mirror of
https://github.com/opencv/opencv.git
synced 2024-11-24 03:00:14 +08:00
85923c8f30
Update zlib-ng to 2.2.1 #26113 Release: https://github.com/zlib-ng/zlib-ng/releases/tag/2.2.1 ARM diagnostics patch: https://github.com/zlib-ng/zlib-ng/pull/1774 ### Pull Request Readiness Checklist See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request - [x] I agree to contribute to the project under Apache 2 License. - [x] To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV - [x] The PR is proposed to the proper branch - [ ] There is a reference to the original bug report and related work - [ ] There is accuracy test, performance test and test data in opencv_extra repository, if applicable Patch to opencv_extra has the same branch name. - [ ] The feature is well documented and sample code can be built with the project CMake
86 lines
3.0 KiB
C
86 lines
3.0 KiB
C
/* deflate_rle.c -- compress data using RLE strategy of deflation algorithm
|
|
*
|
|
* Copyright (C) 1995-2024 Jean-loup Gailly and Mark Adler
|
|
* For conditions of distribution and use, see copyright notice in zlib.h
|
|
*/
|
|
|
|
#include "zbuild.h"
|
|
#include "compare256_rle.h"
|
|
#include "deflate.h"
|
|
#include "deflate_p.h"
|
|
#include "functable.h"
|
|
|
|
#ifdef UNALIGNED_OK
|
|
# if defined(UNALIGNED64_OK) && defined(HAVE_BUILTIN_CTZLL)
|
|
# define compare256_rle compare256_rle_unaligned_64
|
|
# elif defined(HAVE_BUILTIN_CTZ)
|
|
# define compare256_rle compare256_rle_unaligned_32
|
|
# else
|
|
# define compare256_rle compare256_rle_unaligned_16
|
|
# endif
|
|
#else
|
|
# define compare256_rle compare256_rle_c
|
|
#endif
|
|
|
|
/* ===========================================================================
|
|
* For Z_RLE, simply look for runs of bytes, generate matches only of distance
|
|
* one. Do not maintain a hash table. (It will be regenerated if this run of
|
|
* deflate switches away from Z_RLE.)
|
|
*/
|
|
Z_INTERNAL block_state deflate_rle(deflate_state *s, int flush) {
|
|
int bflush = 0; /* set if current block must be flushed */
|
|
unsigned char *scan; /* scan goes up to strend for length of run */
|
|
uint32_t match_len = 0;
|
|
|
|
for (;;) {
|
|
/* Make sure that we always have enough lookahead, except
|
|
* at the end of the input file. We need STD_MAX_MATCH bytes
|
|
* for the longest run, plus one for the unrolled loop.
|
|
*/
|
|
if (s->lookahead <= STD_MAX_MATCH) {
|
|
PREFIX(fill_window)(s);
|
|
if (s->lookahead <= STD_MAX_MATCH && flush == Z_NO_FLUSH)
|
|
return need_more;
|
|
if (s->lookahead == 0)
|
|
break; /* flush the current block */
|
|
}
|
|
|
|
/* See how many times the previous byte repeats */
|
|
if (s->lookahead >= STD_MIN_MATCH && s->strstart > 0) {
|
|
scan = s->window + s->strstart - 1;
|
|
if (scan[0] == scan[1] && scan[1] == scan[2]) {
|
|
match_len = compare256_rle(scan, scan+3)+2;
|
|
match_len = MIN(match_len, s->lookahead);
|
|
match_len = MIN(match_len, STD_MAX_MATCH);
|
|
}
|
|
Assert(scan+match_len <= s->window + s->window_size - 1, "wild scan");
|
|
}
|
|
|
|
/* Emit match if have run of STD_MIN_MATCH or longer, else emit literal */
|
|
if (match_len >= STD_MIN_MATCH) {
|
|
check_match(s, s->strstart, s->strstart - 1, match_len);
|
|
|
|
bflush = zng_tr_tally_dist(s, 1, match_len - STD_MIN_MATCH);
|
|
|
|
s->lookahead -= match_len;
|
|
s->strstart += match_len;
|
|
match_len = 0;
|
|
} else {
|
|
/* No match, output a literal byte */
|
|
bflush = zng_tr_tally_lit(s, s->window[s->strstart]);
|
|
s->lookahead--;
|
|
s->strstart++;
|
|
}
|
|
if (bflush)
|
|
FLUSH_BLOCK(s, 0);
|
|
}
|
|
s->insert = 0;
|
|
if (flush == Z_FINISH) {
|
|
FLUSH_BLOCK(s, 1);
|
|
return finish_done;
|
|
}
|
|
if (s->sym_next)
|
|
FLUSH_BLOCK(s, 0);
|
|
return block_done;
|
|
}
|