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 1.5.10 [March 8, 2012] |
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5 | * Copyright (c) 1998-2012 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 | #ifdef PNG_SAVE_INT_32_SUPPORTED |
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33 | /* The png_save_int_32 function assumes integers are stored in two's |
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34 | * complement format. If this isn't the case, then this routine needs to |
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35 | * be modified to write data in two's complement format. Note that, |
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36 | * the following works correctly even if png_int_32 has more than 32 bits |
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37 | * (compare the more complex code required on read for sign extention.) |
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38 | */ |
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39 | void PNGAPI |
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40 | png_save_int_32(png_bytep buf, png_int_32 i) |
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41 | { |
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42 | buf[0] = (png_byte)((i >> 24) & 0xff); |
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43 | buf[1] = (png_byte)((i >> 16) & 0xff); |
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44 | buf[2] = (png_byte)((i >> 8) & 0xff); |
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45 | buf[3] = (png_byte)(i & 0xff); |
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46 | } |
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47 | #endif |
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48 | |
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49 | /* Place a 16-bit number into a buffer in PNG byte order. |
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50 | * The parameter is declared unsigned int, not png_uint_16, |
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51 | * just to avoid potential problems on pre-ANSI C compilers. |
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52 | */ |
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53 | void PNGAPI |
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54 | png_save_uint_16(png_bytep buf, unsigned int i) |
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55 | { |
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56 | buf[0] = (png_byte)((i >> 8) & 0xff); |
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57 | buf[1] = (png_byte)(i & 0xff); |
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58 | } |
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59 | #endif |
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60 | |
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61 | /* Simple function to write the signature. If we have already written |
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62 | * the magic bytes of the signature, or more likely, the PNG stream is |
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63 | * being embedded into another stream and doesn't need its own signature, |
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64 | * we should call png_set_sig_bytes() to tell libpng how many of the |
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65 | * bytes have already been written. |
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66 | */ |
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67 | void PNGAPI |
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68 | png_write_sig(png_structp png_ptr) |
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69 | { |
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70 | png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10}; |
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71 | |
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72 | #ifdef PNG_IO_STATE_SUPPORTED |
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73 | /* Inform the I/O callback that the signature is being written */ |
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74 | png_ptr->io_state = PNG_IO_WRITING | PNG_IO_SIGNATURE; |
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75 | #endif |
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76 | |
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77 | /* Write the rest of the 8 byte signature */ |
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78 | png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes], |
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79 | (png_size_t)(8 - png_ptr->sig_bytes)); |
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80 | |
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81 | if (png_ptr->sig_bytes < 3) |
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82 | png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE; |
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83 | } |
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84 | |
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85 | /* Write the start of a PNG chunk. The type is the chunk type. |
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86 | * The total_length is the sum of the lengths of all the data you will be |
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87 | * passing in png_write_chunk_data(). |
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88 | */ |
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89 | static void |
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90 | png_write_chunk_header(png_structp png_ptr, png_uint_32 chunk_name, |
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91 | png_uint_32 length) |
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92 | { |
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93 | png_byte buf[8]; |
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94 | |
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95 | #if defined(PNG_DEBUG) && (PNG_DEBUG > 0) |
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96 | PNG_CSTRING_FROM_CHUNK(buf, chunk_name); |
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97 | png_debug2(0, "Writing %s chunk, length = %lu", buf, (unsigned long)length); |
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98 | #endif |
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99 | |
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100 | if (png_ptr == NULL) |
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101 | return; |
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102 | |
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103 | #ifdef PNG_IO_STATE_SUPPORTED |
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104 | /* Inform the I/O callback that the chunk header is being written. |
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105 | * PNG_IO_CHUNK_HDR requires a single I/O call. |
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106 | */ |
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107 | png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_HDR; |
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108 | #endif |
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109 | |
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110 | /* Write the length and the chunk name */ |
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111 | png_save_uint_32(buf, length); |
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112 | png_save_uint_32(buf + 4, chunk_name); |
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113 | png_write_data(png_ptr, buf, 8); |
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114 | |
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115 | /* Put the chunk name into png_ptr->chunk_name */ |
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116 | png_ptr->chunk_name = chunk_name; |
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117 | |
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118 | /* Reset the crc and run it over the chunk name */ |
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119 | png_reset_crc(png_ptr); |
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120 | |
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121 | png_calculate_crc(png_ptr, buf + 4, 4); |
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122 | |
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123 | #ifdef PNG_IO_STATE_SUPPORTED |
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124 | /* Inform the I/O callback that chunk data will (possibly) be written. |
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125 | * PNG_IO_CHUNK_DATA does NOT require a specific number of I/O calls. |
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126 | */ |
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127 | png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_DATA; |
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128 | #endif |
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129 | } |
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130 | |
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131 | void PNGAPI |
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132 | png_write_chunk_start(png_structp png_ptr, png_const_bytep chunk_string, |
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133 | png_uint_32 length) |
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134 | { |
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135 | png_write_chunk_header(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), length); |
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136 | } |
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137 | |
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138 | /* Write the data of a PNG chunk started with png_write_chunk_header(). |
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139 | * Note that multiple calls to this function are allowed, and that the |
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140 | * sum of the lengths from these calls *must* add up to the total_length |
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141 | * given to png_write_chunk_header(). |
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142 | */ |
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143 | void PNGAPI |
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144 | png_write_chunk_data(png_structp png_ptr, png_const_bytep data, |
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145 | png_size_t length) |
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146 | { |
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147 | /* Write the data, and run the CRC over it */ |
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148 | if (png_ptr == NULL) |
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149 | return; |
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150 | |
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151 | if (data != NULL && length > 0) |
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152 | { |
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153 | png_write_data(png_ptr, data, length); |
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154 | |
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155 | /* Update the CRC after writing the data, |
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156 | * in case that the user I/O routine alters it. |
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157 | */ |
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158 | png_calculate_crc(png_ptr, data, length); |
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159 | } |
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160 | } |
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161 | |
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162 | /* Finish a chunk started with png_write_chunk_header(). */ |
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163 | void PNGAPI |
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164 | png_write_chunk_end(png_structp png_ptr) |
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165 | { |
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166 | png_byte buf[4]; |
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167 | |
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168 | if (png_ptr == NULL) return; |
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169 | |
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170 | #ifdef PNG_IO_STATE_SUPPORTED |
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171 | /* Inform the I/O callback that the chunk CRC is being written. |
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172 | * PNG_IO_CHUNK_CRC requires a single I/O function call. |
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173 | */ |
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174 | png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_CRC; |
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175 | #endif |
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176 | |
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177 | /* Write the crc in a single operation */ |
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178 | png_save_uint_32(buf, png_ptr->crc); |
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179 | |
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180 | png_write_data(png_ptr, buf, (png_size_t)4); |
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181 | } |
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182 | |
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183 | /* Write a PNG chunk all at once. The type is an array of ASCII characters |
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184 | * representing the chunk name. The array must be at least 4 bytes in |
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185 | * length, and does not need to be null terminated. To be safe, pass the |
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186 | * pre-defined chunk names here, and if you need a new one, define it |
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187 | * where the others are defined. The length is the length of the data. |
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188 | * All the data must be present. If that is not possible, use the |
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189 | * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end() |
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190 | * functions instead. |
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191 | */ |
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192 | static void |
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193 | png_write_complete_chunk(png_structp png_ptr, png_uint_32 chunk_name, |
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194 | png_const_bytep data, png_size_t length) |
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195 | { |
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196 | if (png_ptr == NULL) |
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197 | return; |
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198 | |
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199 | /* On 64 bit architectures 'length' may not fit in a png_uint_32. */ |
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200 | if (length > PNG_UINT_32_MAX) |
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201 | png_error(png_ptr, "length exceeds PNG maxima"); |
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202 | |
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203 | png_write_chunk_header(png_ptr, chunk_name, (png_uint_32)length); |
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204 | png_write_chunk_data(png_ptr, data, length); |
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205 | png_write_chunk_end(png_ptr); |
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206 | } |
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207 | |
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208 | /* This is the API that calls the internal function above. */ |
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209 | void PNGAPI |
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210 | png_write_chunk(png_structp png_ptr, png_const_bytep chunk_string, |
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211 | png_const_bytep data, png_size_t length) |
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212 | { |
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213 | png_write_complete_chunk(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), data, |
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214 | length); |
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215 | } |
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216 | |
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217 | /* Initialize the compressor for the appropriate type of compression. */ |
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218 | static void |
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219 | png_zlib_claim(png_structp png_ptr, png_uint_32 state) |
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220 | { |
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221 | if (!(png_ptr->zlib_state & PNG_ZLIB_IN_USE)) |
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222 | { |
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223 | /* If already initialized for 'state' do not re-init. */ |
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224 | if (png_ptr->zlib_state != state) |
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225 | { |
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226 | int ret = Z_OK; |
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227 | png_const_charp who = "-"; |
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228 | |
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229 | /* If actually initialized for another state do a deflateEnd. */ |
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230 | if (png_ptr->zlib_state != PNG_ZLIB_UNINITIALIZED) |
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231 | { |
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232 | ret = deflateEnd(&png_ptr->zstream); |
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233 | who = "end"; |
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234 | png_ptr->zlib_state = PNG_ZLIB_UNINITIALIZED; |
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235 | } |
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236 | |
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237 | /* zlib itself detects an incomplete state on deflateEnd */ |
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238 | if (ret == Z_OK) switch (state) |
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239 | { |
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240 | # ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED |
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241 | case PNG_ZLIB_FOR_TEXT: |
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242 | ret = deflateInit2(&png_ptr->zstream, |
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243 | png_ptr->zlib_text_level, png_ptr->zlib_text_method, |
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244 | png_ptr->zlib_text_window_bits, |
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245 | png_ptr->zlib_text_mem_level, png_ptr->zlib_text_strategy); |
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246 | who = "text"; |
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247 | break; |
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248 | # endif |
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249 | |
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250 | case PNG_ZLIB_FOR_IDAT: |
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251 | ret = deflateInit2(&png_ptr->zstream, png_ptr->zlib_level, |
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252 | png_ptr->zlib_method, png_ptr->zlib_window_bits, |
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253 | png_ptr->zlib_mem_level, png_ptr->zlib_strategy); |
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254 | who = "IDAT"; |
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255 | break; |
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256 | |
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257 | default: |
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258 | png_error(png_ptr, "invalid zlib state"); |
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259 | } |
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260 | |
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261 | if (ret == Z_OK) |
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262 | png_ptr->zlib_state = state; |
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263 | |
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264 | else /* an error in deflateEnd or deflateInit2 */ |
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265 | { |
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266 | size_t pos = 0; |
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267 | char msg[64]; |
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268 | |
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269 | pos = png_safecat(msg, sizeof msg, pos, |
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270 | "zlib failed to initialize compressor ("); |
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271 | pos = png_safecat(msg, sizeof msg, pos, who); |
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272 | |
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273 | switch (ret) |
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274 | { |
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275 | case Z_VERSION_ERROR: |
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276 | pos = png_safecat(msg, sizeof msg, pos, ") version error"); |
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277 | break; |
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278 | |
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279 | case Z_STREAM_ERROR: |
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280 | pos = png_safecat(msg, sizeof msg, pos, ") stream error"); |
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281 | break; |
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282 | |
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283 | case Z_MEM_ERROR: |
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284 | pos = png_safecat(msg, sizeof msg, pos, ") memory error"); |
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285 | break; |
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286 | |
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287 | default: |
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288 | pos = png_safecat(msg, sizeof msg, pos, ") unknown error"); |
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289 | break; |
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290 | } |
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291 | |
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292 | png_error(png_ptr, msg); |
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293 | } |
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294 | } |
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295 | |
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296 | /* Here on success, claim the zstream: */ |
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297 | png_ptr->zlib_state |= PNG_ZLIB_IN_USE; |
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298 | } |
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299 | |
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300 | else |
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301 | png_error(png_ptr, "zstream already in use (internal error)"); |
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302 | } |
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303 | |
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304 | /* The opposite: release the stream. It is also reset, this API will warn on |
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305 | * error but will not fail. |
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306 | */ |
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307 | static void |
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308 | png_zlib_release(png_structp png_ptr) |
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309 | { |
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310 | if (png_ptr->zlib_state & PNG_ZLIB_IN_USE) |
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311 | { |
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312 | int ret = deflateReset(&png_ptr->zstream); |
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313 | |
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314 | png_ptr->zlib_state &= ~PNG_ZLIB_IN_USE; |
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315 | |
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316 | if (ret != Z_OK) |
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317 | { |
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318 | png_const_charp err; |
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319 | PNG_WARNING_PARAMETERS(p) |
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320 | |
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321 | switch (ret) |
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322 | { |
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323 | case Z_VERSION_ERROR: |
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324 | err = "version"; |
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325 | break; |
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326 | |
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327 | case Z_STREAM_ERROR: |
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328 | err = "stream"; |
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329 | break; |
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330 | |
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331 | case Z_MEM_ERROR: |
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332 | err = "memory"; |
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333 | break; |
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334 | |
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335 | default: |
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336 | err = "unknown"; |
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337 | break; |
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338 | } |
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339 | |
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340 | png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_d, ret); |
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341 | png_warning_parameter(p, 2, err); |
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342 | |
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343 | if (png_ptr->zstream.msg) |
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344 | err = png_ptr->zstream.msg; |
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345 | else |
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346 | err = "[no zlib message]"; |
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347 | |
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348 | png_warning_parameter(p, 3, err); |
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349 | |
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350 | png_formatted_warning(png_ptr, p, |
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351 | "zlib failed to reset compressor: @1(@2): @3"); |
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352 | } |
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353 | } |
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354 | |
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355 | else |
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356 | png_warning(png_ptr, "zstream not in use (internal error)"); |
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357 | } |
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358 | |
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359 | #ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED |
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360 | /* This pair of functions encapsulates the operation of (a) compressing a |
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361 | * text string, and (b) issuing it later as a series of chunk data writes. |
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362 | * The compression_state structure is shared context for these functions |
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363 | * set up by the caller in order to make the whole mess thread-safe. |
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364 | */ |
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365 | |
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366 | typedef struct |
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367 | { |
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368 | png_const_bytep input; /* The uncompressed input data */ |
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369 | png_size_t input_len; /* Its length */ |
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370 | int num_output_ptr; /* Number of output pointers used */ |
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371 | int max_output_ptr; /* Size of output_ptr */ |
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372 | png_bytep *output_ptr; /* Array of pointers to output */ |
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373 | } compression_state; |
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374 | |
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375 | /* Compress given text into storage in the png_ptr structure */ |
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376 | static int /* PRIVATE */ |
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377 | png_text_compress(png_structp png_ptr, |
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378 | png_const_charp text, png_size_t text_len, int compression, |
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379 | compression_state *comp) |
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380 | { |
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381 | int ret; |
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382 | |
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383 | comp->num_output_ptr = 0; |
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384 | comp->max_output_ptr = 0; |
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385 | comp->output_ptr = NULL; |
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386 | comp->input = NULL; |
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387 | comp->input_len = text_len; |
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388 | |
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389 | /* We may just want to pass the text right through */ |
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390 | if (compression == PNG_TEXT_COMPRESSION_NONE) |
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391 | { |
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392 | comp->input = (png_const_bytep)text; |
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393 | return((int)text_len); |
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394 | } |
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395 | |
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396 | if (compression >= PNG_TEXT_COMPRESSION_LAST) |
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397 | { |
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398 | PNG_WARNING_PARAMETERS(p) |
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399 | |
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400 | png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_d, |
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401 | compression); |
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402 | png_formatted_warning(png_ptr, p, "Unknown compression type @1"); |
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403 | } |
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404 | |
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405 | /* We can't write the chunk until we find out how much data we have, |
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406 | * which means we need to run the compressor first and save the |
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407 | * output. This shouldn't be a problem, as the vast majority of |
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408 | * comments should be reasonable, but we will set up an array of |
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409 | * malloc'd pointers to be sure. |
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410 | * |
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411 | * If we knew the application was well behaved, we could simplify this |
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412 | * greatly by assuming we can always malloc an output buffer large |
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413 | * enough to hold the compressed text ((1001 * text_len / 1000) + 12) |
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414 | * and malloc this directly. The only time this would be a bad idea is |
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415 | * if we can't malloc more than 64K and we have 64K of random input |
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416 | * data, or if the input string is incredibly large (although this |
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417 | * wouldn't cause a failure, just a slowdown due to swapping). |
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418 | */ |
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419 | png_zlib_claim(png_ptr, PNG_ZLIB_FOR_TEXT); |
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420 | |
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421 | /* Set up the compression buffers */ |
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422 | /* TODO: the following cast hides a potential overflow problem. */ |
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423 | png_ptr->zstream.avail_in = (uInt)text_len; |
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424 | |
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425 | /* NOTE: assume zlib doesn't overwrite the input */ |
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426 | png_ptr->zstream.next_in = (Bytef *)text; |
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427 | png_ptr->zstream.avail_out = png_ptr->zbuf_size; |
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428 | png_ptr->zstream.next_out = png_ptr->zbuf; |
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429 | |
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430 | /* This is the same compression loop as in png_write_row() */ |
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431 | do |
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432 | { |
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433 | /* Compress the data */ |
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434 | ret = deflate(&png_ptr->zstream, Z_NO_FLUSH); |
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435 | |
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436 | if (ret != Z_OK) |
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437 | { |
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438 | /* Error */ |
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439 | if (png_ptr->zstream.msg != NULL) |
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440 | png_error(png_ptr, png_ptr->zstream.msg); |
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441 | |
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442 | else |
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443 | png_error(png_ptr, "zlib error"); |
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444 | } |
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445 | |
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446 | /* Check to see if we need more room */ |
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447 | if (!(png_ptr->zstream.avail_out)) |
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448 | { |
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449 | /* Make sure the output array has room */ |
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450 | if (comp->num_output_ptr >= comp->max_output_ptr) |
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451 | { |
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452 | int old_max; |
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453 | |
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454 | old_max = comp->max_output_ptr; |
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455 | comp->max_output_ptr = comp->num_output_ptr + 4; |
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456 | if (comp->output_ptr != NULL) |
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457 | { |
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458 | png_bytepp old_ptr; |
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459 | |
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460 | old_ptr = comp->output_ptr; |
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461 | |
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462 | comp->output_ptr = (png_bytepp)png_malloc(png_ptr, |
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463 | (png_alloc_size_t) |
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464 | (comp->max_output_ptr * png_sizeof(png_charpp))); |
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465 | |
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466 | png_memcpy(comp->output_ptr, old_ptr, old_max |
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467 | * png_sizeof(png_charp)); |
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468 | |
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469 | png_free(png_ptr, old_ptr); |
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470 | } |
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471 | else |
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472 | comp->output_ptr = (png_bytepp)png_malloc(png_ptr, |
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473 | (png_alloc_size_t) |
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474 | (comp->max_output_ptr * png_sizeof(png_charp))); |
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475 | } |
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476 | |
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477 | /* Save the data */ |
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478 | comp->output_ptr[comp->num_output_ptr] = |
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479 | (png_bytep)png_malloc(png_ptr, |
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480 | (png_alloc_size_t)png_ptr->zbuf_size); |
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481 | |
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482 | png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf, |
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483 | png_ptr->zbuf_size); |
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484 | |
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485 | comp->num_output_ptr++; |
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486 | |
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487 | /* and reset the buffer */ |
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488 | png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; |
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489 | png_ptr->zstream.next_out = png_ptr->zbuf; |
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490 | } |
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491 | /* Continue until we don't have any more to compress */ |
---|
492 | } while (png_ptr->zstream.avail_in); |
---|
493 | |
---|
494 | /* Finish the compression */ |
---|
495 | do |
---|
496 | { |
---|
497 | /* Tell zlib we are finished */ |
---|
498 | ret = deflate(&png_ptr->zstream, Z_FINISH); |
---|
499 | |
---|
500 | if (ret == Z_OK) |
---|
501 | { |
---|
502 | /* Check to see if we need more room */ |
---|
503 | if (!(png_ptr->zstream.avail_out)) |
---|
504 | { |
---|
505 | /* Check to make sure our output array has room */ |
---|
506 | if (comp->num_output_ptr >= comp->max_output_ptr) |
---|
507 | { |
---|
508 | int old_max; |
---|
509 | |
---|
510 | old_max = comp->max_output_ptr; |
---|
511 | comp->max_output_ptr = comp->num_output_ptr + 4; |
---|
512 | if (comp->output_ptr != NULL) |
---|
513 | { |
---|
514 | png_bytepp old_ptr; |
---|
515 | |
---|
516 | old_ptr = comp->output_ptr; |
---|
517 | |
---|
518 | /* This could be optimized to realloc() */ |
---|
519 | comp->output_ptr = (png_bytepp)png_malloc(png_ptr, |
---|
520 | (png_alloc_size_t)(comp->max_output_ptr * |
---|
521 | png_sizeof(png_charp))); |
---|
522 | |
---|
523 | png_memcpy(comp->output_ptr, old_ptr, |
---|
524 | old_max * png_sizeof(png_charp)); |
---|
525 | |
---|
526 | png_free(png_ptr, old_ptr); |
---|
527 | } |
---|
528 | |
---|
529 | else |
---|
530 | comp->output_ptr = (png_bytepp)png_malloc(png_ptr, |
---|
531 | (png_alloc_size_t)(comp->max_output_ptr * |
---|
532 | png_sizeof(png_charp))); |
---|
533 | } |
---|
534 | |
---|
535 | /* Save the data */ |
---|
536 | comp->output_ptr[comp->num_output_ptr] = |
---|
537 | (png_bytep)png_malloc(png_ptr, |
---|
538 | (png_alloc_size_t)png_ptr->zbuf_size); |
---|
539 | |
---|
540 | png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf, |
---|
541 | png_ptr->zbuf_size); |
---|
542 | |
---|
543 | comp->num_output_ptr++; |
---|
544 | |
---|
545 | /* and reset the buffer pointers */ |
---|
546 | png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; |
---|
547 | png_ptr->zstream.next_out = png_ptr->zbuf; |
---|
548 | } |
---|
549 | } |
---|
550 | else if (ret != Z_STREAM_END) |
---|
551 | { |
---|
552 | /* We got an error */ |
---|
553 | if (png_ptr->zstream.msg != NULL) |
---|
554 | png_error(png_ptr, png_ptr->zstream.msg); |
---|
555 | |
---|
556 | else |
---|
557 | png_error(png_ptr, "zlib error"); |
---|
558 | } |
---|
559 | } while (ret != Z_STREAM_END); |
---|
560 | |
---|
561 | /* Text length is number of buffers plus last buffer */ |
---|
562 | text_len = png_ptr->zbuf_size * comp->num_output_ptr; |
---|
563 | |
---|
564 | if (png_ptr->zstream.avail_out < png_ptr->zbuf_size) |
---|
565 | text_len += png_ptr->zbuf_size - (png_size_t)png_ptr->zstream.avail_out; |
---|
566 | |
---|
567 | return((int)text_len); |
---|
568 | } |
---|
569 | |
---|
570 | /* Ship the compressed text out via chunk writes */ |
---|
571 | static void /* PRIVATE */ |
---|
572 | png_write_compressed_data_out(png_structp png_ptr, compression_state *comp, |
---|
573 | png_size_t data_len) |
---|
574 | { |
---|
575 | int i; |
---|
576 | |
---|
577 | /* Handle the no-compression case */ |
---|
578 | if (comp->input) |
---|
579 | { |
---|
580 | png_write_chunk_data(png_ptr, comp->input, data_len); |
---|
581 | |
---|
582 | return; |
---|
583 | } |
---|
584 | |
---|
585 | #ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED |
---|
586 | /* The zbuf_size test is because the code below doesn't work if zbuf_size is |
---|
587 | * '1'; simply skip it to avoid memory overwrite. |
---|
588 | */ |
---|
589 | if (data_len >= 2 && comp->input_len < 16384 && png_ptr->zbuf_size > 1) |
---|
590 | { |
---|
591 | unsigned int z_cmf; /* zlib compression method and flags */ |
---|
592 | |
---|
593 | /* Optimize the CMF field in the zlib stream. This hack of the zlib |
---|
594 | * stream is compliant to the stream specification. |
---|
595 | */ |
---|
596 | |
---|
597 | if (comp->num_output_ptr) |
---|
598 | z_cmf = comp->output_ptr[0][0]; |
---|
599 | else |
---|
600 | z_cmf = png_ptr->zbuf[0]; |
---|
601 | |
---|
602 | if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70) |
---|
603 | { |
---|
604 | unsigned int z_cinfo; |
---|
605 | unsigned int half_z_window_size; |
---|
606 | png_size_t uncompressed_text_size = comp->input_len; |
---|
607 | |
---|
608 | z_cinfo = z_cmf >> 4; |
---|
609 | half_z_window_size = 1 << (z_cinfo + 7); |
---|
610 | |
---|
611 | while (uncompressed_text_size <= half_z_window_size && |
---|
612 | half_z_window_size >= 256) |
---|
613 | { |
---|
614 | z_cinfo--; |
---|
615 | half_z_window_size >>= 1; |
---|
616 | } |
---|
617 | |
---|
618 | z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4); |
---|
619 | |
---|
620 | if (comp->num_output_ptr) |
---|
621 | { |
---|
622 | |
---|
623 | if (comp->output_ptr[0][0] != z_cmf) |
---|
624 | { |
---|
625 | int tmp; |
---|
626 | |
---|
627 | comp->output_ptr[0][0] = (png_byte)z_cmf; |
---|
628 | tmp = comp->output_ptr[0][1] & 0xe0; |
---|
629 | tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f; |
---|
630 | comp->output_ptr[0][1] = (png_byte)tmp; |
---|
631 | } |
---|
632 | } |
---|
633 | else |
---|
634 | { |
---|
635 | int tmp; |
---|
636 | |
---|
637 | png_ptr->zbuf[0] = (png_byte)z_cmf; |
---|
638 | tmp = png_ptr->zbuf[1] & 0xe0; |
---|
639 | tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f; |
---|
640 | png_ptr->zbuf[1] = (png_byte)tmp; |
---|
641 | } |
---|
642 | } |
---|
643 | |
---|
644 | else |
---|
645 | png_error(png_ptr, |
---|
646 | "Invalid zlib compression method or flags in non-IDAT chunk"); |
---|
647 | } |
---|
648 | #endif /* PNG_WRITE_OPTIMIZE_CMF_SUPPORTED */ |
---|
649 | |
---|
650 | /* Write saved output buffers, if any */ |
---|
651 | for (i = 0; i < comp->num_output_ptr; i++) |
---|
652 | { |
---|
653 | png_write_chunk_data(png_ptr, comp->output_ptr[i], |
---|
654 | (png_size_t)png_ptr->zbuf_size); |
---|
655 | |
---|
656 | png_free(png_ptr, comp->output_ptr[i]); |
---|
657 | } |
---|
658 | |
---|
659 | if (comp->max_output_ptr != 0) |
---|
660 | png_free(png_ptr, comp->output_ptr); |
---|
661 | |
---|
662 | /* Write anything left in zbuf */ |
---|
663 | if (png_ptr->zstream.avail_out < (png_uint_32)png_ptr->zbuf_size) |
---|
664 | png_write_chunk_data(png_ptr, png_ptr->zbuf, |
---|
665 | (png_size_t)(png_ptr->zbuf_size - png_ptr->zstream.avail_out)); |
---|
666 | |
---|
667 | /* Reset zlib for another zTXt/iTXt or image data */ |
---|
668 | png_zlib_release(png_ptr); |
---|
669 | } |
---|
670 | #endif /* PNG_WRITE_COMPRESSED_TEXT_SUPPORTED */ |
---|
671 | |
---|
672 | /* Write the IHDR chunk, and update the png_struct with the necessary |
---|
673 | * information. Note that the rest of this code depends upon this |
---|
674 | * information being correct. |
---|
675 | */ |
---|
676 | void /* PRIVATE */ |
---|
677 | png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height, |
---|
678 | int bit_depth, int color_type, int compression_type, int filter_type, |
---|
679 | int interlace_type) |
---|
680 | { |
---|
681 | png_byte buf[13]; /* Buffer to store the IHDR info */ |
---|
682 | |
---|
683 | png_debug(1, "in png_write_IHDR"); |
---|
684 | |
---|
685 | /* Check that we have valid input data from the application info */ |
---|
686 | switch (color_type) |
---|
687 | { |
---|
688 | case PNG_COLOR_TYPE_GRAY: |
---|
689 | switch (bit_depth) |
---|
690 | { |
---|
691 | case 1: |
---|
692 | case 2: |
---|
693 | case 4: |
---|
694 | case 8: |
---|
695 | #ifdef PNG_WRITE_16BIT_SUPPORTED |
---|
696 | case 16: |
---|
697 | #endif |
---|
698 | png_ptr->channels = 1; break; |
---|
699 | |
---|
700 | default: |
---|
701 | png_error(png_ptr, |
---|
702 | "Invalid bit depth for grayscale image"); |
---|
703 | } |
---|
704 | break; |
---|
705 | |
---|
706 | case PNG_COLOR_TYPE_RGB: |
---|
707 | #ifdef PNG_WRITE_16BIT_SUPPORTED |
---|
708 | if (bit_depth != 8 && bit_depth != 16) |
---|
709 | #else |
---|
710 | if (bit_depth != 8) |
---|
711 | #endif |
---|
712 | png_error(png_ptr, "Invalid bit depth for RGB image"); |
---|
713 | |
---|
714 | png_ptr->channels = 3; |
---|
715 | break; |
---|
716 | |
---|
717 | case PNG_COLOR_TYPE_PALETTE: |
---|
718 | switch (bit_depth) |
---|
719 | { |
---|
720 | case 1: |
---|
721 | case 2: |
---|
722 | case 4: |
---|
723 | case 8: |
---|
724 | png_ptr->channels = 1; |
---|
725 | break; |
---|
726 | |
---|
727 | default: |
---|
728 | png_error(png_ptr, "Invalid bit depth for paletted image"); |
---|
729 | } |
---|
730 | break; |
---|
731 | |
---|
732 | case PNG_COLOR_TYPE_GRAY_ALPHA: |
---|
733 | if (bit_depth != 8 && bit_depth != 16) |
---|
734 | png_error(png_ptr, "Invalid bit depth for grayscale+alpha image"); |
---|
735 | |
---|
736 | png_ptr->channels = 2; |
---|
737 | break; |
---|
738 | |
---|
739 | case PNG_COLOR_TYPE_RGB_ALPHA: |
---|
740 | #ifdef PNG_WRITE_16BIT_SUPPORTED |
---|
741 | if (bit_depth != 8 && bit_depth != 16) |
---|
742 | #else |
---|
743 | if (bit_depth != 8) |
---|
744 | #endif |
---|
745 | png_error(png_ptr, "Invalid bit depth for RGBA image"); |
---|
746 | |
---|
747 | png_ptr->channels = 4; |
---|
748 | break; |
---|
749 | |
---|
750 | default: |
---|
751 | png_error(png_ptr, "Invalid image color type specified"); |
---|
752 | } |
---|
753 | |
---|
754 | if (compression_type != PNG_COMPRESSION_TYPE_BASE) |
---|
755 | { |
---|
756 | png_warning(png_ptr, "Invalid compression type specified"); |
---|
757 | compression_type = PNG_COMPRESSION_TYPE_BASE; |
---|
758 | } |
---|
759 | |
---|
760 | /* Write filter_method 64 (intrapixel differencing) only if |
---|
761 | * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and |
---|
762 | * 2. Libpng did not write a PNG signature (this filter_method is only |
---|
763 | * used in PNG datastreams that are embedded in MNG datastreams) and |
---|
764 | * 3. The application called png_permit_mng_features with a mask that |
---|
765 | * included PNG_FLAG_MNG_FILTER_64 and |
---|
766 | * 4. The filter_method is 64 and |
---|
767 | * 5. The color_type is RGB or RGBA |
---|
768 | */ |
---|
769 | if ( |
---|
770 | #ifdef PNG_MNG_FEATURES_SUPPORTED |
---|
771 | !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) && |
---|
772 | ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) == 0) && |
---|
773 | (color_type == PNG_COLOR_TYPE_RGB || |
---|
774 | color_type == PNG_COLOR_TYPE_RGB_ALPHA) && |
---|
775 | (filter_type == PNG_INTRAPIXEL_DIFFERENCING)) && |
---|
776 | #endif |
---|
777 | filter_type != PNG_FILTER_TYPE_BASE) |
---|
778 | { |
---|
779 | png_warning(png_ptr, "Invalid filter type specified"); |
---|
780 | filter_type = PNG_FILTER_TYPE_BASE; |
---|
781 | } |
---|
782 | |
---|
783 | #ifdef PNG_WRITE_INTERLACING_SUPPORTED |
---|
784 | if (interlace_type != PNG_INTERLACE_NONE && |
---|
785 | interlace_type != PNG_INTERLACE_ADAM7) |
---|
786 | { |
---|
787 | png_warning(png_ptr, "Invalid interlace type specified"); |
---|
788 | interlace_type = PNG_INTERLACE_ADAM7; |
---|
789 | } |
---|
790 | #else |
---|
791 | interlace_type=PNG_INTERLACE_NONE; |
---|
792 | #endif |
---|
793 | |
---|
794 | /* Save the relevent information */ |
---|
795 | png_ptr->bit_depth = (png_byte)bit_depth; |
---|
796 | png_ptr->color_type = (png_byte)color_type; |
---|
797 | png_ptr->interlaced = (png_byte)interlace_type; |
---|
798 | #ifdef PNG_MNG_FEATURES_SUPPORTED |
---|
799 | png_ptr->filter_type = (png_byte)filter_type; |
---|
800 | #endif |
---|
801 | png_ptr->compression_type = (png_byte)compression_type; |
---|
802 | png_ptr->width = width; |
---|
803 | png_ptr->height = height; |
---|
804 | |
---|
805 | png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels); |
---|
806 | png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width); |
---|
807 | /* Set the usr info, so any transformations can modify it */ |
---|
808 | png_ptr->usr_width = png_ptr->width; |
---|
809 | png_ptr->usr_bit_depth = png_ptr->bit_depth; |
---|
810 | png_ptr->usr_channels = png_ptr->channels; |
---|
811 | |
---|
812 | /* Pack the header information into the buffer */ |
---|
813 | png_save_uint_32(buf, width); |
---|
814 | png_save_uint_32(buf + 4, height); |
---|
815 | buf[8] = (png_byte)bit_depth; |
---|
816 | buf[9] = (png_byte)color_type; |
---|
817 | buf[10] = (png_byte)compression_type; |
---|
818 | buf[11] = (png_byte)filter_type; |
---|
819 | buf[12] = (png_byte)interlace_type; |
---|
820 | |
---|
821 | /* Write the chunk */ |
---|
822 | png_write_complete_chunk(png_ptr, png_IHDR, buf, (png_size_t)13); |
---|
823 | |
---|
824 | /* Initialize zlib with PNG info */ |
---|
825 | png_ptr->zstream.zalloc = png_zalloc; |
---|
826 | png_ptr->zstream.zfree = png_zfree; |
---|
827 | png_ptr->zstream.opaque = (voidpf)png_ptr; |
---|
828 | |
---|
829 | if (!(png_ptr->do_filter)) |
---|
830 | { |
---|
831 | if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE || |
---|
832 | png_ptr->bit_depth < 8) |
---|
833 | png_ptr->do_filter = PNG_FILTER_NONE; |
---|
834 | |
---|
835 | else |
---|
836 | png_ptr->do_filter = PNG_ALL_FILTERS; |
---|
837 | } |
---|
838 | |
---|
839 | if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY)) |
---|
840 | { |
---|
841 | if (png_ptr->do_filter != PNG_FILTER_NONE) |
---|
842 | png_ptr->zlib_strategy = Z_FILTERED; |
---|
843 | |
---|
844 | else |
---|
845 | png_ptr->zlib_strategy = Z_DEFAULT_STRATEGY; |
---|
846 | } |
---|
847 | |
---|
848 | if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_LEVEL)) |
---|
849 | png_ptr->zlib_level = Z_DEFAULT_COMPRESSION; |
---|
850 | |
---|
851 | if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL)) |
---|
852 | png_ptr->zlib_mem_level = 8; |
---|
853 | |
---|
854 | if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS)) |
---|
855 | png_ptr->zlib_window_bits = 15; |
---|
856 | |
---|
857 | if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_METHOD)) |
---|
858 | png_ptr->zlib_method = 8; |
---|
859 | |
---|
860 | #ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED |
---|
861 | #ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED |
---|
862 | if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_STRATEGY)) |
---|
863 | png_ptr->zlib_text_strategy = Z_DEFAULT_STRATEGY; |
---|
864 | |
---|
865 | if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_LEVEL)) |
---|
866 | png_ptr->zlib_text_level = png_ptr->zlib_level; |
---|
867 | |
---|
868 | if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_MEM_LEVEL)) |
---|
869 | png_ptr->zlib_text_mem_level = png_ptr->zlib_mem_level; |
---|
870 | |
---|
871 | if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_WINDOW_BITS)) |
---|
872 | png_ptr->zlib_text_window_bits = png_ptr->zlib_window_bits; |
---|
873 | |
---|
874 | if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_METHOD)) |
---|
875 | png_ptr->zlib_text_method = png_ptr->zlib_method; |
---|
876 | #else |
---|
877 | png_ptr->zlib_text_strategy = Z_DEFAULT_STRATEGY; |
---|
878 | png_ptr->zlib_text_level = png_ptr->zlib_level; |
---|
879 | png_ptr->zlib_text_mem_level = png_ptr->zlib_mem_level; |
---|
880 | png_ptr->zlib_text_window_bits = png_ptr->zlib_window_bits; |
---|
881 | png_ptr->zlib_text_method = png_ptr->zlib_method; |
---|
882 | #endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */ |
---|
883 | #endif /* PNG_WRITE_COMPRESSED_TEXT_SUPPORTED */ |
---|
884 | |
---|
885 | /* Record that the compressor has not yet been initialized. */ |
---|
886 | png_ptr->zlib_state = PNG_ZLIB_UNINITIALIZED; |
---|
887 | |
---|
888 | png_ptr->mode = PNG_HAVE_IHDR; /* not READY_FOR_ZTXT */ |
---|
889 | } |
---|
890 | |
---|
891 | /* Write the palette. We are careful not to trust png_color to be in the |
---|
892 | * correct order for PNG, so people can redefine it to any convenient |
---|
893 | * structure. |
---|
894 | */ |
---|
895 | void /* PRIVATE */ |
---|
896 | png_write_PLTE(png_structp png_ptr, png_const_colorp palette, |
---|
897 | png_uint_32 num_pal) |
---|
898 | { |
---|
899 | png_uint_32 i; |
---|
900 | png_const_colorp pal_ptr; |
---|
901 | png_byte buf[3]; |
---|
902 | |
---|
903 | png_debug(1, "in png_write_PLTE"); |
---|
904 | |
---|
905 | if (( |
---|
906 | #ifdef PNG_MNG_FEATURES_SUPPORTED |
---|
907 | !(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) && |
---|
908 | #endif |
---|
909 | num_pal == 0) || num_pal > 256) |
---|
910 | { |
---|
911 | if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
---|
912 | { |
---|
913 | png_error(png_ptr, "Invalid number of colors in palette"); |
---|
914 | } |
---|
915 | |
---|
916 | else |
---|
917 | { |
---|
918 | png_warning(png_ptr, "Invalid number of colors in palette"); |
---|
919 | return; |
---|
920 | } |
---|
921 | } |
---|
922 | |
---|
923 | if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR)) |
---|
924 | { |
---|
925 | png_warning(png_ptr, |
---|
926 | "Ignoring request to write a PLTE chunk in grayscale PNG"); |
---|
927 | |
---|
928 | return; |
---|
929 | } |
---|
930 | |
---|
931 | png_ptr->num_palette = (png_uint_16)num_pal; |
---|
932 | png_debug1(3, "num_palette = %d", png_ptr->num_palette); |
---|
933 | |
---|
934 | png_write_chunk_header(png_ptr, png_PLTE, (png_uint_32)(num_pal * 3)); |
---|
935 | #ifdef PNG_POINTER_INDEXING_SUPPORTED |
---|
936 | |
---|
937 | for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++) |
---|
938 | { |
---|
939 | buf[0] = pal_ptr->red; |
---|
940 | buf[1] = pal_ptr->green; |
---|
941 | buf[2] = pal_ptr->blue; |
---|
942 | png_write_chunk_data(png_ptr, buf, (png_size_t)3); |
---|
943 | } |
---|
944 | |
---|
945 | #else |
---|
946 | /* This is a little slower but some buggy compilers need to do this |
---|
947 | * instead |
---|
948 | */ |
---|
949 | pal_ptr=palette; |
---|
950 | |
---|
951 | for (i = 0; i < num_pal; i++) |
---|
952 | { |
---|
953 | buf[0] = pal_ptr[i].red; |
---|
954 | buf[1] = pal_ptr[i].green; |
---|
955 | buf[2] = pal_ptr[i].blue; |
---|
956 | png_write_chunk_data(png_ptr, buf, (png_size_t)3); |
---|
957 | } |
---|
958 | |
---|
959 | #endif |
---|
960 | png_write_chunk_end(png_ptr); |
---|
961 | png_ptr->mode |= PNG_HAVE_PLTE; |
---|
962 | } |
---|
963 | |
---|
964 | /* Write an IDAT chunk */ |
---|
965 | void /* PRIVATE */ |
---|
966 | png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length) |
---|
967 | { |
---|
968 | png_debug(1, "in png_write_IDAT"); |
---|
969 | |
---|
970 | #ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED |
---|
971 | if (!(png_ptr->mode & PNG_HAVE_IDAT) && |
---|
972 | png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE) |
---|
973 | { |
---|
974 | /* Optimize the CMF field in the zlib stream. This hack of the zlib |
---|
975 | * stream is compliant to the stream specification. |
---|
976 | */ |
---|
977 | unsigned int z_cmf = data[0]; /* zlib compression method and flags */ |
---|
978 | |
---|
979 | if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70) |
---|
980 | { |
---|
981 | /* Avoid memory underflows and multiplication overflows. |
---|
982 | * |
---|
983 | * The conditions below are practically always satisfied; |
---|
984 | * however, they still must be checked. |
---|
985 | */ |
---|
986 | if (length >= 2 && |
---|
987 | png_ptr->height < 16384 && png_ptr->width < 16384) |
---|
988 | { |
---|
989 | /* Compute the maximum possible length of the datastream */ |
---|
990 | |
---|
991 | /* Number of pixels, plus for each row a filter byte |
---|
992 | * and possibly a padding byte, so increase the maximum |
---|
993 | * size to account for these. |
---|
994 | */ |
---|
995 | unsigned int z_cinfo; |
---|
996 | unsigned int half_z_window_size; |
---|
997 | png_uint_32 uncompressed_idat_size = png_ptr->height * |
---|
998 | ((png_ptr->width * |
---|
999 | png_ptr->channels * png_ptr->bit_depth + 15) >> 3); |
---|
1000 | |
---|
1001 | /* If it's interlaced, each block of 8 rows is sent as up to |
---|
1002 | * 14 rows, i.e., 6 additional rows, each with a filter byte |
---|
1003 | * and possibly a padding byte |
---|
1004 | */ |
---|
1005 | if (png_ptr->interlaced) |
---|
1006 | uncompressed_idat_size += ((png_ptr->height + 7)/8) * |
---|
1007 | (png_ptr->bit_depth < 8 ? 12 : 6); |
---|
1008 | |
---|
1009 | z_cinfo = z_cmf >> 4; |
---|
1010 | half_z_window_size = 1 << (z_cinfo + 7); |
---|
1011 | |
---|
1012 | while (uncompressed_idat_size <= half_z_window_size && |
---|
1013 | half_z_window_size >= 256) |
---|
1014 | { |
---|
1015 | z_cinfo--; |
---|
1016 | half_z_window_size >>= 1; |
---|
1017 | } |
---|
1018 | |
---|
1019 | z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4); |
---|
1020 | |
---|
1021 | if (data[0] != z_cmf) |
---|
1022 | { |
---|
1023 | int tmp; |
---|
1024 | data[0] = (png_byte)z_cmf; |
---|
1025 | tmp = data[1] & 0xe0; |
---|
1026 | tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f; |
---|
1027 | data[1] = (png_byte)tmp; |
---|
1028 | } |
---|
1029 | } |
---|
1030 | } |
---|
1031 | |
---|
1032 | else |
---|
1033 | png_error(png_ptr, |
---|
1034 | "Invalid zlib compression method or flags in IDAT"); |
---|
1035 | } |
---|
1036 | #endif /* PNG_WRITE_OPTIMIZE_CMF_SUPPORTED */ |
---|
1037 | |
---|
1038 | png_write_complete_chunk(png_ptr, png_IDAT, data, length); |
---|
1039 | png_ptr->mode |= PNG_HAVE_IDAT; |
---|
1040 | |
---|
1041 | /* Prior to 1.5.4 this code was replicated in every caller (except at the |
---|
1042 | * end, where it isn't technically necessary). Since this function has |
---|
1043 | * flushed the data we can safely reset the zlib output buffer here. |
---|
1044 | */ |
---|
1045 | png_ptr->zstream.next_out = png_ptr->zbuf; |
---|
1046 | png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; |
---|
1047 | } |
---|
1048 | |
---|
1049 | /* Write an IEND chunk */ |
---|
1050 | void /* PRIVATE */ |
---|
1051 | png_write_IEND(png_structp png_ptr) |
---|
1052 | { |
---|
1053 | png_debug(1, "in png_write_IEND"); |
---|
1054 | |
---|
1055 | png_write_complete_chunk(png_ptr, png_IEND, NULL, (png_size_t)0); |
---|
1056 | png_ptr->mode |= PNG_HAVE_IEND; |
---|
1057 | } |
---|
1058 | |
---|
1059 | #ifdef PNG_WRITE_gAMA_SUPPORTED |
---|
1060 | /* Write a gAMA chunk */ |
---|
1061 | void /* PRIVATE */ |
---|
1062 | png_write_gAMA_fixed(png_structp png_ptr, png_fixed_point file_gamma) |
---|
1063 | { |
---|
1064 | png_byte buf[4]; |
---|
1065 | |
---|
1066 | png_debug(1, "in png_write_gAMA"); |
---|
1067 | |
---|
1068 | /* file_gamma is saved in 1/100,000ths */ |
---|
1069 | png_save_uint_32(buf, (png_uint_32)file_gamma); |
---|
1070 | png_write_complete_chunk(png_ptr, png_gAMA, buf, (png_size_t)4); |
---|
1071 | } |
---|
1072 | #endif |
---|
1073 | |
---|
1074 | #ifdef PNG_WRITE_sRGB_SUPPORTED |
---|
1075 | /* Write a sRGB chunk */ |
---|
1076 | void /* PRIVATE */ |
---|
1077 | png_write_sRGB(png_structp png_ptr, int srgb_intent) |
---|
1078 | { |
---|
1079 | png_byte buf[1]; |
---|
1080 | |
---|
1081 | png_debug(1, "in png_write_sRGB"); |
---|
1082 | |
---|
1083 | if (srgb_intent >= PNG_sRGB_INTENT_LAST) |
---|
1084 | png_warning(png_ptr, |
---|
1085 | "Invalid sRGB rendering intent specified"); |
---|
1086 | |
---|
1087 | buf[0]=(png_byte)srgb_intent; |
---|
1088 | png_write_complete_chunk(png_ptr, png_sRGB, buf, (png_size_t)1); |
---|
1089 | } |
---|
1090 | #endif |
---|
1091 | |
---|
1092 | #ifdef PNG_WRITE_iCCP_SUPPORTED |
---|
1093 | /* Write an iCCP chunk */ |
---|
1094 | void /* PRIVATE */ |
---|
1095 | png_write_iCCP(png_structp png_ptr, png_const_charp name, int compression_type, |
---|
1096 | png_const_charp profile, int profile_len) |
---|
1097 | { |
---|
1098 | png_size_t name_len; |
---|
1099 | png_charp new_name; |
---|
1100 | compression_state comp; |
---|
1101 | int embedded_profile_len = 0; |
---|
1102 | |
---|
1103 | png_debug(1, "in png_write_iCCP"); |
---|
1104 | |
---|
1105 | comp.num_output_ptr = 0; |
---|
1106 | comp.max_output_ptr = 0; |
---|
1107 | comp.output_ptr = NULL; |
---|
1108 | comp.input = NULL; |
---|
1109 | comp.input_len = 0; |
---|
1110 | |
---|
1111 | if ((name_len = png_check_keyword(png_ptr, name, &new_name)) == 0) |
---|
1112 | return; |
---|
1113 | |
---|
1114 | if (compression_type != PNG_COMPRESSION_TYPE_BASE) |
---|
1115 | png_warning(png_ptr, "Unknown compression type in iCCP chunk"); |
---|
1116 | |
---|
1117 | if (profile == NULL) |
---|
1118 | profile_len = 0; |
---|
1119 | |
---|
1120 | if (profile_len > 3) |
---|
1121 | embedded_profile_len = |
---|
1122 | ((*( (png_const_bytep)profile ))<<24) | |
---|
1123 | ((*( (png_const_bytep)profile + 1))<<16) | |
---|
1124 | ((*( (png_const_bytep)profile + 2))<< 8) | |
---|
1125 | ((*( (png_const_bytep)profile + 3)) ); |
---|
1126 | |
---|
1127 | if (embedded_profile_len < 0) |
---|
1128 | { |
---|
1129 | png_warning(png_ptr, |
---|
1130 | "Embedded profile length in iCCP chunk is negative"); |
---|
1131 | |
---|
1132 | png_free(png_ptr, new_name); |
---|
1133 | return; |
---|
1134 | } |
---|
1135 | |
---|
1136 | if (profile_len < embedded_profile_len) |
---|
1137 | { |
---|
1138 | png_warning(png_ptr, |
---|
1139 | "Embedded profile length too large in iCCP chunk"); |
---|
1140 | |
---|
1141 | png_free(png_ptr, new_name); |
---|
1142 | return; |
---|
1143 | } |
---|
1144 | |
---|
1145 | if (profile_len > embedded_profile_len) |
---|
1146 | { |
---|
1147 | png_warning(png_ptr, |
---|
1148 | "Truncating profile to actual length in iCCP chunk"); |
---|
1149 | |
---|
1150 | profile_len = embedded_profile_len; |
---|
1151 | } |
---|
1152 | |
---|
1153 | if (profile_len) |
---|
1154 | profile_len = png_text_compress(png_ptr, profile, |
---|
1155 | (png_size_t)profile_len, PNG_COMPRESSION_TYPE_BASE, &comp); |
---|
1156 | |
---|
1157 | /* Make sure we include the NULL after the name and the compression type */ |
---|
1158 | png_write_chunk_header(png_ptr, png_iCCP, |
---|
1159 | (png_uint_32)(name_len + profile_len + 2)); |
---|
1160 | |
---|
1161 | new_name[name_len + 1] = 0x00; |
---|
1162 | |
---|
1163 | png_write_chunk_data(png_ptr, (png_bytep)new_name, |
---|
1164 | (png_size_t)(name_len + 2)); |
---|
1165 | |
---|
1166 | if (profile_len) |
---|
1167 | { |
---|
1168 | png_write_compressed_data_out(png_ptr, &comp, profile_len); |
---|
1169 | } |
---|
1170 | |
---|
1171 | png_write_chunk_end(png_ptr); |
---|
1172 | png_free(png_ptr, new_name); |
---|
1173 | } |
---|
1174 | #endif |
---|
1175 | |
---|
1176 | #ifdef PNG_WRITE_sPLT_SUPPORTED |
---|
1177 | /* Write a sPLT chunk */ |
---|
1178 | void /* PRIVATE */ |
---|
1179 | png_write_sPLT(png_structp png_ptr, png_const_sPLT_tp spalette) |
---|
1180 | { |
---|
1181 | png_size_t name_len; |
---|
1182 | png_charp new_name; |
---|
1183 | png_byte entrybuf[10]; |
---|
1184 | png_size_t entry_size = (spalette->depth == 8 ? 6 : 10); |
---|
1185 | png_size_t palette_size = entry_size * spalette->nentries; |
---|
1186 | png_sPLT_entryp ep; |
---|
1187 | #ifndef PNG_POINTER_INDEXING_SUPPORTED |
---|
1188 | int i; |
---|
1189 | #endif |
---|
1190 | |
---|
1191 | png_debug(1, "in png_write_sPLT"); |
---|
1192 | |
---|
1193 | if ((name_len = png_check_keyword(png_ptr,spalette->name, &new_name))==0) |
---|
1194 | return; |
---|
1195 | |
---|
1196 | /* Make sure we include the NULL after the name */ |
---|
1197 | png_write_chunk_header(png_ptr, png_sPLT, |
---|
1198 | (png_uint_32)(name_len + 2 + palette_size)); |
---|
1199 | |
---|
1200 | png_write_chunk_data(png_ptr, (png_bytep)new_name, |
---|
1201 | (png_size_t)(name_len + 1)); |
---|
1202 | |
---|
1203 | png_write_chunk_data(png_ptr, &spalette->depth, (png_size_t)1); |
---|
1204 | |
---|
1205 | /* Loop through each palette entry, writing appropriately */ |
---|
1206 | #ifdef PNG_POINTER_INDEXING_SUPPORTED |
---|
1207 | for (ep = spalette->entries; ep<spalette->entries + spalette->nentries; ep++) |
---|
1208 | { |
---|
1209 | if (spalette->depth == 8) |
---|
1210 | { |
---|
1211 | entrybuf[0] = (png_byte)ep->red; |
---|
1212 | entrybuf[1] = (png_byte)ep->green; |
---|
1213 | entrybuf[2] = (png_byte)ep->blue; |
---|
1214 | entrybuf[3] = (png_byte)ep->alpha; |
---|
1215 | png_save_uint_16(entrybuf + 4, ep->frequency); |
---|
1216 | } |
---|
1217 | |
---|
1218 | else |
---|
1219 | { |
---|
1220 | png_save_uint_16(entrybuf + 0, ep->red); |
---|
1221 | png_save_uint_16(entrybuf + 2, ep->green); |
---|
1222 | png_save_uint_16(entrybuf + 4, ep->blue); |
---|
1223 | png_save_uint_16(entrybuf + 6, ep->alpha); |
---|
1224 | png_save_uint_16(entrybuf + 8, ep->frequency); |
---|
1225 | } |
---|
1226 | |
---|
1227 | png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size); |
---|
1228 | } |
---|
1229 | #else |
---|
1230 | ep=spalette->entries; |
---|
1231 | for (i = 0; i>spalette->nentries; i++) |
---|
1232 | { |
---|
1233 | if (spalette->depth == 8) |
---|
1234 | { |
---|
1235 | entrybuf[0] = (png_byte)ep[i].red; |
---|
1236 | entrybuf[1] = (png_byte)ep[i].green; |
---|
1237 | entrybuf[2] = (png_byte)ep[i].blue; |
---|
1238 | entrybuf[3] = (png_byte)ep[i].alpha; |
---|
1239 | png_save_uint_16(entrybuf + 4, ep[i].frequency); |
---|
1240 | } |
---|
1241 | |
---|
1242 | else |
---|
1243 | { |
---|
1244 | png_save_uint_16(entrybuf + 0, ep[i].red); |
---|
1245 | png_save_uint_16(entrybuf + 2, ep[i].green); |
---|
1246 | png_save_uint_16(entrybuf + 4, ep[i].blue); |
---|
1247 | png_save_uint_16(entrybuf + 6, ep[i].alpha); |
---|
1248 | png_save_uint_16(entrybuf + 8, ep[i].frequency); |
---|
1249 | } |
---|
1250 | |
---|
1251 | png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size); |
---|
1252 | } |
---|
1253 | #endif |
---|
1254 | |
---|
1255 | png_write_chunk_end(png_ptr); |
---|
1256 | png_free(png_ptr, new_name); |
---|
1257 | } |
---|
1258 | #endif |
---|
1259 | |
---|
1260 | #ifdef PNG_WRITE_sBIT_SUPPORTED |
---|
1261 | /* Write the sBIT chunk */ |
---|
1262 | void /* PRIVATE */ |
---|
1263 | png_write_sBIT(png_structp png_ptr, png_const_color_8p sbit, int color_type) |
---|
1264 | { |
---|
1265 | png_byte buf[4]; |
---|
1266 | png_size_t size; |
---|
1267 | |
---|
1268 | png_debug(1, "in png_write_sBIT"); |
---|
1269 | |
---|
1270 | /* Make sure we don't depend upon the order of PNG_COLOR_8 */ |
---|
1271 | if (color_type & PNG_COLOR_MASK_COLOR) |
---|
1272 | { |
---|
1273 | png_byte maxbits; |
---|
1274 | |
---|
1275 | maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 : |
---|
1276 | png_ptr->usr_bit_depth); |
---|
1277 | |
---|
1278 | if (sbit->red == 0 || sbit->red > maxbits || |
---|
1279 | sbit->green == 0 || sbit->green > maxbits || |
---|
1280 | sbit->blue == 0 || sbit->blue > maxbits) |
---|
1281 | { |
---|
1282 | png_warning(png_ptr, "Invalid sBIT depth specified"); |
---|
1283 | return; |
---|
1284 | } |
---|
1285 | |
---|
1286 | buf[0] = sbit->red; |
---|
1287 | buf[1] = sbit->green; |
---|
1288 | buf[2] = sbit->blue; |
---|
1289 | size = 3; |
---|
1290 | } |
---|
1291 | |
---|
1292 | else |
---|
1293 | { |
---|
1294 | if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth) |
---|
1295 | { |
---|
1296 | png_warning(png_ptr, "Invalid sBIT depth specified"); |
---|
1297 | return; |
---|
1298 | } |
---|
1299 | |
---|
1300 | buf[0] = sbit->gray; |
---|
1301 | size = 1; |
---|
1302 | } |
---|
1303 | |
---|
1304 | if (color_type & PNG_COLOR_MASK_ALPHA) |
---|
1305 | { |
---|
1306 | if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth) |
---|
1307 | { |
---|
1308 | png_warning(png_ptr, "Invalid sBIT depth specified"); |
---|
1309 | return; |
---|
1310 | } |
---|
1311 | |
---|
1312 | buf[size++] = sbit->alpha; |
---|
1313 | } |
---|
1314 | |
---|
1315 | png_write_complete_chunk(png_ptr, png_sBIT, buf, size); |
---|
1316 | } |
---|
1317 | #endif |
---|
1318 | |
---|
1319 | #ifdef PNG_WRITE_cHRM_SUPPORTED |
---|
1320 | /* Write the cHRM chunk */ |
---|
1321 | void /* PRIVATE */ |
---|
1322 | png_write_cHRM_fixed(png_structp png_ptr, png_fixed_point white_x, |
---|
1323 | png_fixed_point white_y, png_fixed_point red_x, png_fixed_point red_y, |
---|
1324 | png_fixed_point green_x, png_fixed_point green_y, png_fixed_point blue_x, |
---|
1325 | png_fixed_point blue_y) |
---|
1326 | { |
---|
1327 | png_byte buf[32]; |
---|
1328 | |
---|
1329 | png_debug(1, "in png_write_cHRM"); |
---|
1330 | |
---|
1331 | /* Each value is saved in 1/100,000ths */ |
---|
1332 | #ifdef PNG_CHECK_cHRM_SUPPORTED |
---|
1333 | if (png_check_cHRM_fixed(png_ptr, white_x, white_y, red_x, red_y, |
---|
1334 | green_x, green_y, blue_x, blue_y)) |
---|
1335 | #endif |
---|
1336 | { |
---|
1337 | png_save_uint_32(buf, (png_uint_32)white_x); |
---|
1338 | png_save_uint_32(buf + 4, (png_uint_32)white_y); |
---|
1339 | |
---|
1340 | png_save_uint_32(buf + 8, (png_uint_32)red_x); |
---|
1341 | png_save_uint_32(buf + 12, (png_uint_32)red_y); |
---|
1342 | |
---|
1343 | png_save_uint_32(buf + 16, (png_uint_32)green_x); |
---|
1344 | png_save_uint_32(buf + 20, (png_uint_32)green_y); |
---|
1345 | |
---|
1346 | png_save_uint_32(buf + 24, (png_uint_32)blue_x); |
---|
1347 | png_save_uint_32(buf + 28, (png_uint_32)blue_y); |
---|
1348 | |
---|
1349 | png_write_complete_chunk(png_ptr, png_cHRM, buf, (png_size_t)32); |
---|
1350 | } |
---|
1351 | } |
---|
1352 | #endif |
---|
1353 | |
---|
1354 | #ifdef PNG_WRITE_tRNS_SUPPORTED |
---|
1355 | /* Write the tRNS chunk */ |
---|
1356 | void /* PRIVATE */ |
---|
1357 | png_write_tRNS(png_structp png_ptr, png_const_bytep trans_alpha, |
---|
1358 | png_const_color_16p tran, int num_trans, int color_type) |
---|
1359 | { |
---|
1360 | png_byte buf[6]; |
---|
1361 | |
---|
1362 | png_debug(1, "in png_write_tRNS"); |
---|
1363 | |
---|
1364 | if (color_type == PNG_COLOR_TYPE_PALETTE) |
---|
1365 | { |
---|
1366 | if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette) |
---|
1367 | { |
---|
1368 | png_warning(png_ptr, "Invalid number of transparent colors specified"); |
---|
1369 | return; |
---|
1370 | } |
---|
1371 | |
---|
1372 | /* Write the chunk out as it is */ |
---|
1373 | png_write_complete_chunk(png_ptr, png_tRNS, trans_alpha, (png_size_t)num_trans); |
---|
1374 | } |
---|
1375 | |
---|
1376 | else if (color_type == PNG_COLOR_TYPE_GRAY) |
---|
1377 | { |
---|
1378 | /* One 16 bit value */ |
---|
1379 | if (tran->gray >= (1 << png_ptr->bit_depth)) |
---|
1380 | { |
---|
1381 | png_warning(png_ptr, |
---|
1382 | "Ignoring attempt to write tRNS chunk out-of-range for bit_depth"); |
---|
1383 | |
---|
1384 | return; |
---|
1385 | } |
---|
1386 | |
---|
1387 | png_save_uint_16(buf, tran->gray); |
---|
1388 | png_write_complete_chunk(png_ptr, png_tRNS, buf, (png_size_t)2); |
---|
1389 | } |
---|
1390 | |
---|
1391 | else if (color_type == PNG_COLOR_TYPE_RGB) |
---|
1392 | { |
---|
1393 | /* Three 16 bit values */ |
---|
1394 | png_save_uint_16(buf, tran->red); |
---|
1395 | png_save_uint_16(buf + 2, tran->green); |
---|
1396 | png_save_uint_16(buf + 4, tran->blue); |
---|
1397 | #ifdef PNG_WRITE_16BIT_SUPPORTED |
---|
1398 | if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4])) |
---|
1399 | #else |
---|
1400 | if (buf[0] | buf[2] | buf[4]) |
---|
1401 | #endif |
---|
1402 | { |
---|
1403 | png_warning(png_ptr, |
---|
1404 | "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8"); |
---|
1405 | return; |
---|
1406 | } |
---|
1407 | |
---|
1408 | png_write_complete_chunk(png_ptr, png_tRNS, buf, (png_size_t)6); |
---|
1409 | } |
---|
1410 | |
---|
1411 | else |
---|
1412 | { |
---|
1413 | png_warning(png_ptr, "Can't write tRNS with an alpha channel"); |
---|
1414 | } |
---|
1415 | } |
---|
1416 | #endif |
---|
1417 | |
---|
1418 | #ifdef PNG_WRITE_bKGD_SUPPORTED |
---|
1419 | /* Write the background chunk */ |
---|
1420 | void /* PRIVATE */ |
---|
1421 | png_write_bKGD(png_structp png_ptr, png_const_color_16p back, int color_type) |
---|
1422 | { |
---|
1423 | png_byte buf[6]; |
---|
1424 | |
---|
1425 | png_debug(1, "in png_write_bKGD"); |
---|
1426 | |
---|
1427 | if (color_type == PNG_COLOR_TYPE_PALETTE) |
---|
1428 | { |
---|
1429 | if ( |
---|
1430 | #ifdef PNG_MNG_FEATURES_SUPPORTED |
---|
1431 | (png_ptr->num_palette || |
---|
1432 | (!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE))) && |
---|
1433 | #endif |
---|
1434 | back->index >= png_ptr->num_palette) |
---|
1435 | { |
---|
1436 | png_warning(png_ptr, "Invalid background palette index"); |
---|
1437 | return; |
---|
1438 | } |
---|
1439 | |
---|
1440 | buf[0] = back->index; |
---|
1441 | png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)1); |
---|
1442 | } |
---|
1443 | |
---|
1444 | else if (color_type & PNG_COLOR_MASK_COLOR) |
---|
1445 | { |
---|
1446 | png_save_uint_16(buf, back->red); |
---|
1447 | png_save_uint_16(buf + 2, back->green); |
---|
1448 | png_save_uint_16(buf + 4, back->blue); |
---|
1449 | #ifdef PNG_WRITE_16BIT_SUPPORTED |
---|
1450 | if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4])) |
---|
1451 | #else |
---|
1452 | if (buf[0] | buf[2] | buf[4]) |
---|
1453 | #endif |
---|
1454 | { |
---|
1455 | png_warning(png_ptr, |
---|
1456 | "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8"); |
---|
1457 | |
---|
1458 | return; |
---|
1459 | } |
---|
1460 | |
---|
1461 | png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)6); |
---|
1462 | } |
---|
1463 | |
---|
1464 | else |
---|
1465 | { |
---|
1466 | if (back->gray >= (1 << png_ptr->bit_depth)) |
---|
1467 | { |
---|
1468 | png_warning(png_ptr, |
---|
1469 | "Ignoring attempt to write bKGD chunk out-of-range for bit_depth"); |
---|
1470 | |
---|
1471 | return; |
---|
1472 | } |
---|
1473 | |
---|
1474 | png_save_uint_16(buf, back->gray); |
---|
1475 | png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)2); |
---|
1476 | } |
---|
1477 | } |
---|
1478 | #endif |
---|
1479 | |
---|
1480 | #ifdef PNG_WRITE_hIST_SUPPORTED |
---|
1481 | /* Write the histogram */ |
---|
1482 | void /* PRIVATE */ |
---|
1483 | png_write_hIST(png_structp png_ptr, png_const_uint_16p hist, int num_hist) |
---|
1484 | { |
---|
1485 | int i; |
---|
1486 | png_byte buf[3]; |
---|
1487 | |
---|
1488 | png_debug(1, "in png_write_hIST"); |
---|
1489 | |
---|
1490 | if (num_hist > (int)png_ptr->num_palette) |
---|
1491 | { |
---|
1492 | png_debug2(3, "num_hist = %d, num_palette = %d", num_hist, |
---|
1493 | png_ptr->num_palette); |
---|
1494 | |
---|
1495 | png_warning(png_ptr, "Invalid number of histogram entries specified"); |
---|
1496 | return; |
---|
1497 | } |
---|
1498 | |
---|
1499 | png_write_chunk_header(png_ptr, png_hIST, (png_uint_32)(num_hist * 2)); |
---|
1500 | |
---|
1501 | for (i = 0; i < num_hist; i++) |
---|
1502 | { |
---|
1503 | png_save_uint_16(buf, hist[i]); |
---|
1504 | png_write_chunk_data(png_ptr, buf, (png_size_t)2); |
---|
1505 | } |
---|
1506 | |
---|
1507 | png_write_chunk_end(png_ptr); |
---|
1508 | } |
---|
1509 | #endif |
---|
1510 | |
---|
1511 | #if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \ |
---|
1512 | defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED) |
---|
1513 | /* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification, |
---|
1514 | * and if invalid, correct the keyword rather than discarding the entire |
---|
1515 | * chunk. The PNG 1.0 specification requires keywords 1-79 characters in |
---|
1516 | * length, forbids leading or trailing whitespace, multiple internal spaces, |
---|
1517 | * and the non-break space (0x80) from ISO 8859-1. Returns keyword length. |
---|
1518 | * |
---|
1519 | * The new_key is allocated to hold the corrected keyword and must be freed |
---|
1520 | * by the calling routine. This avoids problems with trying to write to |
---|
1521 | * static keywords without having to have duplicate copies of the strings. |
---|
1522 | */ |
---|
1523 | png_size_t /* PRIVATE */ |
---|
1524 | png_check_keyword(png_structp png_ptr, png_const_charp key, png_charpp new_key) |
---|
1525 | { |
---|
1526 | png_size_t key_len; |
---|
1527 | png_const_charp ikp; |
---|
1528 | png_charp kp, dp; |
---|
1529 | int kflag; |
---|
1530 | int kwarn=0; |
---|
1531 | |
---|
1532 | png_debug(1, "in png_check_keyword"); |
---|
1533 | |
---|
1534 | *new_key = NULL; |
---|
1535 | |
---|
1536 | if (key == NULL || (key_len = png_strlen(key)) == 0) |
---|
1537 | { |
---|
1538 | png_warning(png_ptr, "zero length keyword"); |
---|
1539 | return ((png_size_t)0); |
---|
1540 | } |
---|
1541 | |
---|
1542 | png_debug1(2, "Keyword to be checked is '%s'", key); |
---|
1543 | |
---|
1544 | *new_key = (png_charp)png_malloc_warn(png_ptr, (png_uint_32)(key_len + 2)); |
---|
1545 | |
---|
1546 | if (*new_key == NULL) |
---|
1547 | { |
---|
1548 | png_warning(png_ptr, "Out of memory while procesing keyword"); |
---|
1549 | return ((png_size_t)0); |
---|
1550 | } |
---|
1551 | |
---|
1552 | /* Replace non-printing characters with a blank and print a warning */ |
---|
1553 | for (ikp = key, dp = *new_key; *ikp != '\0'; ikp++, dp++) |
---|
1554 | { |
---|
1555 | if ((png_byte)*ikp < 0x20 || |
---|
1556 | ((png_byte)*ikp > 0x7E && (png_byte)*ikp < 0xA1)) |
---|
1557 | { |
---|
1558 | PNG_WARNING_PARAMETERS(p) |
---|
1559 | |
---|
1560 | png_warning_parameter_unsigned(p, 1, PNG_NUMBER_FORMAT_02x, |
---|
1561 | (png_byte)*ikp); |
---|
1562 | png_formatted_warning(png_ptr, p, "invalid keyword character 0x@1"); |
---|
1563 | *dp = ' '; |
---|
1564 | } |
---|
1565 | |
---|
1566 | else |
---|
1567 | { |
---|
1568 | *dp = *ikp; |
---|
1569 | } |
---|
1570 | } |
---|
1571 | *dp = '\0'; |
---|
1572 | |
---|
1573 | /* Remove any trailing white space. */ |
---|
1574 | kp = *new_key + key_len - 1; |
---|
1575 | if (*kp == ' ') |
---|
1576 | { |
---|
1577 | png_warning(png_ptr, "trailing spaces removed from keyword"); |
---|
1578 | |
---|
1579 | while (*kp == ' ') |
---|
1580 | { |
---|
1581 | *(kp--) = '\0'; |
---|
1582 | key_len--; |
---|
1583 | } |
---|
1584 | } |
---|
1585 | |
---|
1586 | /* Remove any leading white space. */ |
---|
1587 | kp = *new_key; |
---|
1588 | if (*kp == ' ') |
---|
1589 | { |
---|
1590 | png_warning(png_ptr, "leading spaces removed from keyword"); |
---|
1591 | |
---|
1592 | while (*kp == ' ') |
---|
1593 | { |
---|
1594 | kp++; |
---|
1595 | key_len--; |
---|
1596 | } |
---|
1597 | } |
---|
1598 | |
---|
1599 | png_debug1(2, "Checking for multiple internal spaces in '%s'", kp); |
---|
1600 | |
---|
1601 | /* Remove multiple internal spaces. */ |
---|
1602 | for (kflag = 0, dp = *new_key; *kp != '\0'; kp++) |
---|
1603 | { |
---|
1604 | if (*kp == ' ' && kflag == 0) |
---|
1605 | { |
---|
1606 | *(dp++) = *kp; |
---|
1607 | kflag = 1; |
---|
1608 | } |
---|
1609 | |
---|
1610 | else if (*kp == ' ') |
---|
1611 | { |
---|
1612 | key_len--; |
---|
1613 | kwarn = 1; |
---|
1614 | } |
---|
1615 | |
---|
1616 | else |
---|
1617 | { |
---|
1618 | *(dp++) = *kp; |
---|
1619 | kflag = 0; |
---|
1620 | } |
---|
1621 | } |
---|
1622 | *dp = '\0'; |
---|
1623 | if (kwarn) |
---|
1624 | png_warning(png_ptr, "extra interior spaces removed from keyword"); |
---|
1625 | |
---|
1626 | if (key_len == 0) |
---|
1627 | { |
---|
1628 | png_free(png_ptr, *new_key); |
---|
1629 | png_warning(png_ptr, "Zero length keyword"); |
---|
1630 | } |
---|
1631 | |
---|
1632 | if (key_len > 79) |
---|
1633 | { |
---|
1634 | png_warning(png_ptr, "keyword length must be 1 - 79 characters"); |
---|
1635 | (*new_key)[79] = '\0'; |
---|
1636 | key_len = 79; |
---|
1637 | } |
---|
1638 | |
---|
1639 | return (key_len); |
---|
1640 | } |
---|
1641 | #endif |
---|
1642 | |
---|
1643 | #ifdef PNG_WRITE_tEXt_SUPPORTED |
---|
1644 | /* Write a tEXt chunk */ |
---|
1645 | void /* PRIVATE */ |
---|
1646 | png_write_tEXt(png_structp png_ptr, png_const_charp key, png_const_charp text, |
---|
1647 | png_size_t text_len) |
---|
1648 | { |
---|
1649 | png_size_t key_len; |
---|
1650 | png_charp new_key; |
---|
1651 | |
---|
1652 | png_debug(1, "in png_write_tEXt"); |
---|
1653 | |
---|
1654 | if ((key_len = png_check_keyword(png_ptr, key, &new_key))==0) |
---|
1655 | return; |
---|
1656 | |
---|
1657 | if (text == NULL || *text == '\0') |
---|
1658 | text_len = 0; |
---|
1659 | |
---|
1660 | else |
---|
1661 | text_len = png_strlen(text); |
---|
1662 | |
---|
1663 | /* Make sure we include the 0 after the key */ |
---|
1664 | png_write_chunk_header(png_ptr, png_tEXt, |
---|
1665 | (png_uint_32)(key_len + text_len + 1)); |
---|
1666 | /* |
---|
1667 | * We leave it to the application to meet PNG-1.0 requirements on the |
---|
1668 | * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of |
---|
1669 | * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them. |
---|
1670 | * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG. |
---|
1671 | */ |
---|
1672 | png_write_chunk_data(png_ptr, (png_bytep)new_key, |
---|
1673 | (png_size_t)(key_len + 1)); |
---|
1674 | |
---|
1675 | if (text_len) |
---|
1676 | png_write_chunk_data(png_ptr, (png_const_bytep)text, |
---|
1677 | (png_size_t)text_len); |
---|
1678 | |
---|
1679 | png_write_chunk_end(png_ptr); |
---|
1680 | png_free(png_ptr, new_key); |
---|
1681 | } |
---|
1682 | #endif |
---|
1683 | |
---|
1684 | #ifdef PNG_WRITE_zTXt_SUPPORTED |
---|
1685 | /* Write a compressed text chunk */ |
---|
1686 | void /* PRIVATE */ |
---|
1687 | png_write_zTXt(png_structp png_ptr, png_const_charp key, png_const_charp text, |
---|
1688 | png_size_t text_len, int compression) |
---|
1689 | { |
---|
1690 | png_size_t key_len; |
---|
1691 | png_byte buf; |
---|
1692 | png_charp new_key; |
---|
1693 | compression_state comp; |
---|
1694 | |
---|
1695 | png_debug(1, "in png_write_zTXt"); |
---|
1696 | |
---|
1697 | comp.num_output_ptr = 0; |
---|
1698 | comp.max_output_ptr = 0; |
---|
1699 | comp.output_ptr = NULL; |
---|
1700 | comp.input = NULL; |
---|
1701 | comp.input_len = 0; |
---|
1702 | |
---|
1703 | if ((key_len = png_check_keyword(png_ptr, key, &new_key)) == 0) |
---|
1704 | { |
---|
1705 | png_free(png_ptr, new_key); |
---|
1706 | return; |
---|
1707 | } |
---|
1708 | |
---|
1709 | if (text == NULL || *text == '\0' || compression==PNG_TEXT_COMPRESSION_NONE) |
---|
1710 | { |
---|
1711 | png_write_tEXt(png_ptr, new_key, text, (png_size_t)0); |
---|
1712 | png_free(png_ptr, new_key); |
---|
1713 | return; |
---|
1714 | } |
---|
1715 | |
---|
1716 | text_len = png_strlen(text); |
---|
1717 | |
---|
1718 | /* Compute the compressed data; do it now for the length */ |
---|
1719 | text_len = png_text_compress(png_ptr, text, text_len, compression, |
---|
1720 | &comp); |
---|
1721 | |
---|
1722 | /* Write start of chunk */ |
---|
1723 | png_write_chunk_header(png_ptr, png_zTXt, |
---|
1724 | (png_uint_32)(key_len+text_len + 2)); |
---|
1725 | |
---|
1726 | /* Write key */ |
---|
1727 | png_write_chunk_data(png_ptr, (png_bytep)new_key, |
---|
1728 | (png_size_t)(key_len + 1)); |
---|
1729 | |
---|
1730 | png_free(png_ptr, new_key); |
---|
1731 | |
---|
1732 | buf = (png_byte)compression; |
---|
1733 | |
---|
1734 | /* Write compression */ |
---|
1735 | png_write_chunk_data(png_ptr, &buf, (png_size_t)1); |
---|
1736 | |
---|
1737 | /* Write the compressed data */ |
---|
1738 | png_write_compressed_data_out(png_ptr, &comp, text_len); |
---|
1739 | |
---|
1740 | /* Close the chunk */ |
---|
1741 | png_write_chunk_end(png_ptr); |
---|
1742 | } |
---|
1743 | #endif |
---|
1744 | |
---|
1745 | #ifdef PNG_WRITE_iTXt_SUPPORTED |
---|
1746 | /* Write an iTXt chunk */ |
---|
1747 | void /* PRIVATE */ |
---|
1748 | png_write_iTXt(png_structp png_ptr, int compression, png_const_charp key, |
---|
1749 | png_const_charp lang, png_const_charp lang_key, png_const_charp text) |
---|
1750 | { |
---|
1751 | png_size_t lang_len, key_len, lang_key_len, text_len; |
---|
1752 | png_charp new_lang; |
---|
1753 | png_charp new_key = NULL; |
---|
1754 | png_byte cbuf[2]; |
---|
1755 | compression_state comp; |
---|
1756 | |
---|
1757 | png_debug(1, "in png_write_iTXt"); |
---|
1758 | |
---|
1759 | comp.num_output_ptr = 0; |
---|
1760 | comp.max_output_ptr = 0; |
---|
1761 | comp.output_ptr = NULL; |
---|
1762 | comp.input = NULL; |
---|
1763 | |
---|
1764 | if ((key_len = png_check_keyword(png_ptr, key, &new_key)) == 0) |
---|
1765 | return; |
---|
1766 | |
---|
1767 | if ((lang_len = png_check_keyword(png_ptr, lang, &new_lang)) == 0) |
---|
1768 | { |
---|
1769 | png_warning(png_ptr, "Empty language field in iTXt chunk"); |
---|
1770 | new_lang = NULL; |
---|
1771 | lang_len = 0; |
---|
1772 | } |
---|
1773 | |
---|
1774 | if (lang_key == NULL) |
---|
1775 | lang_key_len = 0; |
---|
1776 | |
---|
1777 | else |
---|
1778 | lang_key_len = png_strlen(lang_key); |
---|
1779 | |
---|
1780 | if (text == NULL) |
---|
1781 | text_len = 0; |
---|
1782 | |
---|
1783 | else |
---|
1784 | text_len = png_strlen(text); |
---|
1785 | |
---|
1786 | /* Compute the compressed data; do it now for the length */ |
---|
1787 | text_len = png_text_compress(png_ptr, text, text_len, compression - 2, |
---|
1788 | &comp); |
---|
1789 | |
---|
1790 | |
---|
1791 | /* Make sure we include the compression flag, the compression byte, |
---|
1792 | * and the NULs after the key, lang, and lang_key parts |
---|
1793 | */ |
---|
1794 | |
---|
1795 | png_write_chunk_header(png_ptr, png_iTXt, (png_uint_32)( |
---|
1796 | 5 /* comp byte, comp flag, terminators for key, lang and lang_key */ |
---|
1797 | + key_len |
---|
1798 | + lang_len |
---|
1799 | + lang_key_len |
---|
1800 | + text_len)); |
---|
1801 | |
---|
1802 | /* We leave it to the application to meet PNG-1.0 requirements on the |
---|
1803 | * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of |
---|
1804 | * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them. |
---|
1805 | * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG. |
---|
1806 | */ |
---|
1807 | png_write_chunk_data(png_ptr, (png_bytep)new_key, (png_size_t)(key_len + 1)); |
---|
1808 | |
---|
1809 | /* Set the compression flag */ |
---|
1810 | if (compression == PNG_ITXT_COMPRESSION_NONE || |
---|
1811 | compression == PNG_TEXT_COMPRESSION_NONE) |
---|
1812 | cbuf[0] = 0; |
---|
1813 | |
---|
1814 | else /* compression == PNG_ITXT_COMPRESSION_zTXt */ |
---|
1815 | cbuf[0] = 1; |
---|
1816 | |
---|
1817 | /* Set the compression method */ |
---|
1818 | cbuf[1] = 0; |
---|
1819 | |
---|
1820 | png_write_chunk_data(png_ptr, cbuf, (png_size_t)2); |
---|
1821 | |
---|
1822 | cbuf[0] = 0; |
---|
1823 | png_write_chunk_data(png_ptr, (new_lang ? (png_const_bytep)new_lang : cbuf), |
---|
1824 | (png_size_t)(lang_len + 1)); |
---|
1825 | |
---|
1826 | png_write_chunk_data(png_ptr, (lang_key ? (png_const_bytep)lang_key : cbuf), |
---|
1827 | (png_size_t)(lang_key_len + 1)); |
---|
1828 | |
---|
1829 | png_write_compressed_data_out(png_ptr, &comp, text_len); |
---|
1830 | |
---|
1831 | png_write_chunk_end(png_ptr); |
---|
1832 | |
---|
1833 | png_free(png_ptr, new_key); |
---|
1834 | png_free(png_ptr, new_lang); |
---|
1835 | } |
---|
1836 | #endif |
---|
1837 | |
---|
1838 | #ifdef PNG_WRITE_oFFs_SUPPORTED |
---|
1839 | /* Write the oFFs chunk */ |
---|
1840 | void /* PRIVATE */ |
---|
1841 | png_write_oFFs(png_structp png_ptr, png_int_32 x_offset, png_int_32 y_offset, |
---|
1842 | int unit_type) |
---|
1843 | { |
---|
1844 | png_byte buf[9]; |
---|
1845 | |
---|
1846 | png_debug(1, "in png_write_oFFs"); |
---|
1847 | |
---|
1848 | if (unit_type >= PNG_OFFSET_LAST) |
---|
1849 | png_warning(png_ptr, "Unrecognized unit type for oFFs chunk"); |
---|
1850 | |
---|
1851 | png_save_int_32(buf, x_offset); |
---|
1852 | png_save_int_32(buf + 4, y_offset); |
---|
1853 | buf[8] = (png_byte)unit_type; |
---|
1854 | |
---|
1855 | png_write_complete_chunk(png_ptr, png_oFFs, buf, (png_size_t)9); |
---|
1856 | } |
---|
1857 | #endif |
---|
1858 | #ifdef PNG_WRITE_pCAL_SUPPORTED |
---|
1859 | /* Write the pCAL chunk (described in the PNG extensions document) */ |
---|
1860 | void /* PRIVATE */ |
---|
1861 | png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0, |
---|
1862 | png_int_32 X1, int type, int nparams, png_const_charp units, |
---|
1863 | png_charpp params) |
---|
1864 | { |
---|
1865 | png_size_t purpose_len, units_len, total_len; |
---|
1866 | png_size_tp params_len; |
---|
1867 | png_byte buf[10]; |
---|
1868 | png_charp new_purpose; |
---|
1869 | int i; |
---|
1870 | |
---|
1871 | png_debug1(1, "in png_write_pCAL (%d parameters)", nparams); |
---|
1872 | |
---|
1873 | if (type >= PNG_EQUATION_LAST) |
---|
1874 | png_warning(png_ptr, "Unrecognized equation type for pCAL chunk"); |
---|
1875 | |
---|
1876 | purpose_len = png_check_keyword(png_ptr, purpose, &new_purpose) + 1; |
---|
1877 | png_debug1(3, "pCAL purpose length = %d", (int)purpose_len); |
---|
1878 | units_len = png_strlen(units) + (nparams == 0 ? 0 : 1); |
---|
1879 | png_debug1(3, "pCAL units length = %d", (int)units_len); |
---|
1880 | total_len = purpose_len + units_len + 10; |
---|
1881 | |
---|
1882 | params_len = (png_size_tp)png_malloc(png_ptr, |
---|
1883 | (png_alloc_size_t)(nparams * png_sizeof(png_size_t))); |
---|
1884 | |
---|
1885 | /* Find the length of each parameter, making sure we don't count the |
---|
1886 | * null terminator for the last parameter. |
---|
1887 | */ |
---|
1888 | for (i = 0; i < nparams; i++) |
---|
1889 | { |
---|
1890 | params_len[i] = png_strlen(params[i]) + (i == nparams - 1 ? 0 : 1); |
---|
1891 | png_debug2(3, "pCAL parameter %d length = %lu", i, |
---|
1892 | (unsigned long)params_len[i]); |
---|
1893 | total_len += params_len[i]; |
---|
1894 | } |
---|
1895 | |
---|
1896 | png_debug1(3, "pCAL total length = %d", (int)total_len); |
---|
1897 | png_write_chunk_header(png_ptr, png_pCAL, (png_uint_32)total_len); |
---|
1898 | png_write_chunk_data(png_ptr, (png_const_bytep)new_purpose, purpose_len); |
---|
1899 | png_save_int_32(buf, X0); |
---|
1900 | png_save_int_32(buf + 4, X1); |
---|
1901 | buf[8] = (png_byte)type; |
---|
1902 | buf[9] = (png_byte)nparams; |
---|
1903 | png_write_chunk_data(png_ptr, buf, (png_size_t)10); |
---|
1904 | png_write_chunk_data(png_ptr, (png_const_bytep)units, (png_size_t)units_len); |
---|
1905 | |
---|
1906 | png_free(png_ptr, new_purpose); |
---|
1907 | |
---|
1908 | for (i = 0; i < nparams; i++) |
---|
1909 | { |
---|
1910 | png_write_chunk_data(png_ptr, (png_const_bytep)params[i], params_len[i]); |
---|
1911 | } |
---|
1912 | |
---|
1913 | png_free(png_ptr, params_len); |
---|
1914 | png_write_chunk_end(png_ptr); |
---|
1915 | } |
---|
1916 | #endif |
---|
1917 | |
---|
1918 | #ifdef PNG_WRITE_sCAL_SUPPORTED |
---|
1919 | /* Write the sCAL chunk */ |
---|
1920 | void /* PRIVATE */ |
---|
1921 | png_write_sCAL_s(png_structp png_ptr, int unit, png_const_charp width, |
---|
1922 | png_const_charp height) |
---|
1923 | { |
---|
1924 | png_byte buf[64]; |
---|
1925 | png_size_t wlen, hlen, total_len; |
---|
1926 | |
---|
1927 | png_debug(1, "in png_write_sCAL_s"); |
---|
1928 | |
---|
1929 | wlen = png_strlen(width); |
---|
1930 | hlen = png_strlen(height); |
---|
1931 | total_len = wlen + hlen + 2; |
---|
1932 | |
---|
1933 | if (total_len > 64) |
---|
1934 | { |
---|
1935 | png_warning(png_ptr, "Can't write sCAL (buffer too small)"); |
---|
1936 | return; |
---|
1937 | } |
---|
1938 | |
---|
1939 | buf[0] = (png_byte)unit; |
---|
1940 | png_memcpy(buf + 1, width, wlen + 1); /* Append the '\0' here */ |
---|
1941 | png_memcpy(buf + wlen + 2, height, hlen); /* Do NOT append the '\0' here */ |
---|
1942 | |
---|
1943 | png_debug1(3, "sCAL total length = %u", (unsigned int)total_len); |
---|
1944 | png_write_complete_chunk(png_ptr, png_sCAL, buf, total_len); |
---|
1945 | } |
---|
1946 | #endif |
---|
1947 | |
---|
1948 | #ifdef PNG_WRITE_pHYs_SUPPORTED |
---|
1949 | /* Write the pHYs chunk */ |
---|
1950 | void /* PRIVATE */ |
---|
1951 | png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit, |
---|
1952 | png_uint_32 y_pixels_per_unit, |
---|
1953 | int unit_type) |
---|
1954 | { |
---|
1955 | png_byte buf[9]; |
---|
1956 | |
---|
1957 | png_debug(1, "in png_write_pHYs"); |
---|
1958 | |
---|
1959 | if (unit_type >= PNG_RESOLUTION_LAST) |
---|
1960 | png_warning(png_ptr, "Unrecognized unit type for pHYs chunk"); |
---|
1961 | |
---|
1962 | png_save_uint_32(buf, x_pixels_per_unit); |
---|
1963 | png_save_uint_32(buf + 4, y_pixels_per_unit); |
---|
1964 | buf[8] = (png_byte)unit_type; |
---|
1965 | |
---|
1966 | png_write_complete_chunk(png_ptr, png_pHYs, buf, (png_size_t)9); |
---|
1967 | } |
---|
1968 | #endif |
---|
1969 | |
---|
1970 | #ifdef PNG_WRITE_tIME_SUPPORTED |
---|
1971 | /* Write the tIME chunk. Use either png_convert_from_struct_tm() |
---|
1972 | * or png_convert_from_time_t(), or fill in the structure yourself. |
---|
1973 | */ |
---|
1974 | void /* PRIVATE */ |
---|
1975 | png_write_tIME(png_structp png_ptr, png_const_timep mod_time) |
---|
1976 | { |
---|
1977 | png_byte buf[7]; |
---|
1978 | |
---|
1979 | png_debug(1, "in png_write_tIME"); |
---|
1980 | |
---|
1981 | if (mod_time->month > 12 || mod_time->month < 1 || |
---|
1982 | mod_time->day > 31 || mod_time->day < 1 || |
---|
1983 | mod_time->hour > 23 || mod_time->second > 60) |
---|
1984 | { |
---|
1985 | png_warning(png_ptr, "Invalid time specified for tIME chunk"); |
---|
1986 | return; |
---|
1987 | } |
---|
1988 | |
---|
1989 | png_save_uint_16(buf, mod_time->year); |
---|
1990 | buf[2] = mod_time->month; |
---|
1991 | buf[3] = mod_time->day; |
---|
1992 | buf[4] = mod_time->hour; |
---|
1993 | buf[5] = mod_time->minute; |
---|
1994 | buf[6] = mod_time->second; |
---|
1995 | |
---|
1996 | png_write_complete_chunk(png_ptr, png_tIME, buf, (png_size_t)7); |
---|
1997 | } |
---|
1998 | #endif |
---|
1999 | |
---|
2000 | /* Initializes the row writing capability of libpng */ |
---|
2001 | void /* PRIVATE */ |
---|
2002 | png_write_start_row(png_structp png_ptr) |
---|
2003 | { |
---|
2004 | #ifdef PNG_WRITE_INTERLACING_SUPPORTED |
---|
2005 | /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ |
---|
2006 | |
---|
2007 | /* Start of interlace block */ |
---|
2008 | static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; |
---|
2009 | |
---|
2010 | /* Offset to next interlace block */ |
---|
2011 | static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; |
---|
2012 | |
---|
2013 | /* Start of interlace block in the y direction */ |
---|
2014 | static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; |
---|
2015 | |
---|
2016 | /* Offset to next interlace block in the y direction */ |
---|
2017 | static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; |
---|
2018 | #endif |
---|
2019 | |
---|
2020 | png_alloc_size_t buf_size; |
---|
2021 | int usr_pixel_depth; |
---|
2022 | |
---|
2023 | png_debug(1, "in png_write_start_row"); |
---|
2024 | |
---|
2025 | usr_pixel_depth = png_ptr->usr_channels * png_ptr->usr_bit_depth; |
---|
2026 | buf_size = PNG_ROWBYTES(usr_pixel_depth, png_ptr->width) + 1; |
---|
2027 | |
---|
2028 | /* 1.5.6: added to allow checking in the row write code. */ |
---|
2029 | png_ptr->transformed_pixel_depth = png_ptr->pixel_depth; |
---|
2030 | png_ptr->maximum_pixel_depth = (png_byte)usr_pixel_depth; |
---|
2031 | |
---|
2032 | /* Set up row buffer */ |
---|
2033 | png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, buf_size); |
---|
2034 | |
---|
2035 | png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE; |
---|
2036 | |
---|
2037 | #ifdef PNG_WRITE_FILTER_SUPPORTED |
---|
2038 | /* Set up filtering buffer, if using this filter */ |
---|
2039 | if (png_ptr->do_filter & PNG_FILTER_SUB) |
---|
2040 | { |
---|
2041 | png_ptr->sub_row = (png_bytep)png_malloc(png_ptr, png_ptr->rowbytes + 1); |
---|
2042 | |
---|
2043 | png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB; |
---|
2044 | } |
---|
2045 | |
---|
2046 | /* We only need to keep the previous row if we are using one of these. */ |
---|
2047 | if (png_ptr->do_filter & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH)) |
---|
2048 | { |
---|
2049 | /* Set up previous row buffer */ |
---|
2050 | png_ptr->prev_row = (png_bytep)png_calloc(png_ptr, buf_size); |
---|
2051 | |
---|
2052 | if (png_ptr->do_filter & PNG_FILTER_UP) |
---|
2053 | { |
---|
2054 | png_ptr->up_row = (png_bytep)png_malloc(png_ptr, |
---|
2055 | png_ptr->rowbytes + 1); |
---|
2056 | |
---|
2057 | png_ptr->up_row[0] = PNG_FILTER_VALUE_UP; |
---|
2058 | } |
---|
2059 | |
---|
2060 | if (png_ptr->do_filter & PNG_FILTER_AVG) |
---|
2061 | { |
---|
2062 | png_ptr->avg_row = (png_bytep)png_malloc(png_ptr, |
---|
2063 | png_ptr->rowbytes + 1); |
---|
2064 | |
---|
2065 | png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG; |
---|
2066 | } |
---|
2067 | |
---|
2068 | if (png_ptr->do_filter & PNG_FILTER_PAETH) |
---|
2069 | { |
---|
2070 | png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr, |
---|
2071 | png_ptr->rowbytes + 1); |
---|
2072 | |
---|
2073 | png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH; |
---|
2074 | } |
---|
2075 | } |
---|
2076 | #endif /* PNG_WRITE_FILTER_SUPPORTED */ |
---|
2077 | |
---|
2078 | #ifdef PNG_WRITE_INTERLACING_SUPPORTED |
---|
2079 | /* If interlaced, we need to set up width and height of pass */ |
---|
2080 | if (png_ptr->interlaced) |
---|
2081 | { |
---|
2082 | if (!(png_ptr->transformations & PNG_INTERLACE)) |
---|
2083 | { |
---|
2084 | png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 - |
---|
2085 | png_pass_ystart[0]) / png_pass_yinc[0]; |
---|
2086 | |
---|
2087 | png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 - |
---|
2088 | png_pass_start[0]) / png_pass_inc[0]; |
---|
2089 | } |
---|
2090 | |
---|
2091 | else |
---|
2092 | { |
---|
2093 | png_ptr->num_rows = png_ptr->height; |
---|
2094 | png_ptr->usr_width = png_ptr->width; |
---|
2095 | } |
---|
2096 | } |
---|
2097 | |
---|
2098 | else |
---|
2099 | #endif |
---|
2100 | { |
---|
2101 | png_ptr->num_rows = png_ptr->height; |
---|
2102 | png_ptr->usr_width = png_ptr->width; |
---|
2103 | } |
---|
2104 | |
---|
2105 | png_zlib_claim(png_ptr, PNG_ZLIB_FOR_IDAT); |
---|
2106 | png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; |
---|
2107 | png_ptr->zstream.next_out = png_ptr->zbuf; |
---|
2108 | } |
---|
2109 | |
---|
2110 | /* Internal use only. Called when finished processing a row of data. */ |
---|
2111 | void /* PRIVATE */ |
---|
2112 | png_write_finish_row(png_structp png_ptr) |
---|
2113 | { |
---|
2114 | #ifdef PNG_WRITE_INTERLACING_SUPPORTED |
---|
2115 | /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ |
---|
2116 | |
---|
2117 | /* Start of interlace block */ |
---|
2118 | static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; |
---|
2119 | |
---|
2120 | /* Offset to next interlace block */ |
---|
2121 | static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; |
---|
2122 | |
---|
2123 | /* Start of interlace block in the y direction */ |
---|
2124 | static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; |
---|
2125 | |
---|
2126 | /* Offset to next interlace block in the y direction */ |
---|
2127 | static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; |
---|
2128 | #endif |
---|
2129 | |
---|
2130 | int ret; |
---|
2131 | |
---|
2132 | png_debug(1, "in png_write_finish_row"); |
---|
2133 | |
---|
2134 | /* Next row */ |
---|
2135 | png_ptr->row_number++; |
---|
2136 | |
---|
2137 | /* See if we are done */ |
---|
2138 | if (png_ptr->row_number < png_ptr->num_rows) |
---|
2139 | return; |
---|
2140 | |
---|
2141 | #ifdef PNG_WRITE_INTERLACING_SUPPORTED |
---|
2142 | /* If interlaced, go to next pass */ |
---|
2143 | if (png_ptr->interlaced) |
---|
2144 | { |
---|
2145 | png_ptr->row_number = 0; |
---|
2146 | if (png_ptr->transformations & PNG_INTERLACE) |
---|
2147 | { |
---|
2148 | png_ptr->pass++; |
---|
2149 | } |
---|
2150 | |
---|
2151 | else |
---|
2152 | { |
---|
2153 | /* Loop until we find a non-zero width or height pass */ |
---|
2154 | do |
---|
2155 | { |
---|
2156 | png_ptr->pass++; |
---|
2157 | |
---|
2158 | if (png_ptr->pass >= 7) |
---|
2159 | break; |
---|
2160 | |
---|
2161 | png_ptr->usr_width = (png_ptr->width + |
---|
2162 | png_pass_inc[png_ptr->pass] - 1 - |
---|
2163 | png_pass_start[png_ptr->pass]) / |
---|
2164 | png_pass_inc[png_ptr->pass]; |
---|
2165 | |
---|
2166 | png_ptr->num_rows = (png_ptr->height + |
---|
2167 | png_pass_yinc[png_ptr->pass] - 1 - |
---|
2168 | png_pass_ystart[png_ptr->pass]) / |
---|
2169 | png_pass_yinc[png_ptr->pass]; |
---|
2170 | |
---|
2171 | if (png_ptr->transformations & PNG_INTERLACE) |
---|
2172 | break; |
---|
2173 | |
---|
2174 | } while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0); |
---|
2175 | |
---|
2176 | } |
---|
2177 | |
---|
2178 | /* Reset the row above the image for the next pass */ |
---|
2179 | if (png_ptr->pass < 7) |
---|
2180 | { |
---|
2181 | if (png_ptr->prev_row != NULL) |
---|
2182 | png_memset(png_ptr->prev_row, 0, |
---|
2183 | (png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels* |
---|
2184 | png_ptr->usr_bit_depth, png_ptr->width)) + 1); |
---|
2185 | |
---|
2186 | return; |
---|
2187 | } |
---|
2188 | } |
---|
2189 | #endif |
---|
2190 | |
---|
2191 | /* If we get here, we've just written the last row, so we need |
---|
2192 | to flush the compressor */ |
---|
2193 | do |
---|
2194 | { |
---|
2195 | /* Tell the compressor we are done */ |
---|
2196 | ret = deflate(&png_ptr->zstream, Z_FINISH); |
---|
2197 | |
---|
2198 | /* Check for an error */ |
---|
2199 | if (ret == Z_OK) |
---|
2200 | { |
---|
2201 | /* Check to see if we need more room */ |
---|
2202 | if (!(png_ptr->zstream.avail_out)) |
---|
2203 | { |
---|
2204 | png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size); |
---|
2205 | png_ptr->zstream.next_out = png_ptr->zbuf; |
---|
2206 | png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; |
---|
2207 | } |
---|
2208 | } |
---|
2209 | |
---|
2210 | else if (ret != Z_STREAM_END) |
---|
2211 | { |
---|
2212 | if (png_ptr->zstream.msg != NULL) |
---|
2213 | png_error(png_ptr, png_ptr->zstream.msg); |
---|
2214 | |
---|
2215 | else |
---|
2216 | png_error(png_ptr, "zlib error"); |
---|
2217 | } |
---|
2218 | } while (ret != Z_STREAM_END); |
---|
2219 | |
---|
2220 | /* Write any extra space */ |
---|
2221 | if (png_ptr->zstream.avail_out < png_ptr->zbuf_size) |
---|
2222 | { |
---|
2223 | png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size - |
---|
2224 | png_ptr->zstream.avail_out); |
---|
2225 | } |
---|
2226 | |
---|
2227 | png_zlib_release(png_ptr); |
---|
2228 | png_ptr->zstream.data_type = Z_BINARY; |
---|
2229 | } |
---|
2230 | |
---|
2231 | #ifdef PNG_WRITE_INTERLACING_SUPPORTED |
---|
2232 | /* Pick out the correct pixels for the interlace pass. |
---|
2233 | * The basic idea here is to go through the row with a source |
---|
2234 | * pointer and a destination pointer (sp and dp), and copy the |
---|
2235 | * correct pixels for the pass. As the row gets compacted, |
---|
2236 | * sp will always be >= dp, so we should never overwrite anything. |
---|
2237 | * See the default: case for the easiest code to understand. |
---|
2238 | */ |
---|
2239 | void /* PRIVATE */ |
---|
2240 | png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass) |
---|
2241 | { |
---|
2242 | /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ |
---|
2243 | |
---|
2244 | /* Start of interlace block */ |
---|
2245 | static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; |
---|
2246 | |
---|
2247 | /* Offset to next interlace block */ |
---|
2248 | static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; |
---|
2249 | |
---|
2250 | png_debug(1, "in png_do_write_interlace"); |
---|
2251 | |
---|
2252 | /* We don't have to do anything on the last pass (6) */ |
---|
2253 | if (pass < 6) |
---|
2254 | { |
---|
2255 | /* Each pixel depth is handled separately */ |
---|
2256 | switch (row_info->pixel_depth) |
---|
2257 | { |
---|
2258 | case 1: |
---|
2259 | { |
---|
2260 | png_bytep sp; |
---|
2261 | png_bytep dp; |
---|
2262 | int shift; |
---|
2263 | int d; |
---|
2264 | int value; |
---|
2265 | png_uint_32 i; |
---|
2266 | png_uint_32 row_width = row_info->width; |
---|
2267 | |
---|
2268 | dp = row; |
---|
2269 | d = 0; |
---|
2270 | shift = 7; |
---|
2271 | |
---|
2272 | for (i = png_pass_start[pass]; i < row_width; |
---|
2273 | i += png_pass_inc[pass]) |
---|
2274 | { |
---|
2275 | sp = row + (png_size_t)(i >> 3); |
---|
2276 | value = (int)(*sp >> (7 - (int)(i & 0x07))) & 0x01; |
---|
2277 | d |= (value << shift); |
---|
2278 | |
---|
2279 | if (shift == 0) |
---|
2280 | { |
---|
2281 | shift = 7; |
---|
2282 | *dp++ = (png_byte)d; |
---|
2283 | d = 0; |
---|
2284 | } |
---|
2285 | |
---|
2286 | else |
---|
2287 | shift--; |
---|
2288 | |
---|
2289 | } |
---|
2290 | if (shift != 7) |
---|
2291 | *dp = (png_byte)d; |
---|
2292 | |
---|
2293 | break; |
---|
2294 | } |
---|
2295 | |
---|
2296 | case 2: |
---|
2297 | { |
---|
2298 | png_bytep sp; |
---|
2299 | png_bytep dp; |
---|
2300 | int shift; |
---|
2301 | int d; |
---|
2302 | int value; |
---|
2303 | png_uint_32 i; |
---|
2304 | png_uint_32 row_width = row_info->width; |
---|
2305 | |
---|
2306 | dp = row; |
---|
2307 | shift = 6; |
---|
2308 | d = 0; |
---|
2309 | |
---|
2310 | for (i = png_pass_start[pass]; i < row_width; |
---|
2311 | i += png_pass_inc[pass]) |
---|
2312 | { |
---|
2313 | sp = row + (png_size_t)(i >> 2); |
---|
2314 | value = (*sp >> ((3 - (int)(i & 0x03)) << 1)) & 0x03; |
---|
2315 | d |= (value << shift); |
---|
2316 | |
---|
2317 | if (shift == 0) |
---|
2318 | { |
---|
2319 | shift = 6; |
---|
2320 | *dp++ = (png_byte)d; |
---|
2321 | d = 0; |
---|
2322 | } |
---|
2323 | |
---|
2324 | else |
---|
2325 | shift -= 2; |
---|
2326 | } |
---|
2327 | if (shift != 6) |
---|
2328 | *dp = (png_byte)d; |
---|
2329 | |
---|
2330 | break; |
---|
2331 | } |
---|
2332 | |
---|
2333 | case 4: |
---|
2334 | { |
---|
2335 | png_bytep sp; |
---|
2336 | png_bytep dp; |
---|
2337 | int shift; |
---|
2338 | int d; |
---|
2339 | int value; |
---|
2340 | png_uint_32 i; |
---|
2341 | png_uint_32 row_width = row_info->width; |
---|
2342 | |
---|
2343 | dp = row; |
---|
2344 | shift = 4; |
---|
2345 | d = 0; |
---|
2346 | for (i = png_pass_start[pass]; i < row_width; |
---|
2347 | i += png_pass_inc[pass]) |
---|
2348 | { |
---|
2349 | sp = row + (png_size_t)(i >> 1); |
---|
2350 | value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f; |
---|
2351 | d |= (value << shift); |
---|
2352 | |
---|
2353 | if (shift == 0) |
---|
2354 | { |
---|
2355 | shift = 4; |
---|
2356 | *dp++ = (png_byte)d; |
---|
2357 | d = 0; |
---|
2358 | } |
---|
2359 | |
---|
2360 | else |
---|
2361 | shift -= 4; |
---|
2362 | } |
---|
2363 | if (shift != 4) |
---|
2364 | *dp = (png_byte)d; |
---|
2365 | |
---|
2366 | break; |
---|
2367 | } |
---|
2368 | |
---|
2369 | default: |
---|
2370 | { |
---|
2371 | png_bytep sp; |
---|
2372 | png_bytep dp; |
---|
2373 | png_uint_32 i; |
---|
2374 | png_uint_32 row_width = row_info->width; |
---|
2375 | png_size_t pixel_bytes; |
---|
2376 | |
---|
2377 | /* Start at the beginning */ |
---|
2378 | dp = row; |
---|
2379 | |
---|
2380 | /* Find out how many bytes each pixel takes up */ |
---|
2381 | pixel_bytes = (row_info->pixel_depth >> 3); |
---|
2382 | |
---|
2383 | /* Loop through the row, only looking at the pixels that matter */ |
---|
2384 | for (i = png_pass_start[pass]; i < row_width; |
---|
2385 | i += png_pass_inc[pass]) |
---|
2386 | { |
---|
2387 | /* Find out where the original pixel is */ |
---|
2388 | sp = row + (png_size_t)i * pixel_bytes; |
---|
2389 | |
---|
2390 | /* Move the pixel */ |
---|
2391 | if (dp != sp) |
---|
2392 | png_memcpy(dp, sp, pixel_bytes); |
---|
2393 | |
---|
2394 | /* Next pixel */ |
---|
2395 | dp += pixel_bytes; |
---|
2396 | } |
---|
2397 | break; |
---|
2398 | } |
---|
2399 | } |
---|
2400 | /* Set new row width */ |
---|
2401 | row_info->width = (row_info->width + |
---|
2402 | png_pass_inc[pass] - 1 - |
---|
2403 | png_pass_start[pass]) / |
---|
2404 | png_pass_inc[pass]; |
---|
2405 | |
---|
2406 | row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, |
---|
2407 | row_info->width); |
---|
2408 | } |
---|
2409 | } |
---|
2410 | #endif |
---|
2411 | |
---|
2412 | /* This filters the row, chooses which filter to use, if it has not already |
---|
2413 | * been specified by the application, and then writes the row out with the |
---|
2414 | * chosen filter. |
---|
2415 | */ |
---|
2416 | static void png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row, |
---|
2417 | png_size_t row_bytes); |
---|
2418 | |
---|
2419 | #define PNG_MAXSUM (((png_uint_32)(-1)) >> 1) |
---|
2420 | #define PNG_HISHIFT 10 |
---|
2421 | #define PNG_LOMASK ((png_uint_32)0xffffL) |
---|
2422 | #define PNG_HIMASK ((png_uint_32)(~PNG_LOMASK >> PNG_HISHIFT)) |
---|
2423 | void /* PRIVATE */ |
---|
2424 | png_write_find_filter(png_structp png_ptr, png_row_infop row_info) |
---|
2425 | { |
---|
2426 | png_bytep best_row; |
---|
2427 | #ifdef PNG_WRITE_FILTER_SUPPORTED |
---|
2428 | png_bytep prev_row, row_buf; |
---|
2429 | png_uint_32 mins, bpp; |
---|
2430 | png_byte filter_to_do = png_ptr->do_filter; |
---|
2431 | png_size_t row_bytes = row_info->rowbytes; |
---|
2432 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED |
---|
2433 | int num_p_filters = png_ptr->num_prev_filters; |
---|
2434 | #endif |
---|
2435 | |
---|
2436 | png_debug(1, "in png_write_find_filter"); |
---|
2437 | |
---|
2438 | #ifndef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED |
---|
2439 | if (png_ptr->row_number == 0 && filter_to_do == PNG_ALL_FILTERS) |
---|
2440 | { |
---|
2441 | /* These will never be selected so we need not test them. */ |
---|
2442 | filter_to_do &= ~(PNG_FILTER_UP | PNG_FILTER_PAETH); |
---|
2443 | } |
---|
2444 | #endif |
---|
2445 | |
---|
2446 | /* Find out how many bytes offset each pixel is */ |
---|
2447 | bpp = (row_info->pixel_depth + 7) >> 3; |
---|
2448 | |
---|
2449 | prev_row = png_ptr->prev_row; |
---|
2450 | #endif |
---|
2451 | best_row = png_ptr->row_buf; |
---|
2452 | #ifdef PNG_WRITE_FILTER_SUPPORTED |
---|
2453 | row_buf = best_row; |
---|
2454 | mins = PNG_MAXSUM; |
---|
2455 | |
---|
2456 | /* The prediction method we use is to find which method provides the |
---|
2457 | * smallest value when summing the absolute values of the distances |
---|
2458 | * from zero, using anything >= 128 as negative numbers. This is known |
---|
2459 | * as the "minimum sum of absolute differences" heuristic. Other |
---|
2460 | * heuristics are the "weighted minimum sum of absolute differences" |
---|
2461 | * (experimental and can in theory improve compression), and the "zlib |
---|
2462 | * predictive" method (not implemented yet), which does test compressions |
---|
2463 | * of lines using different filter methods, and then chooses the |
---|
2464 | * (series of) filter(s) that give minimum compressed data size (VERY |
---|
2465 | * computationally expensive). |
---|
2466 | * |
---|
2467 | * GRR 980525: consider also |
---|
2468 | * |
---|
2469 | * (1) minimum sum of absolute differences from running average (i.e., |
---|
2470 | * keep running sum of non-absolute differences & count of bytes) |
---|
2471 | * [track dispersion, too? restart average if dispersion too large?] |
---|
2472 | * |
---|
2473 | * (1b) minimum sum of absolute differences from sliding average, probably |
---|
2474 | * with window size <= deflate window (usually 32K) |
---|
2475 | * |
---|
2476 | * (2) minimum sum of squared differences from zero or running average |
---|
2477 | * (i.e., ~ root-mean-square approach) |
---|
2478 | */ |
---|
2479 | |
---|
2480 | |
---|
2481 | /* We don't need to test the 'no filter' case if this is the only filter |
---|
2482 | * that has been chosen, as it doesn't actually do anything to the data. |
---|
2483 | */ |
---|
2484 | if ((filter_to_do & PNG_FILTER_NONE) && filter_to_do != PNG_FILTER_NONE) |
---|
2485 | { |
---|
2486 | png_bytep rp; |
---|
2487 | png_uint_32 sum = 0; |
---|
2488 | png_size_t i; |
---|
2489 | int v; |
---|
2490 | |
---|
2491 | for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++) |
---|
2492 | { |
---|
2493 | v = *rp; |
---|
2494 | sum += (v < 128) ? v : 256 - v; |
---|
2495 | } |
---|
2496 | |
---|
2497 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED |
---|
2498 | if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) |
---|
2499 | { |
---|
2500 | png_uint_32 sumhi, sumlo; |
---|
2501 | int j; |
---|
2502 | sumlo = sum & PNG_LOMASK; |
---|
2503 | sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; /* Gives us some footroom */ |
---|
2504 | |
---|
2505 | /* Reduce the sum if we match any of the previous rows */ |
---|
2506 | for (j = 0; j < num_p_filters; j++) |
---|
2507 | { |
---|
2508 | if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE) |
---|
2509 | { |
---|
2510 | sumlo = (sumlo * png_ptr->filter_weights[j]) >> |
---|
2511 | PNG_WEIGHT_SHIFT; |
---|
2512 | |
---|
2513 | sumhi = (sumhi * png_ptr->filter_weights[j]) >> |
---|
2514 | PNG_WEIGHT_SHIFT; |
---|
2515 | } |
---|
2516 | } |
---|
2517 | |
---|
2518 | /* Factor in the cost of this filter (this is here for completeness, |
---|
2519 | * but it makes no sense to have a "cost" for the NONE filter, as |
---|
2520 | * it has the minimum possible computational cost - none). |
---|
2521 | */ |
---|
2522 | sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >> |
---|
2523 | PNG_COST_SHIFT; |
---|
2524 | |
---|
2525 | sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >> |
---|
2526 | PNG_COST_SHIFT; |
---|
2527 | |
---|
2528 | if (sumhi > PNG_HIMASK) |
---|
2529 | sum = PNG_MAXSUM; |
---|
2530 | |
---|
2531 | else |
---|
2532 | sum = (sumhi << PNG_HISHIFT) + sumlo; |
---|
2533 | } |
---|
2534 | #endif |
---|
2535 | mins = sum; |
---|
2536 | } |
---|
2537 | |
---|
2538 | /* Sub filter */ |
---|
2539 | if (filter_to_do == PNG_FILTER_SUB) |
---|
2540 | /* It's the only filter so no testing is needed */ |
---|
2541 | { |
---|
2542 | png_bytep rp, lp, dp; |
---|
2543 | png_size_t i; |
---|
2544 | |
---|
2545 | for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp; |
---|
2546 | i++, rp++, dp++) |
---|
2547 | { |
---|
2548 | *dp = *rp; |
---|
2549 | } |
---|
2550 | |
---|
2551 | for (lp = row_buf + 1; i < row_bytes; |
---|
2552 | i++, rp++, lp++, dp++) |
---|
2553 | { |
---|
2554 | *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff); |
---|
2555 | } |
---|
2556 | |
---|
2557 | best_row = png_ptr->sub_row; |
---|
2558 | } |
---|
2559 | |
---|
2560 | else if (filter_to_do & PNG_FILTER_SUB) |
---|
2561 | { |
---|
2562 | png_bytep rp, dp, lp; |
---|
2563 | png_uint_32 sum = 0, lmins = mins; |
---|
2564 | png_size_t i; |
---|
2565 | int v; |
---|
2566 | |
---|
2567 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED |
---|
2568 | /* We temporarily increase the "minimum sum" by the factor we |
---|
2569 | * would reduce the sum of this filter, so that we can do the |
---|
2570 | * early exit comparison without scaling the sum each time. |
---|
2571 | */ |
---|
2572 | if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) |
---|
2573 | { |
---|
2574 | int j; |
---|
2575 | png_uint_32 lmhi, lmlo; |
---|
2576 | lmlo = lmins & PNG_LOMASK; |
---|
2577 | lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; |
---|
2578 | |
---|
2579 | for (j = 0; j < num_p_filters; j++) |
---|
2580 | { |
---|
2581 | if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB) |
---|
2582 | { |
---|
2583 | lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> |
---|
2584 | PNG_WEIGHT_SHIFT; |
---|
2585 | |
---|
2586 | lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> |
---|
2587 | PNG_WEIGHT_SHIFT; |
---|
2588 | } |
---|
2589 | } |
---|
2590 | |
---|
2591 | lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> |
---|
2592 | PNG_COST_SHIFT; |
---|
2593 | |
---|
2594 | lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> |
---|
2595 | PNG_COST_SHIFT; |
---|
2596 | |
---|
2597 | if (lmhi > PNG_HIMASK) |
---|
2598 | lmins = PNG_MAXSUM; |
---|
2599 | |
---|
2600 | else |
---|
2601 | lmins = (lmhi << PNG_HISHIFT) + lmlo; |
---|
2602 | } |
---|
2603 | #endif |
---|
2604 | |
---|
2605 | for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp; |
---|
2606 | i++, rp++, dp++) |
---|
2607 | { |
---|
2608 | v = *dp = *rp; |
---|
2609 | |
---|
2610 | sum += (v < 128) ? v : 256 - v; |
---|
2611 | } |
---|
2612 | |
---|
2613 | for (lp = row_buf + 1; i < row_bytes; |
---|
2614 | i++, rp++, lp++, dp++) |
---|
2615 | { |
---|
2616 | v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff); |
---|
2617 | |
---|
2618 | sum += (v < 128) ? v : 256 - v; |
---|
2619 | |
---|
2620 | if (sum > lmins) /* We are already worse, don't continue. */ |
---|
2621 | break; |
---|
2622 | } |
---|
2623 | |
---|
2624 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED |
---|
2625 | if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) |
---|
2626 | { |
---|
2627 | int j; |
---|
2628 | png_uint_32 sumhi, sumlo; |
---|
2629 | sumlo = sum & PNG_LOMASK; |
---|
2630 | sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; |
---|
2631 | |
---|
2632 | for (j = 0; j < num_p_filters; j++) |
---|
2633 | { |
---|
2634 | if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB) |
---|
2635 | { |
---|
2636 | sumlo = (sumlo * png_ptr->inv_filter_weights[j]) >> |
---|
2637 | PNG_WEIGHT_SHIFT; |
---|
2638 | |
---|
2639 | sumhi = (sumhi * png_ptr->inv_filter_weights[j]) >> |
---|
2640 | PNG_WEIGHT_SHIFT; |
---|
2641 | } |
---|
2642 | } |
---|
2643 | |
---|
2644 | sumlo = (sumlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> |
---|
2645 | PNG_COST_SHIFT; |
---|
2646 | |
---|
2647 | sumhi = (sumhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> |
---|
2648 | PNG_COST_SHIFT; |
---|
2649 | |
---|
2650 | if (sumhi > PNG_HIMASK) |
---|
2651 | sum = PNG_MAXSUM; |
---|
2652 | |
---|
2653 | else |
---|
2654 | sum = (sumhi << PNG_HISHIFT) + sumlo; |
---|
2655 | } |
---|
2656 | #endif |
---|
2657 | |
---|
2658 | if (sum < mins) |
---|
2659 | { |
---|
2660 | mins = sum; |
---|
2661 | best_row = png_ptr->sub_row; |
---|
2662 | } |
---|
2663 | } |
---|
2664 | |
---|
2665 | /* Up filter */ |
---|
2666 | if (filter_to_do == PNG_FILTER_UP) |
---|
2667 | { |
---|
2668 | png_bytep rp, dp, pp; |
---|
2669 | png_size_t i; |
---|
2670 | |
---|
2671 | for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1, |
---|
2672 | pp = prev_row + 1; i < row_bytes; |
---|
2673 | i++, rp++, pp++, dp++) |
---|
2674 | { |
---|
2675 | *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff); |
---|
2676 | } |
---|
2677 | |
---|
2678 | best_row = png_ptr->up_row; |
---|
2679 | } |
---|
2680 | |
---|
2681 | else if (filter_to_do & PNG_FILTER_UP) |
---|
2682 | { |
---|
2683 | png_bytep rp, dp, pp; |
---|
2684 | png_uint_32 sum = 0, lmins = mins; |
---|
2685 | png_size_t i; |
---|
2686 | int v; |
---|
2687 | |
---|
2688 | |
---|
2689 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED |
---|
2690 | if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) |
---|
2691 | { |
---|
2692 | int j; |
---|
2693 | png_uint_32 lmhi, lmlo; |
---|
2694 | lmlo = lmins & PNG_LOMASK; |
---|
2695 | lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; |
---|
2696 | |
---|
2697 | for (j = 0; j < num_p_filters; j++) |
---|
2698 | { |
---|
2699 | if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP) |
---|
2700 | { |
---|
2701 | lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> |
---|
2702 | PNG_WEIGHT_SHIFT; |
---|
2703 | |
---|
2704 | lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> |
---|
2705 | PNG_WEIGHT_SHIFT; |
---|
2706 | } |
---|
2707 | } |
---|
2708 | |
---|
2709 | lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >> |
---|
2710 | PNG_COST_SHIFT; |
---|
2711 | |
---|
2712 | lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >> |
---|
2713 | PNG_COST_SHIFT; |
---|
2714 | |
---|
2715 | if (lmhi > PNG_HIMASK) |
---|
2716 | lmins = PNG_MAXSUM; |
---|
2717 | |
---|
2718 | else |
---|
2719 | lmins = (lmhi << PNG_HISHIFT) + lmlo; |
---|
2720 | } |
---|
2721 | #endif |
---|
2722 | |
---|
2723 | for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1, |
---|
2724 | pp = prev_row + 1; i < row_bytes; i++) |
---|
2725 | { |
---|
2726 | v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff); |
---|
2727 | |
---|
2728 | sum += (v < 128) ? v : 256 - v; |
---|
2729 | |
---|
2730 | if (sum > lmins) /* We are already worse, don't continue. */ |
---|
2731 | break; |
---|
2732 | } |
---|
2733 | |
---|
2734 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED |
---|
2735 | if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) |
---|
2736 | { |
---|
2737 | int j; |
---|
2738 | png_uint_32 sumhi, sumlo; |
---|
2739 | sumlo = sum & PNG_LOMASK; |
---|
2740 | sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; |
---|
2741 | |
---|
2742 | for (j = 0; j < num_p_filters; j++) |
---|
2743 | { |
---|
2744 | if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP) |
---|
2745 | { |
---|
2746 | sumlo = (sumlo * png_ptr->filter_weights[j]) >> |
---|
2747 | PNG_WEIGHT_SHIFT; |
---|
2748 | |
---|
2749 | sumhi = (sumhi * png_ptr->filter_weights[j]) >> |
---|
2750 | PNG_WEIGHT_SHIFT; |
---|
2751 | } |
---|
2752 | } |
---|
2753 | |
---|
2754 | sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >> |
---|
2755 | PNG_COST_SHIFT; |
---|
2756 | |
---|
2757 | sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >> |
---|
2758 | PNG_COST_SHIFT; |
---|
2759 | |
---|
2760 | if (sumhi > PNG_HIMASK) |
---|
2761 | sum = PNG_MAXSUM; |
---|
2762 | |
---|
2763 | else |
---|
2764 | sum = (sumhi << PNG_HISHIFT) + sumlo; |
---|
2765 | } |
---|
2766 | #endif |
---|
2767 | |
---|
2768 | if (sum < mins) |
---|
2769 | { |
---|
2770 | mins = sum; |
---|
2771 | best_row = png_ptr->up_row; |
---|
2772 | } |
---|
2773 | } |
---|
2774 | |
---|
2775 | /* Avg filter */ |
---|
2776 | if (filter_to_do == PNG_FILTER_AVG) |
---|
2777 | { |
---|
2778 | png_bytep rp, dp, pp, lp; |
---|
2779 | png_uint_32 i; |
---|
2780 | |
---|
2781 | for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1, |
---|
2782 | pp = prev_row + 1; i < bpp; i++) |
---|
2783 | { |
---|
2784 | *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff); |
---|
2785 | } |
---|
2786 | |
---|
2787 | for (lp = row_buf + 1; i < row_bytes; i++) |
---|
2788 | { |
---|
2789 | *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) |
---|
2790 | & 0xff); |
---|
2791 | } |
---|
2792 | best_row = png_ptr->avg_row; |
---|
2793 | } |
---|
2794 | |
---|
2795 | else if (filter_to_do & PNG_FILTER_AVG) |
---|
2796 | { |
---|
2797 | png_bytep rp, dp, pp, lp; |
---|
2798 | png_uint_32 sum = 0, lmins = mins; |
---|
2799 | png_size_t i; |
---|
2800 | int v; |
---|
2801 | |
---|
2802 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED |
---|
2803 | if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) |
---|
2804 | { |
---|
2805 | int j; |
---|
2806 | png_uint_32 lmhi, lmlo; |
---|
2807 | lmlo = lmins & PNG_LOMASK; |
---|
2808 | lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; |
---|
2809 | |
---|
2810 | for (j = 0; j < num_p_filters; j++) |
---|
2811 | { |
---|
2812 | if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_AVG) |
---|
2813 | { |
---|
2814 | lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> |
---|
2815 | PNG_WEIGHT_SHIFT; |
---|
2816 | |
---|
2817 | lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> |
---|
2818 | PNG_WEIGHT_SHIFT; |
---|
2819 | } |
---|
2820 | } |
---|
2821 | |
---|
2822 | lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >> |
---|
2823 | PNG_COST_SHIFT; |
---|
2824 | |
---|
2825 | lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >> |
---|
2826 | PNG_COST_SHIFT; |
---|
2827 | |
---|
2828 | if (lmhi > PNG_HIMASK) |
---|
2829 | lmins = PNG_MAXSUM; |
---|
2830 | |
---|
2831 | else |
---|
2832 | lmins = (lmhi << PNG_HISHIFT) + lmlo; |
---|
2833 | } |
---|
2834 | #endif |
---|
2835 | |
---|
2836 | for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1, |
---|
2837 | pp = prev_row + 1; i < bpp; i++) |
---|
2838 | { |
---|
2839 | v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff); |
---|
2840 | |
---|
2841 | sum += (v < 128) ? v : 256 - v; |
---|
2842 | } |
---|
2843 | |
---|
2844 | for (lp = row_buf + 1; i < row_bytes; i++) |
---|
2845 | { |
---|
2846 | v = *dp++ = |
---|
2847 | (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff); |
---|
2848 | |
---|
2849 | sum += (v < 128) ? v : 256 - v; |
---|
2850 | |
---|
2851 | if (sum > lmins) /* We are already worse, don't continue. */ |
---|
2852 | break; |
---|
2853 | } |
---|
2854 | |
---|
2855 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED |
---|
2856 | if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) |
---|
2857 | { |
---|
2858 | int j; |
---|
2859 | png_uint_32 sumhi, sumlo; |
---|
2860 | sumlo = sum & PNG_LOMASK; |
---|
2861 | sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; |
---|
2862 | |
---|
2863 | for (j = 0; j < num_p_filters; j++) |
---|
2864 | { |
---|
2865 | if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE) |
---|
2866 | { |
---|
2867 | sumlo = (sumlo * png_ptr->filter_weights[j]) >> |
---|
2868 | PNG_WEIGHT_SHIFT; |
---|
2869 | |
---|
2870 | sumhi = (sumhi * png_ptr->filter_weights[j]) >> |
---|
2871 | PNG_WEIGHT_SHIFT; |
---|
2872 | } |
---|
2873 | } |
---|
2874 | |
---|
2875 | sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >> |
---|
2876 | PNG_COST_SHIFT; |
---|
2877 | |
---|
2878 | sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >> |
---|
2879 | PNG_COST_SHIFT; |
---|
2880 | |
---|
2881 | if (sumhi > PNG_HIMASK) |
---|
2882 | sum = PNG_MAXSUM; |
---|
2883 | |
---|
2884 | else |
---|
2885 | sum = (sumhi << PNG_HISHIFT) + sumlo; |
---|
2886 | } |
---|
2887 | #endif |
---|
2888 | |
---|
2889 | if (sum < mins) |
---|
2890 | { |
---|
2891 | mins = sum; |
---|
2892 | best_row = png_ptr->avg_row; |
---|
2893 | } |
---|
2894 | } |
---|
2895 | |
---|
2896 | /* Paeth filter */ |
---|
2897 | if (filter_to_do == PNG_FILTER_PAETH) |
---|
2898 | { |
---|
2899 | png_bytep rp, dp, pp, cp, lp; |
---|
2900 | png_size_t i; |
---|
2901 | |
---|
2902 | for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1, |
---|
2903 | pp = prev_row + 1; i < bpp; i++) |
---|
2904 | { |
---|
2905 | *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff); |
---|
2906 | } |
---|
2907 | |
---|
2908 | for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++) |
---|
2909 | { |
---|
2910 | int a, b, c, pa, pb, pc, p; |
---|
2911 | |
---|
2912 | b = *pp++; |
---|
2913 | c = *cp++; |
---|
2914 | a = *lp++; |
---|
2915 | |
---|
2916 | p = b - c; |
---|
2917 | pc = a - c; |
---|
2918 | |
---|
2919 | #ifdef PNG_USE_ABS |
---|
2920 | pa = abs(p); |
---|
2921 | pb = abs(pc); |
---|
2922 | pc = abs(p + pc); |
---|
2923 | #else |
---|
2924 | pa = p < 0 ? -p : p; |
---|
2925 | pb = pc < 0 ? -pc : pc; |
---|
2926 | pc = (p + pc) < 0 ? -(p + pc) : p + pc; |
---|
2927 | #endif |
---|
2928 | |
---|
2929 | p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c; |
---|
2930 | |
---|
2931 | *dp++ = (png_byte)(((int)*rp++ - p) & 0xff); |
---|
2932 | } |
---|
2933 | best_row = png_ptr->paeth_row; |
---|
2934 | } |
---|
2935 | |
---|
2936 | else if (filter_to_do & PNG_FILTER_PAETH) |
---|
2937 | { |
---|
2938 | png_bytep rp, dp, pp, cp, lp; |
---|
2939 | png_uint_32 sum = 0, lmins = mins; |
---|
2940 | png_size_t i; |
---|
2941 | int v; |
---|
2942 | |
---|
2943 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED |
---|
2944 | if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) |
---|
2945 | { |
---|
2946 | int j; |
---|
2947 | png_uint_32 lmhi, lmlo; |
---|
2948 | lmlo = lmins & PNG_LOMASK; |
---|
2949 | lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; |
---|
2950 | |
---|
2951 | for (j = 0; j < num_p_filters; j++) |
---|
2952 | { |
---|
2953 | if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH) |
---|
2954 | { |
---|
2955 | lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> |
---|
2956 | PNG_WEIGHT_SHIFT; |
---|
2957 | |
---|
2958 | lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> |
---|
2959 | PNG_WEIGHT_SHIFT; |
---|
2960 | } |
---|
2961 | } |
---|
2962 | |
---|
2963 | lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >> |
---|
2964 | PNG_COST_SHIFT; |
---|
2965 | |
---|
2966 | lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >> |
---|
2967 | PNG_COST_SHIFT; |
---|
2968 | |
---|
2969 | if (lmhi > PNG_HIMASK) |
---|
2970 | lmins = PNG_MAXSUM; |
---|
2971 | |
---|
2972 | else |
---|
2973 | lmins = (lmhi << PNG_HISHIFT) + lmlo; |
---|
2974 | } |
---|
2975 | #endif |
---|
2976 | |
---|
2977 | for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1, |
---|
2978 | pp = prev_row + 1; i < bpp; i++) |
---|
2979 | { |
---|
2980 | v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff); |
---|
2981 | |
---|
2982 | sum += (v < 128) ? v : 256 - v; |
---|
2983 | } |
---|
2984 | |
---|
2985 | for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++) |
---|
2986 | { |
---|
2987 | int a, b, c, pa, pb, pc, p; |
---|
2988 | |
---|
2989 | b = *pp++; |
---|
2990 | c = *cp++; |
---|
2991 | a = *lp++; |
---|
2992 | |
---|
2993 | #ifndef PNG_SLOW_PAETH |
---|
2994 | p = b - c; |
---|
2995 | pc = a - c; |
---|
2996 | #ifdef PNG_USE_ABS |
---|
2997 | pa = abs(p); |
---|
2998 | pb = abs(pc); |
---|
2999 | pc = abs(p + pc); |
---|
3000 | #else |
---|
3001 | pa = p < 0 ? -p : p; |
---|
3002 | pb = pc < 0 ? -pc : pc; |
---|
3003 | pc = (p + pc) < 0 ? -(p + pc) : p + pc; |
---|
3004 | #endif |
---|
3005 | p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c; |
---|
3006 | #else /* PNG_SLOW_PAETH */ |
---|
3007 | p = a + b - c; |
---|
3008 | pa = abs(p - a); |
---|
3009 | pb = abs(p - b); |
---|
3010 | pc = abs(p - c); |
---|
3011 | |
---|
3012 | if (pa <= pb && pa <= pc) |
---|
3013 | p = a; |
---|
3014 | |
---|
3015 | else if (pb <= pc) |
---|
3016 | p = b; |
---|
3017 | |
---|
3018 | else |
---|
3019 | p = c; |
---|
3020 | #endif /* PNG_SLOW_PAETH */ |
---|
3021 | |
---|
3022 | v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff); |
---|
3023 | |
---|
3024 | sum += (v < 128) ? v : 256 - v; |
---|
3025 | |
---|
3026 | if (sum > lmins) /* We are already worse, don't continue. */ |
---|
3027 | break; |
---|
3028 | } |
---|
3029 | |
---|
3030 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED |
---|
3031 | if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) |
---|
3032 | { |
---|
3033 | int j; |
---|
3034 | png_uint_32 sumhi, sumlo; |
---|
3035 | sumlo = sum & PNG_LOMASK; |
---|
3036 | sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; |
---|
3037 | |
---|
3038 | for (j = 0; j < num_p_filters; j++) |
---|
3039 | { |
---|
3040 | if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH) |
---|
3041 | { |
---|
3042 | sumlo = (sumlo * png_ptr->filter_weights[j]) >> |
---|
3043 | PNG_WEIGHT_SHIFT; |
---|
3044 | |
---|
3045 | sumhi = (sumhi * png_ptr->filter_weights[j]) >> |
---|
3046 | PNG_WEIGHT_SHIFT; |
---|
3047 | } |
---|
3048 | } |
---|
3049 | |
---|
3050 | sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >> |
---|
3051 | PNG_COST_SHIFT; |
---|
3052 | |
---|
3053 | sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >> |
---|
3054 | PNG_COST_SHIFT; |
---|
3055 | |
---|
3056 | if (sumhi > PNG_HIMASK) |
---|
3057 | sum = PNG_MAXSUM; |
---|
3058 | |
---|
3059 | else |
---|
3060 | sum = (sumhi << PNG_HISHIFT) + sumlo; |
---|
3061 | } |
---|
3062 | #endif |
---|
3063 | |
---|
3064 | if (sum < mins) |
---|
3065 | { |
---|
3066 | best_row = png_ptr->paeth_row; |
---|
3067 | } |
---|
3068 | } |
---|
3069 | #endif /* PNG_WRITE_FILTER_SUPPORTED */ |
---|
3070 | |
---|
3071 | /* Do the actual writing of the filtered row data from the chosen filter. */ |
---|
3072 | png_write_filtered_row(png_ptr, best_row, row_info->rowbytes+1); |
---|
3073 | |
---|
3074 | #ifdef PNG_WRITE_FILTER_SUPPORTED |
---|
3075 | #ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED |
---|
3076 | /* Save the type of filter we picked this time for future calculations */ |
---|
3077 | if (png_ptr->num_prev_filters > 0) |
---|
3078 | { |
---|
3079 | int j; |
---|
3080 | |
---|
3081 | for (j = 1; j < num_p_filters; j++) |
---|
3082 | { |
---|
3083 | png_ptr->prev_filters[j] = png_ptr->prev_filters[j - 1]; |
---|
3084 | } |
---|
3085 | |
---|
3086 | png_ptr->prev_filters[j] = best_row[0]; |
---|
3087 | } |
---|
3088 | #endif |
---|
3089 | #endif /* PNG_WRITE_FILTER_SUPPORTED */ |
---|
3090 | } |
---|
3091 | |
---|
3092 | |
---|
3093 | /* Do the actual writing of a previously filtered row. */ |
---|
3094 | static void |
---|
3095 | png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row, |
---|
3096 | png_size_t avail/*includes filter byte*/) |
---|
3097 | { |
---|
3098 | png_debug(1, "in png_write_filtered_row"); |
---|
3099 | |
---|
3100 | png_debug1(2, "filter = %d", filtered_row[0]); |
---|
3101 | /* Set up the zlib input buffer */ |
---|
3102 | |
---|
3103 | png_ptr->zstream.next_in = filtered_row; |
---|
3104 | png_ptr->zstream.avail_in = 0; |
---|
3105 | /* Repeat until we have compressed all the data */ |
---|
3106 | do |
---|
3107 | { |
---|
3108 | int ret; /* Return of zlib */ |
---|
3109 | |
---|
3110 | /* Record the number of bytes available - zlib supports at least 65535 |
---|
3111 | * bytes at one step, depending on the size of the zlib type 'uInt', the |
---|
3112 | * maximum size zlib can write at once is ZLIB_IO_MAX (from pngpriv.h). |
---|
3113 | * Use this because on 16 bit systems 'rowbytes' can be up to 65536 (i.e. |
---|
3114 | * one more than 16 bits) and, in this case 'rowbytes+1' can overflow a |
---|
3115 | * uInt. ZLIB_IO_MAX can be safely reduced to cause zlib to be called |
---|
3116 | * with smaller chunks of data. |
---|
3117 | */ |
---|
3118 | if (png_ptr->zstream.avail_in == 0) |
---|
3119 | { |
---|
3120 | if (avail > ZLIB_IO_MAX) |
---|
3121 | { |
---|
3122 | png_ptr->zstream.avail_in = ZLIB_IO_MAX; |
---|
3123 | avail -= ZLIB_IO_MAX; |
---|
3124 | } |
---|
3125 | |
---|
3126 | else |
---|
3127 | { |
---|
3128 | /* So this will fit in the available uInt space: */ |
---|
3129 | png_ptr->zstream.avail_in = (uInt)avail; |
---|
3130 | avail = 0; |
---|
3131 | } |
---|
3132 | } |
---|
3133 | |
---|
3134 | /* Compress the data */ |
---|
3135 | ret = deflate(&png_ptr->zstream, Z_NO_FLUSH); |
---|
3136 | |
---|
3137 | /* Check for compression errors */ |
---|
3138 | if (ret != Z_OK) |
---|
3139 | { |
---|
3140 | if (png_ptr->zstream.msg != NULL) |
---|
3141 | png_error(png_ptr, png_ptr->zstream.msg); |
---|
3142 | |
---|
3143 | else |
---|
3144 | png_error(png_ptr, "zlib error"); |
---|
3145 | } |
---|
3146 | |
---|
3147 | /* See if it is time to write another IDAT */ |
---|
3148 | if (!(png_ptr->zstream.avail_out)) |
---|
3149 | { |
---|
3150 | /* Write the IDAT and reset the zlib output buffer */ |
---|
3151 | png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size); |
---|
3152 | } |
---|
3153 | /* Repeat until all data has been compressed */ |
---|
3154 | } while (avail > 0 || png_ptr->zstream.avail_in > 0); |
---|
3155 | |
---|
3156 | /* Swap the current and previous rows */ |
---|
3157 | if (png_ptr->prev_row != NULL) |
---|
3158 | { |
---|
3159 | png_bytep tptr; |
---|
3160 | |
---|
3161 | tptr = png_ptr->prev_row; |
---|
3162 | png_ptr->prev_row = png_ptr->row_buf; |
---|
3163 | png_ptr->row_buf = tptr; |
---|
3164 | } |
---|
3165 | |
---|
3166 | /* Finish row - updates counters and flushes zlib if last row */ |
---|
3167 | png_write_finish_row(png_ptr); |
---|
3168 | |
---|
3169 | #ifdef PNG_WRITE_FLUSH_SUPPORTED |
---|
3170 | png_ptr->flush_rows++; |
---|
3171 | |
---|
3172 | if (png_ptr->flush_dist > 0 && |
---|
3173 | png_ptr->flush_rows >= png_ptr->flush_dist) |
---|
3174 | { |
---|
3175 | png_write_flush(png_ptr); |
---|
3176 | } |
---|
3177 | #endif |
---|
3178 | } |
---|
3179 | #endif /* PNG_WRITE_SUPPORTED */ |
---|