
|
|
2056 /* Start of interlace block in the y direction */
|
|
|
2057 static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
|
|
|
2058
|
|
|
2059 /* Offset to next interlace block in the y direction */
|
|
|
2060 static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
|
|
|
2061 #endif
|
|
|
2062
|
|
|
2063 png_debug(1, "in png_write_finish_row");
|
|
|
2064
|
|
|
2065 /* Next row */
|
|
|
2066 png_ptr->row_number++;
|
|
|
2067
|
|
|
2068 /* See if we are done */
|
|
|
2069 if (png_ptr->row_number < png_ptr->num_rows)
|
|
|
2070 return;
|
|
|
2071
|
|
|
2072 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
|
|
|
2073 /* If interlaced, go to next pass */
|
|
|
2074 if (png_ptr->interlaced)
|
|
|
2075 {
|
|
|
2076 png_ptr->row_number = 0;
|
|
|
2077 if (png_ptr->transformations & PNG_INTERLACE)
|
|
|
2078 {
|
|
|
2079 png_ptr->pass++;
|
|
|
2080 }
|
|
|
2081
|
|
|
2082 else
|
|
|
2083 {
|
|
|
2084 /* Loop until we find a non-zero width or height pass */
|
|
|
2085 do
|
|
|
2086 {
|
|
|
2087 png_ptr->pass++;
|
|
|
2088
|
|
|
2089 if (png_ptr->pass >= 7)
|
|
|
2090 break;
|
|
|
2091
|
|
|
2092 png_ptr->usr_width = (png_ptr->width +
|
|
|
2093 png_pass_inc[png_ptr->pass] - 1 -
|
|
|
2094 png_pass_start[png_ptr->pass]) /
|
|
|
2095 png_pass_inc[png_ptr->pass];
|
|
|
2096
|
|
|
2097 png_ptr->num_rows = (png_ptr->height +
|
|
|
2098 png_pass_yinc[png_ptr->pass] - 1 -
|
|
|
2099 png_pass_ystart[png_ptr->pass]) /
|
|
|
2100 png_pass_yinc[png_ptr->pass];
|
|
|
2101
|
|
|
2102 if (png_ptr->transformations & PNG_INTERLACE)
|
|
|
2103 break;
|
|
|
2104
|
|
|
2105 } while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0);
|
|
|
2106
|
|
|
2107 }
|
|
|
2108
|
|
|
2109 /* Reset the row above the image for the next pass */
|
|
|
2110 if (png_ptr->pass < 7)
|
|
|
2111 {
|
|
|
2112 if (png_ptr->prev_row != NULL)
|
|
|
2113 memset(png_ptr->prev_row, 0,
|
|
|
2114 (png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels*
|
|
|
2115 png_ptr->usr_bit_depth, png_ptr->width)) + 1);
|
|
|
2116
|
|
|
2117 return;
|
|
|
2118 }
|
|
|
2119 }
|
|
|
2120 #endif
|
|
|
2121
|
|
|
2122 /* If we get here, we've just written the last row, so we need
|
|
|
2123 to flush the compressor */
|
|
|
2124 png_compress_IDAT(png_ptr, NULL, 0, Z_FINISH);
|
|
|
2125 }
|
|
|
2126
|
|
|
2127 #ifdef PNG_WRITE_INTERLACING_SUPPORTED
|
|
|
2128 /* Pick out the correct pixels for the interlace pass.
|
|
|
2129 * The basic idea here is to go through the row with a source
|
|
|
2130 * pointer and a destination pointer (sp and dp), and copy the
|
|
|
2131 * correct pixels for the pass. As the row gets compacted,
|
|
|
2132 * sp will always be >= dp, so we should never overwrite anything.
|
|
|
2133 * See the default: case for the easiest code to understand.
|
|
|
2134 */
|
|
|
2135 void /* PRIVATE */
|
|
|
2136 png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
|
|
|
2137 {
|
|
|
2138 /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
|
|
|
2139
|
|
|
2140 /* Start of interlace block */
|
|
|
2141 static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
|
|
|
2142
|
|
|
2143 /* Offset to next interlace block */
|
|
|
2144 static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
|
|
|
2145
|
|
|
2146 png_debug(1, "in png_do_write_interlace");
|
|
|
2147
|
|
|
2148 /* We don't have to do anything on the last pass (6) */
|
|
|
2149 if (pass < 6)
|
|
|
2150 {
|
|
|
2151 /* Each pixel depth is handled separately */
|
|
|
2152 switch (row_info->pixel_depth)
|
|
|
2153 {
|
|
|
2154 case 1:
|
|
|
2155 {
|
|
|
2156 png_bytep sp;
|
|
|
2157 png_bytep dp;
|
|
|
2158 int shift;
|
|
|
2159 int d;
|
|
|
2160 int value;
|
|
|
2161 png_uint_32 i;
|
|
|
2162 png_uint_32 row_width = row_info->width;
|
|
|
2163
|
|
|
2164 dp = row;
|
|
|
2165 d = 0;
|
|
|
2166 shift = 7;
|
|
|
2167
|
|
|
2168 for (i = png_pass_start[pass]; i < row_width;
|
|
|
2169 i += png_pass_inc[pass])
|
|
|
2170 {
|
|
|
2171 sp = row + (png_size_t)(i >> 3);
|
|
|
2172 value = (int)(*sp >> (7 - (int)(i & 0x07))) & 0x01;
|
|
|
2173 d |= (value << shift);
|
|
|
2174
|
|
|
2175 if (shift == 0)
|
|
|
2176 {
|
|
|
2177 shift = 7;
|
|
|
2178 *dp++ = (png_byte)d;
|
|
|
2179 d = 0;
|
|
|
2180 }
|
|
|
2181
|
|
|
2182 else
|
|
|
2183 shift--;
|
|
|
2184
|
|
|
2185 }
|
|
|
2186 if (shift != 7)
|
|
|
2187 *dp = (png_byte)d;
|
|
|
2188
|
|
|
2189 break;
|
|
|
2190 }
|
|
|
2191
|
|
|
2192 case 2:
|
|
|
2193 {
|
|
|
2194 png_bytep sp;
|
|
|
2195 png_bytep dp;
|
|
|
2196 int shift;
|
|
|
2197 int d;
|
|
|
2198 int value;
|
|
|
2199 png_uint_32 i;
|
|
|
2200 png_uint_32 row_width = row_info->width;
|
|
|
2201
|
|
|
2202 dp = row;
|
|
|
2203 shift = 6;
|
|
|
2204 d = 0;
|
|
|
2205
|
|
|
2206 for (i = png_pass_start[pass]; i < row_width;
|
|
|
2207 i += png_pass_inc[pass])
|
|
|
2208 {
|
|
|
2209 sp = row + (png_size_t)(i >> 2);
|
|
|
2210 value = (*sp >> ((3 - (int)(i & 0x03)) << 1)) & 0x03;
|
|
|
2211 d |= (value << shift);
|
|
|
2212
|
|
|
2213 if (shift == 0)
|
|
|
2214 {
|
|
|
2215 shift = 6;
|
|
|
2216 *dp++ = (png_byte)d;
|
|
|
2217 d = 0;
|
|
|
2218 }
|
|
|
2219
|
|
|
2220 else
|
|
|
2221 shift -= 2;
|
|
|
2222 }
|
|
|
2223 if (shift != 6)
|
|
|
2224 *dp = (png_byte)d;
|
|
|
2225
|
|
|
2226 break;
|
|
|
2227 }
|
|
|
2228
|
|
|
2229 case 4:
|
|
|
2230 {
|
|
|
2231 png_bytep sp;
|
|
|
2232 png_bytep dp;
|
|
|
2233 int shift;
|
|
|
2234 int d;
|
|
|
2235 int value;
|
|
|
2236 png_uint_32 i;
|
|
|
2237 png_uint_32 row_width = row_info->width;
|
|
|
2238
|
|
|
2239 dp = row;
|
|
|
2240 shift = 4;
|
|
|
2241 d = 0;
|
|
|
2242 for (i = png_pass_start[pass]; i < row_width;
|
|
|
2243 i += png_pass_inc[pass])
|
|
|
2244 {
|
|
|
2245 sp = row + (png_size_t)(i >> 1);
|
|
|
2246 value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f;
|
|
|
2247 d |= (value << shift);
|
|
|
2248
|
|
|
2249 if (shift == 0)
|
|
|
2250 {
|
|
|
2251 shift = 4;
|
|
|
2252 *dp++ = (png_byte)d;
|
|
|
2253 d = 0;
|
|
|
2254 }
|
|
|
2255
|
|
|
2256 else
|
|
|
2257 shift -= 4;
|
|
|
2258 }
|
|
|
2259 if (shift != 4)
|
|
|
2260 *dp = (png_byte)d;
|
|
|
2261
|
|
|
2262 break;
|
|
|
2263 }
|
|
|
2264
|
|
|
2265 default:
|
|
|
2266 {
|
|
|
2267 png_bytep sp;
|
|
|
2268 png_bytep dp;
|
|
|
2269 png_uint_32 i;
|
|
|
2270 png_uint_32 row_width = row_info->width;
|
|
|
2271 png_size_t pixel_bytes;
|
|
|
2272
|
|
|
2273 /* Start at the beginning */
|
|
|
2274 dp = row;
|
|
|
2275
|
|
|
2276 /* Find out how many bytes each pixel takes up */
|
|
|
2277 pixel_bytes = (row_info->pixel_depth >> 3);
|
|
|
2278
|
|
|
2279 /* Loop through the row, only looking at the pixels that matter */
|
|
|
2280 for (i = png_pass_start[pass]; i < row_width;
|
|
|
2281 i += png_pass_inc[pass])
|
|
|
2282 {
|
|
|
2283 /* Find out where the original pixel is */
|
|
|
2284 sp = row + (png_size_t)i * pixel_bytes;
|
|
|
2285
|
|
|
2286 /* Move the pixel */
|
|
|
2287 if (dp != sp)
|
|
|
2288 memcpy(dp, sp, pixel_bytes);
|
|
|
2289
|
|
|
2290 /* Next pixel */
|
|
|
2291 dp += pixel_bytes;
|
|
|
2292 }
|
|
|
2293 break;
|
|
|
2294 }
|
|
|
2295 }
|
|
|
2296 /* Set new row width */
|
|
|
2297 row_info->width = (row_info->width +
|
|
|
2298 png_pass_inc[pass] - 1 -
|
|
|
2299 png_pass_start[pass]) /
|
|
|
2300 png_pass_inc[pass];
|
|
|
2301
|
|
|
2302 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
|
|
|
2303 row_info->width);
|
|
|
2304 }
|
|
|
2305 }
|
|
|
2306 #endif
|
|
|
2307
|
|
|
2308 /* This filters the row, chooses which filter to use, if it has not already
|
|
|
2309 * been specified by the application, and then writes the row out with the
|
|
|
2310 * chosen filter.
|
|
|
2311 */
|
|
|
2312 static void
|
|
|
2313 png_write_filtered_row(png_structrp png_ptr, png_bytep filtered_row,
|
|
|
2314 png_size_t row_bytes);
|
|
|
2315
|
|
|
2316 #define PNG_MAXSUM (((png_uint_32)(-1)) >> 1)
|
|
|
2317 #define PNG_HISHIFT 10
|
|
|
2318 #define PNG_LOMASK ((png_uint_32)0xffffL)
|
|
|
2319 #define PNG_HIMASK ((png_uint_32)(~PNG_LOMASK >> PNG_HISHIFT))
|
|
|
2320 void /* PRIVATE */
|
|
|
2321 png_write_find_filter(png_structrp png_ptr, png_row_infop row_info)
|
|
|
2322 {
|
|
|
2323 png_bytep best_row;
|
|
|
2324 #ifdef PNG_WRITE_FILTER_SUPPORTED
|
|
|
2325 png_bytep prev_row, row_buf;
|
|
|
2326 png_uint_32 mins, bpp;
|
|
|
2327 png_byte filter_to_do = png_ptr->do_filter;
|
|
|
2328 png_size_t row_bytes = row_info->rowbytes;
|
|
|
2329 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
|
|
|
2330 int num_p_filters = png_ptr->num_prev_filters;
|
|
|
2331 #endif
|
|
|
2332
|
|
|
2333 png_debug(1, "in png_write_find_filter");
|
|
|
2334
|
|
|
2335 #ifndef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
|
|
|
2336 if (png_ptr->row_number == 0 && filter_to_do == PNG_ALL_FILTERS)
|
|
|
2337 {
|
|
|
2338 /* These will never be selected so we need not test them. */
|
|
|
2339 filter_to_do &= ~(PNG_FILTER_UP | PNG_FILTER_PAETH);
|
|
|
2340 }
|
|
|
2341 #endif
|
|
|
2342
|
|
|
2343 /* Find out how many bytes offset each pixel is */
|
|
|
2344 bpp = (row_info->pixel_depth + 7) >> 3;
|
|
|
2345
|
|
|
2346 prev_row = png_ptr->prev_row;
|
|
|
2347 #endif
|
|
|
2348 best_row = png_ptr->row_buf;
|
|
|
2349 #ifdef PNG_WRITE_FILTER_SUPPORTED
|
|
|
2350 row_buf = best_row;
|
|
|
2351 mins = PNG_MAXSUM;
|
|
|
2352
|
|
|
2353 /* The prediction method we use is to find which method provides the
|
|
|
2354 * smallest value when summing the absolute values of the distances
|
|
|
2355 * from zero, using anything >= 128 as negative numbers. This is known
|
|
|
2356 * as the "minimum sum of absolute differences" heuristic. Other
|
|
|
2357 * heuristics are the "weighted minimum sum of absolute differences"
|
|
|
2358 * (experimental and can in theory improve compression), and the "zlib
|
|
|
2359 * predictive" method (not implemented yet), which does test compressions
|
|
|
2360 * of lines using different filter methods, and then chooses the
|
|
|
2361 * (series of) filter(s) that give minimum compressed data size (VERY
|
|
|
2362 * computationally expensive).
|
|
|
2363 *
|
|
|
2364 * GRR 980525: consider also
|
|
|
2365 *
|
|
|
2366 * (1) minimum sum of absolute differences from running average (i.e.,
|
|
|
2367 * keep running sum of non-absolute differences & count of bytes)
|
|
|
2368 * [track dispersion, too? restart average if dispersion too large?]
|
|
|
2369 *
|
|
|
2370 * (1b) minimum sum of absolute differences from sliding average, probably
|
|
|
2371 * with window size <= deflate window (usually 32K)
|
|
|
2372 *
|
|
|
2373 * (2) minimum sum of squared differences from zero or running average
|
|
|
2374 * (i.e., ~ root-mean-square approach)
|
|
|
2375 */
|
|
|
2376
|
|
|
2377
|
|
|
2378 /* We don't need to test the 'no filter' case if this is the only filter
|
|
|
2379 * that has been chosen, as it doesn't actually do anything to the data.
|
|
|
2380 */
|
|
|
2381 if ((filter_to_do & PNG_FILTER_NONE) && filter_to_do != PNG_FILTER_NONE)
|
|
|
2382 {
|
|
|
2383 png_bytep rp;
|
|
|
2384 png_uint_32 sum = 0;
|
|
|
2385 png_size_t i;
|
|
|
2386 int v;
|
|
|
2387
|
|
|
2388 for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)
|
|
|
2389 {
|
|
|
2390 v = *rp;
|
|
|
2391 sum += (v < 128) ? v : 256 - v;
|
|
|
2392 }
|
|
|
2393
|
|
|
2394 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
|
|
|
2395 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
|
|
|
2396 {
|
|
|
2397 png_uint_32 sumhi, sumlo;
|
|
|
2398 int j;
|
|
|
2399 sumlo = sum & PNG_LOMASK;
|
|
|
2400 sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; /* Gives us some footroom */
|
|
|
2401
|
|
|
2402 /* Reduce the sum if we match any of the previous rows */
|
|
|
2403 for (j = 0; j < num_p_filters; j++)
|
|
|
2404 {
|
|
|
2405 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
|
|
|
2406 {
|
|
|
2407 sumlo = (sumlo * png_ptr->filter_weights[j]) >>
|
|
|
2408 PNG_WEIGHT_SHIFT;
|
|
|
2409
|
|
|
2410 sumhi = (sumhi * png_ptr->filter_weights[j]) >>
|
|
|
2411 PNG_WEIGHT_SHIFT;
|
|
|
2412 }
|
|
|
2413 }
|
|
|
2414
|
|
|
2415 /* Factor in the cost of this filter (this is here for completeness,
|
|
|
2416 * but it makes no sense to have a "cost" for the NONE filter, as
|
|
|
2417 * it has the minimum possible computational cost - none).
|
|
|
2418 */
|
|
|
2419 sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
|
|
|
2420 PNG_COST_SHIFT;
|
|
|
2421
|
|
|
2422 sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
|
|
|
2423 PNG_COST_SHIFT;
|
|
|
2424
|
|
|
2425 if (sumhi > PNG_HIMASK)
|
|
|
2426 sum = PNG_MAXSUM;
|
|
|
2427
|
|
|
2428 else
|
|
|
2429 sum = (sumhi << PNG_HISHIFT) + sumlo;
|
|
|
2430 }
|
|
|
2431 #endif
|
|
|
2432 mins = sum;
|
|
|
2433 }
|
|
|
2434
|
|
|
2435 /* Sub filter */
|
|
|
2436 if (filter_to_do == PNG_FILTER_SUB)
|
|
|
2437 /* It's the only filter so no testing is needed */
|
|
|
2438 {
|
|
|
2439 png_bytep rp, lp, dp;
|
|
|
2440 png_size_t i;
|
|
|
2441
|
|
|
2442 for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
|
|
|
2443 i++, rp++, dp++)
|
|
|
2444 {
|
|
|
2445 *dp = *rp;
|
|
|
2446 }
|
|
|
2447
|
|
|
2448 for (lp = row_buf + 1; i < row_bytes;
|
|
|
2449 i++, rp++, lp++, dp++)
|
|
|
2450 {
|
|
|
2451 *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
|
|
|
2452 }
|
|
|
2453
|
|
|
2454 best_row = png_ptr->sub_row;
|
|
|
2455 }
|
|
|
2456
|
|
|
2457 else if (filter_to_do & PNG_FILTER_SUB)
|
|
|
2458 {
|
|
|
2459 png_bytep rp, dp, lp;
|
|
|
2460 png_uint_32 sum = 0, lmins = mins;
|
|
|
2461 png_size_t i;
|
|
|
2462 int v;
|
|
|
2463
|
|
|
2464 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
|
|
|
2465 /* We temporarily increase the "minimum sum" by the factor we
|
|
|
2466 * would reduce the sum of this filter, so that we can do the
|
|
|
2467 * early exit comparison without scaling the sum each time.
|
|
|
2468 */
|
|
|
2469 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
|
|
|
2470 {
|
|
|
2471 int j;
|
|
|
2472 png_uint_32 lmhi, lmlo;
|
|
|
2473 lmlo = lmins & PNG_LOMASK;
|
|
|
2474 lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
|
|
|
2475
|
|
|
2476 for (j = 0; j < num_p_filters; j++)
|
|
|
2477 {
|
|
|
2478 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
|
|
|
2479 {
|
|
|
2480 lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
|
|
|
2481 PNG_WEIGHT_SHIFT;
|
|
|
2482
|
|
|
2483 lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
|
|
|
2484 PNG_WEIGHT_SHIFT;
|
|
|
2485 }
|
|
|
2486 }
|
|
|
2487
|
|
|
2488 lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
|
|
|
2489 PNG_COST_SHIFT;
|
|
|
2490
|
|
|
2491 lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
|
|
|
2492 PNG_COST_SHIFT;
|
|
|
2493
|
|
|
2494 if (lmhi > PNG_HIMASK)
|
|
|
2495 lmins = PNG_MAXSUM;
|
|
|
2496
|
|
|
2497 else
|
|
|
2498 lmins = (lmhi << PNG_HISHIFT) + lmlo;
|
|
|
2499 }
|
|
|
2500 #endif
|
|
|
2501
|
|
|
2502 for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
|
|
|
2503 i++, rp++, dp++)
|
|
|
2504 {
|
|
|
2505 v = *dp = *rp;
|
|
|
2506
|
|
|
2507 sum += (v < 128) ? v : 256 - v;
|
|
|
2508 }
|
|
|
2509
|
|
|
2510 for (lp = row_buf + 1; i < row_bytes;
|
|
|
2511 i++, rp++, lp++, dp++)
|
|
|
2512 {
|
|
|
2513 v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff);
|
|
|
2514
|
|
|
2515 sum += (v < 128) ? v : 256 - v;
|
|
|
2516
|
|
|
2517 if (sum > lmins) /* We are already worse, don't continue. */
|
|
|
2518 break;
|
|
|
2519 }
|
|
|
2520
|
|
|
2521 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
|
|
|
2522 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
|
|
|
2523 {
|
|
|
2524 int j;
|
|
|
2525 png_uint_32 sumhi, sumlo;
|
|
|
2526 sumlo = sum & PNG_LOMASK;
|
|
|
2527 sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
|
|
|
2528
|
|
|
2529 for (j = 0; j < num_p_filters; j++)
|
|
|
2530 {
|
|
|
2531 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
|
|
|
2532 {
|
|
|
2533 sumlo = (sumlo * png_ptr->inv_filter_weights[j]) >>
|
|
|
2534 PNG_WEIGHT_SHIFT;
|
|
|
2535
|
|
|
2536 sumhi = (sumhi * png_ptr->inv_filter_weights[j]) >>
|
|
|
2537 PNG_WEIGHT_SHIFT;
|
|
|
2538 }
|
|
|
2539 }
|
|
|
2540
|
|
|
2541 sumlo = (sumlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
|
|
|
2542 PNG_COST_SHIFT;
|
|
|
2543
|
|
|
2544 sumhi = (sumhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
|
|
|
2545 PNG_COST_SHIFT;
|
|
|
2546
|
|
|
2547 if (sumhi > PNG_HIMASK)
|
|
|
2548 sum = PNG_MAXSUM;
|
|
|
2549
|
|
|
2550 else
|
|
|
2551 sum = (sumhi << PNG_HISHIFT) + sumlo;
|
|
|
2552 }
|
|
|
2553 #endif
|
|
|
2554
|
|
|
2555 if (sum < mins)
|
|
|
2556 {
|
|
|
2557 mins = sum;
|
|
|
2558 best_row = png_ptr->sub_row;
|
|
|
2559 }
|
|
|
2560 }
|
|
|
2561
|
|
|
2562 /* Up filter */
|
|
|
2563 if (filter_to_do == PNG_FILTER_UP)
|
|
|
2564 {
|
|
|
2565 png_bytep rp, dp, pp;
|
|
|
2566 png_size_t i;
|
|
|
2567
|
|
|
2568 for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
|
|
|
2569 pp = prev_row + 1; i < row_bytes;
|
|
|
2570 i++, rp++, pp++, dp++)
|
|
|
2571 {
|
|
|
2572 *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff);
|
|
|
2573 }
|
|
|
2574
|
|
|
2575 best_row = png_ptr->up_row;
|
|
|
2576 }
|
|
|
2577
|
|
|
2578 else if (filter_to_do & PNG_FILTER_UP)
|
|
|
2579 {
|
|
|
2580 png_bytep rp, dp, pp;
|
|
|
2581 png_uint_32 sum = 0, lmins = mins;
|
|
|
2582 png_size_t i;
|
|
|
2583 int v;
|
|
|
2584
|
|
|
2585
|
|
|
2586 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
|
|
|
2587 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
|
|
|
2588 {
|
|
|
2589 int j;
|
|
|
2590 png_uint_32 lmhi, lmlo;
|
|
|
2591 lmlo = lmins & PNG_LOMASK;
|
|
|
2592 lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
|
|
|
2593
|
|
|
2594 for (j = 0; j < num_p_filters; j++)
|
|
|
2595 {
|
|
|
2596 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
|
|
|
2597 {
|
|
|
2598 lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
|
|
|
2599 PNG_WEIGHT_SHIFT;
|
|
|
2600
|
|
|
2601 lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
|
|
|
2602 PNG_WEIGHT_SHIFT;
|
|
|
2603 }
|
|
|
2604 }
|
|
|
2605
|
|
|
2606 lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
|
|
|
2607 PNG_COST_SHIFT;
|
|
|
2608
|
|
|
2609 lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
|
|
|
2610 PNG_COST_SHIFT;
|
|
|
2611
|
|
|
2612 if (lmhi > PNG_HIMASK)
|
|
|
2613 lmins = PNG_MAXSUM;
|
|
|
2614
|
|
|
2615 else
|
|
|
2616 lmins = (lmhi << PNG_HISHIFT) + lmlo;
|
|
|
2617 }
|
|
|
2618 #endif
|
|
|
2619
|
|
|
2620 for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
|
|
|
2621 pp = prev_row + 1; i < row_bytes; i++)
|
|
|
2622 {
|
|
|
2623 v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
|
|
|
2624
|
|
|
2625 sum += (v < 128) ? v : 256 - v;
|
|
|
2626
|
|
|
2627 if (sum > lmins) /* We are already worse, don't continue. */
|
|
|
2628 break;
|
|
|
2629 }
|
|
|
2630
|
|
|
2631 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
|
|
|
2632 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
|
|
|
2633 {
|
|
|
2634 int j;
|
|
|
2635 png_uint_32 sumhi, sumlo;
|
|
|
2636 sumlo = sum & PNG_LOMASK;
|
|
|
2637 sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
|
|
|
2638
|
|
|
2639 for (j = 0; j < num_p_filters; j++)
|
|
|
2640 {
|
|
|
2641 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
|
|
|
2642 {
|
|
|
2643 sumlo = (sumlo * png_ptr->filter_weights[j]) >>
|
|
|
2644 PNG_WEIGHT_SHIFT;
|
|
|
2645
|
|
|
2646 sumhi = (sumhi * png_ptr->filter_weights[j]) >>
|
|
|
2647 PNG_WEIGHT_SHIFT;
|
|
|
2648 }
|
|
|
2649 }
|
|
|
2650
|
|
|
2651 sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
|
|
|
2652 PNG_COST_SHIFT;
|
|
|
2653
|
|
|
2654 sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
|
|
|
2655 PNG_COST_SHIFT;
|
|
|
2656
|
|
|
2657 if (sumhi > PNG_HIMASK)
|
|
|
2658 sum = PNG_MAXSUM;
|
|
|
2659
|
|
|
2660 else
|
|
|
2661 sum = (sumhi << PNG_HISHIFT) + sumlo;
|
|
|
2662 }
|
|
|
2663 #endif
|
|
|
2664
|
|
|
2665 if (sum < mins)
|
|
|
2666 {
|
|
|
2667 mins = sum;
|
|
|
2668 best_row = png_ptr->up_row;
|
|
|
2669 }
|
|
|
2670 }
|
|
|
2671
|
|
|
2672 /* Avg filter */
|
|
|
2673 if (filter_to_do == PNG_FILTER_AVG)
|
|
|
2674 {
|
|
|
2675 png_bytep rp, dp, pp, lp;
|
|
|
2676 png_uint_32 i;
|
|
|
2677
|
|
|
2678 for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
|
|
|
2679 pp = prev_row + 1; i < bpp; i++)
|
|
|
2680 {
|
|
|
2681 *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
|
|
|
2682 }
|
|
|
2683
|
|
|
2684 for (lp = row_buf + 1; i < row_bytes; i++)
|
|
|
2685 {
|
|
|
2686 *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2))
|
|
|
2687 & 0xff);
|
|
|
2688 }
|
|
|
2689 best_row = png_ptr->avg_row;
|
|
|
2690 }
|
|
|
2691
|
|
|
2692 else if (filter_to_do & PNG_FILTER_AVG)
|
|
|
2693 {
|
|
|
2694 png_bytep rp, dp, pp, lp;
|
|
|
2695 png_uint_32 sum = 0, lmins = mins;
|
|
|
2696 png_size_t i;
|
|
|
2697 int v;
|
|
|
2698
|
|
|
2699 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
|
|
|
2700 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
|
|
|
2701 {
|
|
|
2702 int j;
|
|
|
2703 png_uint_32 lmhi, lmlo;
|
|
|
2704 lmlo = lmins & PNG_LOMASK;
|
|
|
2705 lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
|
|
|
2706
|
|
|
2707 for (j = 0; j < num_p_filters; j++)
|
|
|
2708 {
|
|
|
2709 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_AVG)
|
|
|
2710 {
|
|
|
2711 lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
|
|
|
2712 PNG_WEIGHT_SHIFT;
|
|
|
2713
|
|
|
2714 lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
|
|
|
2715 PNG_WEIGHT_SHIFT;
|
|
|
2716 }
|
|
|
2717 }
|
|
|
2718
|
|
|
2719 lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
|
|
|
2720 PNG_COST_SHIFT;
|
|
|
2721
|
|
|
2722 lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
|
|
|
2723 PNG_COST_SHIFT;
|
|
|
2724
|
|
|
2725 if (lmhi > PNG_HIMASK)
|
|
|
2726 lmins = PNG_MAXSUM;
|
|
|
2727
|
|
|
2728 else
|
|
|
2729 lmins = (lmhi << PNG_HISHIFT) + lmlo;
|
|
|
2730 }
|
|
|
2731 #endif
|
|
|
2732
|
|
|
2733 for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
|
|
|
2734 pp = prev_row + 1; i < bpp; i++)
|
|
|
2735 {
|
|
|
2736 v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff);
|
|
|
2737
|
|
|
2738 sum += (v < 128) ? v : 256 - v;
|
|
|
2739 }
|
|
|
2740
|
|
|
2741 for (lp = row_buf + 1; i < row_bytes; i++)
|
|
|
2742 {
|
|
|
2743 v = *dp++ =
|
|
|
2744 (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff);
|
|
|
2745
|
|
|
2746 sum += (v < 128) ? v : 256 - v;
|
|
|
2747
|
|
|
2748 if (sum > lmins) /* We are already worse, don't continue. */
|
|
|
2749 break;
|
|
|
2750 }
|
|
|
2751
|
|
|
2752 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
|
|
|
2753 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
|
|
|
2754 {
|
|
|
2755 int j;
|
|
|
2756 png_uint_32 sumhi, sumlo;
|
|
|
2757 sumlo = sum & PNG_LOMASK;
|
|
|
2758 sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
|
|
|
2759
|
|
|
2760 for (j = 0; j < num_p_filters; j++)
|
|
|
2761 {
|
|
|
2762 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
|
|
|
2763 {
|
|
|
2764 sumlo = (sumlo * png_ptr->filter_weights[j]) >>
|
|
|
2765 PNG_WEIGHT_SHIFT;
|
|
|
2766
|
|
|
2767 sumhi = (sumhi * png_ptr->filter_weights[j]) >>
|
|
|
2768 PNG_WEIGHT_SHIFT;
|
|
|
2769 }
|
|
|
2770 }
|
|
|
2771
|
|
|
2772 sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
|
|
|
2773 PNG_COST_SHIFT;
|
|
|
2774
|
|
|
2775 sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
|
|
|
2776 PNG_COST_SHIFT;
|
|
|
2777
|
|
|
2778 if (sumhi > PNG_HIMASK)
|
|
|
2779 sum = PNG_MAXSUM;
|
|
|
2780
|
|
|
2781 else
|
|
|
2782 sum = (sumhi << PNG_HISHIFT) + sumlo;
|
|
|
2783 }
|
|
|
2784 #endif
|
|
|
2785
|
|
|
2786 if (sum < mins)
|
|
|
2787 {
|
|
|
2788 mins = sum;
|
|
|
2789 best_row = png_ptr->avg_row;
|
|
|
2790 }
|
|
|
2791 }
|
|
|
2792
|
|
|
2793 /* Paeth filter */
|
|
|
2794 if (filter_to_do == PNG_FILTER_PAETH)
|
|
|
2795 {
|
|
|
2796 png_bytep rp, dp, pp, cp, lp;
|
|
|
2797 png_size_t i;
|
|
|
2798
|
|
|
2799 for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
|
|
|
2800 pp = prev_row + 1; i < bpp; i++)
|
|
|
2801 {
|
|
|
2802 *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
|
|
|
2803 }
|
|
|
2804
|
|
|
2805 for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
|
|
|
2806 {
|
|
|
2807 int a, b, c, pa, pb, pc, p;
|
|
|
2808
|
|
|
2809 b = *pp++;
|
|
|
2810 c = *cp++;
|
|
|
2811 a = *lp++;
|
|
|
2812
|
|
|
2813 p = b - c;
|
|
|
2814 pc = a - c;
|
|
|
2815
|
|
|
2816 #ifdef PNG_USE_ABS
|
|
|
2817 pa = abs(p);
|
|
|
2818 pb = abs(pc);
|
|
|
2819 pc = abs(p + pc);
|
|
|
2820 #else
|
|
|
2821 pa = p < 0 ? -p : p;
|
|
|
2822 pb = pc < 0 ? -pc : pc;
|
|
|
2823 pc = (p + pc) < 0 ? -(p + pc) : p + pc;
|
|
|
2824 #endif
|
|
|
2825
|
|
|
2826 p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
|
|
|
2827
|
|
|
2828 *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
|
|
|
2829 }
|
|
|
2830 best_row = png_ptr->paeth_row;
|
|
|
2831 }
|
|
|
2832
|
|
|
2833 else if (filter_to_do & PNG_FILTER_PAETH)
|
|
|
2834 {
|
|
|
2835 png_bytep rp, dp, pp, cp, lp;
|
|
|
2836 png_uint_32 sum = 0, lmins = mins;
|
|
|
2837 png_size_t i;
|
|
|
2838 int v;
|
|
|
2839
|
|
|
2840 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
|
|
|
2841 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
|
|
|
2842 {
|
|
|
2843 int j;
|
|
|
2844 png_uint_32 lmhi, lmlo;
|
|
|
2845 lmlo = lmins & PNG_LOMASK;
|
|
|
2846 lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
|
|
|
2847
|
|
|
2848 for (j = 0; j < num_p_filters; j++)
|
|
|
2849 {
|
|
|
2850 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
|
|
|
2851 {
|
|
|
2852 lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
|
|
|
2853 PNG_WEIGHT_SHIFT;
|
|
|
2854
|
|
|
2855 lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
|
|
|
2856 PNG_WEIGHT_SHIFT;
|
|
|
2857 }
|
|
|
2858 }
|
|
|
2859
|
|
|
2860 lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
|
|
|
2861 PNG_COST_SHIFT;
|
|
|
2862
|
|
|
2863 lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
|
|
|
2864 PNG_COST_SHIFT;
|
|
|
2865
|
|
|
2866 if (lmhi > PNG_HIMASK)
|
|
|
2867 lmins = PNG_MAXSUM;
|
|
|
2868
|
|
|
2869 else
|
|
|
2870 lmins = (lmhi << PNG_HISHIFT) + lmlo;
|
|
|
2871 }
|
|
|
2872 #endif
|
|
|
2873
|
|
|
2874 for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
|
|
|
2875 pp = prev_row + 1; i < bpp; i++)
|
|
|
2876 {
|
|
|
2877 v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff);
|
|
|
2878
|
|
|
2879 sum += (v < 128) ? v : 256 - v;
|
|
|
2880 }
|
|
|
2881
|
|
|
2882 for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
|
|
|
2883 {
|
|
|
2884 int a, b, c, pa, pb, pc, p;
|
|
|
2885
|
|
|
2886 b = *pp++;
|
|
|
2887 c = *cp++;
|
|
|
2888 a = *lp++;
|
|
|
2889
|
|
|
2890 #ifndef PNG_SLOW_PAETH
|
|
|
2891 p = b - c;
|
|
|
2892 pc = a - c;
|
|
|
2893 #ifdef PNG_USE_ABS
|
|
|
2894 pa = abs(p);
|
|
|
2895 pb = abs(pc);
|
|
|
2896 pc = abs(p + pc);
|
|
|
2897 #else
|
|
|
2898 pa = p < 0 ? -p : p;
|
|
|
2899 pb = pc < 0 ? -pc : pc;
|
|
|
2900 pc = (p + pc) < 0 ? -(p + pc) : p + pc;
|
|
|
2901 #endif
|
|
|
2902 p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
|
|
|
2903 #else /* PNG_SLOW_PAETH */
|
|
|
2904 p = a + b - c;
|
|
|
2905 pa = abs(p - a);
|
|
|
2906 pb = abs(p - b);
|
|
|
2907 pc = abs(p - c);
|
|
|
2908
|
|
|
2909 if (pa <= pb && pa <= pc)
|
|
|
2910 p = a;
|
|
|
2911
|
|
|
2912 else if (pb <= pc)
|
|
|
2913 p = b;
|
|
|
2914
|
|
|
2915 else
|
|
|
2916 p = c;
|
|
|
2917 #endif /* PNG_SLOW_PAETH */
|
|
|
2918
|
|
|
2919 v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff);
|
|
|
2920
|
|
|
2921 sum += (v < 128) ? v : 256 - v;
|
|
|
2922
|
|
|
2923 if (sum > lmins) /* We are already worse, don't continue. */
|
|
|
2924 break;
|
|
|
2925 }
|
|
|
2926
|
|
|
2927 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
|
|
|
2928 if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
|
|
|
2929 {
|
|
|
2930 int j;
|
|
|
2931 png_uint_32 sumhi, sumlo;
|
|
|
2932 sumlo = sum & PNG_LOMASK;
|
|
|
2933 sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
|
|
|
2934
|
|
|
2935 for (j = 0; j < num_p_filters; j++)
|
|
|
2936 {
|
|
|
2937 if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
|
|
|
2938 {
|
|
|
2939 sumlo = (sumlo * png_ptr->filter_weights[j]) >>
|
|
|
2940 PNG_WEIGHT_SHIFT;
|
|
|
2941
|
|
|
2942 sumhi = (sumhi * png_ptr->filter_weights[j]) >>
|
|
|
2943 PNG_WEIGHT_SHIFT;
|
|
|
2944 }
|
|
|
2945 }
|
|
|
2946
|
|
|
2947 sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
|
|
|
2948 PNG_COST_SHIFT;
|
|
|
2949
|
|
|
2950 sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
|
|
|
2951 PNG_COST_SHIFT;
|
|
|
2952
|
|
|
2953 if (sumhi > PNG_HIMASK)
|
|
|
2954 sum = PNG_MAXSUM;
|
|
|
2955
|
|
|
2956 else
|
|
|
2957 sum = (sumhi << PNG_HISHIFT) + sumlo;
|
|
|
2958 }
|
|
|
2959 #endif
|
|
|
2960
|
|
|
2961 if (sum < mins)
|
|
|
2962 {
|
|
|
2963 best_row = png_ptr->paeth_row;
|
|
|
2964 }
|
|
|
2965 }
|
|
|
2966 #endif /* PNG_WRITE_FILTER_SUPPORTED */
|
|
|
2967
|
|
|
2968 /* Do the actual writing of the filtered row data from the chosen filter. */
|
|
|
2969 png_write_filtered_row(png_ptr, best_row, row_info->rowbytes+1);
|
|
|
2970
|
|
|
2971 #ifdef PNG_WRITE_FILTER_SUPPORTED
|
|
|
2972 #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED
|
|
|
2973 /* Save the type of filter we picked this time for future calculations */
|
|
|
2974 if (png_ptr->num_prev_filters > 0)
|
|
|
2975 {
|
|
|
2976 int j;
|
|
|
2977
|
|
|
2978 for (j = 1; j < num_p_filters; j++)
|
|
|
2979 {
|
|
|
2980 png_ptr->prev_filters[j] = png_ptr->prev_filters[j - 1];
|
|
|
2981 }
|
|
|
2982
|
|
|
2983 png_ptr->prev_filters[j] = best_row[0];
|
|
|
2984 }
|
|
|
2985 #endif
|
|
|
2986 #endif /* PNG_WRITE_FILTER_SUPPORTED */
|
|
|
2987 }
|
|
|
2988
|
|
|
2989
|
|
|
2990 /* Do the actual writing of a previously filtered row. */
|
|
|
2991 static void
|
|
|
2992 png_write_filtered_row(png_structrp png_ptr, png_bytep filtered_row,
|
|
|
2993 png_size_t full_row_length/*includes filter byte*/)
|
|
|
2994 {
|
|
|
2995 png_debug(1, "in png_write_filtered_row");
|
|
|
2996
|
|
|
2997 png_debug1(2, "filter = %d", filtered_row[0]);
|
|
|
2998
|
|
|
2999 png_compress_IDAT(png_ptr, filtered_row, full_row_length, Z_NO_FLUSH);
|
|
|
3000
|
|
|
3001 /* Swap the current and previous rows */
|
|
|
3002 if (png_ptr->prev_row != NULL)
|
|
|
3003 {
|
|
|
3004 png_bytep tptr;
|
|
|
3005
|
|
|
3006 tptr = png_ptr->prev_row;
|
|
|
3007 png_ptr->prev_row = png_ptr->row_buf;
|
|
|
3008 png_ptr->row_buf = tptr;
|
|
|
3009 }
|
|
|
3010
|
|
|
3011 /* Finish row - updates counters and flushes zlib if last row */
|
|
|
3012 png_write_finish_row(png_ptr);
|
|
|
3013
|
|
|
3014 #ifdef PNG_WRITE_FLUSH_SUPPORTED
|
|
|
3015 png_ptr->flush_rows++;
|
|
|
3016
|
|
|
3017 if (png_ptr->flush_dist > 0 &&
|
|
|
3018 png_ptr->flush_rows >= png_ptr->flush_dist)
|
|
|
3019 {
|
|
|
3020 png_write_flush(png_ptr);
|
|
|
3021 }
|
|
|
3022 #endif
|
|
|
3023 }
|
|
|
3024 #endif /* PNG_WRITE_SUPPORTED */
|
