1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/libs/libjpeg/jutils.c	Thu Sep 08 06:28:38 2011 +0300
     1.3 @@ -0,0 +1,179 @@
     1.4 +/*
     1.5 + * jutils.c
     1.6 + *
     1.7 + * Copyright (C) 1991-1996, Thomas G. Lane.
     1.8 + * This file is part of the Independent JPEG Group's software.
     1.9 + * For conditions of distribution and use, see the accompanying README file.
    1.10 + *
    1.11 + * This file contains tables and miscellaneous utility routines needed
    1.12 + * for both compression and decompression.
    1.13 + * Note we prefix all global names with "j" to minimize conflicts with
    1.14 + * a surrounding application.
    1.15 + */
    1.16 +
    1.17 +#define JPEG_INTERNALS
    1.18 +#include "jinclude.h"
    1.19 +#include "jpeglib.h"
    1.20 +
    1.21 +
    1.22 +/*
    1.23 + * jpeg_zigzag_order[i] is the zigzag-order position of the i'th element
    1.24 + * of a DCT block read in natural order (left to right, top to bottom).
    1.25 + */
    1.26 +
    1.27 +#if 0				/* This table is not actually needed in v6a */
    1.28 +
    1.29 +const int jpeg_zigzag_order[DCTSIZE2] = {
    1.30 +   0,  1,  5,  6, 14, 15, 27, 28,
    1.31 +   2,  4,  7, 13, 16, 26, 29, 42,
    1.32 +   3,  8, 12, 17, 25, 30, 41, 43,
    1.33 +   9, 11, 18, 24, 31, 40, 44, 53,
    1.34 +  10, 19, 23, 32, 39, 45, 52, 54,
    1.35 +  20, 22, 33, 38, 46, 51, 55, 60,
    1.36 +  21, 34, 37, 47, 50, 56, 59, 61,
    1.37 +  35, 36, 48, 49, 57, 58, 62, 63
    1.38 +};
    1.39 +
    1.40 +#endif
    1.41 +
    1.42 +/*
    1.43 + * jpeg_natural_order[i] is the natural-order position of the i'th element
    1.44 + * of zigzag order.
    1.45 + *
    1.46 + * When reading corrupted data, the Huffman decoders could attempt
    1.47 + * to reference an entry beyond the end of this array (if the decoded
    1.48 + * zero run length reaches past the end of the block).  To prevent
    1.49 + * wild stores without adding an inner-loop test, we put some extra
    1.50 + * "63"s after the real entries.  This will cause the extra coefficient
    1.51 + * to be stored in location 63 of the block, not somewhere random.
    1.52 + * The worst case would be a run-length of 15, which means we need 16
    1.53 + * fake entries.
    1.54 + */
    1.55 +
    1.56 +const int jpeg_natural_order[DCTSIZE2+16] = {
    1.57 +  0,  1,  8, 16,  9,  2,  3, 10,
    1.58 + 17, 24, 32, 25, 18, 11,  4,  5,
    1.59 + 12, 19, 26, 33, 40, 48, 41, 34,
    1.60 + 27, 20, 13,  6,  7, 14, 21, 28,
    1.61 + 35, 42, 49, 56, 57, 50, 43, 36,
    1.62 + 29, 22, 15, 23, 30, 37, 44, 51,
    1.63 + 58, 59, 52, 45, 38, 31, 39, 46,
    1.64 + 53, 60, 61, 54, 47, 55, 62, 63,
    1.65 + 63, 63, 63, 63, 63, 63, 63, 63, /* extra entries for safety in decoder */
    1.66 + 63, 63, 63, 63, 63, 63, 63, 63
    1.67 +};
    1.68 +
    1.69 +
    1.70 +/*
    1.71 + * Arithmetic utilities
    1.72 + */
    1.73 +
    1.74 +GLOBAL(long)
    1.75 +jdiv_round_up (long a, long b)
    1.76 +/* Compute a/b rounded up to next integer, ie, ceil(a/b) */
    1.77 +/* Assumes a >= 0, b > 0 */
    1.78 +{
    1.79 +  return (a + b - 1L) / b;
    1.80 +}
    1.81 +
    1.82 +
    1.83 +GLOBAL(long)
    1.84 +jround_up (long a, long b)
    1.85 +/* Compute a rounded up to next multiple of b, ie, ceil(a/b)*b */
    1.86 +/* Assumes a >= 0, b > 0 */
    1.87 +{
    1.88 +  a += b - 1L;
    1.89 +  return a - (a % b);
    1.90 +}
    1.91 +
    1.92 +
    1.93 +/* On normal machines we can apply MEMCOPY() and MEMZERO() to sample arrays
    1.94 + * and coefficient-block arrays.  This won't work on 80x86 because the arrays
    1.95 + * are FAR and we're assuming a small-pointer memory model.  However, some
    1.96 + * DOS compilers provide far-pointer versions of memcpy() and memset() even
    1.97 + * in the small-model libraries.  These will be used if USE_FMEM is defined.
    1.98 + * Otherwise, the routines below do it the hard way.  (The performance cost
    1.99 + * is not all that great, because these routines aren't very heavily used.)
   1.100 + */
   1.101 +
   1.102 +#ifndef NEED_FAR_POINTERS	/* normal case, same as regular macros */
   1.103 +#define FMEMCOPY(dest,src,size)	MEMCOPY(dest,src,size)
   1.104 +#define FMEMZERO(target,size)	MEMZERO(target,size)
   1.105 +#else				/* 80x86 case, define if we can */
   1.106 +#ifdef USE_FMEM
   1.107 +#define FMEMCOPY(dest,src,size)	_fmemcpy((void FAR *)(dest), (const void FAR *)(src), (size_t)(size))
   1.108 +#define FMEMZERO(target,size)	_fmemset((void FAR *)(target), 0, (size_t)(size))
   1.109 +#endif
   1.110 +#endif
   1.111 +
   1.112 +
   1.113 +GLOBAL(void)
   1.114 +jcopy_sample_rows (JSAMPARRAY input_array, int source_row,
   1.115 +		   JSAMPARRAY output_array, int dest_row,
   1.116 +		   int num_rows, JDIMENSION num_cols)
   1.117 +/* Copy some rows of samples from one place to another.
   1.118 + * num_rows rows are copied from input_array[source_row++]
   1.119 + * to output_array[dest_row++]; these areas may overlap for duplication.
   1.120 + * The source and destination arrays must be at least as wide as num_cols.
   1.121 + */
   1.122 +{
   1.123 +  register JSAMPROW inptr, outptr;
   1.124 +#ifdef FMEMCOPY
   1.125 +  register size_t count = (size_t) (num_cols * SIZEOF(JSAMPLE));
   1.126 +#else
   1.127 +  register JDIMENSION count;
   1.128 +#endif
   1.129 +  register int row;
   1.130 +
   1.131 +  input_array += source_row;
   1.132 +  output_array += dest_row;
   1.133 +
   1.134 +  for (row = num_rows; row > 0; row--) {
   1.135 +    inptr = *input_array++;
   1.136 +    outptr = *output_array++;
   1.137 +#ifdef FMEMCOPY
   1.138 +    FMEMCOPY(outptr, inptr, count);
   1.139 +#else
   1.140 +    for (count = num_cols; count > 0; count--)
   1.141 +      *outptr++ = *inptr++;	/* needn't bother with GETJSAMPLE() here */
   1.142 +#endif
   1.143 +  }
   1.144 +}
   1.145 +
   1.146 +
   1.147 +GLOBAL(void)
   1.148 +jcopy_block_row (JBLOCKROW input_row, JBLOCKROW output_row,
   1.149 +		 JDIMENSION num_blocks)
   1.150 +/* Copy a row of coefficient blocks from one place to another. */
   1.151 +{
   1.152 +#ifdef FMEMCOPY
   1.153 +  FMEMCOPY(output_row, input_row, num_blocks * (DCTSIZE2 * SIZEOF(JCOEF)));
   1.154 +#else
   1.155 +  register JCOEFPTR inptr, outptr;
   1.156 +  register long count;
   1.157 +
   1.158 +  inptr = (JCOEFPTR) input_row;
   1.159 +  outptr = (JCOEFPTR) output_row;
   1.160 +  for (count = (long) num_blocks * DCTSIZE2; count > 0; count--) {
   1.161 +    *outptr++ = *inptr++;
   1.162 +  }
   1.163 +#endif
   1.164 +}
   1.165 +
   1.166 +
   1.167 +GLOBAL(void)
   1.168 +jzero_far (void FAR * target, size_t bytestozero)
   1.169 +/* Zero out a chunk of FAR memory. */
   1.170 +/* This might be sample-array data, block-array data, or alloc_large data. */
   1.171 +{
   1.172 +#ifdef FMEMZERO
   1.173 +  FMEMZERO(target, bytestozero);
   1.174 +#else
   1.175 +  register char FAR * ptr = (char FAR *) target;
   1.176 +  register size_t count;
   1.177 +
   1.178 +  for (count = bytestozero; count > 0; count--) {
   1.179 +    *ptr++ = 0;
   1.180 +  }
   1.181 +#endif
   1.182 +}