2 /* pngrutil.c - utilities to read a PNG file
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4 * Last changed in libpng 1.6.20 [December 3, 2014]
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5 * Copyright (c) 1998-2002,2004,2006-2015 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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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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13 * This file contains routines that are only called from within
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14 * libpng itself during the course of reading an image.
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17 #include "pngpriv.h"
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19 #ifdef PNG_READ_SUPPORTED
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22 png_get_uint_31(png_const_structrp png_ptr, png_const_bytep buf)
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24 png_uint_32 uval = png_get_uint_32(buf);
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26 if (uval > PNG_UINT_31_MAX)
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27 png_error(png_ptr, "PNG unsigned integer out of range");
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32 #if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_READ_cHRM_SUPPORTED)
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33 /* The following is a variation on the above for use with the fixed
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34 * point values used for gAMA and cHRM. Instead of png_error it
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35 * issues a warning and returns (-1) - an invalid value because both
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36 * gAMA and cHRM use *unsigned* integers for fixed point values.
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38 #define PNG_FIXED_ERROR (-1)
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40 static png_fixed_point /* PRIVATE */
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41 png_get_fixed_point(png_structrp png_ptr, png_const_bytep buf)
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43 png_uint_32 uval = png_get_uint_32(buf);
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45 if (uval <= PNG_UINT_31_MAX)
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46 return (png_fixed_point)uval; /* known to be in range */
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48 /* The caller can turn off the warning by passing NULL. */
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49 if (png_ptr != NULL)
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50 png_warning(png_ptr, "PNG fixed point integer out of range");
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52 return PNG_FIXED_ERROR;
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56 #ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED
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57 /* NOTE: the read macros will obscure these definitions, so that if
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58 * PNG_USE_READ_MACROS is set the library will not use them internally,
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59 * but the APIs will still be available externally.
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61 * The parentheses around "PNGAPI function_name" in the following three
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62 * functions are necessary because they allow the macros to co-exist with
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63 * these (unused but exported) functions.
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66 /* Grab an unsigned 32-bit integer from a buffer in big-endian format. */
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68 png_get_uint_32)(png_const_bytep buf)
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71 ((png_uint_32)(*(buf )) << 24) +
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72 ((png_uint_32)(*(buf + 1)) << 16) +
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73 ((png_uint_32)(*(buf + 2)) << 8) +
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74 ((png_uint_32)(*(buf + 3)) ) ;
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79 /* Grab a signed 32-bit integer from a buffer in big-endian format. The
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80 * data is stored in the PNG file in two's complement format and there
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81 * is no guarantee that a 'png_int_32' is exactly 32 bits, therefore
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82 * the following code does a two's complement to native conversion.
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85 png_get_int_32)(png_const_bytep buf)
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87 png_uint_32 uval = png_get_uint_32(buf);
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88 if ((uval & 0x80000000) == 0) /* non-negative */
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91 uval = (uval ^ 0xffffffff) + 1; /* 2's complement: -x = ~x+1 */
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92 if ((uval & 0x80000000) == 0) /* no overflow */
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93 return -(png_int_32)uval;
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94 /* The following has to be safe; this function only gets called on PNG data
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95 * and if we get here that data is invalid. 0 is the most safe value and
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96 * if not then an attacker would surely just generate a PNG with 0 instead.
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101 /* Grab an unsigned 16-bit integer from a buffer in big-endian format. */
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102 png_uint_16 (PNGAPI
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103 png_get_uint_16)(png_const_bytep buf)
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105 /* ANSI-C requires an int value to accomodate at least 16 bits so this
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106 * works and allows the compiler not to worry about possible narrowing
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107 * on 32-bit systems. (Pre-ANSI systems did not make integers smaller
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108 * than 16 bits either.)
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111 ((unsigned int)(*buf) << 8) +
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112 ((unsigned int)(*(buf + 1)));
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114 return (png_uint_16)val;
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117 #endif /* READ_INT_FUNCTIONS */
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119 /* Read and check the PNG file signature */
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121 png_read_sig(png_structrp png_ptr, png_inforp info_ptr)
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123 png_size_t num_checked, num_to_check;
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125 /* Exit if the user application does not expect a signature. */
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126 if (png_ptr->sig_bytes >= 8)
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129 num_checked = png_ptr->sig_bytes;
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130 num_to_check = 8 - num_checked;
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132 #ifdef PNG_IO_STATE_SUPPORTED
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133 png_ptr->io_state = PNG_IO_READING | PNG_IO_SIGNATURE;
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136 /* The signature must be serialized in a single I/O call. */
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137 png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check);
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138 png_ptr->sig_bytes = 8;
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140 if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check) != 0)
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142 if (num_checked < 4 &&
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143 png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
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144 png_error(png_ptr, "Not a PNG file");
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146 png_error(png_ptr, "PNG file corrupted by ASCII conversion");
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148 if (num_checked < 3)
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149 png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
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152 /* Read the chunk header (length + type name).
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153 * Put the type name into png_ptr->chunk_name, and return the length.
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155 png_uint_32 /* PRIVATE */
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156 png_read_chunk_header(png_structrp png_ptr)
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159 png_uint_32 length;
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161 #ifdef PNG_IO_STATE_SUPPORTED
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162 png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_HDR;
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165 /* Read the length and the chunk name.
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166 * This must be performed in a single I/O call.
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168 png_read_data(png_ptr, buf, 8);
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169 length = png_get_uint_31(png_ptr, buf);
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171 /* Put the chunk name into png_ptr->chunk_name. */
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172 png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(buf+4);
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174 png_debug2(0, "Reading %lx chunk, length = %lu",
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175 (unsigned long)png_ptr->chunk_name, (unsigned long)length);
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177 /* Reset the crc and run it over the chunk name. */
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178 png_reset_crc(png_ptr);
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179 png_calculate_crc(png_ptr, buf + 4, 4);
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181 /* Check to see if chunk name is valid. */
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182 png_check_chunk_name(png_ptr, png_ptr->chunk_name);
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184 #ifdef PNG_IO_STATE_SUPPORTED
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185 png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_DATA;
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191 /* Read data, and (optionally) run it through the CRC. */
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193 png_crc_read(png_structrp png_ptr, png_bytep buf, png_uint_32 length)
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195 if (png_ptr == NULL)
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198 png_read_data(png_ptr, buf, length);
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199 png_calculate_crc(png_ptr, buf, length);
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202 /* Optionally skip data and then check the CRC. Depending on whether we
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203 * are reading an ancillary or critical chunk, and how the program has set
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204 * things up, we may calculate the CRC on the data and print a message.
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205 * Returns '1' if there was a CRC error, '0' otherwise.
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208 png_crc_finish(png_structrp png_ptr, png_uint_32 skip)
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210 /* The size of the local buffer for inflate is a good guess as to a
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211 * reasonable size to use for buffering reads from the application.
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216 png_byte tmpbuf[PNG_INFLATE_BUF_SIZE];
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218 len = (sizeof tmpbuf);
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223 png_crc_read(png_ptr, tmpbuf, len);
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226 if (png_crc_error(png_ptr) != 0)
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228 if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name) != 0 ?
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229 (png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) == 0 :
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230 (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE) != 0)
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232 png_chunk_warning(png_ptr, "CRC error");
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236 png_chunk_error(png_ptr, "CRC error");
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244 /* Compare the CRC stored in the PNG file with that calculated by libpng from
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245 * the data it has read thus far.
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248 png_crc_error(png_structrp png_ptr)
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250 png_byte crc_bytes[4];
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254 if (PNG_CHUNK_ANCILLARY(png_ptr->chunk_name) != 0)
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256 if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) ==
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257 (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN))
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261 else /* critical */
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263 if ((png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) != 0)
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267 #ifdef PNG_IO_STATE_SUPPORTED
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268 png_ptr->io_state = PNG_IO_READING | PNG_IO_CHUNK_CRC;
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271 /* The chunk CRC must be serialized in a single I/O call. */
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272 png_read_data(png_ptr, crc_bytes, 4);
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276 crc = png_get_uint_32(crc_bytes);
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277 return ((int)(crc != png_ptr->crc));
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284 #if defined(PNG_READ_iCCP_SUPPORTED) || defined(PNG_READ_iTXt_SUPPORTED) ||\
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285 defined(PNG_READ_pCAL_SUPPORTED) || defined(PNG_READ_sCAL_SUPPORTED) ||\
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286 defined(PNG_READ_sPLT_SUPPORTED) || defined(PNG_READ_tEXt_SUPPORTED) ||\
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287 defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_SEQUENTIAL_READ_SUPPORTED)
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288 /* Manage the read buffer; this simply reallocates the buffer if it is not small
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289 * enough (or if it is not allocated). The routine returns a pointer to the
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290 * buffer; if an error occurs and 'warn' is set the routine returns NULL, else
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291 * it will call png_error (via png_malloc) on failure. (warn == 2 means
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295 png_read_buffer(png_structrp png_ptr, png_alloc_size_t new_size, int warn)
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297 png_bytep buffer = png_ptr->read_buffer;
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299 if (buffer != NULL && new_size > png_ptr->read_buffer_size)
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301 png_ptr->read_buffer = NULL;
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302 png_ptr->read_buffer = NULL;
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303 png_ptr->read_buffer_size = 0;
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304 png_free(png_ptr, buffer);
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308 if (buffer == NULL)
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310 buffer = png_voidcast(png_bytep, png_malloc_base(png_ptr, new_size));
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312 if (buffer != NULL)
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314 png_ptr->read_buffer = buffer;
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315 png_ptr->read_buffer_size = new_size;
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318 else if (warn < 2) /* else silent */
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321 png_chunk_warning(png_ptr, "insufficient memory to read chunk");
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324 png_chunk_error(png_ptr, "insufficient memory to read chunk");
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330 #endif /* READ_iCCP|iTXt|pCAL|sCAL|sPLT|tEXt|zTXt|SEQUENTIAL_READ */
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332 /* png_inflate_claim: claim the zstream for some nefarious purpose that involves
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333 * decompression. Returns Z_OK on success, else a zlib error code. It checks
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334 * the owner but, in final release builds, just issues a warning if some other
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335 * chunk apparently owns the stream. Prior to release it does a png_error.
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338 png_inflate_claim(png_structrp png_ptr, png_uint_32 owner)
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340 if (png_ptr->zowner != 0)
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344 PNG_STRING_FROM_CHUNK(msg, png_ptr->zowner);
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345 /* So the message that results is "<chunk> using zstream"; this is an
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346 * internal error, but is very useful for debugging. i18n requirements
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349 (void)png_safecat(msg, (sizeof msg), 4, " using zstream");
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350 #if PNG_RELEASE_BUILD
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351 png_chunk_warning(png_ptr, msg);
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352 png_ptr->zowner = 0;
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354 png_chunk_error(png_ptr, msg);
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358 /* Implementation note: unlike 'png_deflate_claim' this internal function
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359 * does not take the size of the data as an argument. Some efficiency could
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360 * be gained by using this when it is known *if* the zlib stream itself does
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361 * not record the number; however, this is an illusion: the original writer
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362 * of the PNG may have selected a lower window size, and we really must
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363 * follow that because, for systems with with limited capabilities, we
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364 * would otherwise reject the application's attempts to use a smaller window
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365 * size (zlib doesn't have an interface to say "this or lower"!).
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367 * inflateReset2 was added to zlib 1.2.4; before this the window could not be
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368 * reset, therefore it is necessary to always allocate the maximum window
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369 * size with earlier zlibs just in case later compressed chunks need it.
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372 int ret; /* zlib return code */
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373 #if PNG_ZLIB_VERNUM >= 0x1240
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375 # if defined(PNG_SET_OPTION_SUPPORTED) && defined(PNG_MAXIMUM_INFLATE_WINDOW)
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378 if (((png_ptr->options >> PNG_MAXIMUM_INFLATE_WINDOW) & 3) ==
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382 png_ptr->zstream_start = 0; /* fixed window size */
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388 png_ptr->zstream_start = 1;
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391 # define window_bits 0
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395 /* Set this for safety, just in case the previous owner left pointers to
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396 * memory allocations.
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398 png_ptr->zstream.next_in = NULL;
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399 png_ptr->zstream.avail_in = 0;
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400 png_ptr->zstream.next_out = NULL;
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401 png_ptr->zstream.avail_out = 0;
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403 if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0)
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405 #if PNG_ZLIB_VERNUM < 0x1240
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406 ret = inflateReset(&png_ptr->zstream);
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408 ret = inflateReset2(&png_ptr->zstream, window_bits);
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414 #if PNG_ZLIB_VERNUM < 0x1240
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415 ret = inflateInit(&png_ptr->zstream);
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417 ret = inflateInit2(&png_ptr->zstream, window_bits);
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421 png_ptr->flags |= PNG_FLAG_ZSTREAM_INITIALIZED;
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425 png_ptr->zowner = owner;
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428 png_zstream_error(png_ptr, ret);
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434 # undef window_bits
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438 #if PNG_ZLIB_VERNUM >= 0x1240
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439 /* Handle the start of the inflate stream if we called inflateInit2(strm,0);
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440 * in this case some zlib versions skip validation of the CINFO field and, in
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441 * certain circumstances, libpng may end up displaying an invalid image, in
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442 * contrast to implementations that call zlib in the normal way (e.g. libpng
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446 png_zlib_inflate(png_structrp png_ptr, int flush)
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448 if (png_ptr->zstream_start && png_ptr->zstream.avail_in > 0)
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450 if ((*png_ptr->zstream.next_in >> 4) > 7)
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452 png_ptr->zstream.msg = "invalid window size (libpng)";
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453 return Z_DATA_ERROR;
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456 png_ptr->zstream_start = 0;
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459 return inflate(&png_ptr->zstream, flush);
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461 #endif /* Zlib >= 1.2.4 */
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463 #ifdef PNG_READ_COMPRESSED_TEXT_SUPPORTED
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464 /* png_inflate now returns zlib error codes including Z_OK and Z_STREAM_END to
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465 * allow the caller to do multiple calls if required. If the 'finish' flag is
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466 * set Z_FINISH will be passed to the final inflate() call and Z_STREAM_END must
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467 * be returned or there has been a problem, otherwise Z_SYNC_FLUSH is used and
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468 * Z_OK or Z_STREAM_END will be returned on success.
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470 * The input and output sizes are updated to the actual amounts of data consumed
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471 * or written, not the amount available (as in a z_stream). The data pointers
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472 * are not changed, so the next input is (data+input_size) and the next
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473 * available output is (output+output_size).
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476 png_inflate(png_structrp png_ptr, png_uint_32 owner, int finish,
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477 /* INPUT: */ png_const_bytep input, png_uint_32p input_size_ptr,
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478 /* OUTPUT: */ png_bytep output, png_alloc_size_t *output_size_ptr)
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480 if (png_ptr->zowner == owner) /* Else not claimed */
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483 png_alloc_size_t avail_out = *output_size_ptr;
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484 png_uint_32 avail_in = *input_size_ptr;
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486 /* zlib can't necessarily handle more than 65535 bytes at once (i.e. it
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487 * can't even necessarily handle 65536 bytes) because the type uInt is
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488 * "16 bits or more". Consequently it is necessary to chunk the input to
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489 * zlib. This code uses ZLIB_IO_MAX, from pngpriv.h, as the maximum (the
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490 * maximum value that can be stored in a uInt.) It is possible to set
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491 * ZLIB_IO_MAX to a lower value in pngpriv.h and this may sometimes have
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492 * a performance advantage, because it reduces the amount of data accessed
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493 * at each step and that may give the OS more time to page it in.
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495 png_ptr->zstream.next_in = PNGZ_INPUT_CAST(input);
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496 /* avail_in and avail_out are set below from 'size' */
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497 png_ptr->zstream.avail_in = 0;
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498 png_ptr->zstream.avail_out = 0;
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500 /* Read directly into the output if it is available (this is set to
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501 * a local buffer below if output is NULL).
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503 if (output != NULL)
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504 png_ptr->zstream.next_out = output;
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509 Byte local_buffer[PNG_INFLATE_BUF_SIZE];
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511 /* zlib INPUT BUFFER */
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512 /* The setting of 'avail_in' used to be outside the loop; by setting it
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513 * inside it is possible to chunk the input to zlib and simply rely on
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514 * zlib to advance the 'next_in' pointer. This allows arbitrary
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515 * amounts of data to be passed through zlib at the unavoidable cost of
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516 * requiring a window save (memcpy of up to 32768 output bytes)
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517 * every ZLIB_IO_MAX input bytes.
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519 avail_in += png_ptr->zstream.avail_in; /* not consumed last time */
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521 avail = ZLIB_IO_MAX;
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523 if (avail_in < avail)
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524 avail = (uInt)avail_in; /* safe: < than ZLIB_IO_MAX */
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527 png_ptr->zstream.avail_in = avail;
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529 /* zlib OUTPUT BUFFER */
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530 avail_out += png_ptr->zstream.avail_out; /* not written last time */
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532 avail = ZLIB_IO_MAX; /* maximum zlib can process */
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534 if (output == NULL)
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536 /* Reset the output buffer each time round if output is NULL and
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537 * make available the full buffer, up to 'remaining_space'
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539 png_ptr->zstream.next_out = local_buffer;
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540 if ((sizeof local_buffer) < avail)
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541 avail = (sizeof local_buffer);
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544 if (avail_out < avail)
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545 avail = (uInt)avail_out; /* safe: < ZLIB_IO_MAX */
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547 png_ptr->zstream.avail_out = avail;
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548 avail_out -= avail;
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550 /* zlib inflate call */
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551 /* In fact 'avail_out' may be 0 at this point, that happens at the end
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552 * of the read when the final LZ end code was not passed at the end of
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553 * the previous chunk of input data. Tell zlib if we have reached the
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554 * end of the output buffer.
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556 ret = PNG_INFLATE(png_ptr, avail_out > 0 ? Z_NO_FLUSH :
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557 (finish ? Z_FINISH : Z_SYNC_FLUSH));
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558 } while (ret == Z_OK);
\r
560 /* For safety kill the local buffer pointer now */
\r
561 if (output == NULL)
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562 png_ptr->zstream.next_out = NULL;
\r
564 /* Claw back the 'size' and 'remaining_space' byte counts. */
\r
565 avail_in += png_ptr->zstream.avail_in;
\r
566 avail_out += png_ptr->zstream.avail_out;
\r
568 /* Update the input and output sizes; the updated values are the amount
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569 * consumed or written, effectively the inverse of what zlib uses.
\r
572 *output_size_ptr -= avail_out;
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575 *input_size_ptr -= avail_in;
\r
577 /* Ensure png_ptr->zstream.msg is set (even in the success case!) */
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578 png_zstream_error(png_ptr, ret);
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584 /* This is a bad internal error. The recovery assigns to the zstream msg
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585 * pointer, which is not owned by the caller, but this is safe; it's only
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588 png_ptr->zstream.msg = PNGZ_MSG_CAST("zstream unclaimed");
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589 return Z_STREAM_ERROR;
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594 * Decompress trailing data in a chunk. The assumption is that read_buffer
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595 * points at an allocated area holding the contents of a chunk with a
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596 * trailing compressed part. What we get back is an allocated area
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597 * holding the original prefix part and an uncompressed version of the
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598 * trailing part (the malloc area passed in is freed).
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601 png_decompress_chunk(png_structrp png_ptr,
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602 png_uint_32 chunklength, png_uint_32 prefix_size,
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603 png_alloc_size_t *newlength /* must be initialized to the maximum! */,
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604 int terminate /*add a '\0' to the end of the uncompressed data*/)
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606 /* TODO: implement different limits for different types of chunk.
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608 * The caller supplies *newlength set to the maximum length of the
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609 * uncompressed data, but this routine allocates space for the prefix and
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610 * maybe a '\0' terminator too. We have to assume that 'prefix_size' is
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611 * limited only by the maximum chunk size.
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613 png_alloc_size_t limit = PNG_SIZE_MAX;
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615 # ifdef PNG_SET_USER_LIMITS_SUPPORTED
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616 if (png_ptr->user_chunk_malloc_max > 0 &&
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617 png_ptr->user_chunk_malloc_max < limit)
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618 limit = png_ptr->user_chunk_malloc_max;
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619 # elif PNG_USER_CHUNK_MALLOC_MAX > 0
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620 if (PNG_USER_CHUNK_MALLOC_MAX < limit)
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621 limit = PNG_USER_CHUNK_MALLOC_MAX;
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624 if (limit >= prefix_size + (terminate != 0))
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628 limit -= prefix_size + (terminate != 0);
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630 if (limit < *newlength)
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631 *newlength = limit;
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633 /* Now try to claim the stream. */
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634 ret = png_inflate_claim(png_ptr, png_ptr->chunk_name);
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638 png_uint_32 lzsize = chunklength - prefix_size;
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640 ret = png_inflate(png_ptr, png_ptr->chunk_name, 1/*finish*/,
\r
641 /* input: */ png_ptr->read_buffer + prefix_size, &lzsize,
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642 /* output: */ NULL, newlength);
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644 if (ret == Z_STREAM_END)
\r
646 /* Use 'inflateReset' here, not 'inflateReset2' because this
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647 * preserves the previously decided window size (otherwise it would
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648 * be necessary to store the previous window size.) In practice
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649 * this doesn't matter anyway, because png_inflate will call inflate
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650 * with Z_FINISH in almost all cases, so the window will not be
\r
653 if (inflateReset(&png_ptr->zstream) == Z_OK)
\r
655 /* Because of the limit checks above we know that the new,
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656 * expanded, size will fit in a size_t (let alone an
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657 * png_alloc_size_t). Use png_malloc_base here to avoid an
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658 * extra OOM message.
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660 png_alloc_size_t new_size = *newlength;
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661 png_alloc_size_t buffer_size = prefix_size + new_size +
\r
663 png_bytep text = png_voidcast(png_bytep, png_malloc_base(png_ptr,
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668 ret = png_inflate(png_ptr, png_ptr->chunk_name, 1/*finish*/,
\r
669 png_ptr->read_buffer + prefix_size, &lzsize,
\r
670 text + prefix_size, newlength);
\r
672 if (ret == Z_STREAM_END)
\r
674 if (new_size == *newlength)
\r
676 if (terminate != 0)
\r
677 text[prefix_size + *newlength] = 0;
\r
679 if (prefix_size > 0)
\r
680 memcpy(text, png_ptr->read_buffer, prefix_size);
\r
683 png_bytep old_ptr = png_ptr->read_buffer;
\r
685 png_ptr->read_buffer = text;
\r
686 png_ptr->read_buffer_size = buffer_size;
\r
687 text = old_ptr; /* freed below */
\r
693 /* The size changed on the second read, there can be no
\r
694 * guarantee that anything is correct at this point.
\r
695 * The 'msg' pointer has been set to "unexpected end of
\r
696 * LZ stream", which is fine, but return an error code
\r
697 * that the caller won't accept.
\r
699 ret = PNG_UNEXPECTED_ZLIB_RETURN;
\r
703 else if (ret == Z_OK)
\r
704 ret = PNG_UNEXPECTED_ZLIB_RETURN; /* for safety */
\r
706 /* Free the text pointer (this is the old read_buffer on
\r
709 png_free(png_ptr, text);
\r
711 /* This really is very benign, but it's still an error because
\r
712 * the extra space may otherwise be used as a Trojan Horse.
\r
714 if (ret == Z_STREAM_END &&
\r
715 chunklength - prefix_size != lzsize)
\r
716 png_chunk_benign_error(png_ptr, "extra compressed data");
\r
721 /* Out of memory allocating the buffer */
\r
723 png_zstream_error(png_ptr, Z_MEM_ERROR);
\r
729 /* inflateReset failed, store the error message */
\r
730 png_zstream_error(png_ptr, ret);
\r
732 if (ret == Z_STREAM_END)
\r
733 ret = PNG_UNEXPECTED_ZLIB_RETURN;
\r
737 else if (ret == Z_OK)
\r
738 ret = PNG_UNEXPECTED_ZLIB_RETURN;
\r
740 /* Release the claimed stream */
\r
741 png_ptr->zowner = 0;
\r
744 else /* the claim failed */ if (ret == Z_STREAM_END) /* impossible! */
\r
745 ret = PNG_UNEXPECTED_ZLIB_RETURN;
\r
752 /* Application/configuration limits exceeded */
\r
753 png_zstream_error(png_ptr, Z_MEM_ERROR);
\r
754 return Z_MEM_ERROR;
\r
757 #endif /* READ_COMPRESSED_TEXT */
\r
759 #ifdef PNG_READ_iCCP_SUPPORTED
\r
760 /* Perform a partial read and decompress, producing 'avail_out' bytes and
\r
761 * reading from the current chunk as required.
\r
764 png_inflate_read(png_structrp png_ptr, png_bytep read_buffer, uInt read_size,
\r
765 png_uint_32p chunk_bytes, png_bytep next_out, png_alloc_size_t *out_size,
\r
768 if (png_ptr->zowner == png_ptr->chunk_name)
\r
772 /* next_in and avail_in must have been initialized by the caller. */
\r
773 png_ptr->zstream.next_out = next_out;
\r
774 png_ptr->zstream.avail_out = 0; /* set in the loop */
\r
778 if (png_ptr->zstream.avail_in == 0)
\r
780 if (read_size > *chunk_bytes)
\r
781 read_size = (uInt)*chunk_bytes;
\r
782 *chunk_bytes -= read_size;
\r
785 png_crc_read(png_ptr, read_buffer, read_size);
\r
787 png_ptr->zstream.next_in = read_buffer;
\r
788 png_ptr->zstream.avail_in = read_size;
\r
791 if (png_ptr->zstream.avail_out == 0)
\r
793 uInt avail = ZLIB_IO_MAX;
\r
794 if (avail > *out_size)
\r
795 avail = (uInt)*out_size;
\r
796 *out_size -= avail;
\r
798 png_ptr->zstream.avail_out = avail;
\r
801 /* Use Z_SYNC_FLUSH when there is no more chunk data to ensure that all
\r
802 * the available output is produced; this allows reading of truncated
\r
805 ret = PNG_INFLATE(png_ptr,
\r
806 *chunk_bytes > 0 ? Z_NO_FLUSH : (finish ? Z_FINISH : Z_SYNC_FLUSH));
\r
808 while (ret == Z_OK && (*out_size > 0 || png_ptr->zstream.avail_out > 0));
\r
810 *out_size += png_ptr->zstream.avail_out;
\r
811 png_ptr->zstream.avail_out = 0; /* Should not be required, but is safe */
\r
813 /* Ensure the error message pointer is always set: */
\r
814 png_zstream_error(png_ptr, ret);
\r
820 png_ptr->zstream.msg = PNGZ_MSG_CAST("zstream unclaimed");
\r
821 return Z_STREAM_ERROR;
\r
826 /* Read and check the IDHR chunk */
\r
829 png_handle_IHDR(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
\r
832 png_uint_32 width, height;
\r
833 int bit_depth, color_type, compression_type, filter_type;
\r
834 int interlace_type;
\r
836 png_debug(1, "in png_handle_IHDR");
\r
838 if ((png_ptr->mode & PNG_HAVE_IHDR) != 0)
\r
839 png_chunk_error(png_ptr, "out of place");
\r
841 /* Check the length */
\r
843 png_chunk_error(png_ptr, "invalid");
\r
845 png_ptr->mode |= PNG_HAVE_IHDR;
\r
847 png_crc_read(png_ptr, buf, 13);
\r
848 png_crc_finish(png_ptr, 0);
\r
850 width = png_get_uint_31(png_ptr, buf);
\r
851 height = png_get_uint_31(png_ptr, buf + 4);
\r
852 bit_depth = buf[8];
\r
853 color_type = buf[9];
\r
854 compression_type = buf[10];
\r
855 filter_type = buf[11];
\r
856 interlace_type = buf[12];
\r
858 /* Set internal variables */
\r
859 png_ptr->width = width;
\r
860 png_ptr->height = height;
\r
861 png_ptr->bit_depth = (png_byte)bit_depth;
\r
862 png_ptr->interlaced = (png_byte)interlace_type;
\r
863 png_ptr->color_type = (png_byte)color_type;
\r
864 #ifdef PNG_MNG_FEATURES_SUPPORTED
\r
865 png_ptr->filter_type = (png_byte)filter_type;
\r
867 png_ptr->compression_type = (png_byte)compression_type;
\r
869 /* Find number of channels */
\r
870 switch (png_ptr->color_type)
\r
872 default: /* invalid, png_set_IHDR calls png_error */
\r
873 case PNG_COLOR_TYPE_GRAY:
\r
874 case PNG_COLOR_TYPE_PALETTE:
\r
875 png_ptr->channels = 1;
\r
878 case PNG_COLOR_TYPE_RGB:
\r
879 png_ptr->channels = 3;
\r
882 case PNG_COLOR_TYPE_GRAY_ALPHA:
\r
883 png_ptr->channels = 2;
\r
886 case PNG_COLOR_TYPE_RGB_ALPHA:
\r
887 png_ptr->channels = 4;
\r
891 /* Set up other useful info */
\r
892 png_ptr->pixel_depth = (png_byte)(png_ptr->bit_depth * png_ptr->channels);
\r
893 png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->width);
\r
894 png_debug1(3, "bit_depth = %d", png_ptr->bit_depth);
\r
895 png_debug1(3, "channels = %d", png_ptr->channels);
\r
896 png_debug1(3, "rowbytes = %lu", (unsigned long)png_ptr->rowbytes);
\r
897 png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth,
\r
898 color_type, interlace_type, compression_type, filter_type);
\r
901 /* Read and check the palette */
\r
903 png_handle_PLTE(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
\r
905 png_color palette[PNG_MAX_PALETTE_LENGTH];
\r
906 int max_palette_length, num, i;
\r
907 #ifdef PNG_POINTER_INDEXING_SUPPORTED
\r
908 png_colorp pal_ptr;
\r
911 png_debug(1, "in png_handle_PLTE");
\r
913 if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
\r
914 png_chunk_error(png_ptr, "missing IHDR");
\r
916 /* Moved to before the 'after IDAT' check below because otherwise duplicate
\r
917 * PLTE chunks are potentially ignored (the spec says there shall not be more
\r
918 * than one PLTE, the error is not treated as benign, so this check trumps
\r
919 * the requirement that PLTE appears before IDAT.)
\r
921 else if ((png_ptr->mode & PNG_HAVE_PLTE) != 0)
\r
922 png_chunk_error(png_ptr, "duplicate");
\r
924 else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
\r
926 /* This is benign because the non-benign error happened before, when an
\r
927 * IDAT was encountered in a color-mapped image with no PLTE.
\r
929 png_crc_finish(png_ptr, length);
\r
930 png_chunk_benign_error(png_ptr, "out of place");
\r
934 png_ptr->mode |= PNG_HAVE_PLTE;
\r
936 if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0)
\r
938 png_crc_finish(png_ptr, length);
\r
939 png_chunk_benign_error(png_ptr, "ignored in grayscale PNG");
\r
943 #ifndef PNG_READ_OPT_PLTE_SUPPORTED
\r
944 if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
\r
946 png_crc_finish(png_ptr, length);
\r
951 if (length > 3*PNG_MAX_PALETTE_LENGTH || length % 3)
\r
953 png_crc_finish(png_ptr, length);
\r
955 if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
\r
956 png_chunk_benign_error(png_ptr, "invalid");
\r
959 png_chunk_error(png_ptr, "invalid");
\r
964 /* The cast is safe because 'length' is less than 3*PNG_MAX_PALETTE_LENGTH */
\r
965 num = (int)length / 3;
\r
967 /* If the palette has 256 or fewer entries but is too large for the bit
\r
968 * depth, we don't issue an error, to preserve the behavior of previous
\r
969 * libpng versions. We silently truncate the unused extra palette entries
\r
972 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
\r
973 max_palette_length = (1 << png_ptr->bit_depth);
\r
975 max_palette_length = PNG_MAX_PALETTE_LENGTH;
\r
977 if (num > max_palette_length)
\r
978 num = max_palette_length;
\r
980 #ifdef PNG_POINTER_INDEXING_SUPPORTED
\r
981 for (i = 0, pal_ptr = palette; i < num; i++, pal_ptr++)
\r
985 png_crc_read(png_ptr, buf, 3);
\r
986 pal_ptr->red = buf[0];
\r
987 pal_ptr->green = buf[1];
\r
988 pal_ptr->blue = buf[2];
\r
991 for (i = 0; i < num; i++)
\r
995 png_crc_read(png_ptr, buf, 3);
\r
996 /* Don't depend upon png_color being any order */
\r
997 palette[i].red = buf[0];
\r
998 palette[i].green = buf[1];
\r
999 palette[i].blue = buf[2];
\r
1003 /* If we actually need the PLTE chunk (ie for a paletted image), we do
\r
1004 * whatever the normal CRC configuration tells us. However, if we
\r
1005 * have an RGB image, the PLTE can be considered ancillary, so
\r
1006 * we will act as though it is.
\r
1008 #ifndef PNG_READ_OPT_PLTE_SUPPORTED
\r
1009 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
\r
1012 png_crc_finish(png_ptr, (int) length - num * 3);
\r
1015 #ifndef PNG_READ_OPT_PLTE_SUPPORTED
\r
1016 else if (png_crc_error(png_ptr) != 0) /* Only if we have a CRC error */
\r
1018 /* If we don't want to use the data from an ancillary chunk,
\r
1019 * we have two options: an error abort, or a warning and we
\r
1020 * ignore the data in this chunk (which should be OK, since
\r
1021 * it's considered ancillary for a RGB or RGBA image).
\r
1023 * IMPLEMENTATION NOTE: this is only here because png_crc_finish uses the
\r
1024 * chunk type to determine whether to check the ancillary or the critical
\r
1027 if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_USE) == 0)
\r
1029 if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) != 0)
\r
1033 png_chunk_error(png_ptr, "CRC error");
\r
1036 /* Otherwise, we (optionally) emit a warning and use the chunk. */
\r
1037 else if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) == 0)
\r
1038 png_chunk_warning(png_ptr, "CRC error");
\r
1042 /* TODO: png_set_PLTE has the side effect of setting png_ptr->palette to its
\r
1043 * own copy of the palette. This has the side effect that when png_start_row
\r
1044 * is called (this happens after any call to png_read_update_info) the
\r
1045 * info_ptr palette gets changed. This is extremely unexpected and
\r
1048 * Fix this by not sharing the palette in this way.
\r
1050 png_set_PLTE(png_ptr, info_ptr, palette, num);
\r
1052 /* The three chunks, bKGD, hIST and tRNS *must* appear after PLTE and before
\r
1053 * IDAT. Prior to 1.6.0 this was not checked; instead the code merely
\r
1054 * checked the apparent validity of a tRNS chunk inserted before PLTE on a
\r
1055 * palette PNG. 1.6.0 attempts to rigorously follow the standard and
\r
1056 * therefore does a benign error if the erroneous condition is detected *and*
\r
1057 * cancels the tRNS if the benign error returns. The alternative is to
\r
1058 * amend the standard since it would be rather hypocritical of the standards
\r
1059 * maintainers to ignore it.
\r
1061 #ifdef PNG_READ_tRNS_SUPPORTED
\r
1062 if (png_ptr->num_trans > 0 ||
\r
1063 (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS) != 0))
\r
1065 /* Cancel this because otherwise it would be used if the transforms
\r
1066 * require it. Don't cancel the 'valid' flag because this would prevent
\r
1067 * detection of duplicate chunks.
\r
1069 png_ptr->num_trans = 0;
\r
1071 if (info_ptr != NULL)
\r
1072 info_ptr->num_trans = 0;
\r
1074 png_chunk_benign_error(png_ptr, "tRNS must be after");
\r
1078 #ifdef PNG_READ_hIST_SUPPORTED
\r
1079 if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST) != 0)
\r
1080 png_chunk_benign_error(png_ptr, "hIST must be after");
\r
1083 #ifdef PNG_READ_bKGD_SUPPORTED
\r
1084 if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD) != 0)
\r
1085 png_chunk_benign_error(png_ptr, "bKGD must be after");
\r
1089 void /* PRIVATE */
\r
1090 png_handle_IEND(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
\r
1092 png_debug(1, "in png_handle_IEND");
\r
1094 if ((png_ptr->mode & PNG_HAVE_IHDR) == 0 ||
\r
1095 (png_ptr->mode & PNG_HAVE_IDAT) == 0)
\r
1096 png_chunk_error(png_ptr, "out of place");
\r
1098 png_ptr->mode |= (PNG_AFTER_IDAT | PNG_HAVE_IEND);
\r
1100 png_crc_finish(png_ptr, length);
\r
1103 png_chunk_benign_error(png_ptr, "invalid");
\r
1105 PNG_UNUSED(info_ptr)
\r
1108 #ifdef PNG_READ_gAMA_SUPPORTED
\r
1109 void /* PRIVATE */
\r
1110 png_handle_gAMA(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
\r
1112 png_fixed_point igamma;
\r
1115 png_debug(1, "in png_handle_gAMA");
\r
1117 if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
\r
1118 png_chunk_error(png_ptr, "missing IHDR");
\r
1120 else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0)
\r
1122 png_crc_finish(png_ptr, length);
\r
1123 png_chunk_benign_error(png_ptr, "out of place");
\r
1129 png_crc_finish(png_ptr, length);
\r
1130 png_chunk_benign_error(png_ptr, "invalid");
\r
1134 png_crc_read(png_ptr, buf, 4);
\r
1136 if (png_crc_finish(png_ptr, 0) != 0)
\r
1139 igamma = png_get_fixed_point(NULL, buf);
\r
1141 png_colorspace_set_gamma(png_ptr, &png_ptr->colorspace, igamma);
\r
1142 png_colorspace_sync(png_ptr, info_ptr);
\r
1146 #ifdef PNG_READ_sBIT_SUPPORTED
\r
1147 void /* PRIVATE */
\r
1148 png_handle_sBIT(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
\r
1150 unsigned int truelen, i;
\r
1151 png_byte sample_depth;
\r
1154 png_debug(1, "in png_handle_sBIT");
\r
1156 if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
\r
1157 png_chunk_error(png_ptr, "missing IHDR");
\r
1159 else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0)
\r
1161 png_crc_finish(png_ptr, length);
\r
1162 png_chunk_benign_error(png_ptr, "out of place");
\r
1166 if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sBIT) != 0)
\r
1168 png_crc_finish(png_ptr, length);
\r
1169 png_chunk_benign_error(png_ptr, "duplicate");
\r
1173 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
\r
1181 truelen = png_ptr->channels;
\r
1182 sample_depth = png_ptr->bit_depth;
\r
1185 if (length != truelen || length > 4)
\r
1187 png_chunk_benign_error(png_ptr, "invalid");
\r
1188 png_crc_finish(png_ptr, length);
\r
1192 buf[0] = buf[1] = buf[2] = buf[3] = sample_depth;
\r
1193 png_crc_read(png_ptr, buf, truelen);
\r
1195 if (png_crc_finish(png_ptr, 0) != 0)
\r
1198 for (i=0; i<truelen; ++i)
\r
1200 if (buf[i] == 0 || buf[i] > sample_depth)
\r
1202 png_chunk_benign_error(png_ptr, "invalid");
\r
1207 if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
\r
1209 png_ptr->sig_bit.red = buf[0];
\r
1210 png_ptr->sig_bit.green = buf[1];
\r
1211 png_ptr->sig_bit.blue = buf[2];
\r
1212 png_ptr->sig_bit.alpha = buf[3];
\r
1217 png_ptr->sig_bit.gray = buf[0];
\r
1218 png_ptr->sig_bit.red = buf[0];
\r
1219 png_ptr->sig_bit.green = buf[0];
\r
1220 png_ptr->sig_bit.blue = buf[0];
\r
1221 png_ptr->sig_bit.alpha = buf[1];
\r
1224 png_set_sBIT(png_ptr, info_ptr, &(png_ptr->sig_bit));
\r
1228 #ifdef PNG_READ_cHRM_SUPPORTED
\r
1229 void /* PRIVATE */
\r
1230 png_handle_cHRM(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
\r
1235 png_debug(1, "in png_handle_cHRM");
\r
1237 if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
\r
1238 png_chunk_error(png_ptr, "missing IHDR");
\r
1240 else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0)
\r
1242 png_crc_finish(png_ptr, length);
\r
1243 png_chunk_benign_error(png_ptr, "out of place");
\r
1249 png_crc_finish(png_ptr, length);
\r
1250 png_chunk_benign_error(png_ptr, "invalid");
\r
1254 png_crc_read(png_ptr, buf, 32);
\r
1256 if (png_crc_finish(png_ptr, 0) != 0)
\r
1259 xy.whitex = png_get_fixed_point(NULL, buf);
\r
1260 xy.whitey = png_get_fixed_point(NULL, buf + 4);
\r
1261 xy.redx = png_get_fixed_point(NULL, buf + 8);
\r
1262 xy.redy = png_get_fixed_point(NULL, buf + 12);
\r
1263 xy.greenx = png_get_fixed_point(NULL, buf + 16);
\r
1264 xy.greeny = png_get_fixed_point(NULL, buf + 20);
\r
1265 xy.bluex = png_get_fixed_point(NULL, buf + 24);
\r
1266 xy.bluey = png_get_fixed_point(NULL, buf + 28);
\r
1268 if (xy.whitex == PNG_FIXED_ERROR ||
\r
1269 xy.whitey == PNG_FIXED_ERROR ||
\r
1270 xy.redx == PNG_FIXED_ERROR ||
\r
1271 xy.redy == PNG_FIXED_ERROR ||
\r
1272 xy.greenx == PNG_FIXED_ERROR ||
\r
1273 xy.greeny == PNG_FIXED_ERROR ||
\r
1274 xy.bluex == PNG_FIXED_ERROR ||
\r
1275 xy.bluey == PNG_FIXED_ERROR)
\r
1277 png_chunk_benign_error(png_ptr, "invalid values");
\r
1281 /* If a colorspace error has already been output skip this chunk */
\r
1282 if ((png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) != 0)
\r
1285 if ((png_ptr->colorspace.flags & PNG_COLORSPACE_FROM_cHRM) != 0)
\r
1287 png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID;
\r
1288 png_colorspace_sync(png_ptr, info_ptr);
\r
1289 png_chunk_benign_error(png_ptr, "duplicate");
\r
1293 png_ptr->colorspace.flags |= PNG_COLORSPACE_FROM_cHRM;
\r
1294 (void)png_colorspace_set_chromaticities(png_ptr, &png_ptr->colorspace, &xy,
\r
1295 1/*prefer cHRM values*/);
\r
1296 png_colorspace_sync(png_ptr, info_ptr);
\r
1300 #ifdef PNG_READ_sRGB_SUPPORTED
\r
1301 void /* PRIVATE */
\r
1302 png_handle_sRGB(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
\r
1306 png_debug(1, "in png_handle_sRGB");
\r
1308 if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
\r
1309 png_chunk_error(png_ptr, "missing IHDR");
\r
1311 else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0)
\r
1313 png_crc_finish(png_ptr, length);
\r
1314 png_chunk_benign_error(png_ptr, "out of place");
\r
1320 png_crc_finish(png_ptr, length);
\r
1321 png_chunk_benign_error(png_ptr, "invalid");
\r
1325 png_crc_read(png_ptr, &intent, 1);
\r
1327 if (png_crc_finish(png_ptr, 0) != 0)
\r
1330 /* If a colorspace error has already been output skip this chunk */
\r
1331 if ((png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) != 0)
\r
1334 /* Only one sRGB or iCCP chunk is allowed, use the HAVE_INTENT flag to detect
\r
1337 if ((png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_INTENT) != 0)
\r
1339 png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID;
\r
1340 png_colorspace_sync(png_ptr, info_ptr);
\r
1341 png_chunk_benign_error(png_ptr, "too many profiles");
\r
1345 (void)png_colorspace_set_sRGB(png_ptr, &png_ptr->colorspace, intent);
\r
1346 png_colorspace_sync(png_ptr, info_ptr);
\r
1348 #endif /* READ_sRGB */
\r
1350 #ifdef PNG_READ_iCCP_SUPPORTED
\r
1351 void /* PRIVATE */
\r
1352 png_handle_iCCP(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
\r
1353 /* Note: this does not properly handle profiles that are > 64K under DOS */
\r
1355 png_const_charp errmsg = NULL; /* error message output, or no error */
\r
1356 int finished = 0; /* crc checked */
\r
1358 png_debug(1, "in png_handle_iCCP");
\r
1360 if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
\r
1361 png_chunk_error(png_ptr, "missing IHDR");
\r
1363 else if ((png_ptr->mode & (PNG_HAVE_IDAT|PNG_HAVE_PLTE)) != 0)
\r
1365 png_crc_finish(png_ptr, length);
\r
1366 png_chunk_benign_error(png_ptr, "out of place");
\r
1370 /* Consistent with all the above colorspace handling an obviously *invalid*
\r
1371 * chunk is just ignored, so does not invalidate the color space. An
\r
1372 * alternative is to set the 'invalid' flags at the start of this routine
\r
1373 * and only clear them in they were not set before and all the tests pass.
\r
1374 * The minimum 'deflate' stream is assumed to be just the 2 byte header and
\r
1375 * 4 byte checksum. The keyword must be at least one character and there is
\r
1376 * a terminator (0) byte and the compression method.
\r
1380 png_crc_finish(png_ptr, length);
\r
1381 png_chunk_benign_error(png_ptr, "too short");
\r
1385 /* If a colorspace error has already been output skip this chunk */
\r
1386 if ((png_ptr->colorspace.flags & PNG_COLORSPACE_INVALID) != 0)
\r
1388 png_crc_finish(png_ptr, length);
\r
1392 /* Only one sRGB or iCCP chunk is allowed, use the HAVE_INTENT flag to detect
\r
1395 if ((png_ptr->colorspace.flags & PNG_COLORSPACE_HAVE_INTENT) == 0)
\r
1397 uInt read_length, keyword_length;
\r
1400 /* Find the keyword; the keyword plus separator and compression method
\r
1401 * bytes can be at most 81 characters long.
\r
1403 read_length = 81; /* maximum */
\r
1404 if (read_length > length)
\r
1405 read_length = (uInt)length;
\r
1407 png_crc_read(png_ptr, (png_bytep)keyword, read_length);
\r
1408 length -= read_length;
\r
1410 keyword_length = 0;
\r
1411 while (keyword_length < 80 && keyword_length < read_length &&
\r
1412 keyword[keyword_length] != 0)
\r
1415 /* TODO: make the keyword checking common */
\r
1416 if (keyword_length >= 1 && keyword_length <= 79)
\r
1418 /* We only understand '0' compression - deflate - so if we get a
\r
1419 * different value we can't safely decode the chunk.
\r
1421 if (keyword_length+1 < read_length &&
\r
1422 keyword[keyword_length+1] == PNG_COMPRESSION_TYPE_BASE)
\r
1424 read_length -= keyword_length+2;
\r
1426 if (png_inflate_claim(png_ptr, png_iCCP) == Z_OK)
\r
1428 Byte profile_header[132];
\r
1429 Byte local_buffer[PNG_INFLATE_BUF_SIZE];
\r
1430 png_alloc_size_t size = (sizeof profile_header);
\r
1432 png_ptr->zstream.next_in = (Bytef*)keyword + (keyword_length+2);
\r
1433 png_ptr->zstream.avail_in = read_length;
\r
1434 (void)png_inflate_read(png_ptr, local_buffer,
\r
1435 (sizeof local_buffer), &length, profile_header, &size,
\r
1436 0/*finish: don't, because the output is too small*/);
\r
1440 /* We have the ICC profile header; do the basic header checks.
\r
1442 const png_uint_32 profile_length =
\r
1443 png_get_uint_32(profile_header);
\r
1445 if (png_icc_check_length(png_ptr, &png_ptr->colorspace,
\r
1446 keyword, profile_length) != 0)
\r
1448 /* The length is apparently ok, so we can check the 132
\r
1451 if (png_icc_check_header(png_ptr, &png_ptr->colorspace,
\r
1452 keyword, profile_length, profile_header,
\r
1453 png_ptr->color_type) != 0)
\r
1455 /* Now read the tag table; a variable size buffer is
\r
1456 * needed at this point, allocate one for the whole
\r
1457 * profile. The header check has already validated
\r
1458 * that none of these stuff will overflow.
\r
1460 const png_uint_32 tag_count = png_get_uint_32(
\r
1461 profile_header+128);
\r
1462 png_bytep profile = png_read_buffer(png_ptr,
\r
1463 profile_length, 2/*silent*/);
\r
1465 if (profile != NULL)
\r
1467 memcpy(profile, profile_header,
\r
1468 (sizeof profile_header));
\r
1470 size = 12 * tag_count;
\r
1472 (void)png_inflate_read(png_ptr, local_buffer,
\r
1473 (sizeof local_buffer), &length,
\r
1474 profile + (sizeof profile_header), &size, 0);
\r
1476 /* Still expect a buffer error because we expect
\r
1477 * there to be some tag data!
\r
1481 if (png_icc_check_tag_table(png_ptr,
\r
1482 &png_ptr->colorspace, keyword, profile_length,
\r
1485 /* The profile has been validated for basic
\r
1486 * security issues, so read the whole thing in.
\r
1488 size = profile_length - (sizeof profile_header)
\r
1491 (void)png_inflate_read(png_ptr, local_buffer,
\r
1492 (sizeof local_buffer), &length,
\r
1493 profile + (sizeof profile_header) +
\r
1494 12 * tag_count, &size, 1/*finish*/);
\r
1496 if (length > 0 && !(png_ptr->flags &
\r
1497 PNG_FLAG_BENIGN_ERRORS_WARN))
\r
1498 errmsg = "extra compressed data";
\r
1500 /* But otherwise allow extra data: */
\r
1501 else if (size == 0)
\r
1505 /* This can be handled completely, so
\r
1508 png_chunk_warning(png_ptr,
\r
1509 "extra compressed data");
\r
1512 png_crc_finish(png_ptr, length);
\r
1515 # ifdef PNG_sRGB_SUPPORTED
\r
1516 /* Check for a match against sRGB */
\r
1517 png_icc_set_sRGB(png_ptr,
\r
1518 &png_ptr->colorspace, profile,
\r
1519 png_ptr->zstream.adler);
\r
1522 /* Steal the profile for info_ptr. */
\r
1523 if (info_ptr != NULL)
\r
1525 png_free_data(png_ptr, info_ptr,
\r
1526 PNG_FREE_ICCP, 0);
\r
1528 info_ptr->iccp_name = png_voidcast(char*,
\r
1529 png_malloc_base(png_ptr,
\r
1530 keyword_length+1));
\r
1531 if (info_ptr->iccp_name != NULL)
\r
1533 memcpy(info_ptr->iccp_name, keyword,
\r
1534 keyword_length+1);
\r
1535 info_ptr->iccp_proflen =
\r
1537 info_ptr->iccp_profile = profile;
\r
1538 png_ptr->read_buffer = NULL; /*steal*/
\r
1539 info_ptr->free_me |= PNG_FREE_ICCP;
\r
1540 info_ptr->valid |= PNG_INFO_iCCP;
\r
1545 png_ptr->colorspace.flags |=
\r
1546 PNG_COLORSPACE_INVALID;
\r
1547 errmsg = "out of memory";
\r
1551 /* else the profile remains in the read
\r
1552 * buffer which gets reused for subsequent
\r
1556 if (info_ptr != NULL)
\r
1557 png_colorspace_sync(png_ptr, info_ptr);
\r
1559 if (errmsg == NULL)
\r
1561 png_ptr->zowner = 0;
\r
1566 else if (size > 0)
\r
1567 errmsg = "truncated";
\r
1569 #ifndef __COVERITY__
\r
1571 errmsg = png_ptr->zstream.msg;
\r
1575 /* else png_icc_check_tag_table output an error */
\r
1578 else /* profile truncated */
\r
1579 errmsg = png_ptr->zstream.msg;
\r
1583 errmsg = "out of memory";
\r
1586 /* else png_icc_check_header output an error */
\r
1589 /* else png_icc_check_length output an error */
\r
1592 else /* profile truncated */
\r
1593 errmsg = png_ptr->zstream.msg;
\r
1595 /* Release the stream */
\r
1596 png_ptr->zowner = 0;
\r
1599 else /* png_inflate_claim failed */
\r
1600 errmsg = png_ptr->zstream.msg;
\r
1604 errmsg = "bad compression method"; /* or missing */
\r
1608 errmsg = "bad keyword";
\r
1612 errmsg = "too many profiles";
\r
1614 /* Failure: the reason is in 'errmsg' */
\r
1615 if (finished == 0)
\r
1616 png_crc_finish(png_ptr, length);
\r
1618 png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID;
\r
1619 png_colorspace_sync(png_ptr, info_ptr);
\r
1620 if (errmsg != NULL) /* else already output */
\r
1621 png_chunk_benign_error(png_ptr, errmsg);
\r
1623 #endif /* READ_iCCP */
\r
1625 #ifdef PNG_READ_sPLT_SUPPORTED
\r
1626 void /* PRIVATE */
\r
1627 png_handle_sPLT(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
\r
1628 /* Note: this does not properly handle chunks that are > 64K under DOS */
\r
1630 png_bytep entry_start, buffer;
\r
1631 png_sPLT_t new_palette;
\r
1632 png_sPLT_entryp pp;
\r
1633 png_uint_32 data_length;
\r
1634 int entry_size, i;
\r
1635 png_uint_32 skip = 0;
\r
1637 png_size_t max_dl;
\r
1639 png_debug(1, "in png_handle_sPLT");
\r
1641 #ifdef PNG_USER_LIMITS_SUPPORTED
\r
1642 if (png_ptr->user_chunk_cache_max != 0)
\r
1644 if (png_ptr->user_chunk_cache_max == 1)
\r
1646 png_crc_finish(png_ptr, length);
\r
1650 if (--png_ptr->user_chunk_cache_max == 1)
\r
1652 png_warning(png_ptr, "No space in chunk cache for sPLT");
\r
1653 png_crc_finish(png_ptr, length);
\r
1659 if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
\r
1660 png_chunk_error(png_ptr, "missing IHDR");
\r
1662 else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
\r
1664 png_crc_finish(png_ptr, length);
\r
1665 png_chunk_benign_error(png_ptr, "out of place");
\r
1669 #ifdef PNG_MAX_MALLOC_64K
\r
1670 if (length > 65535U)
\r
1672 png_crc_finish(png_ptr, length);
\r
1673 png_chunk_benign_error(png_ptr, "too large to fit in memory");
\r
1678 buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/);
\r
1679 if (buffer == NULL)
\r
1681 png_crc_finish(png_ptr, length);
\r
1682 png_chunk_benign_error(png_ptr, "out of memory");
\r
1687 /* WARNING: this may break if size_t is less than 32 bits; it is assumed
\r
1688 * that the PNG_MAX_MALLOC_64K test is enabled in this case, but this is a
\r
1689 * potential breakage point if the types in pngconf.h aren't exactly right.
\r
1691 png_crc_read(png_ptr, buffer, length);
\r
1693 if (png_crc_finish(png_ptr, skip) != 0)
\r
1696 buffer[length] = 0;
\r
1698 for (entry_start = buffer; *entry_start; entry_start++)
\r
1699 /* Empty loop to find end of name */ ;
\r
1703 /* A sample depth should follow the separator, and we should be on it */
\r
1704 if (length < 2U || entry_start > buffer + (length - 2U))
\r
1706 png_warning(png_ptr, "malformed sPLT chunk");
\r
1710 new_palette.depth = *entry_start++;
\r
1711 entry_size = (new_palette.depth == 8 ? 6 : 10);
\r
1712 /* This must fit in a png_uint_32 because it is derived from the original
\r
1713 * chunk data length.
\r
1715 data_length = length - (png_uint_32)(entry_start - buffer);
\r
1717 /* Integrity-check the data length */
\r
1718 if ((data_length % entry_size) != 0)
\r
1720 png_warning(png_ptr, "sPLT chunk has bad length");
\r
1724 dl = (png_int_32)(data_length / entry_size);
\r
1725 max_dl = PNG_SIZE_MAX / (sizeof (png_sPLT_entry));
\r
1729 png_warning(png_ptr, "sPLT chunk too long");
\r
1733 new_palette.nentries = (png_int_32)(data_length / entry_size);
\r
1735 new_palette.entries = (png_sPLT_entryp)png_malloc_warn(
\r
1736 png_ptr, new_palette.nentries * (sizeof (png_sPLT_entry)));
\r
1738 if (new_palette.entries == NULL)
\r
1740 png_warning(png_ptr, "sPLT chunk requires too much memory");
\r
1744 #ifdef PNG_POINTER_INDEXING_SUPPORTED
\r
1745 for (i = 0; i < new_palette.nentries; i++)
\r
1747 pp = new_palette.entries + i;
\r
1749 if (new_palette.depth == 8)
\r
1751 pp->red = *entry_start++;
\r
1752 pp->green = *entry_start++;
\r
1753 pp->blue = *entry_start++;
\r
1754 pp->alpha = *entry_start++;
\r
1759 pp->red = png_get_uint_16(entry_start); entry_start += 2;
\r
1760 pp->green = png_get_uint_16(entry_start); entry_start += 2;
\r
1761 pp->blue = png_get_uint_16(entry_start); entry_start += 2;
\r
1762 pp->alpha = png_get_uint_16(entry_start); entry_start += 2;
\r
1765 pp->frequency = png_get_uint_16(entry_start); entry_start += 2;
\r
1768 pp = new_palette.entries;
\r
1770 for (i = 0; i < new_palette.nentries; i++)
\r
1773 if (new_palette.depth == 8)
\r
1775 pp[i].red = *entry_start++;
\r
1776 pp[i].green = *entry_start++;
\r
1777 pp[i].blue = *entry_start++;
\r
1778 pp[i].alpha = *entry_start++;
\r
1783 pp[i].red = png_get_uint_16(entry_start); entry_start += 2;
\r
1784 pp[i].green = png_get_uint_16(entry_start); entry_start += 2;
\r
1785 pp[i].blue = png_get_uint_16(entry_start); entry_start += 2;
\r
1786 pp[i].alpha = png_get_uint_16(entry_start); entry_start += 2;
\r
1789 pp[i].frequency = png_get_uint_16(entry_start); entry_start += 2;
\r
1793 /* Discard all chunk data except the name and stash that */
\r
1794 new_palette.name = (png_charp)buffer;
\r
1796 png_set_sPLT(png_ptr, info_ptr, &new_palette, 1);
\r
1798 png_free(png_ptr, new_palette.entries);
\r
1800 #endif /* READ_sPLT */
\r
1802 #ifdef PNG_READ_tRNS_SUPPORTED
\r
1803 void /* PRIVATE */
\r
1804 png_handle_tRNS(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
\r
1806 png_byte readbuf[PNG_MAX_PALETTE_LENGTH];
\r
1808 png_debug(1, "in png_handle_tRNS");
\r
1810 if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
\r
1811 png_chunk_error(png_ptr, "missing IHDR");
\r
1813 else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
\r
1815 png_crc_finish(png_ptr, length);
\r
1816 png_chunk_benign_error(png_ptr, "out of place");
\r
1820 else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tRNS) != 0)
\r
1822 png_crc_finish(png_ptr, length);
\r
1823 png_chunk_benign_error(png_ptr, "duplicate");
\r
1827 if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
\r
1833 png_crc_finish(png_ptr, length);
\r
1834 png_chunk_benign_error(png_ptr, "invalid");
\r
1838 png_crc_read(png_ptr, buf, 2);
\r
1839 png_ptr->num_trans = 1;
\r
1840 png_ptr->trans_color.gray = png_get_uint_16(buf);
\r
1843 else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
\r
1849 png_crc_finish(png_ptr, length);
\r
1850 png_chunk_benign_error(png_ptr, "invalid");
\r
1854 png_crc_read(png_ptr, buf, length);
\r
1855 png_ptr->num_trans = 1;
\r
1856 png_ptr->trans_color.red = png_get_uint_16(buf);
\r
1857 png_ptr->trans_color.green = png_get_uint_16(buf + 2);
\r
1858 png_ptr->trans_color.blue = png_get_uint_16(buf + 4);
\r
1861 else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
\r
1863 if ((png_ptr->mode & PNG_HAVE_PLTE) == 0)
\r
1865 /* TODO: is this actually an error in the ISO spec? */
\r
1866 png_crc_finish(png_ptr, length);
\r
1867 png_chunk_benign_error(png_ptr, "out of place");
\r
1871 if (length > (unsigned int) png_ptr->num_palette ||
\r
1872 length > (unsigned int) PNG_MAX_PALETTE_LENGTH ||
\r
1875 png_crc_finish(png_ptr, length);
\r
1876 png_chunk_benign_error(png_ptr, "invalid");
\r
1880 png_crc_read(png_ptr, readbuf, length);
\r
1881 png_ptr->num_trans = (png_uint_16)length;
\r
1886 png_crc_finish(png_ptr, length);
\r
1887 png_chunk_benign_error(png_ptr, "invalid with alpha channel");
\r
1891 if (png_crc_finish(png_ptr, 0) != 0)
\r
1893 png_ptr->num_trans = 0;
\r
1897 /* TODO: this is a horrible side effect in the palette case because the
\r
1898 * png_struct ends up with a pointer to the tRNS buffer owned by the
\r
1899 * png_info. Fix this.
\r
1901 png_set_tRNS(png_ptr, info_ptr, readbuf, png_ptr->num_trans,
\r
1902 &(png_ptr->trans_color));
\r
1906 #ifdef PNG_READ_bKGD_SUPPORTED
\r
1907 void /* PRIVATE */
\r
1908 png_handle_bKGD(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
\r
1910 unsigned int truelen;
\r
1912 png_color_16 background;
\r
1914 png_debug(1, "in png_handle_bKGD");
\r
1916 if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
\r
1917 png_chunk_error(png_ptr, "missing IHDR");
\r
1919 else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0 ||
\r
1920 (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
\r
1921 (png_ptr->mode & PNG_HAVE_PLTE) == 0))
\r
1923 png_crc_finish(png_ptr, length);
\r
1924 png_chunk_benign_error(png_ptr, "out of place");
\r
1928 else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD) != 0)
\r
1930 png_crc_finish(png_ptr, length);
\r
1931 png_chunk_benign_error(png_ptr, "duplicate");
\r
1935 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
\r
1938 else if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
\r
1944 if (length != truelen)
\r
1946 png_crc_finish(png_ptr, length);
\r
1947 png_chunk_benign_error(png_ptr, "invalid");
\r
1951 png_crc_read(png_ptr, buf, truelen);
\r
1953 if (png_crc_finish(png_ptr, 0) != 0)
\r
1956 /* We convert the index value into RGB components so that we can allow
\r
1957 * arbitrary RGB values for background when we have transparency, and
\r
1958 * so it is easy to determine the RGB values of the background color
\r
1959 * from the info_ptr struct.
\r
1961 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
\r
1963 background.index = buf[0];
\r
1965 if (info_ptr != NULL && info_ptr->num_palette != 0)
\r
1967 if (buf[0] >= info_ptr->num_palette)
\r
1969 png_chunk_benign_error(png_ptr, "invalid index");
\r
1973 background.red = (png_uint_16)png_ptr->palette[buf[0]].red;
\r
1974 background.green = (png_uint_16)png_ptr->palette[buf[0]].green;
\r
1975 background.blue = (png_uint_16)png_ptr->palette[buf[0]].blue;
\r
1979 background.red = background.green = background.blue = 0;
\r
1981 background.gray = 0;
\r
1984 else if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0) /* GRAY */
\r
1986 background.index = 0;
\r
1988 background.green =
\r
1990 background.gray = png_get_uint_16(buf);
\r
1995 background.index = 0;
\r
1996 background.red = png_get_uint_16(buf);
\r
1997 background.green = png_get_uint_16(buf + 2);
\r
1998 background.blue = png_get_uint_16(buf + 4);
\r
1999 background.gray = 0;
\r
2002 png_set_bKGD(png_ptr, info_ptr, &background);
\r
2006 #ifdef PNG_READ_hIST_SUPPORTED
\r
2007 void /* PRIVATE */
\r
2008 png_handle_hIST(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
\r
2010 unsigned int num, i;
\r
2011 png_uint_16 readbuf[PNG_MAX_PALETTE_LENGTH];
\r
2013 png_debug(1, "in png_handle_hIST");
\r
2015 if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
\r
2016 png_chunk_error(png_ptr, "missing IHDR");
\r
2018 else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0 ||
\r
2019 (png_ptr->mode & PNG_HAVE_PLTE) == 0)
\r
2021 png_crc_finish(png_ptr, length);
\r
2022 png_chunk_benign_error(png_ptr, "out of place");
\r
2026 else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST) != 0)
\r
2028 png_crc_finish(png_ptr, length);
\r
2029 png_chunk_benign_error(png_ptr, "duplicate");
\r
2033 num = length / 2 ;
\r
2035 if (num != (unsigned int) png_ptr->num_palette ||
\r
2036 num > (unsigned int) PNG_MAX_PALETTE_LENGTH)
\r
2038 png_crc_finish(png_ptr, length);
\r
2039 png_chunk_benign_error(png_ptr, "invalid");
\r
2043 for (i = 0; i < num; i++)
\r
2047 png_crc_read(png_ptr, buf, 2);
\r
2048 readbuf[i] = png_get_uint_16(buf);
\r
2051 if (png_crc_finish(png_ptr, 0) != 0)
\r
2054 png_set_hIST(png_ptr, info_ptr, readbuf);
\r
2058 #ifdef PNG_READ_pHYs_SUPPORTED
\r
2059 void /* PRIVATE */
\r
2060 png_handle_pHYs(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
\r
2063 png_uint_32 res_x, res_y;
\r
2066 png_debug(1, "in png_handle_pHYs");
\r
2068 if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
\r
2069 png_chunk_error(png_ptr, "missing IHDR");
\r
2071 else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
\r
2073 png_crc_finish(png_ptr, length);
\r
2074 png_chunk_benign_error(png_ptr, "out of place");
\r
2078 else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs) != 0)
\r
2080 png_crc_finish(png_ptr, length);
\r
2081 png_chunk_benign_error(png_ptr, "duplicate");
\r
2087 png_crc_finish(png_ptr, length);
\r
2088 png_chunk_benign_error(png_ptr, "invalid");
\r
2092 png_crc_read(png_ptr, buf, 9);
\r
2094 if (png_crc_finish(png_ptr, 0) != 0)
\r
2097 res_x = png_get_uint_32(buf);
\r
2098 res_y = png_get_uint_32(buf + 4);
\r
2099 unit_type = buf[8];
\r
2100 png_set_pHYs(png_ptr, info_ptr, res_x, res_y, unit_type);
\r
2104 #ifdef PNG_READ_oFFs_SUPPORTED
\r
2105 void /* PRIVATE */
\r
2106 png_handle_oFFs(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
\r
2109 png_int_32 offset_x, offset_y;
\r
2112 png_debug(1, "in png_handle_oFFs");
\r
2114 if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
\r
2115 png_chunk_error(png_ptr, "missing IHDR");
\r
2117 else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
\r
2119 png_crc_finish(png_ptr, length);
\r
2120 png_chunk_benign_error(png_ptr, "out of place");
\r
2124 else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs) != 0)
\r
2126 png_crc_finish(png_ptr, length);
\r
2127 png_chunk_benign_error(png_ptr, "duplicate");
\r
2133 png_crc_finish(png_ptr, length);
\r
2134 png_chunk_benign_error(png_ptr, "invalid");
\r
2138 png_crc_read(png_ptr, buf, 9);
\r
2140 if (png_crc_finish(png_ptr, 0) != 0)
\r
2143 offset_x = png_get_int_32(buf);
\r
2144 offset_y = png_get_int_32(buf + 4);
\r
2145 unit_type = buf[8];
\r
2146 png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, unit_type);
\r
2150 #ifdef PNG_READ_pCAL_SUPPORTED
\r
2151 /* Read the pCAL chunk (described in the PNG Extensions document) */
\r
2152 void /* PRIVATE */
\r
2153 png_handle_pCAL(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
\r
2155 png_int_32 X0, X1;
\r
2156 png_byte type, nparams;
\r
2157 png_bytep buffer, buf, units, endptr;
\r
2158 png_charpp params;
\r
2161 png_debug(1, "in png_handle_pCAL");
\r
2163 if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
\r
2164 png_chunk_error(png_ptr, "missing IHDR");
\r
2166 else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
\r
2168 png_crc_finish(png_ptr, length);
\r
2169 png_chunk_benign_error(png_ptr, "out of place");
\r
2173 else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_pCAL) != 0)
\r
2175 png_crc_finish(png_ptr, length);
\r
2176 png_chunk_benign_error(png_ptr, "duplicate");
\r
2180 png_debug1(2, "Allocating and reading pCAL chunk data (%u bytes)",
\r
2183 buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/);
\r
2185 if (buffer == NULL)
\r
2187 png_crc_finish(png_ptr, length);
\r
2188 png_chunk_benign_error(png_ptr, "out of memory");
\r
2192 png_crc_read(png_ptr, buffer, length);
\r
2194 if (png_crc_finish(png_ptr, 0) != 0)
\r
2197 buffer[length] = 0; /* Null terminate the last string */
\r
2199 png_debug(3, "Finding end of pCAL purpose string");
\r
2200 for (buf = buffer; *buf; buf++)
\r
2201 /* Empty loop */ ;
\r
2203 endptr = buffer + length;
\r
2205 /* We need to have at least 12 bytes after the purpose string
\r
2206 * in order to get the parameter information.
\r
2208 if (endptr - buf <= 12)
\r
2210 png_chunk_benign_error(png_ptr, "invalid");
\r
2214 png_debug(3, "Reading pCAL X0, X1, type, nparams, and units");
\r
2215 X0 = png_get_int_32((png_bytep)buf+1);
\r
2216 X1 = png_get_int_32((png_bytep)buf+5);
\r
2218 nparams = buf[10];
\r
2221 png_debug(3, "Checking pCAL equation type and number of parameters");
\r
2222 /* Check that we have the right number of parameters for known
\r
2225 if ((type == PNG_EQUATION_LINEAR && nparams != 2) ||
\r
2226 (type == PNG_EQUATION_BASE_E && nparams != 3) ||
\r
2227 (type == PNG_EQUATION_ARBITRARY && nparams != 3) ||
\r
2228 (type == PNG_EQUATION_HYPERBOLIC && nparams != 4))
\r
2230 png_chunk_benign_error(png_ptr, "invalid parameter count");
\r
2234 else if (type >= PNG_EQUATION_LAST)
\r
2236 png_chunk_benign_error(png_ptr, "unrecognized equation type");
\r
2239 for (buf = units; *buf; buf++)
\r
2240 /* Empty loop to move past the units string. */ ;
\r
2242 png_debug(3, "Allocating pCAL parameters array");
\r
2244 params = png_voidcast(png_charpp, png_malloc_warn(png_ptr,
\r
2245 nparams * (sizeof (png_charp))));
\r
2247 if (params == NULL)
\r
2249 png_chunk_benign_error(png_ptr, "out of memory");
\r
2253 /* Get pointers to the start of each parameter string. */
\r
2254 for (i = 0; i < nparams; i++)
\r
2256 buf++; /* Skip the null string terminator from previous parameter. */
\r
2258 png_debug1(3, "Reading pCAL parameter %d", i);
\r
2260 for (params[i] = (png_charp)buf; buf <= endptr && *buf != 0; buf++)
\r
2261 /* Empty loop to move past each parameter string */ ;
\r
2263 /* Make sure we haven't run out of data yet */
\r
2266 png_free(png_ptr, params);
\r
2267 png_chunk_benign_error(png_ptr, "invalid data");
\r
2272 png_set_pCAL(png_ptr, info_ptr, (png_charp)buffer, X0, X1, type, nparams,
\r
2273 (png_charp)units, params);
\r
2275 png_free(png_ptr, params);
\r
2279 #ifdef PNG_READ_sCAL_SUPPORTED
\r
2280 /* Read the sCAL chunk */
\r
2281 void /* PRIVATE */
\r
2282 png_handle_sCAL(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
\r
2288 png_debug(1, "in png_handle_sCAL");
\r
2290 if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
\r
2291 png_chunk_error(png_ptr, "missing IHDR");
\r
2293 else if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
\r
2295 png_crc_finish(png_ptr, length);
\r
2296 png_chunk_benign_error(png_ptr, "out of place");
\r
2300 else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_sCAL) != 0)
\r
2302 png_crc_finish(png_ptr, length);
\r
2303 png_chunk_benign_error(png_ptr, "duplicate");
\r
2307 /* Need unit type, width, \0, height: minimum 4 bytes */
\r
2308 else if (length < 4)
\r
2310 png_crc_finish(png_ptr, length);
\r
2311 png_chunk_benign_error(png_ptr, "invalid");
\r
2315 png_debug1(2, "Allocating and reading sCAL chunk data (%u bytes)",
\r
2318 buffer = png_read_buffer(png_ptr, length+1, 2/*silent*/);
\r
2320 if (buffer == NULL)
\r
2322 png_chunk_benign_error(png_ptr, "out of memory");
\r
2323 png_crc_finish(png_ptr, length);
\r
2327 png_crc_read(png_ptr, buffer, length);
\r
2328 buffer[length] = 0; /* Null terminate the last string */
\r
2330 if (png_crc_finish(png_ptr, 0) != 0)
\r
2333 /* Validate the unit. */
\r
2334 if (buffer[0] != 1 && buffer[0] != 2)
\r
2336 png_chunk_benign_error(png_ptr, "invalid unit");
\r
2340 /* Validate the ASCII numbers, need two ASCII numbers separated by
\r
2341 * a '\0' and they need to fit exactly in the chunk data.
\r
2346 if (png_check_fp_number((png_const_charp)buffer, length, &state, &i) == 0 ||
\r
2347 i >= length || buffer[i++] != 0)
\r
2348 png_chunk_benign_error(png_ptr, "bad width format");
\r
2350 else if (PNG_FP_IS_POSITIVE(state) == 0)
\r
2351 png_chunk_benign_error(png_ptr, "non-positive width");
\r
2355 png_size_t heighti = i;
\r
2358 if (png_check_fp_number((png_const_charp)buffer, length,
\r
2359 &state, &i) == 0 || i != length)
\r
2360 png_chunk_benign_error(png_ptr, "bad height format");
\r
2362 else if (PNG_FP_IS_POSITIVE(state) == 0)
\r
2363 png_chunk_benign_error(png_ptr, "non-positive height");
\r
2366 /* This is the (only) success case. */
\r
2367 png_set_sCAL_s(png_ptr, info_ptr, buffer[0],
\r
2368 (png_charp)buffer+1, (png_charp)buffer+heighti);
\r
2373 #ifdef PNG_READ_tIME_SUPPORTED
\r
2374 void /* PRIVATE */
\r
2375 png_handle_tIME(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
\r
2378 png_time mod_time;
\r
2380 png_debug(1, "in png_handle_tIME");
\r
2382 if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
\r
2383 png_chunk_error(png_ptr, "missing IHDR");
\r
2385 else if (info_ptr != NULL && (info_ptr->valid & PNG_INFO_tIME) != 0)
\r
2387 png_crc_finish(png_ptr, length);
\r
2388 png_chunk_benign_error(png_ptr, "duplicate");
\r
2392 if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
\r
2393 png_ptr->mode |= PNG_AFTER_IDAT;
\r
2397 png_crc_finish(png_ptr, length);
\r
2398 png_chunk_benign_error(png_ptr, "invalid");
\r
2402 png_crc_read(png_ptr, buf, 7);
\r
2404 if (png_crc_finish(png_ptr, 0) != 0)
\r
2407 mod_time.second = buf[6];
\r
2408 mod_time.minute = buf[5];
\r
2409 mod_time.hour = buf[4];
\r
2410 mod_time.day = buf[3];
\r
2411 mod_time.month = buf[2];
\r
2412 mod_time.year = png_get_uint_16(buf);
\r
2414 png_set_tIME(png_ptr, info_ptr, &mod_time);
\r
2418 #ifdef PNG_READ_tEXt_SUPPORTED
\r
2419 /* Note: this does not properly handle chunks that are > 64K under DOS */
\r
2420 void /* PRIVATE */
\r
2421 png_handle_tEXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
\r
2423 png_text text_info;
\r
2427 png_uint_32 skip = 0;
\r
2429 png_debug(1, "in png_handle_tEXt");
\r
2431 #ifdef PNG_USER_LIMITS_SUPPORTED
\r
2432 if (png_ptr->user_chunk_cache_max != 0)
\r
2434 if (png_ptr->user_chunk_cache_max == 1)
\r
2436 png_crc_finish(png_ptr, length);
\r
2440 if (--png_ptr->user_chunk_cache_max == 1)
\r
2442 png_crc_finish(png_ptr, length);
\r
2443 png_chunk_benign_error(png_ptr, "no space in chunk cache");
\r
2449 if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
\r
2450 png_chunk_error(png_ptr, "missing IHDR");
\r
2452 if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
\r
2453 png_ptr->mode |= PNG_AFTER_IDAT;
\r
2455 #ifdef PNG_MAX_MALLOC_64K
\r
2456 if (length > 65535U)
\r
2458 png_crc_finish(png_ptr, length);
\r
2459 png_chunk_benign_error(png_ptr, "too large to fit in memory");
\r
2464 buffer = png_read_buffer(png_ptr, length+1, 1/*warn*/);
\r
2466 if (buffer == NULL)
\r
2468 png_chunk_benign_error(png_ptr, "out of memory");
\r
2472 png_crc_read(png_ptr, buffer, length);
\r
2474 if (png_crc_finish(png_ptr, skip) != 0)
\r
2477 key = (png_charp)buffer;
\r
2480 for (text = key; *text; text++)
\r
2481 /* Empty loop to find end of key */ ;
\r
2483 if (text != key + length)
\r
2486 text_info.compression = PNG_TEXT_COMPRESSION_NONE;
\r
2487 text_info.key = key;
\r
2488 text_info.lang = NULL;
\r
2489 text_info.lang_key = NULL;
\r
2490 text_info.itxt_length = 0;
\r
2491 text_info.text = text;
\r
2492 text_info.text_length = strlen(text);
\r
2494 if (png_set_text_2(png_ptr, info_ptr, &text_info, 1) != 0)
\r
2495 png_warning(png_ptr, "Insufficient memory to process text chunk");
\r
2499 #ifdef PNG_READ_zTXt_SUPPORTED
\r
2500 /* Note: this does not correctly handle chunks that are > 64K under DOS */
\r
2501 void /* PRIVATE */
\r
2502 png_handle_zTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
\r
2504 png_const_charp errmsg = NULL;
\r
2506 png_uint_32 keyword_length;
\r
2508 png_debug(1, "in png_handle_zTXt");
\r
2510 #ifdef PNG_USER_LIMITS_SUPPORTED
\r
2511 if (png_ptr->user_chunk_cache_max != 0)
\r
2513 if (png_ptr->user_chunk_cache_max == 1)
\r
2515 png_crc_finish(png_ptr, length);
\r
2519 if (--png_ptr->user_chunk_cache_max == 1)
\r
2521 png_crc_finish(png_ptr, length);
\r
2522 png_chunk_benign_error(png_ptr, "no space in chunk cache");
\r
2528 if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
\r
2529 png_chunk_error(png_ptr, "missing IHDR");
\r
2531 if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
\r
2532 png_ptr->mode |= PNG_AFTER_IDAT;
\r
2534 buffer = png_read_buffer(png_ptr, length, 2/*silent*/);
\r
2536 if (buffer == NULL)
\r
2538 png_crc_finish(png_ptr, length);
\r
2539 png_chunk_benign_error(png_ptr, "out of memory");
\r
2543 png_crc_read(png_ptr, buffer, length);
\r
2545 if (png_crc_finish(png_ptr, 0) != 0)
\r
2548 /* TODO: also check that the keyword contents match the spec! */
\r
2549 for (keyword_length = 0;
\r
2550 keyword_length < length && buffer[keyword_length] != 0;
\r
2552 /* Empty loop to find end of name */ ;
\r
2554 if (keyword_length > 79 || keyword_length < 1)
\r
2555 errmsg = "bad keyword";
\r
2557 /* zTXt must have some LZ data after the keyword, although it may expand to
\r
2558 * zero bytes; we need a '\0' at the end of the keyword, the compression type
\r
2559 * then the LZ data:
\r
2561 else if (keyword_length + 3 > length)
\r
2562 errmsg = "truncated";
\r
2564 else if (buffer[keyword_length+1] != PNG_COMPRESSION_TYPE_BASE)
\r
2565 errmsg = "unknown compression type";
\r
2569 png_alloc_size_t uncompressed_length = PNG_SIZE_MAX;
\r
2571 /* TODO: at present png_decompress_chunk imposes a single application
\r
2572 * level memory limit, this should be split to different values for iCCP
\r
2573 * and text chunks.
\r
2575 if (png_decompress_chunk(png_ptr, length, keyword_length+2,
\r
2576 &uncompressed_length, 1/*terminate*/) == Z_STREAM_END)
\r
2580 /* It worked; png_ptr->read_buffer now looks like a tEXt chunk except
\r
2581 * for the extra compression type byte and the fact that it isn't
\r
2582 * necessarily '\0' terminated.
\r
2584 buffer = png_ptr->read_buffer;
\r
2585 buffer[uncompressed_length+(keyword_length+2)] = 0;
\r
2587 text.compression = PNG_TEXT_COMPRESSION_zTXt;
\r
2588 text.key = (png_charp)buffer;
\r
2589 text.text = (png_charp)(buffer + keyword_length+2);
\r
2590 text.text_length = uncompressed_length;
\r
2591 text.itxt_length = 0;
\r
2593 text.lang_key = NULL;
\r
2595 if (png_set_text_2(png_ptr, info_ptr, &text, 1) != 0)
\r
2596 errmsg = "insufficient memory";
\r
2600 errmsg = png_ptr->zstream.msg;
\r
2603 if (errmsg != NULL)
\r
2604 png_chunk_benign_error(png_ptr, errmsg);
\r
2608 #ifdef PNG_READ_iTXt_SUPPORTED
\r
2609 /* Note: this does not correctly handle chunks that are > 64K under DOS */
\r
2610 void /* PRIVATE */
\r
2611 png_handle_iTXt(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
\r
2613 png_const_charp errmsg = NULL;
\r
2615 png_uint_32 prefix_length;
\r
2617 png_debug(1, "in png_handle_iTXt");
\r
2619 #ifdef PNG_USER_LIMITS_SUPPORTED
\r
2620 if (png_ptr->user_chunk_cache_max != 0)
\r
2622 if (png_ptr->user_chunk_cache_max == 1)
\r
2624 png_crc_finish(png_ptr, length);
\r
2628 if (--png_ptr->user_chunk_cache_max == 1)
\r
2630 png_crc_finish(png_ptr, length);
\r
2631 png_chunk_benign_error(png_ptr, "no space in chunk cache");
\r
2637 if ((png_ptr->mode & PNG_HAVE_IHDR) == 0)
\r
2638 png_chunk_error(png_ptr, "missing IHDR");
\r
2640 if ((png_ptr->mode & PNG_HAVE_IDAT) != 0)
\r
2641 png_ptr->mode |= PNG_AFTER_IDAT;
\r
2643 buffer = png_read_buffer(png_ptr, length+1, 1/*warn*/);
\r
2645 if (buffer == NULL)
\r
2647 png_crc_finish(png_ptr, length);
\r
2648 png_chunk_benign_error(png_ptr, "out of memory");
\r
2652 png_crc_read(png_ptr, buffer, length);
\r
2654 if (png_crc_finish(png_ptr, 0) != 0)
\r
2657 /* First the keyword. */
\r
2658 for (prefix_length=0;
\r
2659 prefix_length < length && buffer[prefix_length] != 0;
\r
2661 /* Empty loop */ ;
\r
2663 /* Perform a basic check on the keyword length here. */
\r
2664 if (prefix_length > 79 || prefix_length < 1)
\r
2665 errmsg = "bad keyword";
\r
2667 /* Expect keyword, compression flag, compression type, language, translated
\r
2668 * keyword (both may be empty but are 0 terminated) then the text, which may
\r
2671 else if (prefix_length + 5 > length)
\r
2672 errmsg = "truncated";
\r
2674 else if (buffer[prefix_length+1] == 0 ||
\r
2675 (buffer[prefix_length+1] == 1 &&
\r
2676 buffer[prefix_length+2] == PNG_COMPRESSION_TYPE_BASE))
\r
2678 int compressed = buffer[prefix_length+1] != 0;
\r
2679 png_uint_32 language_offset, translated_keyword_offset;
\r
2680 png_alloc_size_t uncompressed_length = 0;
\r
2682 /* Now the language tag */
\r
2683 prefix_length += 3;
\r
2684 language_offset = prefix_length;
\r
2686 for (; prefix_length < length && buffer[prefix_length] != 0;
\r
2688 /* Empty loop */ ;
\r
2690 /* WARNING: the length may be invalid here, this is checked below. */
\r
2691 translated_keyword_offset = ++prefix_length;
\r
2693 for (; prefix_length < length && buffer[prefix_length] != 0;
\r
2695 /* Empty loop */ ;
\r
2697 /* prefix_length should now be at the trailing '\0' of the translated
\r
2698 * keyword, but it may already be over the end. None of this arithmetic
\r
2699 * can overflow because chunks are at most 2^31 bytes long, but on 16-bit
\r
2700 * systems the available allocation may overflow.
\r
2704 if (compressed == 0 && prefix_length <= length)
\r
2705 uncompressed_length = length - prefix_length;
\r
2707 else if (compressed != 0 && prefix_length < length)
\r
2709 uncompressed_length = PNG_SIZE_MAX;
\r
2711 /* TODO: at present png_decompress_chunk imposes a single application
\r
2712 * level memory limit, this should be split to different values for
\r
2713 * iCCP and text chunks.
\r
2715 if (png_decompress_chunk(png_ptr, length, prefix_length,
\r
2716 &uncompressed_length, 1/*terminate*/) == Z_STREAM_END)
\r
2717 buffer = png_ptr->read_buffer;
\r
2720 errmsg = png_ptr->zstream.msg;
\r
2724 errmsg = "truncated";
\r
2726 if (errmsg == NULL)
\r
2730 buffer[uncompressed_length+prefix_length] = 0;
\r
2732 if (compressed == 0)
\r
2733 text.compression = PNG_ITXT_COMPRESSION_NONE;
\r
2736 text.compression = PNG_ITXT_COMPRESSION_zTXt;
\r
2738 text.key = (png_charp)buffer;
\r
2739 text.lang = (png_charp)buffer + language_offset;
\r
2740 text.lang_key = (png_charp)buffer + translated_keyword_offset;
\r
2741 text.text = (png_charp)buffer + prefix_length;
\r
2742 text.text_length = 0;
\r
2743 text.itxt_length = uncompressed_length;
\r
2745 if (png_set_text_2(png_ptr, info_ptr, &text, 1) != 0)
\r
2746 errmsg = "insufficient memory";
\r
2751 errmsg = "bad compression info";
\r
2753 if (errmsg != NULL)
\r
2754 png_chunk_benign_error(png_ptr, errmsg);
\r
2758 #ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
\r
2759 /* Utility function for png_handle_unknown; set up png_ptr::unknown_chunk */
\r
2761 png_cache_unknown_chunk(png_structrp png_ptr, png_uint_32 length)
\r
2763 png_alloc_size_t limit = PNG_SIZE_MAX;
\r
2765 if (png_ptr->unknown_chunk.data != NULL)
\r
2767 png_free(png_ptr, png_ptr->unknown_chunk.data);
\r
2768 png_ptr->unknown_chunk.data = NULL;
\r
2771 # ifdef PNG_SET_USER_LIMITS_SUPPORTED
\r
2772 if (png_ptr->user_chunk_malloc_max > 0 &&
\r
2773 png_ptr->user_chunk_malloc_max < limit)
\r
2774 limit = png_ptr->user_chunk_malloc_max;
\r
2776 # elif PNG_USER_CHUNK_MALLOC_MAX > 0
\r
2777 if (PNG_USER_CHUNK_MALLOC_MAX < limit)
\r
2778 limit = PNG_USER_CHUNK_MALLOC_MAX;
\r
2781 if (length <= limit)
\r
2783 PNG_CSTRING_FROM_CHUNK(png_ptr->unknown_chunk.name, png_ptr->chunk_name);
\r
2784 /* The following is safe because of the PNG_SIZE_MAX init above */
\r
2785 png_ptr->unknown_chunk.size = (png_size_t)length/*SAFE*/;
\r
2786 /* 'mode' is a flag array, only the bottom four bits matter here */
\r
2787 png_ptr->unknown_chunk.location = (png_byte)png_ptr->mode/*SAFE*/;
\r
2790 png_ptr->unknown_chunk.data = NULL;
\r
2794 /* Do a 'warn' here - it is handled below. */
\r
2795 png_ptr->unknown_chunk.data = png_voidcast(png_bytep,
\r
2796 png_malloc_warn(png_ptr, length));
\r
2800 if (png_ptr->unknown_chunk.data == NULL && length > 0)
\r
2802 /* This is benign because we clean up correctly */
\r
2803 png_crc_finish(png_ptr, length);
\r
2804 png_chunk_benign_error(png_ptr, "unknown chunk exceeds memory limits");
\r
2811 png_crc_read(png_ptr, png_ptr->unknown_chunk.data, length);
\r
2812 png_crc_finish(png_ptr, 0);
\r
2816 #endif /* READ_UNKNOWN_CHUNKS */
\r
2818 /* Handle an unknown, or known but disabled, chunk */
\r
2819 void /* PRIVATE */
\r
2820 png_handle_unknown(png_structrp png_ptr, png_inforp info_ptr,
\r
2821 png_uint_32 length, int keep)
\r
2823 int handled = 0; /* the chunk was handled */
\r
2825 png_debug(1, "in png_handle_unknown");
\r
2827 #ifdef PNG_READ_UNKNOWN_CHUNKS_SUPPORTED
\r
2828 /* NOTE: this code is based on the code in libpng-1.4.12 except for fixing
\r
2829 * the bug which meant that setting a non-default behavior for a specific
\r
2830 * chunk would be ignored (the default was always used unless a user
\r
2831 * callback was installed).
\r
2833 * 'keep' is the value from the png_chunk_unknown_handling, the setting for
\r
2834 * this specific chunk_name, if PNG_HANDLE_AS_UNKNOWN_SUPPORTED, if not it
\r
2835 * will always be PNG_HANDLE_CHUNK_AS_DEFAULT and it needs to be set here.
\r
2836 * This is just an optimization to avoid multiple calls to the lookup
\r
2839 # ifndef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
\r
2840 # ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
\r
2841 keep = png_chunk_unknown_handling(png_ptr, png_ptr->chunk_name);
\r
2845 /* One of the following methods will read the chunk or skip it (at least one
\r
2846 * of these is always defined because this is the only way to switch on
\r
2847 * PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
\r
2849 # ifdef PNG_READ_USER_CHUNKS_SUPPORTED
\r
2850 /* The user callback takes precedence over the chunk keep value, but the
\r
2851 * keep value is still required to validate a save of a critical chunk.
\r
2853 if (png_ptr->read_user_chunk_fn != NULL)
\r
2855 if (png_cache_unknown_chunk(png_ptr, length) != 0)
\r
2857 /* Callback to user unknown chunk handler */
\r
2858 int ret = (*(png_ptr->read_user_chunk_fn))(png_ptr,
\r
2859 &png_ptr->unknown_chunk);
\r
2862 * negative: An error occurred; png_chunk_error will be called.
\r
2863 * zero: The chunk was not handled, the chunk will be discarded
\r
2864 * unless png_set_keep_unknown_chunks has been used to set
\r
2865 * a 'keep' behavior for this particular chunk, in which
\r
2866 * case that will be used. A critical chunk will cause an
\r
2867 * error at this point unless it is to be saved.
\r
2868 * positive: The chunk was handled, libpng will ignore/discard it.
\r
2871 png_chunk_error(png_ptr, "error in user chunk");
\r
2873 else if (ret == 0)
\r
2875 /* If the keep value is 'default' or 'never' override it, but
\r
2876 * still error out on critical chunks unless the keep value is
\r
2877 * 'always' While this is weird it is the behavior in 1.4.12.
\r
2878 * A possible improvement would be to obey the value set for the
\r
2879 * chunk, but this would be an API change that would probably
\r
2880 * damage some applications.
\r
2882 * The png_app_warning below catches the case that matters, where
\r
2883 * the application has not set specific save or ignore for this
\r
2884 * chunk or global save or ignore.
\r
2886 if (keep < PNG_HANDLE_CHUNK_IF_SAFE)
\r
2888 # ifdef PNG_SET_UNKNOWN_CHUNKS_SUPPORTED
\r
2889 if (png_ptr->unknown_default < PNG_HANDLE_CHUNK_IF_SAFE)
\r
2891 png_chunk_warning(png_ptr, "Saving unknown chunk:");
\r
2892 png_app_warning(png_ptr,
\r
2893 "forcing save of an unhandled chunk;"
\r
2894 " please call png_set_keep_unknown_chunks");
\r
2895 /* with keep = PNG_HANDLE_CHUNK_IF_SAFE */
\r
2898 keep = PNG_HANDLE_CHUNK_IF_SAFE;
\r
2902 else /* chunk was handled */
\r
2905 /* Critical chunks can be safely discarded at this point. */
\r
2906 keep = PNG_HANDLE_CHUNK_NEVER;
\r
2911 keep = PNG_HANDLE_CHUNK_NEVER; /* insufficient memory */
\r
2915 /* Use the SAVE_UNKNOWN_CHUNKS code or skip the chunk */
\r
2916 # endif /* READ_USER_CHUNKS */
\r
2918 # ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
\r
2920 /* keep is currently just the per-chunk setting, if there was no
\r
2921 * setting change it to the global default now (not that this may
\r
2922 * still be AS_DEFAULT) then obtain the cache of the chunk if required,
\r
2923 * if not simply skip the chunk.
\r
2925 if (keep == PNG_HANDLE_CHUNK_AS_DEFAULT)
\r
2926 keep = png_ptr->unknown_default;
\r
2928 if (keep == PNG_HANDLE_CHUNK_ALWAYS ||
\r
2929 (keep == PNG_HANDLE_CHUNK_IF_SAFE &&
\r
2930 PNG_CHUNK_ANCILLARY(png_ptr->chunk_name)))
\r
2932 if (png_cache_unknown_chunk(png_ptr, length) == 0)
\r
2933 keep = PNG_HANDLE_CHUNK_NEVER;
\r
2937 png_crc_finish(png_ptr, length);
\r
2940 # ifndef PNG_READ_USER_CHUNKS_SUPPORTED
\r
2941 # error no method to support READ_UNKNOWN_CHUNKS
\r
2945 /* If here there is no read callback pointer set and no support is
\r
2946 * compiled in to just save the unknown chunks, so simply skip this
\r
2947 * chunk. If 'keep' is something other than AS_DEFAULT or NEVER then
\r
2948 * the app has erroneously asked for unknown chunk saving when there
\r
2951 if (keep > PNG_HANDLE_CHUNK_NEVER)
\r
2952 png_app_error(png_ptr, "no unknown chunk support available");
\r
2954 png_crc_finish(png_ptr, length);
\r
2958 # ifdef PNG_STORE_UNKNOWN_CHUNKS_SUPPORTED
\r
2959 /* Now store the chunk in the chunk list if appropriate, and if the limits
\r
2962 if (keep == PNG_HANDLE_CHUNK_ALWAYS ||
\r
2963 (keep == PNG_HANDLE_CHUNK_IF_SAFE &&
\r
2964 PNG_CHUNK_ANCILLARY(png_ptr->chunk_name)))
\r
2966 # ifdef PNG_USER_LIMITS_SUPPORTED
\r
2967 switch (png_ptr->user_chunk_cache_max)
\r
2970 png_ptr->user_chunk_cache_max = 1;
\r
2971 png_chunk_benign_error(png_ptr, "no space in chunk cache");
\r
2972 /* FALL THROUGH */
\r
2974 /* NOTE: prior to 1.6.0 this case resulted in an unknown critical
\r
2975 * chunk being skipped, now there will be a hard error below.
\r
2979 default: /* not at limit */
\r
2980 --(png_ptr->user_chunk_cache_max);
\r
2981 /* FALL THROUGH */
\r
2982 case 0: /* no limit */
\r
2983 # endif /* USER_LIMITS */
\r
2984 /* Here when the limit isn't reached or when limits are compiled
\r
2985 * out; store the chunk.
\r
2987 png_set_unknown_chunks(png_ptr, info_ptr,
\r
2988 &png_ptr->unknown_chunk, 1);
\r
2990 # ifdef PNG_USER_LIMITS_SUPPORTED
\r
2995 # else /* no store support: the chunk must be handled by the user callback */
\r
2996 PNG_UNUSED(info_ptr)
\r
2999 /* Regardless of the error handling below the cached data (if any) can be
\r
3000 * freed now. Notice that the data is not freed if there is a png_error, but
\r
3001 * it will be freed by destroy_read_struct.
\r
3003 if (png_ptr->unknown_chunk.data != NULL)
\r
3004 png_free(png_ptr, png_ptr->unknown_chunk.data);
\r
3005 png_ptr->unknown_chunk.data = NULL;
\r
3007 #else /* !PNG_READ_UNKNOWN_CHUNKS_SUPPORTED */
\r
3008 /* There is no support to read an unknown chunk, so just skip it. */
\r
3009 png_crc_finish(png_ptr, length);
\r
3010 PNG_UNUSED(info_ptr)
\r
3012 #endif /* !READ_UNKNOWN_CHUNKS */
\r
3014 /* Check for unhandled critical chunks */
\r
3015 if (handled == 0 && PNG_CHUNK_CRITICAL(png_ptr->chunk_name))
\r
3016 png_chunk_error(png_ptr, "unhandled critical chunk");
\r
3019 /* This function is called to verify that a chunk name is valid.
\r
3020 * This function can't have the "critical chunk check" incorporated
\r
3021 * into it, since in the future we will need to be able to call user
\r
3022 * functions to handle unknown critical chunks after we check that
\r
3023 * the chunk name itself is valid.
\r
3026 /* Bit hacking: the test for an invalid byte in the 4 byte chunk name is:
\r
3028 * ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
\r
3031 void /* PRIVATE */
\r
3032 png_check_chunk_name(png_structrp png_ptr, png_uint_32 chunk_name)
\r
3036 png_debug(1, "in png_check_chunk_name");
\r
3038 for (i=1; i<=4; ++i)
\r
3040 int c = chunk_name & 0xff;
\r
3042 if (c < 65 || c > 122 || (c > 90 && c < 97))
\r
3043 png_chunk_error(png_ptr, "invalid chunk type");
\r
3049 /* Combines the row recently read in with the existing pixels in the row. This
\r
3050 * routine takes care of alpha and transparency if requested. This routine also
\r
3051 * handles the two methods of progressive display of interlaced images,
\r
3052 * depending on the 'display' value; if 'display' is true then the whole row
\r
3053 * (dp) is filled from the start by replicating the available pixels. If
\r
3054 * 'display' is false only those pixels present in the pass are filled in.
\r
3056 void /* PRIVATE */
\r
3057 png_combine_row(png_const_structrp png_ptr, png_bytep dp, int display)
\r
3059 unsigned int pixel_depth = png_ptr->transformed_pixel_depth;
\r
3060 png_const_bytep sp = png_ptr->row_buf + 1;
\r
3061 png_alloc_size_t row_width = png_ptr->width;
\r
3062 unsigned int pass = png_ptr->pass;
\r
3063 png_bytep end_ptr = 0;
\r
3064 png_byte end_byte = 0;
\r
3065 unsigned int end_mask;
\r
3067 png_debug(1, "in png_combine_row");
\r
3069 /* Added in 1.5.6: it should not be possible to enter this routine until at
\r
3070 * least one row has been read from the PNG data and transformed.
\r
3072 if (pixel_depth == 0)
\r
3073 png_error(png_ptr, "internal row logic error");
\r
3075 /* Added in 1.5.4: the pixel depth should match the information returned by
\r
3076 * any call to png_read_update_info at this point. Do not continue if we got
\r
3079 if (png_ptr->info_rowbytes != 0 && png_ptr->info_rowbytes !=
\r
3080 PNG_ROWBYTES(pixel_depth, row_width))
\r
3081 png_error(png_ptr, "internal row size calculation error");
\r
3083 /* Don't expect this to ever happen: */
\r
3084 if (row_width == 0)
\r
3085 png_error(png_ptr, "internal row width error");
\r
3087 /* Preserve the last byte in cases where only part of it will be overwritten,
\r
3088 * the multiply below may overflow, we don't care because ANSI-C guarantees
\r
3089 * we get the low bits.
\r
3091 end_mask = (pixel_depth * row_width) & 7;
\r
3092 if (end_mask != 0)
\r
3094 /* end_ptr == NULL is a flag to say do nothing */
\r
3095 end_ptr = dp + PNG_ROWBYTES(pixel_depth, row_width) - 1;
\r
3096 end_byte = *end_ptr;
\r
3097 # ifdef PNG_READ_PACKSWAP_SUPPORTED
\r
3098 if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
\r
3099 /* little-endian byte */
\r
3100 end_mask = 0xff << end_mask;
\r
3102 else /* big-endian byte */
\r
3104 end_mask = 0xff >> end_mask;
\r
3105 /* end_mask is now the bits to *keep* from the destination row */
\r
3108 /* For non-interlaced images this reduces to a memcpy(). A memcpy()
\r
3109 * will also happen if interlacing isn't supported or if the application
\r
3110 * does not call png_set_interlace_handling(). In the latter cases the
\r
3111 * caller just gets a sequence of the unexpanded rows from each interlace
\r
3114 #ifdef PNG_READ_INTERLACING_SUPPORTED
\r
3115 if (png_ptr->interlaced != 0 &&
\r
3116 (png_ptr->transformations & PNG_INTERLACE) != 0 &&
\r
3117 pass < 6 && (display == 0 ||
\r
3118 /* The following copies everything for 'display' on passes 0, 2 and 4. */
\r
3119 (display == 1 && (pass & 1) != 0)))
\r
3121 /* Narrow images may have no bits in a pass; the caller should handle
\r
3122 * this, but this test is cheap:
\r
3124 if (row_width <= PNG_PASS_START_COL(pass))
\r
3127 if (pixel_depth < 8)
\r
3129 /* For pixel depths up to 4 bpp the 8-pixel mask can be expanded to fit
\r
3130 * into 32 bits, then a single loop over the bytes using the four byte
\r
3131 * values in the 32-bit mask can be used. For the 'display' option the
\r
3132 * expanded mask may also not require any masking within a byte. To
\r
3133 * make this work the PACKSWAP option must be taken into account - it
\r
3134 * simply requires the pixels to be reversed in each byte.
\r
3136 * The 'regular' case requires a mask for each of the first 6 passes,
\r
3137 * the 'display' case does a copy for the even passes in the range
\r
3138 * 0..6. This has already been handled in the test above.
\r
3140 * The masks are arranged as four bytes with the first byte to use in
\r
3141 * the lowest bits (little-endian) regardless of the order (PACKSWAP or
\r
3142 * not) of the pixels in each byte.
\r
3144 * NOTE: the whole of this logic depends on the caller of this function
\r
3145 * only calling it on rows appropriate to the pass. This function only
\r
3146 * understands the 'x' logic; the 'y' logic is handled by the caller.
\r
3148 * The following defines allow generation of compile time constant bit
\r
3149 * masks for each pixel depth and each possibility of swapped or not
\r
3150 * swapped bytes. Pass 'p' is in the range 0..6; 'x', a pixel index,
\r
3151 * is in the range 0..7; and the result is 1 if the pixel is to be
\r
3152 * copied in the pass, 0 if not. 'S' is for the sparkle method, 'B'
\r
3153 * for the block method.
\r
3155 * With some compilers a compile time expression of the general form:
\r
3157 * (shift >= 32) ? (a >> (shift-32)) : (b >> shift)
\r
3159 * Produces warnings with values of 'shift' in the range 33 to 63
\r
3160 * because the right hand side of the ?: expression is evaluated by
\r
3161 * the compiler even though it isn't used. Microsoft Visual C (various
\r
3162 * versions) and the Intel C compiler are known to do this. To avoid
\r
3163 * this the following macros are used in 1.5.6. This is a temporary
\r
3164 * solution to avoid destabilizing the code during the release process.
\r
3166 # if PNG_USE_COMPILE_TIME_MASKS
\r
3167 # define PNG_LSR(x,s) ((x)>>((s) & 0x1f))
\r
3168 # define PNG_LSL(x,s) ((x)<<((s) & 0x1f))
\r
3170 # define PNG_LSR(x,s) ((x)>>(s))
\r
3171 # define PNG_LSL(x,s) ((x)<<(s))
\r
3173 # define S_COPY(p,x) (((p)<4 ? PNG_LSR(0x80088822,(3-(p))*8+(7-(x))) :\
\r
3174 PNG_LSR(0xaa55ff00,(7-(p))*8+(7-(x)))) & 1)
\r
3175 # define B_COPY(p,x) (((p)<4 ? PNG_LSR(0xff0fff33,(3-(p))*8+(7-(x))) :\
\r
3176 PNG_LSR(0xff55ff00,(7-(p))*8+(7-(x)))) & 1)
\r
3178 /* Return a mask for pass 'p' pixel 'x' at depth 'd'. The mask is
\r
3179 * little endian - the first pixel is at bit 0 - however the extra
\r
3180 * parameter 's' can be set to cause the mask position to be swapped
\r
3181 * within each byte, to match the PNG format. This is done by XOR of
\r
3182 * the shift with 7, 6 or 4 for bit depths 1, 2 and 4.
\r
3184 # define PIXEL_MASK(p,x,d,s) \
\r
3185 (PNG_LSL(((PNG_LSL(1U,(d)))-1),(((x)*(d))^((s)?8-(d):0))))
\r
3187 /* Hence generate the appropriate 'block' or 'sparkle' pixel copy mask.
\r
3189 # define S_MASKx(p,x,d,s) (S_COPY(p,x)?PIXEL_MASK(p,x,d,s):0)
\r
3190 # define B_MASKx(p,x,d,s) (B_COPY(p,x)?PIXEL_MASK(p,x,d,s):0)
\r
3192 /* Combine 8 of these to get the full mask. For the 1-bpp and 2-bpp
\r
3193 * cases the result needs replicating, for the 4-bpp case the above
\r
3194 * generates a full 32 bits.
\r
3196 # define MASK_EXPAND(m,d) ((m)*((d)==1?0x01010101:((d)==2?0x00010001:1)))
\r
3198 # define S_MASK(p,d,s) MASK_EXPAND(S_MASKx(p,0,d,s) + S_MASKx(p,1,d,s) +\
\r
3199 S_MASKx(p,2,d,s) + S_MASKx(p,3,d,s) + S_MASKx(p,4,d,s) +\
\r
3200 S_MASKx(p,5,d,s) + S_MASKx(p,6,d,s) + S_MASKx(p,7,d,s), d)
\r
3202 # define B_MASK(p,d,s) MASK_EXPAND(B_MASKx(p,0,d,s) + B_MASKx(p,1,d,s) +\
\r
3203 B_MASKx(p,2,d,s) + B_MASKx(p,3,d,s) + B_MASKx(p,4,d,s) +\
\r
3204 B_MASKx(p,5,d,s) + B_MASKx(p,6,d,s) + B_MASKx(p,7,d,s), d)
\r
3206 #if PNG_USE_COMPILE_TIME_MASKS
\r
3207 /* Utility macros to construct all the masks for a depth/swap
\r
3208 * combination. The 's' parameter says whether the format is PNG
\r
3209 * (big endian bytes) or not. Only the three odd-numbered passes are
\r
3210 * required for the display/block algorithm.
\r
3212 # define S_MASKS(d,s) { S_MASK(0,d,s), S_MASK(1,d,s), S_MASK(2,d,s),\
\r
3213 S_MASK(3,d,s), S_MASK(4,d,s), S_MASK(5,d,s) }
\r
3215 # define B_MASKS(d,s) { B_MASK(1,d,s), B_MASK(3,d,s), B_MASK(5,d,s) }
\r
3217 # define DEPTH_INDEX(d) ((d)==1?0:((d)==2?1:2))
\r
3219 /* Hence the pre-compiled masks indexed by PACKSWAP (or not), depth and
\r
3222 static PNG_CONST png_uint_32 row_mask[2/*PACKSWAP*/][3/*depth*/][6] =
\r
3224 /* Little-endian byte masks for PACKSWAP */
\r
3225 { S_MASKS(1,0), S_MASKS(2,0), S_MASKS(4,0) },
\r
3226 /* Normal (big-endian byte) masks - PNG format */
\r
3227 { S_MASKS(1,1), S_MASKS(2,1), S_MASKS(4,1) }
\r
3230 /* display_mask has only three entries for the odd passes, so index by
\r
3233 static PNG_CONST png_uint_32 display_mask[2][3][3] =
\r
3235 /* Little-endian byte masks for PACKSWAP */
\r
3236 { B_MASKS(1,0), B_MASKS(2,0), B_MASKS(4,0) },
\r
3237 /* Normal (big-endian byte) masks - PNG format */
\r
3238 { B_MASKS(1,1), B_MASKS(2,1), B_MASKS(4,1) }
\r
3241 # define MASK(pass,depth,display,png)\
\r
3242 ((display)?display_mask[png][DEPTH_INDEX(depth)][pass>>1]:\
\r
3243 row_mask[png][DEPTH_INDEX(depth)][pass])
\r
3245 #else /* !PNG_USE_COMPILE_TIME_MASKS */
\r
3246 /* This is the runtime alternative: it seems unlikely that this will
\r
3247 * ever be either smaller or faster than the compile time approach.
\r
3249 # define MASK(pass,depth,display,png)\
\r
3250 ((display)?B_MASK(pass,depth,png):S_MASK(pass,depth,png))
\r
3251 #endif /* !USE_COMPILE_TIME_MASKS */
\r
3253 /* Use the appropriate mask to copy the required bits. In some cases
\r
3254 * the byte mask will be 0 or 0xff; optimize these cases. row_width is
\r
3255 * the number of pixels, but the code copies bytes, so it is necessary
\r
3256 * to special case the end.
\r
3258 png_uint_32 pixels_per_byte = 8 / pixel_depth;
\r
3261 # ifdef PNG_READ_PACKSWAP_SUPPORTED
\r
3262 if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
\r
3263 mask = MASK(pass, pixel_depth, display, 0);
\r
3267 mask = MASK(pass, pixel_depth, display, 1);
\r
3273 /* It doesn't matter in the following if png_uint_32 has more than
\r
3274 * 32 bits because the high bits always match those in m<<24; it is,
\r
3275 * however, essential to use OR here, not +, because of this.
\r
3278 mask = (m >> 8) | (m << 24); /* rotate right to good compilers */
\r
3281 if (m != 0) /* something to copy */
\r
3284 *dp = (png_byte)((*dp & ~m) | (*sp & m));
\r
3289 /* NOTE: this may overwrite the last byte with garbage if the image
\r
3290 * is not an exact number of bytes wide; libpng has always done
\r
3293 if (row_width <= pixels_per_byte)
\r
3294 break; /* May need to restore part of the last byte */
\r
3296 row_width -= pixels_per_byte;
\r
3302 else /* pixel_depth >= 8 */
\r
3304 unsigned int bytes_to_copy, bytes_to_jump;
\r
3306 /* Validate the depth - it must be a multiple of 8 */
\r
3307 if (pixel_depth & 7)
\r
3308 png_error(png_ptr, "invalid user transform pixel depth");
\r
3310 pixel_depth >>= 3; /* now in bytes */
\r
3311 row_width *= pixel_depth;
\r
3313 /* Regardless of pass number the Adam 7 interlace always results in a
\r
3314 * fixed number of pixels to copy then to skip. There may be a
\r
3315 * different number of pixels to skip at the start though.
\r
3318 unsigned int offset = PNG_PASS_START_COL(pass) * pixel_depth;
\r
3320 row_width -= offset;
\r
3325 /* Work out the bytes to copy. */
\r
3328 /* When doing the 'block' algorithm the pixel in the pass gets
\r
3329 * replicated to adjacent pixels. This is why the even (0,2,4,6)
\r
3330 * passes are skipped above - the entire expanded row is copied.
\r
3332 bytes_to_copy = (1<<((6-pass)>>1)) * pixel_depth;
\r
3334 /* But don't allow this number to exceed the actual row width. */
\r
3335 if (bytes_to_copy > row_width)
\r
3336 bytes_to_copy = (unsigned int)/*SAFE*/row_width;
\r
3339 else /* normal row; Adam7 only ever gives us one pixel to copy. */
\r
3340 bytes_to_copy = pixel_depth;
\r
3342 /* In Adam7 there is a constant offset between where the pixels go. */
\r
3343 bytes_to_jump = PNG_PASS_COL_OFFSET(pass) * pixel_depth;
\r
3345 /* And simply copy these bytes. Some optimization is possible here,
\r
3346 * depending on the value of 'bytes_to_copy'. Special case the low
\r
3347 * byte counts, which we know to be frequent.
\r
3349 * Notice that these cases all 'return' rather than 'break' - this
\r
3350 * avoids an unnecessary test on whether to restore the last byte
\r
3353 switch (bytes_to_copy)
\r
3360 if (row_width <= bytes_to_jump)
\r
3363 dp += bytes_to_jump;
\r
3364 sp += bytes_to_jump;
\r
3365 row_width -= bytes_to_jump;
\r
3369 /* There is a possibility of a partial copy at the end here; this
\r
3370 * slows the code down somewhat.
\r
3374 dp[0] = sp[0], dp[1] = sp[1];
\r
3376 if (row_width <= bytes_to_jump)
\r
3379 sp += bytes_to_jump;
\r
3380 dp += bytes_to_jump;
\r
3381 row_width -= bytes_to_jump;
\r
3383 while (row_width > 1);
\r
3385 /* And there can only be one byte left at this point: */
\r
3390 /* This can only be the RGB case, so each copy is exactly one
\r
3391 * pixel and it is not necessary to check for a partial copy.
\r
3395 dp[0] = sp[0], dp[1] = sp[1], dp[2] = sp[2];
\r
3397 if (row_width <= bytes_to_jump)
\r
3400 sp += bytes_to_jump;
\r
3401 dp += bytes_to_jump;
\r
3402 row_width -= bytes_to_jump;
\r
3406 #if PNG_ALIGN_TYPE != PNG_ALIGN_NONE
\r
3407 /* Check for double byte alignment and, if possible, use a
\r
3408 * 16-bit copy. Don't attempt this for narrow images - ones that
\r
3409 * are less than an interlace panel wide. Don't attempt it for
\r
3410 * wide bytes_to_copy either - use the memcpy there.
\r
3412 if (bytes_to_copy < 16 /*else use memcpy*/ &&
\r
3413 png_isaligned(dp, png_uint_16) &&
\r
3414 png_isaligned(sp, png_uint_16) &&
\r
3415 bytes_to_copy % (sizeof (png_uint_16)) == 0 &&
\r
3416 bytes_to_jump % (sizeof (png_uint_16)) == 0)
\r
3418 /* Everything is aligned for png_uint_16 copies, but try for
\r
3419 * png_uint_32 first.
\r
3421 if (png_isaligned(dp, png_uint_32) != 0 &&
\r
3422 png_isaligned(sp, png_uint_32) != 0 &&
\r
3423 bytes_to_copy % (sizeof (png_uint_32)) == 0 &&
\r
3424 bytes_to_jump % (sizeof (png_uint_32)) == 0)
\r
3426 png_uint_32p dp32 = png_aligncast(png_uint_32p,dp);
\r
3427 png_const_uint_32p sp32 = png_aligncastconst(
\r
3428 png_const_uint_32p, sp);
\r
3429 size_t skip = (bytes_to_jump-bytes_to_copy) /
\r
3430 (sizeof (png_uint_32));
\r
3434 size_t c = bytes_to_copy;
\r
3437 *dp32++ = *sp32++;
\r
3438 c -= (sizeof (png_uint_32));
\r
3442 if (row_width <= bytes_to_jump)
\r
3447 row_width -= bytes_to_jump;
\r
3449 while (bytes_to_copy <= row_width);
\r
3451 /* Get to here when the row_width truncates the final copy.
\r
3452 * There will be 1-3 bytes left to copy, so don't try the
\r
3453 * 16-bit loop below.
\r
3455 dp = (png_bytep)dp32;
\r
3456 sp = (png_const_bytep)sp32;
\r
3459 while (--row_width > 0);
\r
3463 /* Else do it in 16-bit quantities, but only if the size is
\r
3468 png_uint_16p dp16 = png_aligncast(png_uint_16p, dp);
\r
3469 png_const_uint_16p sp16 = png_aligncastconst(
\r
3470 png_const_uint_16p, sp);
\r
3471 size_t skip = (bytes_to_jump-bytes_to_copy) /
\r
3472 (sizeof (png_uint_16));
\r
3476 size_t c = bytes_to_copy;
\r
3479 *dp16++ = *sp16++;
\r
3480 c -= (sizeof (png_uint_16));
\r
3484 if (row_width <= bytes_to_jump)
\r
3489 row_width -= bytes_to_jump;
\r
3491 while (bytes_to_copy <= row_width);
\r
3493 /* End of row - 1 byte left, bytes_to_copy > row_width: */
\r
3494 dp = (png_bytep)dp16;
\r
3495 sp = (png_const_bytep)sp16;
\r
3498 while (--row_width > 0);
\r
3502 #endif /* ALIGN_TYPE code */
\r
3504 /* The true default - use a memcpy: */
\r
3507 memcpy(dp, sp, bytes_to_copy);
\r
3509 if (row_width <= bytes_to_jump)
\r
3512 sp += bytes_to_jump;
\r
3513 dp += bytes_to_jump;
\r
3514 row_width -= bytes_to_jump;
\r
3515 if (bytes_to_copy > row_width)
\r
3516 bytes_to_copy = (unsigned int)/*SAFE*/row_width;
\r
3521 } /* pixel_depth >= 8 */
\r
3523 /* Here if pixel_depth < 8 to check 'end_ptr' below. */
\r
3526 #endif /* READ_INTERLACING */
\r
3528 /* If here then the switch above wasn't used so just memcpy the whole row
\r
3529 * from the temporary row buffer (notice that this overwrites the end of the
\r
3530 * destination row if it is a partial byte.)
\r
3532 memcpy(dp, sp, PNG_ROWBYTES(pixel_depth, row_width));
\r
3534 /* Restore the overwritten bits from the last byte if necessary. */
\r
3535 if (end_ptr != NULL)
\r
3536 *end_ptr = (png_byte)((end_byte & end_mask) | (*end_ptr & ~end_mask));
\r
3539 #ifdef PNG_READ_INTERLACING_SUPPORTED
\r
3540 void /* PRIVATE */
\r
3541 png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass,
\r
3542 png_uint_32 transformations /* Because these may affect the byte layout */)
\r
3544 /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
\r
3545 /* Offset to next interlace block */
\r
3546 static PNG_CONST int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
\r
3548 png_debug(1, "in png_do_read_interlace");
\r
3549 if (row != NULL && row_info != NULL)
\r
3551 png_uint_32 final_width;
\r
3553 final_width = row_info->width * png_pass_inc[pass];
\r
3555 switch (row_info->pixel_depth)
\r
3559 png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 3);
\r
3560 png_bytep dp = row + (png_size_t)((final_width - 1) >> 3);
\r
3561 int sshift, dshift;
\r
3562 int s_start, s_end, s_inc;
\r
3563 int jstop = png_pass_inc[pass];
\r
3568 #ifdef PNG_READ_PACKSWAP_SUPPORTED
\r
3569 if ((transformations & PNG_PACKSWAP) != 0)
\r
3571 sshift = (int)((row_info->width + 7) & 0x07);
\r
3572 dshift = (int)((final_width + 7) & 0x07);
\r
3581 sshift = 7 - (int)((row_info->width + 7) & 0x07);
\r
3582 dshift = 7 - (int)((final_width + 7) & 0x07);
\r
3588 for (i = 0; i < row_info->width; i++)
\r
3590 v = (png_byte)((*sp >> sshift) & 0x01);
\r
3591 for (j = 0; j < jstop; j++)
\r
3593 unsigned int tmp = *dp & (0x7f7f >> (7 - dshift));
\r
3594 tmp |= v << dshift;
\r
3595 *dp = (png_byte)(tmp & 0xff);
\r
3597 if (dshift == s_end)
\r
3607 if (sshift == s_end)
\r
3621 png_bytep sp = row + (png_uint_32)((row_info->width - 1) >> 2);
\r
3622 png_bytep dp = row + (png_uint_32)((final_width - 1) >> 2);
\r
3623 int sshift, dshift;
\r
3624 int s_start, s_end, s_inc;
\r
3625 int jstop = png_pass_inc[pass];
\r
3628 #ifdef PNG_READ_PACKSWAP_SUPPORTED
\r
3629 if ((transformations & PNG_PACKSWAP) != 0)
\r
3631 sshift = (int)(((row_info->width + 3) & 0x03) << 1);
\r
3632 dshift = (int)(((final_width + 3) & 0x03) << 1);
\r
3641 sshift = (int)((3 - ((row_info->width + 3) & 0x03)) << 1);
\r
3642 dshift = (int)((3 - ((final_width + 3) & 0x03)) << 1);
\r
3648 for (i = 0; i < row_info->width; i++)
\r
3653 v = (png_byte)((*sp >> sshift) & 0x03);
\r
3654 for (j = 0; j < jstop; j++)
\r
3656 unsigned int tmp = *dp & (0x3f3f >> (6 - dshift));
\r
3657 tmp |= v << dshift;
\r
3658 *dp = (png_byte)(tmp & 0xff);
\r
3660 if (dshift == s_end)
\r
3670 if (sshift == s_end)
\r
3684 png_bytep sp = row + (png_size_t)((row_info->width - 1) >> 1);
\r
3685 png_bytep dp = row + (png_size_t)((final_width - 1) >> 1);
\r
3686 int sshift, dshift;
\r
3687 int s_start, s_end, s_inc;
\r
3689 int jstop = png_pass_inc[pass];
\r
3691 #ifdef PNG_READ_PACKSWAP_SUPPORTED
\r
3692 if ((transformations & PNG_PACKSWAP) != 0)
\r
3694 sshift = (int)(((row_info->width + 1) & 0x01) << 2);
\r
3695 dshift = (int)(((final_width + 1) & 0x01) << 2);
\r
3704 sshift = (int)((1 - ((row_info->width + 1) & 0x01)) << 2);
\r
3705 dshift = (int)((1 - ((final_width + 1) & 0x01)) << 2);
\r
3711 for (i = 0; i < row_info->width; i++)
\r
3713 png_byte v = (png_byte)((*sp >> sshift) & 0x0f);
\r
3716 for (j = 0; j < jstop; j++)
\r
3718 unsigned int tmp = *dp & (0xf0f >> (4 - dshift));
\r
3719 tmp |= v << dshift;
\r
3720 *dp = (png_byte)(tmp & 0xff);
\r
3722 if (dshift == s_end)
\r
3732 if (sshift == s_end)
\r
3746 png_size_t pixel_bytes = (row_info->pixel_depth >> 3);
\r
3748 png_bytep sp = row + (png_size_t)(row_info->width - 1)
\r
3751 png_bytep dp = row + (png_size_t)(final_width - 1) * pixel_bytes;
\r
3753 int jstop = png_pass_inc[pass];
\r
3756 for (i = 0; i < row_info->width; i++)
\r
3758 png_byte v[8]; /* SAFE; pixel_depth does not exceed 64 */
\r
3761 memcpy(v, sp, pixel_bytes);
\r
3763 for (j = 0; j < jstop; j++)
\r
3765 memcpy(dp, v, pixel_bytes);
\r
3766 dp -= pixel_bytes;
\r
3769 sp -= pixel_bytes;
\r
3775 row_info->width = final_width;
\r
3776 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, final_width);
\r
3778 #ifndef PNG_READ_PACKSWAP_SUPPORTED
\r
3779 PNG_UNUSED(transformations) /* Silence compiler warning */
\r
3782 #endif /* READ_INTERLACING */
\r
3785 png_read_filter_row_sub(png_row_infop row_info, png_bytep row,
\r
3786 png_const_bytep prev_row)
\r
3789 png_size_t istop = row_info->rowbytes;
\r
3790 unsigned int bpp = (row_info->pixel_depth + 7) >> 3;
\r
3791 png_bytep rp = row + bpp;
\r
3793 PNG_UNUSED(prev_row)
\r
3795 for (i = bpp; i < istop; i++)
\r
3797 *rp = (png_byte)(((int)(*rp) + (int)(*(rp-bpp))) & 0xff);
\r
3803 png_read_filter_row_up(png_row_infop row_info, png_bytep row,
\r
3804 png_const_bytep prev_row)
\r
3807 png_size_t istop = row_info->rowbytes;
\r
3808 png_bytep rp = row;
\r
3809 png_const_bytep pp = prev_row;
\r
3811 for (i = 0; i < istop; i++)
\r
3813 *rp = (png_byte)(((int)(*rp) + (int)(*pp++)) & 0xff);
\r
3819 png_read_filter_row_avg(png_row_infop row_info, png_bytep row,
\r
3820 png_const_bytep prev_row)
\r
3823 png_bytep rp = row;
\r
3824 png_const_bytep pp = prev_row;
\r
3825 unsigned int bpp = (row_info->pixel_depth + 7) >> 3;
\r
3826 png_size_t istop = row_info->rowbytes - bpp;
\r
3828 for (i = 0; i < bpp; i++)
\r
3830 *rp = (png_byte)(((int)(*rp) +
\r
3831 ((int)(*pp++) / 2 )) & 0xff);
\r
3836 for (i = 0; i < istop; i++)
\r
3838 *rp = (png_byte)(((int)(*rp) +
\r
3839 (int)(*pp++ + *(rp-bpp)) / 2 ) & 0xff);
\r
3846 png_read_filter_row_paeth_1byte_pixel(png_row_infop row_info, png_bytep row,
\r
3847 png_const_bytep prev_row)
\r
3849 png_bytep rp_end = row + row_info->rowbytes;
\r
3852 /* First pixel/byte */
\r
3855 *row++ = (png_byte)a;
\r
3858 while (row < rp_end)
\r
3860 int b, pa, pb, pc, p;
\r
3862 a &= 0xff; /* From previous iteration or start */
\r
3868 #ifdef PNG_USE_ABS
\r
3873 pa = p < 0 ? -p : p;
\r
3874 pb = pc < 0 ? -pc : pc;
\r
3875 pc = (p + pc) < 0 ? -(p + pc) : p + pc;
\r
3878 /* Find the best predictor, the least of pa, pb, pc favoring the earlier
\r
3879 * ones in the case of a tie.
\r
3881 if (pb < pa) pa = pb, a = b;
\r
3882 if (pc < pa) a = c;
\r
3884 /* Calculate the current pixel in a, and move the previous row pixel to c
\r
3885 * for the next time round the loop
\r
3889 *row++ = (png_byte)a;
\r
3894 png_read_filter_row_paeth_multibyte_pixel(png_row_infop row_info, png_bytep row,
\r
3895 png_const_bytep prev_row)
\r
3897 int bpp = (row_info->pixel_depth + 7) >> 3;
\r
3898 png_bytep rp_end = row + bpp;
\r
3900 /* Process the first pixel in the row completely (this is the same as 'up'
\r
3901 * because there is only one candidate predictor for the first row).
\r
3903 while (row < rp_end)
\r
3905 int a = *row + *prev_row++;
\r
3906 *row++ = (png_byte)a;
\r
3910 rp_end += row_info->rowbytes - bpp;
\r
3912 while (row < rp_end)
\r
3914 int a, b, c, pa, pb, pc, p;
\r
3916 c = *(prev_row - bpp);
\r
3923 #ifdef PNG_USE_ABS
\r
3928 pa = p < 0 ? -p : p;
\r
3929 pb = pc < 0 ? -pc : pc;
\r
3930 pc = (p + pc) < 0 ? -(p + pc) : p + pc;
\r
3933 if (pb < pa) pa = pb, a = b;
\r
3934 if (pc < pa) a = c;
\r
3937 *row++ = (png_byte)a;
\r
3942 png_init_filter_functions(png_structrp pp)
\r
3943 /* This function is called once for every PNG image (except for PNG images
\r
3944 * that only use PNG_FILTER_VALUE_NONE for all rows) to set the
\r
3945 * implementations required to reverse the filtering of PNG rows. Reversing
\r
3946 * the filter is the first transformation performed on the row data. It is
\r
3947 * performed in place, therefore an implementation can be selected based on
\r
3948 * the image pixel format. If the implementation depends on image width then
\r
3949 * take care to ensure that it works correctly if the image is interlaced -
\r
3950 * interlacing causes the actual row width to vary.
\r
3953 unsigned int bpp = (pp->pixel_depth + 7) >> 3;
\r
3955 pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub;
\r
3956 pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up;
\r
3957 pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg;
\r
3959 pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
\r
3960 png_read_filter_row_paeth_1byte_pixel;
\r
3962 pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
\r
3963 png_read_filter_row_paeth_multibyte_pixel;
\r
3965 #ifdef PNG_FILTER_OPTIMIZATIONS
\r
3966 /* To use this define PNG_FILTER_OPTIMIZATIONS as the name of a function to
\r
3967 * call to install hardware optimizations for the above functions; simply
\r
3968 * replace whatever elements of the pp->read_filter[] array with a hardware
\r
3969 * specific (or, for that matter, generic) optimization.
\r
3971 * To see an example of this examine what configure.ac does when
\r
3972 * --enable-arm-neon is specified on the command line.
\r
3974 // PNG_FILTER_OPTIMIZATIONS(pp, bpp); // TO-TO: Fix NEON support
\r
3978 void /* PRIVATE */
\r
3979 png_read_filter_row(png_structrp pp, png_row_infop row_info, png_bytep row,
\r
3980 png_const_bytep prev_row, int filter)
\r
3982 /* OPTIMIZATION: DO NOT MODIFY THIS FUNCTION, instead #define
\r
3983 * PNG_FILTER_OPTIMIZATIONS to a function that overrides the generic
\r
3984 * implementations. See png_init_filter_functions above.
\r
3986 if (filter > PNG_FILTER_VALUE_NONE && filter < PNG_FILTER_VALUE_LAST)
\r
3988 if (pp->read_filter[0] == NULL)
\r
3989 png_init_filter_functions(pp);
\r
3991 pp->read_filter[filter-1](row_info, row, prev_row);
\r
3995 #ifdef PNG_SEQUENTIAL_READ_SUPPORTED
\r
3996 void /* PRIVATE */
\r
3997 png_read_IDAT_data(png_structrp png_ptr, png_bytep output,
\r
3998 png_alloc_size_t avail_out)
\r
4000 /* Loop reading IDATs and decompressing the result into output[avail_out] */
\r
4001 png_ptr->zstream.next_out = output;
\r
4002 png_ptr->zstream.avail_out = 0; /* safety: set below */
\r
4004 if (output == NULL)
\r
4010 png_byte tmpbuf[PNG_INFLATE_BUF_SIZE];
\r
4012 if (png_ptr->zstream.avail_in == 0)
\r
4017 while (png_ptr->idat_size == 0)
\r
4019 png_crc_finish(png_ptr, 0);
\r
4021 png_ptr->idat_size = png_read_chunk_header(png_ptr);
\r
4022 /* This is an error even in the 'check' case because the code just
\r
4023 * consumed a non-IDAT header.
\r
4025 if (png_ptr->chunk_name != png_IDAT)
\r
4026 png_error(png_ptr, "Not enough image data");
\r
4029 avail_in = png_ptr->IDAT_read_size;
\r
4031 if (avail_in > png_ptr->idat_size)
\r
4032 avail_in = (uInt)png_ptr->idat_size;
\r
4034 /* A PNG with a gradually increasing IDAT size will defeat this attempt
\r
4035 * to minimize memory usage by causing lots of re-allocs, but
\r
4036 * realistically doing IDAT_read_size re-allocs is not likely to be a
\r
4039 buffer = png_read_buffer(png_ptr, avail_in, 0/*error*/);
\r
4041 png_crc_read(png_ptr, buffer, avail_in);
\r
4042 png_ptr->idat_size -= avail_in;
\r
4044 png_ptr->zstream.next_in = buffer;
\r
4045 png_ptr->zstream.avail_in = avail_in;
\r
4048 /* And set up the output side. */
\r
4049 if (output != NULL) /* standard read */
\r
4051 uInt out = ZLIB_IO_MAX;
\r
4053 if (out > avail_out)
\r
4054 out = (uInt)avail_out;
\r
4057 png_ptr->zstream.avail_out = out;
\r
4060 else /* after last row, checking for end */
\r
4062 png_ptr->zstream.next_out = tmpbuf;
\r
4063 png_ptr->zstream.avail_out = (sizeof tmpbuf);
\r
4066 /* Use NO_FLUSH; this gives zlib the maximum opportunity to optimize the
\r
4067 * process. If the LZ stream is truncated the sequential reader will
\r
4068 * terminally damage the stream, above, by reading the chunk header of the
\r
4069 * following chunk (it then exits with png_error).
\r
4071 * TODO: deal more elegantly with truncated IDAT lists.
\r
4073 ret = PNG_INFLATE(png_ptr, Z_NO_FLUSH);
\r
4075 /* Take the unconsumed output back. */
\r
4076 if (output != NULL)
\r
4077 avail_out += png_ptr->zstream.avail_out;
\r
4079 else /* avail_out counts the extra bytes */
\r
4080 avail_out += (sizeof tmpbuf) - png_ptr->zstream.avail_out;
\r
4082 png_ptr->zstream.avail_out = 0;
\r
4084 if (ret == Z_STREAM_END)
\r
4086 /* Do this for safety; we won't read any more into this row. */
\r
4087 png_ptr->zstream.next_out = NULL;
\r
4089 png_ptr->mode |= PNG_AFTER_IDAT;
\r
4090 png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
\r
4092 if (png_ptr->zstream.avail_in > 0 || png_ptr->idat_size > 0)
\r
4093 png_chunk_benign_error(png_ptr, "Extra compressed data");
\r
4099 png_zstream_error(png_ptr, ret);
\r
4101 if (output != NULL)
\r
4102 png_chunk_error(png_ptr, png_ptr->zstream.msg);
\r
4104 else /* checking */
\r
4106 png_chunk_benign_error(png_ptr, png_ptr->zstream.msg);
\r
4110 } while (avail_out > 0);
\r
4112 if (avail_out > 0)
\r
4114 /* The stream ended before the image; this is the same as too few IDATs so
\r
4115 * should be handled the same way.
\r
4117 if (output != NULL)
\r
4118 png_error(png_ptr, "Not enough image data");
\r
4120 else /* the deflate stream contained extra data */
\r
4121 png_chunk_benign_error(png_ptr, "Too much image data");
\r
4125 void /* PRIVATE */
\r
4126 png_read_finish_IDAT(png_structrp png_ptr)
\r
4128 /* We don't need any more data and the stream should have ended, however the
\r
4129 * LZ end code may actually not have been processed. In this case we must
\r
4130 * read it otherwise stray unread IDAT data or, more likely, an IDAT chunk
\r
4131 * may still remain to be consumed.
\r
4133 if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0)
\r
4135 /* The NULL causes png_read_IDAT_data to swallow any remaining bytes in
\r
4136 * the compressed stream, but the stream may be damaged too, so even after
\r
4137 * this call we may need to terminate the zstream ownership.
\r
4139 png_read_IDAT_data(png_ptr, NULL, 0);
\r
4140 png_ptr->zstream.next_out = NULL; /* safety */
\r
4142 /* Now clear everything out for safety; the following may not have been
\r
4145 if ((png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED) == 0)
\r
4147 png_ptr->mode |= PNG_AFTER_IDAT;
\r
4148 png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED;
\r
4152 /* If the zstream has not been released do it now *and* terminate the reading
\r
4153 * of the final IDAT chunk.
\r
4155 if (png_ptr->zowner == png_IDAT)
\r
4157 /* Always do this; the pointers otherwise point into the read buffer. */
\r
4158 png_ptr->zstream.next_in = NULL;
\r
4159 png_ptr->zstream.avail_in = 0;
\r
4161 /* Now we no longer own the zstream. */
\r
4162 png_ptr->zowner = 0;
\r
4164 /* The slightly weird semantics of the sequential IDAT reading is that we
\r
4165 * are always in or at the end of an IDAT chunk, so we always need to do a
\r
4166 * crc_finish here. If idat_size is non-zero we also need to read the
\r
4167 * spurious bytes at the end of the chunk now.
\r
4169 (void)png_crc_finish(png_ptr, png_ptr->idat_size);
\r
4173 void /* PRIVATE */
\r
4174 png_read_finish_row(png_structrp png_ptr)
\r
4176 /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
\r
4178 /* Start of interlace block */
\r
4179 static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
\r
4181 /* Offset to next interlace block */
\r
4182 static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
\r
4184 /* Start of interlace block in the y direction */
\r
4185 static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
\r
4187 /* Offset to next interlace block in the y direction */
\r
4188 static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
\r
4190 png_debug(1, "in png_read_finish_row");
\r
4191 png_ptr->row_number++;
\r
4192 if (png_ptr->row_number < png_ptr->num_rows)
\r
4195 if (png_ptr->interlaced != 0)
\r
4197 png_ptr->row_number = 0;
\r
4199 /* TO DO: don't do this if prev_row isn't needed (requires
\r
4200 * read-ahead of the next row's filter byte.
\r
4202 memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
\r
4208 if (png_ptr->pass >= 7)
\r
4211 png_ptr->iwidth = (png_ptr->width +
\r
4212 png_pass_inc[png_ptr->pass] - 1 -
\r
4213 png_pass_start[png_ptr->pass]) /
\r
4214 png_pass_inc[png_ptr->pass];
\r
4216 if ((png_ptr->transformations & PNG_INTERLACE) == 0)
\r
4218 png_ptr->num_rows = (png_ptr->height +
\r
4219 png_pass_yinc[png_ptr->pass] - 1 -
\r
4220 png_pass_ystart[png_ptr->pass]) /
\r
4221 png_pass_yinc[png_ptr->pass];
\r
4224 else /* if (png_ptr->transformations & PNG_INTERLACE) */
\r
4225 break; /* libpng deinterlacing sees every row */
\r
4227 } while (png_ptr->num_rows == 0 || png_ptr->iwidth == 0);
\r
4229 if (png_ptr->pass < 7)
\r
4233 /* Here after at the end of the last row of the last pass. */
\r
4234 png_read_finish_IDAT(png_ptr);
\r
4236 #endif /* SEQUENTIAL_READ */
\r
4238 void /* PRIVATE */
\r
4239 png_read_start_row(png_structrp png_ptr)
\r
4241 /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
\r
4243 /* Start of interlace block */
\r
4244 static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
\r
4246 /* Offset to next interlace block */
\r
4247 static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
\r
4249 /* Start of interlace block in the y direction */
\r
4250 static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
\r
4252 /* Offset to next interlace block in the y direction */
\r
4253 static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
\r
4255 int max_pixel_depth;
\r
4256 png_size_t row_bytes;
\r
4258 png_debug(1, "in png_read_start_row");
\r
4260 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
\r
4261 png_init_read_transformations(png_ptr);
\r
4263 if (png_ptr->interlaced != 0)
\r
4265 if ((png_ptr->transformations & PNG_INTERLACE) == 0)
\r
4266 png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
\r
4267 png_pass_ystart[0]) / png_pass_yinc[0];
\r
4270 png_ptr->num_rows = png_ptr->height;
\r
4272 png_ptr->iwidth = (png_ptr->width +
\r
4273 png_pass_inc[png_ptr->pass] - 1 -
\r
4274 png_pass_start[png_ptr->pass]) /
\r
4275 png_pass_inc[png_ptr->pass];
\r
4280 png_ptr->num_rows = png_ptr->height;
\r
4281 png_ptr->iwidth = png_ptr->width;
\r
4284 max_pixel_depth = png_ptr->pixel_depth;
\r
4286 /* WARNING: * png_read_transform_info (pngrtran.c) performs a simpler set of
\r
4287 * calculations to calculate the final pixel depth, then
\r
4288 * png_do_read_transforms actually does the transforms. This means that the
\r
4289 * code which effectively calculates this value is actually repeated in three
\r
4290 * separate places. They must all match. Innocent changes to the order of
\r
4291 * transformations can and will break libpng in a way that causes memory
\r
4296 #ifdef PNG_READ_PACK_SUPPORTED
\r
4297 if ((png_ptr->transformations & PNG_PACK) != 0 && png_ptr->bit_depth < 8)
\r
4298 max_pixel_depth = 8;
\r
4301 #ifdef PNG_READ_EXPAND_SUPPORTED
\r
4302 if ((png_ptr->transformations & PNG_EXPAND) != 0)
\r
4304 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
\r
4306 if (png_ptr->num_trans != 0)
\r
4307 max_pixel_depth = 32;
\r
4310 max_pixel_depth = 24;
\r
4313 else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
\r
4315 if (max_pixel_depth < 8)
\r
4316 max_pixel_depth = 8;
\r
4318 if (png_ptr->num_trans != 0)
\r
4319 max_pixel_depth *= 2;
\r
4322 else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB)
\r
4324 if (png_ptr->num_trans != 0)
\r
4326 max_pixel_depth *= 4;
\r
4327 max_pixel_depth /= 3;
\r
4333 #ifdef PNG_READ_EXPAND_16_SUPPORTED
\r
4334 if ((png_ptr->transformations & PNG_EXPAND_16) != 0)
\r
4336 # ifdef PNG_READ_EXPAND_SUPPORTED
\r
4337 /* In fact it is an error if it isn't supported, but checking is
\r
4340 if ((png_ptr->transformations & PNG_EXPAND) != 0)
\r
4342 if (png_ptr->bit_depth < 16)
\r
4343 max_pixel_depth *= 2;
\r
4347 png_ptr->transformations &= ~PNG_EXPAND_16;
\r
4351 #ifdef PNG_READ_FILLER_SUPPORTED
\r
4352 if ((png_ptr->transformations & (PNG_FILLER)) != 0)
\r
4354 if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY)
\r
4356 if (max_pixel_depth <= 8)
\r
4357 max_pixel_depth = 16;
\r
4360 max_pixel_depth = 32;
\r
4363 else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB ||
\r
4364 png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
\r
4366 if (max_pixel_depth <= 32)
\r
4367 max_pixel_depth = 32;
\r
4370 max_pixel_depth = 64;
\r
4375 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
\r
4376 if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0)
\r
4379 #ifdef PNG_READ_EXPAND_SUPPORTED
\r
4380 (png_ptr->num_trans != 0 &&
\r
4381 (png_ptr->transformations & PNG_EXPAND) != 0) ||
\r
4383 #ifdef PNG_READ_FILLER_SUPPORTED
\r
4384 (png_ptr->transformations & (PNG_FILLER)) != 0 ||
\r
4386 png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
\r
4388 if (max_pixel_depth <= 16)
\r
4389 max_pixel_depth = 32;
\r
4392 max_pixel_depth = 64;
\r
4397 if (max_pixel_depth <= 8)
\r
4399 if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
\r
4400 max_pixel_depth = 32;
\r
4403 max_pixel_depth = 24;
\r
4406 else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
\r
4407 max_pixel_depth = 64;
\r
4410 max_pixel_depth = 48;
\r
4415 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) && \
\r
4416 defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
\r
4417 if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0)
\r
4419 int user_pixel_depth = png_ptr->user_transform_depth *
\r
4420 png_ptr->user_transform_channels;
\r
4422 if (user_pixel_depth > max_pixel_depth)
\r
4423 max_pixel_depth = user_pixel_depth;
\r
4427 /* This value is stored in png_struct and double checked in the row read
\r
4430 png_ptr->maximum_pixel_depth = (png_byte)max_pixel_depth;
\r
4431 png_ptr->transformed_pixel_depth = 0; /* calculated on demand */
\r
4433 /* Align the width on the next larger 8 pixels. Mainly used
\r
4436 row_bytes = ((png_ptr->width + 7) & ~((png_uint_32)7));
\r
4437 /* Calculate the maximum bytes needed, adding a byte and a pixel
\r
4438 * for safety's sake
\r
4440 row_bytes = PNG_ROWBYTES(max_pixel_depth, row_bytes) +
\r
4441 1 + ((max_pixel_depth + 7) >> 3);
\r
4443 #ifdef PNG_MAX_MALLOC_64K
\r
4444 if (row_bytes > (png_uint_32)65536L)
\r
4445 png_error(png_ptr, "This image requires a row greater than 64KB");
\r
4448 if (row_bytes + 48 > png_ptr->old_big_row_buf_size)
\r
4450 png_free(png_ptr, png_ptr->big_row_buf);
\r
4451 png_free(png_ptr, png_ptr->big_prev_row);
\r
4453 if (png_ptr->interlaced != 0)
\r
4454 png_ptr->big_row_buf = (png_bytep)png_calloc(png_ptr,
\r
4458 png_ptr->big_row_buf = (png_bytep)png_malloc(png_ptr, row_bytes + 48);
\r
4460 png_ptr->big_prev_row = (png_bytep)png_malloc(png_ptr, row_bytes + 48);
\r
4462 #ifdef PNG_ALIGNED_MEMORY_SUPPORTED
\r
4463 /* Use 16-byte aligned memory for row_buf with at least 16 bytes
\r
4464 * of padding before and after row_buf; treat prev_row similarly.
\r
4465 * NOTE: the alignment is to the start of the pixels, one beyond the start
\r
4466 * of the buffer, because of the filter byte. Prior to libpng 1.5.6 this
\r
4467 * was incorrect; the filter byte was aligned, which had the exact
\r
4468 * opposite effect of that intended.
\r
4471 png_bytep temp = png_ptr->big_row_buf + 32;
\r
4472 int extra = (int)((temp - (png_bytep)0) & 0x0f);
\r
4473 png_ptr->row_buf = temp - extra - 1/*filter byte*/;
\r
4475 temp = png_ptr->big_prev_row + 32;
\r
4476 extra = (int)((temp - (png_bytep)0) & 0x0f);
\r
4477 png_ptr->prev_row = temp - extra - 1/*filter byte*/;
\r
4481 /* Use 31 bytes of padding before and 17 bytes after row_buf. */
\r
4482 png_ptr->row_buf = png_ptr->big_row_buf + 31;
\r
4483 png_ptr->prev_row = png_ptr->big_prev_row + 31;
\r
4485 png_ptr->old_big_row_buf_size = row_bytes + 48;
\r
4488 #ifdef PNG_MAX_MALLOC_64K
\r
4489 if (png_ptr->rowbytes > 65535)
\r
4490 png_error(png_ptr, "This image requires a row greater than 64KB");
\r
4493 if (png_ptr->rowbytes > (PNG_SIZE_MAX - 1))
\r
4494 png_error(png_ptr, "Row has too many bytes to allocate in memory");
\r
4496 memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1);
\r
4498 png_debug1(3, "width = %u,", png_ptr->width);
\r
4499 png_debug1(3, "height = %u,", png_ptr->height);
\r
4500 png_debug1(3, "iwidth = %u,", png_ptr->iwidth);
\r
4501 png_debug1(3, "num_rows = %u,", png_ptr->num_rows);
\r
4502 png_debug1(3, "rowbytes = %lu,", (unsigned long)png_ptr->rowbytes);
\r
4503 png_debug1(3, "irowbytes = %lu",
\r
4504 (unsigned long)PNG_ROWBYTES(png_ptr->pixel_depth, png_ptr->iwidth) + 1);
\r
4506 /* The sequential reader needs a buffer for IDAT, but the progressive reader
\r
4507 * does not, so free the read buffer now regardless; the sequential reader
\r
4508 * reallocates it on demand.
\r
4510 if (png_ptr->read_buffer != 0)
\r
4512 png_bytep buffer = png_ptr->read_buffer;
\r
4514 png_ptr->read_buffer_size = 0;
\r
4515 png_ptr->read_buffer = NULL;
\r
4516 png_free(png_ptr, buffer);
\r
4519 /* Finally claim the zstream for the inflate of the IDAT data, use the bits
\r
4520 * value from the stream (note that this will result in a fatal error if the
\r
4521 * IDAT stream has a bogus deflate header window_bits value, but this should
\r
4522 * not be happening any longer!)
\r
4524 if (png_inflate_claim(png_ptr, png_IDAT) != Z_OK)
\r
4525 png_error(png_ptr, png_ptr->zstream.msg);
\r
4527 png_ptr->flags |= PNG_FLAG_ROW_INIT;
\r
projects / irrlicht.git / blob