| Index: third_party/libjpeg_turbo/jutils.c
|
| ===================================================================
|
| --- third_party/libjpeg_turbo/jutils.c (revision 0)
|
| +++ third_party/libjpeg_turbo/jutils.c (revision 0)
|
| @@ -0,0 +1,179 @@
|
| +/*
|
| + * jutils.c
|
| + *
|
| + * Copyright (C) 1991-1996, Thomas G. Lane.
|
| + * This file is part of the Independent JPEG Group's software.
|
| + * For conditions of distribution and use, see the accompanying README file.
|
| + *
|
| + * This file contains tables and miscellaneous utility routines needed
|
| + * for both compression and decompression.
|
| + * Note we prefix all global names with "j" to minimize conflicts with
|
| + * a surrounding application.
|
| + */
|
| +
|
| +#define JPEG_INTERNALS
|
| +#include "jinclude.h"
|
| +#include "jpeglib.h"
|
| +
|
| +
|
| +/*
|
| + * jpeg_zigzag_order[i] is the zigzag-order position of the i'th element
|
| + * of a DCT block read in natural order (left to right, top to bottom).
|
| + */
|
| +
|
| +#if 0 /* This table is not actually needed in v6a */
|
| +
|
| +const int jpeg_zigzag_order[DCTSIZE2] = {
|
| + 0, 1, 5, 6, 14, 15, 27, 28,
|
| + 2, 4, 7, 13, 16, 26, 29, 42,
|
| + 3, 8, 12, 17, 25, 30, 41, 43,
|
| + 9, 11, 18, 24, 31, 40, 44, 53,
|
| + 10, 19, 23, 32, 39, 45, 52, 54,
|
| + 20, 22, 33, 38, 46, 51, 55, 60,
|
| + 21, 34, 37, 47, 50, 56, 59, 61,
|
| + 35, 36, 48, 49, 57, 58, 62, 63
|
| +};
|
| +
|
| +#endif
|
| +
|
| +/*
|
| + * jpeg_natural_order[i] is the natural-order position of the i'th element
|
| + * of zigzag order.
|
| + *
|
| + * When reading corrupted data, the Huffman decoders could attempt
|
| + * to reference an entry beyond the end of this array (if the decoded
|
| + * zero run length reaches past the end of the block). To prevent
|
| + * wild stores without adding an inner-loop test, we put some extra
|
| + * "63"s after the real entries. This will cause the extra coefficient
|
| + * to be stored in location 63 of the block, not somewhere random.
|
| + * The worst case would be a run-length of 15, which means we need 16
|
| + * fake entries.
|
| + */
|
| +
|
| +const int jpeg_natural_order[DCTSIZE2+16] = {
|
| + 0, 1, 8, 16, 9, 2, 3, 10,
|
| + 17, 24, 32, 25, 18, 11, 4, 5,
|
| + 12, 19, 26, 33, 40, 48, 41, 34,
|
| + 27, 20, 13, 6, 7, 14, 21, 28,
|
| + 35, 42, 49, 56, 57, 50, 43, 36,
|
| + 29, 22, 15, 23, 30, 37, 44, 51,
|
| + 58, 59, 52, 45, 38, 31, 39, 46,
|
| + 53, 60, 61, 54, 47, 55, 62, 63,
|
| + 63, 63, 63, 63, 63, 63, 63, 63, /* extra entries for safety in decoder */
|
| + 63, 63, 63, 63, 63, 63, 63, 63
|
| +};
|
| +
|
| +
|
| +/*
|
| + * Arithmetic utilities
|
| + */
|
| +
|
| +GLOBAL(long)
|
| +jdiv_round_up (long a, long b)
|
| +/* Compute a/b rounded up to next integer, ie, ceil(a/b) */
|
| +/* Assumes a >= 0, b > 0 */
|
| +{
|
| + return (a + b - 1L) / b;
|
| +}
|
| +
|
| +
|
| +GLOBAL(size_t)
|
| +jround_up (size_t a, size_t b)
|
| +/* Compute a rounded up to next multiple of b, ie, ceil(a/b)*b */
|
| +/* Assumes a >= 0, b > 0 */
|
| +{
|
| + a += b - 1L;
|
| + return a - (a % b);
|
| +}
|
| +
|
| +
|
| +/* On normal machines we can apply MEMCOPY() and MEMZERO() to sample arrays
|
| + * and coefficient-block arrays. This won't work on 80x86 because the arrays
|
| + * are FAR and we're assuming a small-pointer memory model. However, some
|
| + * DOS compilers provide far-pointer versions of memcpy() and memset() even
|
| + * in the small-model libraries. These will be used if USE_FMEM is defined.
|
| + * Otherwise, the routines below do it the hard way. (The performance cost
|
| + * is not all that great, because these routines aren't very heavily used.)
|
| + */
|
| +
|
| +#ifndef NEED_FAR_POINTERS /* normal case, same as regular macros */
|
| +#define FMEMCOPY(dest,src,size) MEMCOPY(dest,src,size)
|
| +#define FMEMZERO(target,size) MEMZERO(target,size)
|
| +#else /* 80x86 case, define if we can */
|
| +#ifdef USE_FMEM
|
| +#define FMEMCOPY(dest,src,size) _fmemcpy((void FAR *)(dest), (const void FAR *)(src), (size_t)(size))
|
| +#define FMEMZERO(target,size) _fmemset((void FAR *)(target), 0, (size_t)(size))
|
| +#endif
|
| +#endif
|
| +
|
| +
|
| +GLOBAL(void)
|
| +jcopy_sample_rows (JSAMPARRAY input_array, int source_row,
|
| + JSAMPARRAY output_array, int dest_row,
|
| + int num_rows, JDIMENSION num_cols)
|
| +/* Copy some rows of samples from one place to another.
|
| + * num_rows rows are copied from input_array[source_row++]
|
| + * to output_array[dest_row++]; these areas may overlap for duplication.
|
| + * The source and destination arrays must be at least as wide as num_cols.
|
| + */
|
| +{
|
| + register JSAMPROW inptr, outptr;
|
| +#ifdef FMEMCOPY
|
| + register size_t count = (size_t) (num_cols * SIZEOF(JSAMPLE));
|
| +#else
|
| + register JDIMENSION count;
|
| +#endif
|
| + register int row;
|
| +
|
| + input_array += source_row;
|
| + output_array += dest_row;
|
| +
|
| + for (row = num_rows; row > 0; row--) {
|
| + inptr = *input_array++;
|
| + outptr = *output_array++;
|
| +#ifdef FMEMCOPY
|
| + FMEMCOPY(outptr, inptr, count);
|
| +#else
|
| + for (count = num_cols; count > 0; count--)
|
| + *outptr++ = *inptr++; /* needn't bother with GETJSAMPLE() here */
|
| +#endif
|
| + }
|
| +}
|
| +
|
| +
|
| +GLOBAL(void)
|
| +jcopy_block_row (JBLOCKROW input_row, JBLOCKROW output_row,
|
| + JDIMENSION num_blocks)
|
| +/* Copy a row of coefficient blocks from one place to another. */
|
| +{
|
| +#ifdef FMEMCOPY
|
| + FMEMCOPY(output_row, input_row, num_blocks * (DCTSIZE2 * SIZEOF(JCOEF)));
|
| +#else
|
| + register JCOEFPTR inptr, outptr;
|
| + register long count;
|
| +
|
| + inptr = (JCOEFPTR) input_row;
|
| + outptr = (JCOEFPTR) output_row;
|
| + for (count = (long) num_blocks * DCTSIZE2; count > 0; count--) {
|
| + *outptr++ = *inptr++;
|
| + }
|
| +#endif
|
| +}
|
| +
|
| +
|
| +GLOBAL(void)
|
| +jzero_far (void FAR * target, size_t bytestozero)
|
| +/* Zero out a chunk of FAR memory. */
|
| +/* This might be sample-array data, block-array data, or alloc_large data. */
|
| +{
|
| +#ifdef FMEMZERO
|
| + FMEMZERO(target, bytestozero);
|
| +#else
|
| + register char FAR * ptr = (char FAR *) target;
|
| + register size_t count;
|
| +
|
| + for (count = bytestozero; count > 0; count--) {
|
| + *ptr++ = 0;
|
| + }
|
| +#endif
|
| +}
|
|
|