/lib/cximage-6.0/jbig/jbig.c
C | 3195 lines | 2199 code | 342 blank | 654 comment | 734 complexity | 03e6499b90c85bf79ba05d9f2496ed12 MD5 | raw file
Possible License(s): GPL-3.0, CC-BY-SA-3.0, LGPL-2.0, 0BSD, Unlicense, GPL-2.0, AGPL-1.0, BSD-3-Clause, LGPL-2.1, LGPL-3.0
- /*
- * Portable Free JBIG image compression library
- *
- * Markus Kuhn -- http://www.cl.cam.ac.uk/~mgk25/
- *
- * $Id: jbig.c,v 1.22 2004-06-11 15:17:06+01 mgk25 Exp $
- *
- * This module implements a portable standard C encoder and decoder
- * using the JBIG lossless bi-level image compression algorithm as
- * specified in International Standard ISO 11544:1993 or equivalently
- * as specified in ITU-T Recommendation T.82. See the file jbig.doc
- * for usage instructions and application examples.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- *
- * If you want to use this program under different license conditions,
- * then contact the author for an arrangement.
- *
- * It is possible that certain products which can be built using this
- * software module might form inventions protected by patent rights in
- * some countries (e.g., by patents about arithmetic coding algorithms
- * owned by IBM and AT&T in the USA). Provision of this software by the
- * author does NOT include any licences for any patents. In those
- * countries where a patent licence is required for certain applications
- * of this software module, you will have to obtain such a licence
- * yourself.
- */
- #ifdef DEBUG
- #include <stdio.h>
- #else
- #ifndef NDEBUG
- #define NDEBUG
- #endif
- #endif
- #include <stdlib.h>
- #include <string.h>
- #include <assert.h>
- #include "jbig.h"
- /* optional export of arithmetic coder functions for test purposes */
- #ifdef TEST_CODEC
- #define ARITH
- #define ARITH_INL
- #else
- #define ARITH static
- #ifdef __GNUC__
- #define ARITH_INL static __inline__
- #else
- #define ARITH_INL static
- #endif
- #endif
- #define MX_MAX 127 /* maximal supported mx offset for
- * adaptive template in the encoder */
- #define TPB2CX 0x195 /* contexts for TP special pixels */
- #define TPB3CX 0x0e5
- #define TPDCX 0xc3f
- /* marker codes */
- #define MARKER_STUFF 0x00
- #define MARKER_RESERVE 0x01
- #define MARKER_SDNORM 0x02
- #define MARKER_SDRST 0x03
- #define MARKER_ABORT 0x04
- #define MARKER_NEWLEN 0x05
- #define MARKER_ATMOVE 0x06
- #define MARKER_COMMENT 0x07
- #define MARKER_ESC 0xff
- /* loop array indices */
- #define STRIPE 0
- #define LAYER 1
- #define PLANE 2
- /* special jbg_buf pointers (instead of NULL) */
- #define SDE_DONE ((struct jbg_buf *) -1)
- #define SDE_TODO ((struct jbg_buf *) 0)
- /* object code version id */
- const char jbg_version[] =
- " JBIG-KIT " JBG_VERSION " -- Markus Kuhn -- "
- "$Id: jbig.c,v 1.22 2004-06-11 15:17:06+01 mgk25 Exp $ ";
- /*
- * the following array specifies for each combination of the 3
- * ordering bits, which ii[] variable represents which dimension
- * of s->sde.
- */
- static const int iindex[8][3] = {
- { 2, 1, 0 }, /* no ordering bit set */
- { -1, -1, -1}, /* SMID -> illegal combination */
- { 2, 0, 1 }, /* ILEAVE */
- { 1, 0, 2 }, /* SMID + ILEAVE */
- { 0, 2, 1 }, /* SEQ */
- { 1, 2, 0 }, /* SEQ + SMID */
- { 0, 1, 2 }, /* SEQ + ILEAVE */
- { -1, -1, -1 } /* SEQ + SMID + ILEAVE -> illegal combination */
- };
- /*
- * Array [language][message] with text string error messages that correspond
- * to return values from public functions in this library.
- */
- #define NEMSG 9 /* number of error codes */
- #define NEMSG_LANG 3 /* number of supported languages */
- static const char *errmsg[NEMSG_LANG][NEMSG] = {
- /* English (JBG_EN) */
- {
- "Everything is ok", /* JBG_EOK */
- "Reached specified maximum size", /* JBG_EOK_INTR */
- "Unexpected end of data", /* JBG_EAGAIN */
- "Not enough memory available", /* JBG_ENOMEM */
- "ABORT marker found", /* JBG_EABORT */
- "Unknown marker segment encountered", /* JBG_EMARKER */
- "Incremental BIE does not fit to previous one", /* JBG_ENOCONT */
- "Invalid data encountered", /* JBG_EINVAL */
- "Unimplemented features used" /* JBG_EIMPL */
- },
- /* German (JBG_DE_8859_1) */
- {
- "Kein Problem aufgetreten", /* JBG_EOK */
- "Angegebene maximale Bildgr\366\337e erreicht", /* JBG_EOK_INTR */
- "Unerwartetes Ende der Daten", /* JBG_EAGAIN */
- "Nicht gen\374gend Speicher vorhanden", /* JBG_ENOMEM */
- "Es wurde eine Abbruch-Sequenz gefunden", /* JBG_EABORT */
- "Eine unbekannte Markierungssequenz wurde gefunden", /* JBG_EMARKER */
- "Neue Daten passen nicht zu vorangegangenen Daten", /* JBG_ENOCONT */
- "Es wurden ung\374ltige Daten gefunden", /* JBG_EINVAL */
- "Noch nicht implementierte Optionen wurden benutzt" /* JBG_EIMPL */
- },
- /* German (JBG_DE_UTF_8) */
- {
- "Kein Problem aufgetreten", /* JBG_EOK */
- "Angegebene maximale Bildgr\303\266\303\237e erreicht", /* JBG_EOK_INTR */
- "Unerwartetes Ende der Daten", /* JBG_EAGAIN */
- "Nicht gen\303\274gend Speicher vorhanden", /* JBG_ENOMEM */
- "Es wurde eine Abbruch-Sequenz gefunden", /* JBG_EABORT */
- "Eine unbekannte Markierungssequenz wurde gefunden", /* JBG_EMARKER */
- "Neue Daten passen nicht zu vorangegangenen Daten", /* JBG_ENOCONT */
- "Es wurden ung\303\274ltige Daten gefunden", /* JBG_EINVAL */
- "Noch nicht implementierte Optionen wurden benutzt" /* JBG_EIMPL */
- }
- };
- /*
- * The following three functions are the only places in this code, were
- * C library memory management functions are called. The whole JBIG
- * library has been designed in order to allow multi-threaded
- * execution. No static or global variables are used, so all fuctions
- * are fully reentrant. However if you want to use this multi-thread
- * capability and your malloc, realloc and free are not reentrant,
- * then simply add the necessary semaphores or mutex primitives below.
- * In contrast to C's malloc() and realloc(), but like C's calloc(),
- * these functions take two parameters nmemb and size that are multiplied
- * before being passed on to the corresponding C function.
- * This we can catch all overflows during a size_t multiplication a
- * a single place.
- */
- #ifndef SIZE_MAX
- #define SIZE_MAX ((size_t) -1) /* largest value of size_t */
- #endif
- static void *checked_malloc(size_t nmemb, size_t size)
- {
- void *p;
- /* Full manual exception handling is ugly here for performance
- * reasons. If an adequate handling of lack of memory is required,
- * then use C++ and throw a C++ exception instead of abort(). */
- /* assert that nmemb * size <= SIZE_MAX */
- if (size > SIZE_MAX / nmemb)
- abort();
-
- p = malloc(nmemb * size);
- if (!p)
- abort();
- #if 0
- fprintf(stderr, "%p = malloc(%lu * %lu)\n", p,
- (unsigned long) nmemb, (unsigned long) size);
- #endif
- return p;
- }
- static void *checked_realloc(void *ptr, size_t nmemb, size_t size)
- {
- void *p;
- /* Full manual exception handling is ugly here for performance
- * reasons. If an adequate handling of lack of memory is required,
- * then use C++ and throw a C++ exception here instead of abort(). */
- /* assert that nmemb * size <= SIZE_MAX */
- if (size > SIZE_MAX / nmemb)
- abort();
-
- p = realloc(ptr, nmemb * size);
- if (!p)
- abort();
- #if 0
- fprintf(stderr, "%p = realloc(%p, %lu * %lu)\n", p, ptr,
- (unsigned long) nmemb, (unsigned long) size);
- #endif
- return p;
- }
- static void checked_free(void *ptr)
- {
- free(ptr);
- #if 0
- fprintf(stderr, "free(%p)\n", ptr);
- #endif
- }
- /*
- * The next functions implement the arithmedic encoder and decoder
- * required for JBIG. The same algorithm is also used in the arithmetic
- * variant of JPEG.
- */
- #ifdef DEBUG
- static long encoded_pixels = 0;
- #endif
- ARITH void arith_encode_init(struct jbg_arenc_state *s, int reuse_st)
- {
- int i;
-
- if (!reuse_st)
- for (i = 0; i < 4096; s->st[i++] = 0);
- s->c = 0;
- s->a = 0x10000L;
- s->sc = 0;
- s->ct = 11;
- s->buffer = -1; /* empty */
-
- return;
- }
- ARITH void arith_encode_flush(struct jbg_arenc_state *s)
- {
- unsigned long temp;
- #ifdef DEBUG
- fprintf(stderr, " encoded pixels = %ld, a = %05lx, c = %08lx\n",
- encoded_pixels, s->a, s->c);
- #endif
- /* find the s->c in the coding interval with the largest
- * number of trailing zero bits */
- if ((temp = (s->a - 1 + s->c) & 0xffff0000L) < s->c)
- s->c = temp + 0x8000;
- else
- s->c = temp;
- /* send remaining bytes to output */
- s->c <<= s->ct;
- if (s->c & 0xf8000000L) {
- /* one final overflow has to be handled */
- if (s->buffer >= 0) {
- s->byte_out(s->buffer + 1, s->file);
- if (s->buffer + 1 == MARKER_ESC)
- s->byte_out(MARKER_STUFF, s->file);
- }
- /* output 0x00 bytes only when more non-0x00 will follow */
- if (s->c & 0x7fff800L)
- for (; s->sc; --s->sc)
- s->byte_out(0x00, s->file);
- } else {
- if (s->buffer >= 0)
- s->byte_out(s->buffer, s->file);
- /* T.82 figure 30 says buffer+1 for the above line! Typo? */
- for (; s->sc; --s->sc) {
- s->byte_out(0xff, s->file);
- s->byte_out(MARKER_STUFF, s->file);
- }
- }
- /* output final bytes only if they are not 0x00 */
- if (s->c & 0x7fff800L) {
- s->byte_out((s->c >> 19) & 0xff, s->file);
- if (((s->c >> 19) & 0xff) == MARKER_ESC)
- s->byte_out(MARKER_STUFF, s->file);
- if (s->c & 0x7f800L) {
- s->byte_out((s->c >> 11) & 0xff, s->file);
- if (((s->c >> 11) & 0xff) == MARKER_ESC)
- s->byte_out(MARKER_STUFF, s->file);
- }
- }
- return;
- }
- ARITH_INL void arith_encode(struct jbg_arenc_state *s, int cx, int pix)
- {
- extern short jbg_lsz[];
- extern unsigned char jbg_nmps[], jbg_nlps[];
- register unsigned lsz, ss;
- register unsigned char *st;
- long temp;
- #ifdef DEBUG
- ++encoded_pixels;
- #endif
- assert(cx >= 0 && cx < 4096);
- st = s->st + cx;
- ss = *st & 0x7f;
- assert(ss < 113);
- lsz = jbg_lsz[ss];
- #if 0
- fprintf(stderr, "pix = %d, cx = %d, mps = %d, st = %3d, lsz = 0x%04x, "
- "a = 0x%05lx, c = 0x%08lx, ct = %2d, buf = 0x%02x\n",
- pix, cx, !!(s->st[cx] & 0x80), ss, lsz, s->a, s->c, s->ct,
- s->buffer);
- #endif
- if (((pix << 7) ^ s->st[cx]) & 0x80) {
- /* encode the less probable symbol */
- if ((s->a -= lsz) >= lsz) {
- /* If the interval size (lsz) for the less probable symbol (LPS)
- * is larger than the interval size for the MPS, then exchange
- * the two symbols for coding efficiency, otherwise code the LPS
- * as usual: */
- s->c += s->a;
- s->a = lsz;
- }
- /* Check whether MPS/LPS exchange is necessary
- * and chose next probability estimator status */
- *st &= 0x80;
- *st ^= jbg_nlps[ss];
- } else {
- /* encode the more probable symbol */
- if ((s->a -= lsz) & 0xffff8000L)
- return; /* A >= 0x8000 -> ready, no renormalization required */
- if (s->a < lsz) {
- /* If the interval size (lsz) for the less probable symbol (LPS)
- * is larger than the interval size for the MPS, then exchange
- * the two symbols for coding efficiency: */
- s->c += s->a;
- s->a = lsz;
- }
- /* chose next probability estimator status */
- *st &= 0x80;
- *st |= jbg_nmps[ss];
- }
- /* renormalization of coding interval */
- do {
- s->a <<= 1;
- s->c <<= 1;
- --s->ct;
- if (s->ct == 0) {
- /* another byte is ready for output */
- temp = s->c >> 19;
- if (temp & 0xffffff00L) {
- /* handle overflow over all buffered 0xff bytes */
- if (s->buffer >= 0) {
- ++s->buffer;
- s->byte_out(s->buffer, s->file);
- if (s->buffer == MARKER_ESC)
- s->byte_out(MARKER_STUFF, s->file);
- }
- for (; s->sc; --s->sc)
- s->byte_out(0x00, s->file);
- s->buffer = temp & 0xff; /* new output byte, might overflow later */
- assert(s->buffer != 0xff);
- /* can s->buffer really never become 0xff here? */
- } else if (temp == 0xff) {
- /* buffer 0xff byte (which might overflow later) */
- ++s->sc;
- } else {
- /* output all buffered 0xff bytes, they will not overflow any more */
- if (s->buffer >= 0)
- s->byte_out(s->buffer, s->file);
- for (; s->sc; --s->sc) {
- s->byte_out(0xff, s->file);
- s->byte_out(MARKER_STUFF, s->file);
- }
- s->buffer = temp; /* buffer new output byte (can still overflow) */
- }
- s->c &= 0x7ffffL;
- s->ct = 8;
- }
- } while (s->a < 0x8000);
-
- return;
- }
- ARITH void arith_decode_init(struct jbg_ardec_state *s, int reuse_st)
- {
- int i;
-
- if (!reuse_st)
- for (i = 0; i < 4096; s->st[i++] = 0);
- s->c = 0;
- s->a = 1;
- s->ct = 0;
- s->result = JBG_OK;
- s->startup = 1;
- return;
- }
- ARITH_INL int arith_decode(struct jbg_ardec_state *s, int cx)
- {
- extern short jbg_lsz[];
- extern unsigned char jbg_nmps[], jbg_nlps[];
- register unsigned lsz, ss;
- register unsigned char *st;
- int pix;
- /* renormalization */
- while (s->a < 0x8000 || s->startup) {
- if (s->ct < 1 && s->result != JBG_READY) {
- /* first we have to move a new byte into s->c */
- if (s->pscd_ptr >= s->pscd_end) {
- s->result = JBG_MORE;
- return -1;
- }
- if (*s->pscd_ptr == 0xff)
- if (s->pscd_ptr + 1 >= s->pscd_end) {
- s->result = JBG_MARKER;
- return -1;
- } else {
- if (*(s->pscd_ptr + 1) == MARKER_STUFF) {
- s->c |= 0xffL << (8 - s->ct);
- s->ct += 8;
- s->pscd_ptr += 2;
- s->result = JBG_OK;
- } else
- s->result = JBG_READY;
- }
- else {
- s->c |= (long)*(s->pscd_ptr++) << (8 - s->ct);
- s->ct += 8;
- s->result = JBG_OK;
- }
- }
- s->c <<= 1;
- s->a <<= 1;
- --s->ct;
- if (s->a == 0x10000L)
- s->startup = 0;
- }
- st = s->st + cx;
- ss = *st & 0x7f;
- assert(ss < 113);
- lsz = jbg_lsz[ss];
- #if 0
- fprintf(stderr, "cx = %d, mps = %d, st = %3d, lsz = 0x%04x, a = 0x%05lx, "
- "c = 0x%08lx, ct = %2d\n",
- cx, !!(s->st[cx] & 0x80), ss, lsz, s->a, s->c, s->ct);
- #endif
- if ((s->c >> 16) < (s->a -= lsz))
- if (s->a & 0xffff8000L)
- return *st >> 7;
- else {
- /* MPS_EXCHANGE */
- if (s->a < lsz) {
- pix = 1 - (*st >> 7);
- /* Check whether MPS/LPS exchange is necessary
- * and chose next probability estimator status */
- *st &= 0x80;
- *st ^= jbg_nlps[ss];
- } else {
- pix = *st >> 7;
- *st &= 0x80;
- *st |= jbg_nmps[ss];
- }
- }
- else {
- /* LPS_EXCHANGE */
- if (s->a < lsz) {
- s->c -= s->a << 16;
- s->a = lsz;
- pix = *st >> 7;
- *st &= 0x80;
- *st |= jbg_nmps[ss];
- } else {
- s->c -= s->a << 16;
- s->a = lsz;
- pix = 1 - (*st >> 7);
- /* Check whether MPS/LPS exchange is necessary
- * and chose next probability estimator status */
- *st &= 0x80;
- *st ^= jbg_nlps[ss];
- }
- }
- return pix;
- }
- /*
- * Memory management for buffers which are used for temporarily
- * storing SDEs by the encoder.
- *
- * The following functions manage a set of struct jbg_buf storage
- * containers were each can keep JBG_BUFSIZE bytes. The jbg_buf
- * containers can be linked to form linear double-chained lists for
- * which a number of operations are provided. Blocks which are
- * tempoarily not used any more are returned to a freelist which each
- * encoder keeps. Only the destructor of the encoder actually returns
- * the block via checked_free() to the stdlib memory management.
- */
- /*
- * Allocate a new buffer block and initialize it. Try to get it from
- * the free_list, and if it is empty, call checked_malloc().
- */
- static struct jbg_buf *jbg_buf_init(struct jbg_buf **free_list)
- {
- struct jbg_buf *new_block;
-
- /* Test whether a block from the free list is available */
- if (*free_list) {
- new_block = *free_list;
- *free_list = new_block->next;
- } else {
- /* request a new memory block */
- new_block = (struct jbg_buf *) checked_malloc(1, sizeof(struct jbg_buf));
- }
- new_block->len = 0;
- new_block->next = NULL;
- new_block->previous = NULL;
- new_block->last = new_block;
- new_block->free_list = free_list;
- return new_block;
- }
- /*
- * Return an entire free_list to the memory management of stdlib.
- * This is only done by jbg_enc_free().
- */
- static void jbg_buf_free(struct jbg_buf **free_list)
- {
- struct jbg_buf *tmp;
-
- while (*free_list) {
- tmp = (*free_list)->next;
- checked_free(*free_list);
- *free_list = tmp;
- }
-
- return;
- }
- /*
- * Append a single byte to a single list that starts with the block
- * *(struct jbg_buf *) head. The type of *head is void here in order to
- * keep the interface of the arithmetic encoder gereric, which uses this
- * function as a call-back function in order to deliver single bytes
- * for a PSCD.
- */
- static void jbg_buf_write(int b, void *head)
- {
- struct jbg_buf *now;
- now = ((struct jbg_buf *) head)->last;
- if (now->len < JBG_BUFSIZE - 1) {
- now->d[now->len++] = b;
- return;
- }
- now->next = jbg_buf_init(((struct jbg_buf *) head)->free_list);
- now->next->previous = now;
- now->next->d[now->next->len++] = b;
- ((struct jbg_buf *) head)->last = now->next;
- return;
- }
- /*
- * Remove any trailing zero bytes from the end of a linked jbg_buf list,
- * however make sure that no zero byte is removed which directly
- * follows a 0xff byte (i.e., keep MARKER_ESC MARKER_STUFF sequences
- * intact). This function is used to remove any redundant final zero
- * bytes from a PSCD.
- */
- static void jbg_buf_remove_zeros(struct jbg_buf *head)
- {
- struct jbg_buf *last;
- while (1) {
- /* remove trailing 0x00 in last block of list until this block is empty */
- last = head->last;
- while (last->len && last->d[last->len - 1] == 0)
- last->len--;
- /* if block became really empty, remove it in case it is not the
- * only remaining block and then loop to next block */
- if (last->previous && !last->len) {
- head->last->next = *head->free_list;
- *head->free_list = head->last;
- head->last = last->previous;
- head->last->next = NULL;
- } else
- break;
- }
- /*
- * If the final non-zero byte is 0xff (MARKER_ESC), then we just have
- * removed a MARKER_STUFF and we will append it again now in order
- * to preserve PSCD status of byte stream.
- */
- if (head->last->len && head->last->d[head->last->len - 1] == MARKER_ESC)
- jbg_buf_write(MARKER_STUFF, head);
-
- return;
- }
- /*
- * The jbg_buf list which starts with block *new_prefix is concatenated
- * with the list which starts with block **start and *start will then point
- * to the first block of the new list.
- */
- static void jbg_buf_prefix(struct jbg_buf *new_prefix, struct jbg_buf **start)
- {
- new_prefix->last->next = *start;
- new_prefix->last->next->previous = new_prefix->last;
- new_prefix->last = new_prefix->last->next->last;
- *start = new_prefix;
-
- return;
- }
- /*
- * Send the contents of a jbg_buf list that starts with block **head to
- * the call back function data_out and return the blocks of the jbg_buf
- * list to the freelist from which these jbg_buf blocks have been taken.
- * After the call, *head == NULL.
- */
- static void jbg_buf_output(struct jbg_buf **head,
- void (*data_out)(unsigned char *start,
- size_t len, void *file),
- void *file)
- {
- struct jbg_buf *tmp;
-
- while (*head) {
- data_out((*head)->d, (*head)->len, file);
- tmp = (*head)->next;
- (*head)->next = *(*head)->free_list;
- *(*head)->free_list = *head;
- *head = tmp;
- }
-
- return;
- }
- /*
- * Calculate y = ceil(x/2) applied n times, which is equivalent to
- * y = ceil(x/(2^n)). This function is used to
- * determine the number of pixels per row or column after n resolution
- * reductions. E.g. X[d-1] = jbg_ceil_half(X[d], 1) and X[0] =
- * jbg_ceil_half(X[d], d) as defined in clause 6.2.3 of T.82.
- */
- unsigned long jbg_ceil_half(unsigned long x, int n)
- {
- unsigned long mask;
-
- assert(n >= 0 && n < 32);
- mask = (1UL << n) - 1; /* the lowest n bits are 1 here */
- return (x >> n) + ((mask & x) != 0);
- }
- /*
- * Set L0 (the number of lines in a stripe at lowest resolution)
- * to a default value, such that there are about 35 stripes, as
- * suggested in Annex C of ITU-T T.82, without exceeding the
- * limit 128/2^D suggested in Annex A.
- */
- static void jbg_set_default_l0(struct jbg_enc_state *s)
- {
- s->l0 = jbg_ceil_half(s->yd, s->d) / 35; /* 35 stripes/image */
- while ((s->l0 << s->d) > 128) /* but <= 128 lines/stripe */
- --s->l0;
- if (s->l0 < 2) s->l0 = 2;
- }
- /*
- * Calculate the number of stripes, as defined in clause 6.2.3 of T.82.
- */
- static unsigned long jbg_stripes(unsigned long l0, unsigned long yd,
- unsigned long d)
- {
- unsigned long y0 = jbg_ceil_half(yd, d);
- return y0 / l0 + (y0 % l0 != 0);
- }
- /*
- * Initialize the status struct for the encoder.
- */
- void jbg_enc_init(struct jbg_enc_state *s, unsigned long x, unsigned long y,
- int planes, unsigned char **p,
- void (*data_out)(unsigned char *start, size_t len,
- void *file),
- void *file)
- {
- unsigned long l, lx;
- int i;
- extern char jbg_resred[], jbg_dptable[];
- s->xd = x;
- s->yd = y;
- s->yd1 = y; /* This is the hight initially announced in BIH. To provoke
- generation of NEWLEN for T.85 compatibility tests,
- overwrite with new value s->yd1 > s->yd */
- s->planes = planes;
- s->data_out = data_out;
- s->file = file;
- s->d = 0;
- s->dl = 0;
- s->dh = s->d;
- jbg_set_default_l0(s);
- s->mx = 8;
- s->my = 0;
- s->order = JBG_ILEAVE | JBG_SMID;
- s->options = JBG_TPBON | JBG_TPDON | JBG_DPON;
- s->dppriv = jbg_dptable;
- s->res_tab = jbg_resred;
-
- s->highres = (int *) checked_malloc(planes, sizeof(int));
- s->lhp[0] = p;
- s->lhp[1] = (unsigned char **)
- checked_malloc(planes, sizeof(unsigned char *));
- for (i = 0; i < planes; i++) {
- s->highres[i] = 0;
- s->lhp[1][i] = (unsigned char *)
- checked_malloc(jbg_ceil_half(y, 1), jbg_ceil_half(x, 1+3));
- }
-
- s->free_list = NULL;
- s->s = (struct jbg_arenc_state *)
- checked_malloc(s->planes, sizeof(struct jbg_arenc_state));
- s->tx = (int *) checked_malloc(s->planes, sizeof(int));
- lx = jbg_ceil_half(x, 1);
- s->tp = (char *) checked_malloc(lx, sizeof(char));
- for (l = 0; l < lx; s->tp[l++] = 2);
- s->sde = NULL;
- return;
- }
- /*
- * This function selects the number of differential layers based on
- * the maximum size requested for the lowest resolution layer. If
- * possible, a number of differential layers is selected, which will
- * keep the size of the lowest resolution layer below or equal to the
- * given width x and height y. However not more than 6 differential
- * resolution layers will be used. In addition, a reasonable value for
- * l0 (height of one stripe in the lowest resolution layer) is
- * selected, which obeys the recommended limitations for l0 in annex A
- * and C of the JBIG standard. The selected number of resolution layers
- * is returned.
- */
- int jbg_enc_lrlmax(struct jbg_enc_state *s, unsigned long x,
- unsigned long y)
- {
- for (s->d = 0; s->d < 6; s->d++)
- if (jbg_ceil_half(s->xd, s->d) <= x && jbg_ceil_half(s->yd, s->d) <= y)
- break;
- s->dl = 0;
- s->dh = s->d;
- jbg_set_default_l0(s);
- return s->d;
- }
- /*
- * As an alternative to jbg_enc_lrlmax(), the following function allows
- * to specify the number of layers directly. The stripe height and layer
- * range is also adjusted automatically here.
- */
- void jbg_enc_layers(struct jbg_enc_state *s, int d)
- {
- if (d < 0 || d > 31)
- return;
- s->d = d;
- s->dl = 0;
- s->dh = s->d;
- jbg_set_default_l0(s);
- return;
- }
- /*
- * Specify the highest and lowest resolution layers which will be
- * written to the output file. Call this function not before
- * jbg_enc_layers() or jbg_enc_lrlmax(), because these two functions
- * reset the lowest and highest resolution layer to default values.
- * Negative values are ignored. The total number of layers is returned.
- */
- int jbg_enc_lrange(struct jbg_enc_state *s, int dl, int dh)
- {
- if (dl >= 0 && dl <= s->d) s->dl = dl;
- if (dh >= s->dl && dh <= s->d) s->dh = dh;
- return s->d;
- }
- /*
- * The following function allows to specify the bits describing the
- * options of the format as well as the maximum AT movement window and
- * the number of layer 0 lines per stripes.
- */
- void jbg_enc_options(struct jbg_enc_state *s, int order, int options,
- unsigned long l0, int mx, int my)
- {
- if (order >= 0 && order <= 0x0f) s->order = order;
- if (options >= 0) s->options = options;
- if (l0 > 0) s->l0 = l0;
- if (mx >= 0 && my < 128) s->mx = mx;
- if (my >= 0 && my < 256) s->my = my;
- return;
- }
- /*
- * This function actually does all the tricky work involved in producing
- * a SDE, which is stored in the appropriate s->sde[][][] element
- * for later output in the correct order.
- */
- static void encode_sde(struct jbg_enc_state *s,
- long stripe, int layer, int plane)
- {
- unsigned char *hp, *lp1, *lp2, *p0, *p1, *q1, *q2;
- unsigned long hl, ll, hx, hy, lx, ly, hbpl, lbpl;
- unsigned long line_h0 = 0, line_h1 = 0;
- unsigned long line_h2, line_h3, line_l1, line_l2, line_l3;
- struct jbg_arenc_state *se;
- unsigned long i, j, y;
- long o;
- unsigned a, p, t;
- int ltp, ltp_old, cx;
- unsigned long c_all, c[MX_MAX + 1], cmin, cmax, clmin, clmax;
- int tmax, at_determined;
- int new_tx;
- long new_tx_line = -1;
- struct jbg_buf *new_jbg_buf;
- #ifdef DEBUG
- static long tp_lines, tp_exceptions, tp_pixels, dp_pixels;
- static long encoded_pixels;
- #endif
- /* return immediately if this stripe has already been encoded */
- if (s->sde[stripe][layer][plane] != SDE_TODO)
- return;
- #ifdef DEBUG
- if (stripe == 0)
- tp_lines = tp_exceptions = tp_pixels = dp_pixels = encoded_pixels = 0;
- fprintf(stderr, "encode_sde: s/d/p = %2ld/%2d/%2d\n",
- stripe, layer, plane);
- #endif
- /* number of lines per stripe in highres image */
- hl = s->l0 << layer;
- /* number of lines per stripe in lowres image */
- ll = hl >> 1;
- /* current line number in highres image */
- y = stripe * hl;
- /* number of pixels in highres image */
- hx = jbg_ceil_half(s->xd, s->d - layer);
- hy = jbg_ceil_half(s->yd, s->d - layer);
- /* number of pixels in lowres image */
- lx = jbg_ceil_half(hx, 1);
- ly = jbg_ceil_half(hy, 1);
- /* bytes per line in highres and lowres image */
- hbpl = jbg_ceil_half(hx, 3);
- lbpl = jbg_ceil_half(lx, 3);
- /* pointer to first image byte of highres stripe */
- hp = s->lhp[s->highres[plane]][plane] + stripe * hl * hbpl;
- lp2 = s->lhp[1 - s->highres[plane]][plane] + stripe * ll * lbpl;
- lp1 = lp2 + lbpl;
-
- /* initialize arithmetic encoder */
- se = s->s + plane;
- arith_encode_init(se, stripe != 0);
- s->sde[stripe][layer][plane] = jbg_buf_init(&s->free_list);
- se->byte_out = jbg_buf_write;
- se->file = s->sde[stripe][layer][plane];
- /* initialize adaptive template movement algorithm */
- c_all = 0;
- for (t = 0; t <= s->mx; t++)
- c[t] = 0;
- if (stripe == 0)
- s->tx[plane] = 0;
- new_tx = -1;
- at_determined = 0; /* we haven't yet decided the template move */
- if (s->mx == 0)
- at_determined = 1;
- /* initialize typical prediction */
- ltp = 0;
- if (stripe == 0)
- ltp_old = 0;
- else {
- ltp_old = 1;
- p1 = hp - hbpl;
- if (y > 1) {
- q1 = p1 - hbpl;
- while (p1 < hp && (ltp_old = (*p1++ == *q1++)) != 0);
- } else
- while (p1 < hp && (ltp_old = (*p1++ == 0)) != 0);
- }
- if (layer == 0) {
- /*
- * Encode lowest resolution layer
- */
- for (i = 0; i < hl && y < hy; i++, y++) {
- /* check whether it is worth to perform an ATMOVE */
- if (!at_determined && c_all > 2048) {
- cmin = clmin = 0xffffffffL;
- cmax = clmax = 0;
- tmax = 0;
- for (t = (s->options & JBG_LRLTWO) ? 5 : 3; t <= s->mx; t++) {
- if (c[t] > cmax) cmax = c[t];
- if (c[t] < cmin) cmin = c[t];
- if (c[t] > c[tmax]) tmax = t;
- }
- clmin = (c[0] < cmin) ? c[0] : cmin;
- clmax = (c[0] > cmax) ? c[0] : cmax;
- if (c_all - cmax < (c_all >> 3) &&
- cmax - c[s->tx[plane]] > c_all - cmax &&
- cmax - c[s->tx[plane]] > (c_all >> 4) &&
- /* ^ T.82 said < here, fixed in Cor.1/25 */
- cmax - (c_all - c[s->tx[plane]]) > c_all - cmax &&
- cmax - (c_all - c[s->tx[plane]]) > (c_all >> 4) &&
- cmax - cmin > (c_all >> 2) &&
- (s->tx[plane] || clmax - clmin > (c_all >> 3))) {
- /* we have decided to perform an ATMOVE */
- new_tx = tmax;
- if (!(s->options & JBG_DELAY_AT)) {
- new_tx_line = i;
- s->tx[plane] = new_tx;
- }
- #ifdef DEBUG
- fprintf(stderr, "ATMOVE: line=%ld, tx=%d, c_all=%ld\n",
- i, new_tx, c_all);
- #endif
- }
- at_determined = 1;
- }
- assert(s->tx[plane] >= 0); /* i.e., tx can safely be cast to unsigned */
-
- /* typical prediction */
- if (s->options & JBG_TPBON) {
- ltp = 1;
- p1 = hp;
- if (y > 0) {
- q1 = hp - hbpl;
- while (q1 < hp && (ltp = (*p1++ == *q1++)) != 0);
- } else
- while (p1 < hp + hbpl && (ltp = (*p1++ == 0)) != 0);
- arith_encode(se, (s->options & JBG_LRLTWO) ? TPB2CX : TPB3CX,
- ltp == ltp_old);
- #ifdef DEBUG
- tp_lines += ltp;
- #endif
- ltp_old = ltp;
- if (ltp) {
- /* skip next line */
- hp += hbpl;
- continue;
- }
- }
- /*
- * Layout of the variables line_h1, line_h2, line_h3, which contain
- * as bits the neighbour pixels of the currently coded pixel X:
- *
- * 76543210765432107654321076543210 line_h3
- * 76543210765432107654321076543210 line_h2
- * 76543210765432107654321X76543210 line_h1
- */
-
- line_h1 = line_h2 = line_h3 = 0;
- if (y > 0) line_h2 = (long)*(hp - hbpl) << 8;
- if (y > 1) line_h3 = (long)*(hp - hbpl - hbpl) << 8;
-
- /* encode line */
- for (j = 0; j < hx; hp++) {
- line_h1 |= *hp;
- if (j < hbpl * 8 - 8 && y > 0) {
- line_h2 |= *(hp - hbpl + 1);
- if (y > 1)
- line_h3 |= *(hp - hbpl - hbpl + 1);
- }
- if (s->options & JBG_LRLTWO) {
- /* two line template */
- do {
- line_h1 <<= 1; line_h2 <<= 1; line_h3 <<= 1;
- if (s->tx[plane]) {
- if ((unsigned) s->tx[plane] > j)
- a = 0;
- else {
- o = (j - s->tx[plane]) - (j & ~7L);
- a = (hp[o >> 3] >> (7 - (o & 7))) & 1;
- a <<= 4;
- }
- assert(s->tx[plane] > 23 ||
- a == ((line_h1 >> (4 + s->tx[plane])) & 0x010));
- arith_encode(se, (((line_h2 >> 10) & 0x3e0) | a |
- ((line_h1 >> 9) & 0x00f)),
- (line_h1 >> 8) & 1);
- }
- else
- arith_encode(se, (((line_h2 >> 10) & 0x3f0) |
- ((line_h1 >> 9) & 0x00f)),
- (line_h1 >> 8) & 1);
- #ifdef DEBUG
- encoded_pixels++;
- #endif
- /* statistics for adaptive template changes */
- if (!at_determined && j >= s->mx && j < hx-2) {
- p = (line_h1 & 0x100) != 0; /* current pixel value */
- c[0] += ((unsigned int)((line_h2 & 0x4000) != 0)) == p; /* default position */
- assert(!(((line_h2 >> 6) ^ line_h1) & 0x100) ==
- (((line_h2 & 0x4000) != 0) == p));
- for (t = 5; t <= s->mx && t <= j; t++) {
- o = (j - t) - (j & ~7L);
- a = (hp[o >> 3] >> (7 - (o & 7))) & 1;
- assert(t > 23 ||
- (a == p) == !(((line_h1 >> t) ^ line_h1) & 0x100));
- c[t] += a == p;
- }
- for (; t <= s->mx; t++) {
- c[t] += 0 == p;
- }
- ++c_all;
- }
- } while (++j & 7 && j < hx);
- } else {
- /* three line template */
- do {
- line_h1 <<= 1; line_h2 <<= 1; line_h3 <<= 1;
- if (s->tx[plane]) {
- if ((unsigned) s->tx[plane] > j)
- a = 0;
- else {
- o = (j - s->tx[plane]) - (j & ~7L);
- a = (hp[o >> 3] >> (7 - (o & 7))) & 1;
- a <<= 2;
- }
- assert(s->tx[plane] > 23 ||
- a == ((line_h1 >> (6 + s->tx[plane])) & 0x004));
- arith_encode(se, (((line_h3 >> 8) & 0x380) |
- ((line_h2 >> 12) & 0x078) | a |
- ((line_h1 >> 9) & 0x003)),
- (line_h1 >> 8) & 1);
- } else
- arith_encode(se, (((line_h3 >> 8) & 0x380) |
- ((line_h2 >> 12) & 0x07c) |
- ((line_h1 >> 9) & 0x003)),
- (line_h1 >> 8) & 1);
- #ifdef DEBUG
- encoded_pixels++;
- #endif
- /* statistics for adaptive template changes */
- if (!at_determined && j >= s->mx && j < hx-2) {
- p = (line_h1 & 0x100) != 0; /* current pixel value */
- c[0] += ((unsigned int)((line_h2 & 0x4000) != 0)) == p; /* default position */
- assert(!(((line_h2 >> 6) ^ line_h1) & 0x100) ==
- (((line_h2 & 0x4000) != 0) == p));
- for (t = 3; t <= s->mx && t <= j; t++) {
- o = (j - t) - (j & ~7L);
- a = (hp[o >> 3] >> (7 - (o & 7))) & 1;
- assert(t > 23 ||
- (a == p) == !(((line_h1 >> t) ^ line_h1) & 0x100));
- c[t] += a == p;
- }
- for (; t <= s->mx; t++) {
- c[t] += 0 == p;
- }
- ++c_all;
- }
- } while (++j & 7 && j < hx);
- } /* if (s->options & JBG_LRLTWO) */
- } /* for (j = ...) */
- } /* for (i = ...) */
- } else {
- /*
- * Encode differential layer
- */
-
- for (i = 0; i < hl && y < hy; i++, y++) {
- /* check whether it is worth to perform an ATMOVE */
- if (!at_determined && c_all > 2048) {
- cmin = clmin = 0xffffffffL;
- cmax = clmax = 0;
- tmax = 0;
- for (t = 3; t <= s->mx; t++) {
- if (c[t] > cmax) cmax = c[t];
- if (c[t] < cmin) cmin = c[t];
- if (c[t] > c[tmax]) tmax = t;
- }
- clmin = (c[0] < cmin) ? c[0] : cmin;
- clmax = (c[0] > cmax) ? c[0] : cmax;
- if (c_all - cmax < (c_all >> 3) &&
- cmax - c[s->tx[plane]] > c_all - cmax &&
- cmax - c[s->tx[plane]] > (c_all >> 4) &&
- /* ^ T.82 said < here, fixed in Cor.1/25 */
- cmax - (c_all - c[s->tx[plane]]) > c_all - cmax &&
- cmax - (c_all - c[s->tx[plane]]) > (c_all >> 4) &&
- cmax - cmin > (c_all >> 2) &&
- (s->tx[plane] || clmax - clmin > (c_all >> 3))) {
- /* we have decided to perform an ATMOVE */
- new_tx = tmax;
- if (!(s->options & JBG_DELAY_AT)) {
- new_tx_line = i;
- s->tx[plane] = new_tx;
- }
- #ifdef DEBUG
- fprintf(stderr, "ATMOVE: line=%ld, tx=%d, c_all=%ld\n",
- i, new_tx, c_all);
- #endif
- }
- at_determined = 1;
- }
-
- if ((i >> 1) >= ll - 1 || (y >> 1) >= ly - 1)
- lp1 = lp2;
- /* typical prediction */
- if (s->options & JBG_TPDON && (i & 1) == 0) {
- q1 = lp1; q2 = lp2;
- p0 = p1 = hp;
- if (i < hl - 1 && y < hy - 1)
- p0 = hp + hbpl;
- if (y > 1)
- line_l3 = (long)*(q2 - lbpl) << 8;
- else
- line_l3 = 0;
- line_l2 = (long)*q2 << 8;
- line_l1 = (long)*q1 << 8;
- ltp = 1;
- for (j = 0; j < lx && ltp; q1++, q2++) {
- if (j < lbpl * 8 - 8) {
- if (y > 1)
- line_l3 |= *(q2 - lbpl + 1);
- line_l2 |= *(q2 + 1);
- line_l1 |= *(q1 + 1);
- }
- do {
- if ((j >> 2) < hbpl) {
- line_h1 = *(p1++);
- line_h0 = *(p0++);
- }
- do {
- line_l3 <<= 1;
- line_l2 <<= 1;
- line_l1 <<= 1;
- line_h1 <<= 2;
- line_h0 <<= 2;
- cx = (((line_l3 >> 15) & 0x007) |
- ((line_l2 >> 12) & 0x038) |
- ((line_l1 >> 9) & 0x1c0));
- if (cx == 0x000)
- if ((line_h1 & 0x300) == 0 && (line_h0 & 0x300) == 0)
- s->tp[j] = 0;
- else {
- ltp = 0;
- #ifdef DEBUG
- tp_exceptions++;
- #endif
- }
- else if (cx == 0x1ff)
- if ((line_h1 & 0x300) == 0x300 && (line_h0 & 0x300) == 0x300)
- s->tp[j] = 1;
- else {
- ltp = 0;
- #ifdef DEBUG
- tp_exceptions++;
- #endif
- }
- else
- s->tp[j] = 2;
- } while (++j & 3 && j < lx);
- } while (j & 7 && j < lx);
- } /* for (j = ...) */
- arith_encode(se, TPDCX, !ltp);
- #ifdef DEBUG
- tp_lines += ltp;
- #endif
- }
- /*
- * Layout of the variables line_h1, line_h2, line_h3, which contain
- * as bits the high resolution neighbour pixels of the currently coded
- * highres pixel X:
- *
- * 76543210 76543210 76543210 76543210 line_h3
- * 76543210 76543210 76543210 76543210 line_h2
- * 76543210 76543210 7654321X 76543210 line_h1
- *
- * Layout of the variables line_l1, line_l2, line_l3, which contain
- * the low resolution pixels near the currently coded pixel as bits.
- * The lowres pixel in which the currently coded highres pixel is
- * located is marked as Y:
- *
- * 76543210 76543210 76543210 76543210 line_l3
- * 76543210 7654321Y 76543210 76543210 line_l2
- * 76543210 76543210 76543210 76543210 line_l1
- */
-
- line_h1 = line_h2 = line_h3 = line_l1 = line_l2 = line_l3 = 0;
- if (y > 0) line_h2 = (long)*(hp - hbpl) << 8;
- if (y > 1) {
- line_h3 = (long)*(hp - hbpl - hbpl) << 8;
- line_l3 = (long)*(lp2 - lbpl) << 8;
- }
- line_l2 = (long)*lp2 << 8;
- line_l1 = (long)*lp1 << 8;
-
- /* encode line */
- for (j = 0; j < hx; lp1++, lp2++) {
- if ((j >> 1) < lbpl * 8 - 8) {
- if (y > 1)
- line_l3 |= *(lp2 - lbpl + 1);
- line_l2 |= *(lp2 + 1);
- line_l1 |= *(lp1 + 1);
- }
- do { /* ... while (j & 15 && j < hx) */
- assert(hp - (s->lhp[s->highres[plane]][plane] +
- (stripe * hl + i) * hbpl)
- == (ptrdiff_t) j >> 3);
- assert(lp2 - (s->lhp[1-s->highres[plane]][plane] +
- (stripe * ll + (i>>1)) * lbpl)
- == (ptrdiff_t) j >> 4);
- line_h1 |= *hp;
- if (j < hbpl * 8 - 8) {
- if (y > 0) {
- line_h2 |= *(hp - hbpl + 1);
- if (y > 1)
- line_h3 |= *(hp - hbpl - hbpl + 1);
- }
- }
- do { /* ... while (j & 7 && j < hx) */
- line_l1 <<= 1; line_l2 <<= 1; line_l3 <<= 1;
- if (ltp && s->tp[j >> 1] < 2) {
- /* pixel are typical and have not to be encoded */
- line_h1 <<= 2; line_h2 <<= 2; line_h3 <<= 2;
- #ifdef DEBUG
- do {
- ++tp_pixels;
- } while (++j & 1 && j < hx);
- #else
- j += 2;
- #endif
- } else
- do { /* ... while (++j & 1 && j < hx) */
- line_h1 <<= 1; line_h2 <<= 1; line_h3 <<= 1;
- /* deterministic prediction */
- if (s->options & JBG_DPON) {
- if ((y & 1) == 0) {
- if ((j & 1) == 0) {
- /* phase 0 */
- if (s->dppriv[((line_l3 >> 16) & 0x003) |
- ((line_l2 >> 14) & 0x00c) |
- ((line_h1 >> 5) & 0x010) |
- ((line_h2 >> 10) & 0x0e0)] < 2) {
- #ifdef DEBUG
- ++dp_pixels;
- #endif
- continue;
- }
- } else {
- /* phase 1 */
- if (s->dppriv[(((line_l3 >> 16) & 0x003) |
- ((line_l2 >> 14) & 0x00c) |
- ((line_h1 >> 5) & 0x030) |
- ((line_h2 >> 10) & 0x1c0)) + 256] < 2) {
- #ifdef DEBUG
- ++dp_pixels;
- #endif
- continue;
- }
- }
- } else {
- if ((j & 1) == 0) {
- /* phase 2 */
- if (s->dppriv[(((line_l3 >> 16) & 0x003) |
- ((line_l2 >> 14) & 0x00c) |
- ((line_h1 >> 5) & 0x010) |
- ((line_h2 >> 10) & 0x0e0) |
- ((line_h3 >> 7) & 0x700)) + 768] < 2) {
- #ifdef DEBUG
- ++dp_pixels;
- #endif
- continue;
- }
- } else {
- /* phase 3 */
- if (s->dppriv[(((line_l3 >> 16) & 0x003) |
- ((line_l2 >> 14) & 0x00c) |
- ((line_h1 >> 5) & 0x030) |
- ((line_h2 >> 10) & 0x1c0) |
- ((line_h3 >> 7) & 0xe00)) + 2816] < 2) {
- #ifdef DEBUG
- ++dp_pixels;
- #endif
- continue;
- }
- }
- }
- }
- /* determine context */
- if (s->tx[plane]) {
- if ((unsigned) s->tx[plane] > j)
- a = 0;
- else {
- o = (j - s->tx[plane]) - (j & ~7L);
- a = (hp[o >> 3] >> (7 - (o & 7))) & 1;
- a <<= 4;
- }
- assert(s->tx[plane] > 23 ||
- a == ((line_h1 >> (4 + s->tx[plane])) & 0x010));
- cx = (((line_h1 >> 9) & 0x003) | a |
- ((line_h2 >> 13) & 0x00c) |
- ((line_h3 >> 11) & 0x020));
- } else
- cx = (((line_h1 >> 9) & 0x003) |
- ((line_h2 >> 13) & 0x01c) |
- ((line_h3 >> 11) & 0x020));
- if (j & 1)
- cx |= (((line_l2 >> 9) & 0x0c0) |
- ((line_l1 >> 7) & 0x300)) | (1UL << 10);
- else
- cx |= (((line_l2 >> 10) & 0x0c0) |
- ((line_l1 >> 8) & 0x300));
- cx |= (y & 1) << 11;
- arith_encode(se, cx, (line_h1 >> 8) & 1);
- #ifdef DEBUG
- encoded_pixels++;
- #endif
-
- /* statistics for adaptive template changes */
- if (!at_determined && j >= s->mx) {
- c[0] += !(((line_h2 >> 6) ^ line_h1) & 0x100);
- for (t = 3; t <= s->mx; t++)
- c[t] += !(((line_h1 >> t) ^ line_h1) & 0x100);
- ++c_all;
- }
-
- } while (++j & 1 && j < hx);
- } while (j & 7 && j < hx);
- hp++;
- } while (j & 15 && j < hx);
- } /* for (j = ...) */
- /* low resolution pixels are used twice */
- if ((i & 1) == 0) {
- lp1 -= lbpl;
- lp2 -= lbpl;
- }
-
- } /* for (i = ...) */
- }
-
- arith_encode_flush(se);
- jbg_buf_remove_zeros(s->sde[stripe][layer][plane]);
- jbg_buf_write(MARKER_ESC, s->sde[stripe][layer][plane]);
- jbg_buf_write(MARKER_SDNORM, s->sde[stripe][layer][plane]);
- /* add ATMOVE */
- if (new_tx != -1) {
- if (s->options & JBG_DELAY_AT) {
- /* ATMOVE will become active at the first line of the next stripe */
- s->tx[plane] = new_tx;
- jbg_buf_write(MARKER_ESC, s->sde[stripe][layer][plane]);
- jbg_buf_write(MARKER_ATMOVE, s->sde[stripe][layer][plane]);
- jbg_buf_write(0, s->sde[stripe][layer][plane]);
- jbg_buf_write(0, s->sde[stripe][layer][plane]);
- jbg_buf_write(0, s->sde[stripe][layer][plane]);
- jbg_buf_write(0, s->sde[stripe][layer][plane]);
- jbg_buf_write(s->tx[plane], s->sde[stripe][layer][plane]);
- jbg_buf_write(0, s->sde[stripe][layer][plane]);
- } else {
- /* ATMOVE has already become active during this stripe
- * => we have to prefix the SDE data with an ATMOVE marker */
- new_jbg_buf = jbg_buf_init(&s->free_list);
- jbg_buf_write(MARKER_ESC, new_jbg_buf);
- jbg_buf_write(MARKER_ATMOVE, new_jbg_buf);
- jbg_buf_write((new_tx_line >> 24) & 0xff, new_jbg_buf);
- jbg_buf_write((new_tx_line >> 16) & 0xff, new_jbg_buf);
- jbg_buf_write((new_tx_line >> 8) & 0xff, new_jbg_buf);
- jbg_buf_write(new_tx_line & 0xff, new_jbg_buf);
- jbg_buf_write(new_tx, new_jbg_buf);
- jbg_buf_write(0, new_jbg_buf);
- jbg_buf_prefix(new_jbg_buf, &s->sde[stripe][layer][plane]);
- }
- }
- #if 0
- if (stripe == s->stripes - 1)
- fprintf(stderr, "tp_lines = %ld, tp_exceptions = %ld, tp_pixels = %ld, "
- "dp_pixels = %ld, encoded_pixels = %ld\n",
- tp_lines, tp_exceptions, tp_pixels, dp_pixels, encoded_pixels);
- #endif
- return;
- }
- /*
- * Create the next lower resolution version of an image
- */
- static void resolution_reduction(struct jbg_enc_state *s, int plane,
- int higher_layer)
- {
- unsigned long hx, hy, lx, ly, hbpl, lbpl;
- unsigned char *hp1, *hp2, *hp3, *lp;
- unsigned long line_h1, line_h2, line_h3, line_l2;
- unsigned long i, j;
- int pix, k, l;
- /* number of pixels in highres image */
- hx = jbg_ceil_half(s->xd, s->d - higher_layer);
- hy = jbg_ceil_half(s->yd, s->d - higher_layer);
- /* number of pixels in lowres image */
- lx = jbg_ceil_half(hx, 1);
- ly = jbg_ceil_half(hy, 1);
- /* bytes per line in highres and lowres image */
- hbpl = jbg_ceil_half(hx, 3);
- lbpl = jbg_ceil_half(lx, 3);
- /* pointers to first image bytes */
- hp2 = s->lhp[s->highres[plane]][plane];
- hp1 = hp2 + hbpl;
- hp3 = hp2 - hbpl;
- lp = s->lhp[1 - s->highres[plane]][plane];
-
- #ifdef DEBUG
- fprintf(stderr, "resolution_reduction: plane = %d, higher_layer = %d\n",
- plane, higher_layer);
- #endif
- /*
- * Layout of the variables line_h1, line_h2, line_h3, which contain
- * as bits the high resolution neighbour pixels of the currently coded
- * lowres pixel /\:
- * \/
- *
- * 76543210 76543210 76543210 76543210 line_h3
- * 76543210 76543210 765432/\ 76543210 line_h2
- * 76543210 76543210 765432\/ 76543210 line_h1
- *
- * Layout of the variable line_l2, which contains the low resolution
- * pixels near the currently coded pixel as bits. The lowres pixel
- * which is currently coded is marked as X:
- *
- * 76543210 76543210 76543210 76543210 line_l2
- * X
- */
- for (i = 0; i < ly; i++) {
- if (2*i + 1 >= hy)
- hp1 = hp2;
- pix = 0;
- line_h1 = line_h2 = line_h3 = line_l2 = 0;
- for (j = 0; j < lbpl * 8; j += 8) {
- *lp = 0;
- line_l2 |= i ? *(lp-lbpl) : 0;
- for (k = 0; k < 8 && j + k < lx; k += 4) {
- if (((j + k) >> 2) < hbpl) {
- line_h3 |= i ? *hp3 : 0;
- ++hp3;
- line_h2 |= *(hp2++);
- line_h1 |= *(hp1++);
- }
- for (l = 0; l < 4 && j + k + l < lx; l++) {
- line_h3 <<= 2;
- line_h2 <<= 2;
- line_h1 <<= 2;
- line_l2 <<= 1;
- pix = s->res_tab[((line_h1 >> 8) & 0x007) |
- ((line_h2 >> 5) & 0x038) |
- ((line_h3 >> 2) & 0x1c0) |
- (pix << 9) | ((line_l2 << 2) & 0xc00)];
- *lp = (*lp << 1) | pix;
- }
- }
- ++lp;
- }
- *(lp - 1) <<= lbpl * 8 - lx;
- hp1 += hbpl;
- hp2 += hbpl;
- hp3 += hbpl;
- }
- #ifdef DEBUG
- {
- FILE *f;
- char fn[50];
-
- sprintf(fn, "dbg_d=%02d.pbm", higher_layer - 1);
- f = fopen(fn, "wb");
- fprintf(f, "P4\n%lu %lu\n", lx, ly);
- fwrite(s->lhp[1 - s->highres[plane]][plane], 1, lbpl * ly, f);
- fclose(f);
- }
- #endif
- return;
- }
- /*
- * This function is called inside the three loops of jbg_enc_out() in
- * order to write the next SDE. It has first to generate the required
- * SDE and all SDEs which have to be encoded before this SDE can be
- * created. The problem here is that if we want to output a lower
- * resolution layer, we have to allpy the resolution reduction
- * algorithm in order to get it. As we try to safe as much memory as
- * possible, the resolution reduction will overwrite previous higher
- * resolution bitmaps. Consequently, we have to encode and buffer SDEs
- * which depend on higher resolution layers before we can start the
- * resolution reduction. All this logic about which SDE has to be
- * encoded before resolution reduction is allowed is handled here.
- * This approach might be a little bit more complex than alternative
- * ways to do it, but it allows us to do the encoding with the minimal
- * possible amount of temporary memory.
- */
- static void output_sde(struct jbg_enc_state *s,
- unsigned long stripe, int layer, int plane)
- {
- int lfcl; /* lowest fully coded layer */
- long i;
- unsigned long u;
-
- assert(s->sde[stripe][layer][plane] != SDE_DONE);
- if (s->sde[stripe][layer][plane] != SDE_TODO) {
- #ifdef DEBUG
- fprintf(stderr, "writing SDE: s/d/p = %2lu/%2d/%2d\n",
- stripe, layer, plane);
- #endif
- jbg_buf_output(&s->sde[stripe][layer][plane], s->data_out, s->file);
- s->sde[stripe][layer][plane] = SDE_DONE;
- return;
- }
- /* Determine the smallest resolution layer in this plane for which
- * not yet all stripes have been encoded into SDEs. This layer will
- * have to be completely coded, before we can apply the next
- * resolution reduction step. */
- lfcl = 0;
- for (i = s->d; i >= 0; i--)
- if (s->sde[s->stripes - 1][i][plane] == SDE_TODO) {
- lfcl = i + 1;
- break;
- }
- if (lfcl > s->d && s->d > 0 && stripe == 0) {
- /* perform the first resolution reduction */
- resolution_reduction(s, plane, s->d);
- }
- /* In case HITOLO is not used, we have to encode and store the higher
- * resolution layers first, although we do not need them right now. */
- while (lfcl - 1 > layer) {
- for (u = 0; u < s->stripes; u++)
- encode_sde(s, u, lfcl - 1, plane);
- --lfcl;
- s->highres[plane] ^= 1;
- if (lfcl > 1)
- resolution_reduction(s, plane, lfcl - 1);
- }
-
- encode_sde(s, stripe, layer, plane);
- #ifdef DEBUG
- fprintf(stderr, "writing SDE: s/d/p = %2lu/%2d/%2d\n", stripe, layer, plane);
- #endif
- jbg_buf_output(&s->sde[stripe][layer][plane], s->data_out, s->file);
- s->sde[stripe][layer][plane] = SDE_DONE;
-
- if (stripe == s->stripes - 1 && layer > 0 &&
- s->sde[0][layer-1][plane] == SDE_TODO) {
- s->highres[plane] ^= 1;
- if (layer > 1)
- resolution_reduction(s, plane, layer - 1);
- }
-
- return;
- }
- /*
- * Convert the table which controls the deterministic prediction
- * process from the internal format into the representation required
- * for the 1728 byte long DPTABLE element of a BIH.
- *
- * The bit order of the DPTABLE format (see also ITU-T T.82 figure 13) is
- *
- * high res: 4 5 6 low res: 0 1
- * 7 8 9 2 3
- * 10 11 12
- *
- * were 4 table entries are packed into one byte, while we here use
- * internally an unpacked 6912 byte long table indexed by the following
- * bit order:
- *
- * high res: 7 6 5 high res: 8 7 6 low res: 1 0
- * (phase 0) 4 . . (phase 1) 5 4 . 3 2
- * . . . . . .
- *
- * high res: 10 9 8 high res: 11 10 9
- * (phase 2) 7 6 5 (phase 3) 8 7 6
- * 4 . . 5 4 .
- */
- void jbg_int2dppriv(unsigned char *dptable, const char *internal)
- {
- int i, j, k;
- int trans0[ 8] = { 1, 0, 3, 2, 7, 6, 5, 4 };
- int trans1[ 9] = { 1, 0, 3, 2, 8, 7, 6, 5, 4 };
- int trans2[11] = { 1, 0, 3, 2, 10, 9, 8, 7, 6, 5, 4 };
- int trans3[12] = { 1, 0, 3, 2, 11, 10, 9, 8, 7, 6, 5, 4 };
-
- for (i = 0; i < 1728; dptable[i++] = 0);
- #define FILL_TABLE1(offset, len, trans) \
- for (i = 0; i < len; i++) { \
- k = 0; \
- for (j = 0; j < 8; j++) \
- k |= ((i >> j) & 1) << trans[j]; \
- dptable[(i + offset) >> 2] |= \
- (internal[k + offset] & 3) << ((3 - (i&3)) << 1); \
- }
- FILL_TABLE1( 0, 256, trans0);
- FILL_TABLE1( 256, 512, trans1);
- FILL_TABLE1( 768, 2048, trans2);
- FILL_TABLE1(2816, 4096, trans3);
- return;
- }
- /*
- * Convert the table which controls the deterministic prediction
- * process from the 1728 byte long DPTABLE format into the 6912 byte long
- * internal format.
- */
- void jbg_dppriv2int(char *internal, const unsigned char *dptable)
- {
- int i, j, k;
- int trans0[ 8] = { 1, 0, 3, 2, 7, 6, 5, 4 };
- int trans1[ 9] = { 1, 0, 3, 2, 8, 7, 6, 5, 4 };
- int trans2[11] = { 1, 0, 3, 2, 10, 9, 8, 7, 6, 5, 4 };
- int trans3[12] = { 1, 0, 3, 2, 11, 10, 9, 8, 7, 6, 5, 4 };
-
- #define FILL_TABLE2(offset, len, trans) \
- for (i = 0; i < len; i++) { \
- k = 0; \
- for (j = 0; j < 8; j++) \
- k |= ((i >> j) & 1) << trans[j]; \
- internal[k + offset] = \
- (dptable[(i + offset) >> 2] >> ((3 - (i & 3)) << 1)) & 3; \
- }
- FILL_TABLE2( 0, 256, trans0);
- FILL_TABLE2( 256, 512, trans1);
- FILL_TABLE2( 768, 2048, trans2);
- FILL_TABLE2(2816, 4096, trans3);
- return;
- }
- /*
- * Encode one full BIE and pass the generated data to the specified
- * call-back function
- */
- void jbg_enc_out(struct jbg_enc_state *s)
- {
- unsigned long bpl;
- unsigned char buf[20];
- unsigned long xd, yd, y;
- long ii[3], is[3], ie[3]; /* generic variables for the 3 nested loops */
- unsigned long stripe;
- int layer, plane;
- int order;
- unsigned char dpbuf[1728];
- extern char jbg_dptable[];
- /* some sanity checks */
- s->order &= JBG_HITOLO | JBG_SEQ | JBG_ILEAVE | JBG_SMID;
- order = s->order & (JBG_SEQ | JBG_ILEAVE | JBG_SMID);
- if (iindex[order][0] < 0)
- s->order = order = JBG_SMID | JBG_ILEAVE;
- if (s->options & JBG_DPON && s->dppriv != jbg_dptable)
- s->options |= JBG_DPPRIV;
- if (s->mx > MX_MAX)
- s->mx = MX_MAX;
- s->my = 0;
- if (s->mx && s->mx < ((s->options & JBG_LRLTWO) ? 5U : 3U))
- s->mx = 0;
- if (s->d > 255 || s->d < 0 || s->dh > s->d || s->dh < 0 ||
- s->dl < 0 || s->dl > s->dh || s->planes < 0 || s->planes > 255)
- return;
- /* prevent uint32 overflow: s->l0 * 2 ^ s->d < 2 ^ 32 */
- if (s->d > 31 || (s->d != 0 && s->l0 >= (1UL << (32 - s->d))))
- return;
- if (s->yd1 < s->yd)
- s->yd1 = s->yd;
- if (s->yd1 > s->yd)
- s->options |= JBG_VLENGTH;
- /* ensure correct zero padding of bitmap at the final byte of each line */
- if (s->xd & 7) {
- bpl = jbg_ceil_half(s->xd, 3); /* bytes per line */
- for (plane = 0; plane < s->planes; plane++)
- for (y = 0; y < s->yd; y++)
- s->lhp[0][plane][y * bpl + bpl - 1] &= ~((1 << (8 - (s->xd & 7))) - 1);
- }
- /* prepare BIH */
- buf[0] = s->dl;
- buf[1] = s->dh;
- buf[2] = s->planes;
- buf[3] = 0;
- xd = jbg_ceil_half(s->xd, s->d - s->dh);
- yd = jbg_ceil_half(s->yd1, s->d - s->dh);
- buf[4] = (unsigned char)(xd >> 24);
- buf[5] = (unsigned char)((xd >> 16) & 0xff);
- buf[6] = (unsigned char)((xd >> 8) & 0xff);
- buf[7] = (unsigned char)(xd & 0xff);
- buf[8] = (unsigned char)(yd >> 24);
- buf[9] = (unsigned char)((yd >> 16) & 0xff);
- buf[10] = (unsigned char)((yd >> 8) & 0xff);
- buf[11] = (unsigned char)(yd & 0xff);
- buf[12] = (unsigned char)(s->l0 >> 24);
- buf[13] = (unsigned char)((s->l0 >> 16) & 0xff);
- buf[14] = (unsigned char)((s->l0 >> 8) & 0xff);
- buf[15] = (unsigned char)(s->l0 & 0xff);
- buf[16] = (unsigned char)(s->mx);
- buf[17] = (unsigned char)(s->my);
- buf[18] = (unsigned char)(s->order);
- buf[19] = (unsigned char)(s->options & 0x7f);
- #if 0
- /* sanitize L0 (if it was set to 0xffffffff for T.85-style NEWLEN tests) */
- if (s->l0 > (s->yd >> s->d))
- s->l0 = s->yd >> s->d;
- #endif
- /* calculate number of stripes that will be required */
- s->stripes = jbg_stripes(s->l0, s->yd, s->d);
- /* allocate buffers for SDE pointers */
- if (s->sde == NULL) {
- s->sde = (struct jbg_buf ****)
- checked_malloc(s->stripes, sizeof(struct jbg_buf ***));
- for (stripe = 0; stripe < s->stripes; stripe++) {
- s->sde[stripe] = (struct jbg_buf ***)
- checked_malloc(s->d + 1, sizeof(struct jbg_buf **));
- for (layer = 0; layer < s->d + 1; layer++) {
- s->sde[stripe][layer] = (struct jbg_buf **)
- checked_malloc(s->planes, sizeof(struct jbg_buf *));
- for (plane = 0; plane < s->planes; plane++)
- s->sde[stripe][layer][plane] = SDE_TODO;
- }
- }
- }
- /* output BIH */
- s->data_out(buf, 20, s->file);
- if ((s->options & (JBG_DPON | JBG_DPPRIV | JBG_DPLAST)) ==
- (JBG_DPON | JBG_DPPRIV)) {
- /* write private table */
- jbg_int2dppriv(dpbuf, s->dppriv);
- s->data_out(dpbuf, 1728, s->file);
- }
- #if 0
- /*
- * Encode everything first. This is a simple-minded alternative to
- * all the tricky on-demand encoding logic in output_sde() for
- * debugging purposes.
- */
- for (layer = s->dh; layer >= s->dl; layer--) {
- for (plane = 0; plane < s->planes; plane++) {
- if (layer > 0)
- resolution_reduction(s, plane, layer);
- for (stripe = 0; stripe < s->stripes; stripe++)
- encode_sde(s, stripe, layer, plane);
- s->highres[plane] ^= 1;
- }
- }
- #endif
- /*
- * Generic loops over all SDEs. Which loop represents layer, plane and
- * stripe depends on the option flags.
- */
- /* start and end value vor each loop */
- is[iindex[order][STRIPE]] = 0;
- ie[iindex[order][STRIPE]] = s->stripes - 1;
- is[iindex[order][LAYER]] = s->dl;
- ie[iindex[order][LAYER]] = s->dh;
- is[iindex[order][PLANE]] = 0;
- ie[iindex[order][PLANE]] = s->planes - 1;
- for (ii[0] = is[0]; ii[0] <= ie[0]; ii[0]++)
- for (ii[1] = is[1]; ii[1] <= ie[1]; ii[1]++)
- for (ii[2] = is[2]; ii[2] <= ie[2]; ii[2]++) {
-
- stripe = ii[iindex[order][STRIPE]];
- if (s->order & JBG_HITOLO)
- layer = s->dh - (ii[iindex[order][LAYER]] - s->dl);
- else
- layer = ii[iindex[order][LAYER]];
- plane = ii[iindex[order][PLANE]];
- output_sde(s, stripe, layer, plane);
- /*
- * When we generate a NEWLEN test case (s->yd1 > s->yd), output
- * NEWLEN after last stripe if we have only a single
- * resolution layer or plane (see ITU-T T.85 profile), otherwise
- * output NEWLEN before last stripe.
- */
- if (s->yd1 > s->yd &&
- (stripe == s->stripes - 1 ||
- (stripe == s->stripes - 2 &&
- (s->dl != s->dh || s->planes > 1)))) {
- s->yd1 = s->yd;
- yd = jbg_ceil_half(s->yd, s->d - s->dh);
- buf[0] = MARKER_ESC;
- buf[1] = MARKER_NEWLEN;
- buf[2] = (unsigned char)(yd >> 24);
- buf[3] = (unsigned char)((yd >> 16) & 0xff);
- buf[4] = (unsigned char)((yd >> 8) & 0xff);
- buf[5] = (unsigned char)(yd & 0xff);
- s->data_out(buf, 6, s->file);
- #ifdef DEBUG
- fprintf(stderr, "NEWLEN: yd=%lu\n", yd);
- #endif
- if (stripe == s->stripes - 1) {
- buf[1] = MARKER_SDNORM;
- s->data_out(buf, 2, s->file);
- }
- }
- }
- return;
- }
- void jbg_enc_free(struct jbg_enc_state *s)
- {
- unsigned long stripe;
- int layer, plane;
- #ifdef DEBUG
- fprintf(stderr, "jbg_enc_free(%p)\n", (void *) s);
- #endif
- /* clear buffers for SDEs */
- if (s->sde) {
- for (stripe = 0; stripe < s->stripes; stripe++) {
- for (layer = 0; layer < s->d + 1; layer++) {
- for (plane = 0; plane < s->planes; plane++)
- if (s->sde[stripe][layer][plane] != SDE_DONE &&
- s->sde[stripe][layer][plane] != SDE_TODO)
- jbg_buf_free(&s->sde[stripe][layer][plane]);
- checked_free(s->sde[stripe][layer]);
- }
- checked_free(s->sde[stripe]);
- }
- checked_free(s->sde);
- }
- /* clear free_list */
- jbg_buf_free(&s->free_list);
- /* clear memory for arithmetic encoder states */
- checked_free(s->s);
- /* clear memory for differential-layer typical prediction buffer */
- checked_free(s->tp);
- /* clear memory for adaptive template pixel offsets */
- checked_free(s->tx);
- /* clear lowres image buffers */
- if (s->lhp[1]) {
- for (plane = 0; plane < s->planes; plane++)
- checked_free(s->lhp[1][plane]);
- checked_free(s->lhp[1]);
- }
-
- /* clear buffer for index of highres image in lhp */
- checked_free(s->highres);
-
- return;
- }
- /*
- * Convert the error codes used by jbg_dec_in() into a string
- * written in the selected language and character set.
- */
- const char *jbg_strerror(int errnum, int language)
- {
- if (errnum < 0 || errnum >= NEMSG)
- return "Unknown error code passed to jbg_strerror()";
- if (language < 0 || language >= NEMSG_LANG)
- return "Unknown language code passed to jbg_strerror()";
- return errmsg[language][errnum];
- }
- /*
- * The constructor for a decoder
- */
- void jbg_dec_init(struct jbg_dec_state *s)
- {
- s->order = 0;
- s->d = -1;
- s->bie_len = 0;
- s->buf_len = 0;
- s->dppriv = NULL;
- s->xmax = 4294967295UL;
- s->ymax = 4294967295UL;
- s->dmax = 256;
- s->s = NULL;
- return;
- }
- /*
- * Specify a maximum image size for the decoder. If the JBIG file has
- * the order bit ILEAVE, but not the bit SEQ set, then the decoder
- * will abort to decode after the image has reached the maximal
- * resolution layer which is still not wider than xmax or higher than
- * ymax.
- */
- void jbg_dec_maxsize(struct jbg_dec_state *s, unsigned long xmax,
- unsigned long ymax)
- {
- if (xmax > 0) s->xmax = xmax;
- if (ymax > 0) s->ymax = ymax;
- return;
- }
- /*
- * Decode the new len PSDC bytes to which data points and add them to
- * the current stripe. Return the number of bytes which have actually
- * been read (this will be less than len if a marker segment was
- * part of the data or if the final byte was 0xff were this code
- * can not determine, whether we have a marker segment.
- */
- static size_t decode_pscd(struct jbg_dec_state *s, unsigned char *data,
- size_t len)
- {
- unsigned long stripe;
- unsigned int layer, plane;
- unsigned long hl, ll, y, hx, hy, lx, ly, hbpl, lbpl;
- unsigned char *hp, *lp1, *lp2, *p1, *q1;
- register unsigned long line_h1, line_h2, line_h3;
- register unsigned long line_l1, line_l2, line_l3;
- struct jbg_ardec_state *se;
- unsigned long x;
- long o;
- unsigned a;
- int n;
- int pix, cx = 0, slntp, tx;
- /* SDE loop variables */
- stripe = s->ii[iindex[s->order & 7][STRIPE]];
- layer = s->ii[iindex[s->order & 7][LAYER]];
- plane = s->ii[iindex[s->order & 7][PLANE]];
- /* forward data to arithmetic decoder */
- se = s->s[plane] + layer - s->dl;
- se->pscd_ptr = data;
- se->pscd_end = data + len;
-
- /* number of lines per stripe in highres image */
- hl = s->l0 << layer;
- /* number of lines per stripe in lowres image */
- ll = hl >> 1;
- /* current line number in highres image */
- y = stripe * hl + s->i;
- /* number of pixels in highres image */
- hx = jbg_ceil_half(s->xd, s->d - layer);
- hy = jbg_ceil_half(s->yd, s->d - layer);
- /* number of pixels in lowres image */
- lx = jbg_ceil_half(hx, 1);
- ly = jbg_ceil_half(hy, 1);
- /* bytes per line in highres and lowres image */
- hbpl = jbg_ceil_half(hx, 3);
- lbpl = jbg_ceil_half(lx, 3);
- /* pointer to highres and lowres image bytes */
- hp = s->lhp[ layer & 1][plane] + (stripe * hl + s->i) * hbpl +
- (s->x >> 3);
- lp2 = s->lhp[(layer-1) & 1][plane] + (stripe * ll + (s->i >> 1)) * lbpl +
- (s->x >> 4);
- lp1 = lp2 + lbpl;
- /* restore a few local variables */
- line_h1 = s->line_h1;
- line_h2 = s->line_h2;
- line_h3 = s->line_h3;
- line_l1 = s->line_l1;
- line_l2 = s->line_l2;
- line_l3 = s->line_l3;
- x = s->x;
- if (s->x == 0 && s->i == 0 &&
- (stripe == 0 || s->reset[plane][layer - s->dl])) {
- s->tx[plane][layer - s->dl] = s->ty[plane][layer - s->dl] = 0;
- if (s->pseudo)
- s->lntp[plane][layer - s->dl] = 1;
- }
- #ifdef DEBUG
- if (s->x == 0 && s->i == 0 && s->pseudo)
- fprintf(stderr, "decode_pscd(%p, %p, %ld): s/d/p = %2lu/%2u/%2u\n",
- (void *) s, (void *) data, (long) len, stripe, layer, plane);
- #endif
- if (layer == 0) {
- /*
- * Decode lowest resolution layer
- */
- for (; s->i < hl && y < hy; s->i++, y++) {
- /* adaptive template changes */
- if (x == 0)
- for (n = 0; n < s->at_moves; n++)
- if (s->at_line[n] == s->i) {
- s->tx[plane][layer - s->dl] = s->at_tx[n];
- s->ty[plane][layer - s->dl] = s->at_ty[n];
- #ifdef DEBUG
- fprintf(stderr, "ATMOVE: line=%lu, tx=%d, ty=%d.\n", s->i,
- s->tx[plane][layer - s->dl], s->ty[plane][layer - s->dl]);
- #endif
- }
- tx = s->tx[plane][layer - s->dl];
- assert(tx >= 0); /* i.e., tx can safely be cast to unsigned */
- /* typical prediction */
- if (s->options & JBG_TPBON && s->pseudo) {
- slntp = arith_decode(se, (s->options & JBG_LRLTWO) ? TPB2CX : TPB3CX);
- if (se->result == JBG_MORE || se->result == JBG_MARKER)
- goto leave;
- s->lntp[plane][layer - s->dl] =
- !(slntp ^ s->lntp[plane][layer - s->dl]);
- if (s->lntp[plane][layer - s->dl]) {
- /* this line is 'not typical' and has to be coded completely */
- s->pseudo = 0;
- } else {
- /* this line is 'typical' (i.e. identical to the previous one) */
- p1 = hp;
- if (s->i == 0 && (stripe == 0 || s->reset[plane][layer - s->dl]))
- while (p1 < hp + hbpl) *p1++ = 0;
- else {
- q1 = hp - hbpl;
- while (q1 < hp) *p1++ = *q1++;
- }
- hp += hbpl;
- continue;
- }
- }
-
- /*
- * Layout of the variables line_h1, line_h2, line_h3, which contain
- * as bits the neighbour pixels of the currently decoded pixel X:
- *
- * 76543210 76543210 76543210 76543210 line_h3
- * 76543210 76543210 76543210 76543210 line_h2
- * 76543210 76543210 76543210 76543210 X line_h1
- */
-
- if (x == 0) {
- line_h1 = line_h2 = line_h3 = 0;
- if (s->i > 0 || (y > 0 && !s->reset[plane][layer - s->dl]))
- line_h2 = (long)*(hp - hbpl) << 8;
- if (s->i > 1 || (y > 1 && !s->reset[plane][layer - s->dl]))
- line_h3 = (long)*(hp - hbpl - hbpl) << 8;
- }
-
- /*
- * Another tiny JBIG standard bug:
- *
- * While implementing the line_h3 handling here, I discovered
- * another problem with the ITU-T T.82(1993 E) specification.
- * This might be a somewhat pathological case, however. The
- * standard is unclear about how a decoder should behave in the
- * following situation:
- *
- * Assume we are in layer 0 and all stripes are single lines
- * (L0=1 allowed by table 9). We are now decoding the first (and
- * only) line of the third stripe. Assume, the first stripe was
- * terminated by SDRST and the second stripe was terminated by
- * SDNORM. While decoding the only line of the third stripe with
- * the three-line template, we need access to pixels from the
- * previous two stripes. We know that the previous stripe
- * terminated with SDNROM, so we access the pixel from the
- * second stripe. But do we have to replace the pixels from the
- * first stripe by background pixels, because this stripe ended
- * with SDRST? The standard, especially clause 6.2.5 does never
- * mention this case, so the behaviour is undefined here. My
- * current implementation remembers only the marker used to
- * terminate the previous stripe. In the above example, the
- * pixels of the first stripe are accessed despite the fact that
- * this stripe ended with SDRST. An alternative (only slightly
- * more complicated) implementation would be to remember the end
- * marker (SDNORM or SDRST) of the previous two stripes in a
- * plane/layer and to act accordingly when accessing the two
- * previous lines. What am I supposed to do here?
- *
- * As the standard is unclear about the correct behaviour in the
- * situation of the above example, I strongly suggest to avoid
- * the following situation while encoding data with JBIG:
- *
- * LRLTWO = 0, L0=1 and both SDNORM and SDRST appear in layer 0.
- *
- * I guess that only a very few if any encoders will switch
- * between SDNORM and SDRST, so let us hope that this ambiguity
- * in the standard will never cause any interoperability
- * problems.
- *
- * Markus Kuhn -- 1995-04-30
- */
- /* decode line */
- while (x < hx) {
- if ((x & 7) == 0) {
- if (x < hbpl * 8 - 8 &&
- (s->i > 0 || (y > 0 && !s->reset[plane][layer - s->dl]))) {
- line_h2 |= *(hp - hbpl + 1);
- if (s->i > 1 || (y > 1 && !s->reset[plane][layer - s->dl]))
- line_h3 |= *(hp - hbpl - hbpl + 1);
- }
- }
- if (s->options & JBG_LRLTWO) {
- /* two line template */
- do {
- if (tx) {
- if ((unsigned) tx > x)
- a = 0;
- else if (tx < 8)
- a = ((line_h1 >> (tx - 5)) & 0x010);
- else {
- o = (x - tx) - (x & ~7L);
- a = (hp[o >> 3] >> (7 - (o & 7))) & 1;
- a <<= 4;
- }
- assert(tx > 31 ||
- a == ((line_h1 >> (tx - 5)) & 0x010));
- pix = arith_decode(se, (((line_h2 >> 9) & 0x3e0) | a |
- (line_h1 & 0x00f)));
- } else
- pix = arith_decode(se, (((line_h2 >> 9) & 0x3f0) |
- (line_h1 & 0x00f)));
- if (se->result == JBG_MORE || se->result == JBG_MARKER)
- goto leave;
- line_h1 = (line_h1 << 1) | pix;
- line_h2 <<= 1;
- } while ((++x & 7) && x < hx);
- } else {
- /* three line template */
- do {
- if (tx) {
- if ((unsigned) tx > x)
- a = 0;
- else if (tx < 8)
- a = ((line_h1 >> (tx - 3)) & 0x004);
- else {
- o = (x - tx) - (x & ~7L);
- a = (hp[o >> 3] >> (7 - (o & 7))) & 1;
- a <<= 2;
- }
- assert(tx > 31 ||
- a == ((line_h1 >> (tx - 3)) & 0x004));
- pix = arith_decode(se, (((line_h3 >> 7) & 0x380) |
- ((line_h2 >> 11) & 0x078) | a |
- (line_h1 & 0x003)));
- } else
- pix = arith_decode(se, (((line_h3 >> 7) & 0x380) |
- ((line_h2 >> 11) & 0x07c) |
- (line_h1 & 0x003)));
- if (se->result == JBG_MORE || se->result == JBG_MARKER)
- goto leave;
-
- line_h1 = (line_h1 << 1) | pix;
- line_h2 <<= 1;
- line_h3 <<= 1;
- } while ((++x & 7) && x < hx);
- } /* if (s->options & JBG_LRLTWO) */
- *hp++ = (unsigned char)(line_h1);
- } /* while */
- *(hp - 1) <<= hbpl * 8 - hx;
- x = 0;
- s->pseudo = 1;
- } /* for (i = ...) */
-
- } else {
- /*
- * Decode differential layer
- */
- for (; s->i < hl && y < hy; s->i++, y++) {
- /* adaptive template changes */
- if (x == 0)
- for (n = 0; n < s->at_moves; n++)
- if (s->at_line[n] == s->i) {
- s->tx[plane][layer - s->dl] = s->at_tx[n];
- s->ty[plane][layer - s->dl] = s->at_ty[n];
- #ifdef DEBUG
- fprintf(stderr, "ATMOVE: line=%lu, tx=%d, ty=%d.\n", s->i,
- s->tx[plane][layer - s->dl], s->ty[plane][layer - s->dl]);
- #endif
- }
- tx = s->tx[plane][layer - s->dl];
- /* handle lower border of low-resolution image */
- if ((s->i >> 1) >= ll - 1 || (y >> 1) >= ly - 1)
- lp1 = lp2;
- /* typical prediction */
- if (s->options & JBG_TPDON && s->pseudo) {
- s->lntp[plane][layer - s->dl] = arith_decode(se, TPDCX);
- if (se->result == JBG_MORE || se->result == JBG_MARKER)
- goto leave;
- s->pseudo = 0;
- }
- /*
- * Layout of the variables line_h1, line_h2, line_h3, which contain
- * as bits the high resolution neighbour pixels of the currently
- * decoded highres pixel X:
- *
- * 76543210 76543210 76543210 76543210 line_h3
- * 76543210 76543210 76543210 76543210 line_h2
- * 76543210 76543210 76543210 76543210 X line_h1
- *
- * Layout of the variables line_l1, line_l2, line_l3, which contain
- * the low resolution pixels near the currently decoded pixel as bits.
- * The lowres pixel in which the currently coded highres pixel is
- * located is marked as Y:
- *
- * 76543210 76543210 76543210 76543210 line_l3
- * 76543210 76543210 Y6543210 76543210 line_l2
- * 76543210 76543210 76543210 76543210 line_l1
- */
-
- if (x == 0) {
- line_h1 = line_h2 = line_h3 = line_l1 = line_l2 = line_l3 = 0;
- if (s->i > 0 || (y > 0 && !s->reset[plane][layer - s->dl])) {
- line_h2 = (long)*(hp - hbpl) << 8;
- if (s->i > 1 || (y > 1 && !s->reset[plane][layer - s->dl]))
- line_h3 = (long)*(hp - hbpl - hbpl) << 8;
- }
- if (s->i > 1 || (y > 1 && !s->reset[plane][layer-s->dl]))
- line_l3 = (long)*(lp2 - lbpl) << 8;
- line_l2 = (long)*lp2 << 8;
- line_l1 = (long)*lp1 << 8;
- }
-
- /* decode line */
- while (x < hx) {
- if ((x & 15) == 0)
- if ((x >> 1) < lbpl * 8 - 8) {
- line_l1 |= *(lp1 + 1);
- line_l2 |= *(lp2 + 1);
- if (s->i > 1 ||
- (y > 1 && !s->reset[plane][layer - s->dl]))
- line_l3 |= *(lp2 - lbpl + 1);
- }
- do {
- assert(hp - (s->lhp[ layer &1][plane] + (stripe * hl + s->i)
- * hbpl) == (ptrdiff_t) x >> 3);
- assert(lp2 - (s->lhp[(layer-1) &1][plane] + (stripe * ll + (s->i>>1))
- * lbpl) == (ptrdiff_t) x >> 4);
- if ((x & 7) == 0)
- if (x < hbpl * 8 - 8) {
- if (s->i > 0 || (y > 0 && !s->reset[plane][layer - s->dl])) {
- line_h2 |= *(hp + 1 - hbpl);
- if (s->i > 1 || (y > 1 && !s->reset[plane][layer - s->dl]))
- line_h3 |= *(hp + 1 - hbpl - hbpl);
- }
- }
- do {
- if (!s->lntp[plane][layer - s->dl])
- cx = (((line_l3 >> 14) & 0x007) |
- ((line_l2 >> 11) & 0x038) |
- ((line_l1 >> 8) & 0x1c0));
- if (!s->lntp[plane][layer - s->dl] &&
- (cx == 0x000 || cx == 0x1ff)) {
- /* pixels are typical and have not to be decoded */
- do {
- line_h1 = (line_h1 << 1) | (cx & 1);
- } while ((++x & 1) && x < hx);
- line_h2 <<= 2; line_h3 <<= 2;
- } else
- do {
-
- /* deterministic prediction */
- if (s->options & JBG_DPON)
- if ((y & 1) == 0)
- if ((x & 1) == 0)
- /* phase 0 */
- pix = s->dppriv[((line_l3 >> 15) & 0x003) |
- ((line_l2 >> 13) & 0x00c) |
- ((line_h1 << 4) & 0x010) |
- ((line_h2 >> 9) & 0x0e0)];
- else
- /* phase 1 */
- pix = s->dppriv[(((line_l3 >> 15) & 0x003) |
- ((line_l2 >> 13) & 0x00c) |
- ((line_h1 << 4) & 0x030) |
- ((line_h2 >> 9) & 0x1c0)) + 256];
- else
- if ((x & 1) == 0)
- /* phase 2 */
- pix = s->dppriv[(((line_l3 >> 15) & 0x003) |
- ((line_l2 >> 13) & 0x00c) |
- ((line_h1 << 4) & 0x010) |
- ((line_h2 >> 9) & 0x0e0) |
- ((line_h3 >> 6) & 0x700)) + 768];
- else
- /* phase 3 */
- pix = s->dppriv[(((line_l3 >> 15) & 0x003) |
- ((line_l2 >> 13) & 0x00c) |
- ((line_h1 << 4) & 0x030) |
- ((line_h2 >> 9) & 0x1c0) |
- ((line_h3 >> 6) & 0xe00)) + 2816];
- else
- pix = 2;
- if (pix & 2) {
- if (tx)
- cx = ((line_h1 & 0x003) |
- (((line_h1 << 2) >> (tx - 3)) & 0x010) |
- ((line_h2 >> 12) & 0x00c) |
- ((line_h3 >> 10) & 0x020));
- else
- cx = ((line_h1 & 0x003) |
- ((line_h2 >> 12) & 0x01c) |
- ((line_h3 >> 10) & 0x020));
- if (x & 1)
- cx |= (((line_l2 >> 8) & 0x0c0) |
- ((line_l1 >> 6) & 0x300)) | (1UL << 10);
- else
- cx |= (((line_l2 >> 9) & 0x0c0) |
- ((line_l1 >> 7) & 0x300));
- cx |= (y & 1) << 11;
- pix = arith_decode(se, cx);
- if (se->result == JBG_MORE || se->result == JBG_MARKER)
- goto leave;
- }
- line_h1 = (line_h1 << 1) | pix;
- line_h2 <<= 1;
- line_h3 <<= 1;
-
- } while ((++x & 1) && x < hx);
- line_l1 <<= 1; line_l2 <<= 1; line_l3 <<= 1;
- } while ((x & 7) && x < hx);
- *hp++ = (unsigned char)(line_h1);
- } while ((x & 15) && x < hx);
- ++lp1;
- ++lp2;
- } /* while */
- x = 0;
-
- *(hp - 1) <<= hbpl * 8 - hx;
- if ((s->i & 1) == 0) {
- /* low resolution pixels are used twice */
- lp1 -= lbpl;
- lp2 -= lbpl;
- } else
- s->pseudo = 1;
-
- } /* for (i = ...) */
-
- }
- leave:
- /* save a few local variables */
- s->line_h1 = line_h1;
- s->line_h2 = line_h2;
- s->line_h3 = line_h3;
- s->line_l1 = line_l1;
- s->line_l2 = line_l2;
- s->line_l3 = line_l3;
- s->x = x;
- return se->pscd_ptr - data;
- }
- /*
- * Provide a new BIE fragment to the decoder.
- *
- * If cnt is not NULL, then *cnt will contain after the call the
- * number of actually read bytes. If the data was not complete, then
- * the return value will be JBG_EAGAIN and *cnt == len. In case this
- * function has returned with JBG_EOK, then it has reached the end of
- * a BIE but it can be called again with data from the next BIE if
- * there exists one in order to get to a higher resolution layer. In
- * case the return value was JBG_EOK_INTR then this function can be
- * called again with the rest of the BIE, because parsing the BIE has
- * been interrupted by a jbg_dec_maxsize() specification. In both
- * cases the remaining len - *cnt bytes of the previous block will
- * have to passed to this function again (if len > *cnt). In case of
- * any other return value than JBG_EOK, JBG_EOK_INTR or JBG_EAGAIN, a
- * serious problem has occured and the only function you should call
- * is jbg_dec_free() in order to remove the mess (and probably
- * jbg_strerror() in order to find out what to tell the user).
- */
- int jbg_dec_in(struct jbg_dec_state *s, unsigned char *data, size_t len,
- size_t *cnt)
- {
- int i, j, required_length;
- unsigned long x, y;
- unsigned long is[3], ie[3];
- extern char jbg_dptable[];
- size_t dummy_cnt;
- if (!cnt) cnt = &dummy_cnt;
- *cnt = 0;
- if (len < 1) return JBG_EAGAIN;
- /* read in 20-byte BIH */
- if (s->bie_len < 20) {
- while (s->bie_len < 20 && *cnt < len)
- s->buffer[s->bie_len++] = data[(*cnt)++];
- if (s->bie_len < 20)
- return JBG_EAGAIN;
- if (s->buffer[1] < s->buffer[0])
- return JBG_EINVAL;
- /* test whether this looks like a valid JBIG header at all */
- if (s->buffer[3] != 0 || (s->buffer[18] & 0xf0) != 0 ||
- (s->buffer[19] & 0x80) != 0)
- return JBG_EINVAL;
- if (s->buffer[0] != s->d + 1)
- return JBG_ENOCONT;
- s->dl = s->buffer[0];
- s->d = s->buffer[1];
- if (s->dl == 0)
- s->planes = s->buffer[2];
- else
- if (s->planes != s->buffer[2])
- return JBG_ENOCONT;
- x = (((long) s->buffer[ 4] << 24) | ((long) s->buffer[ 5] << 16) |
- ((long) s->buffer[ 6] << 8) | (long) s->buffer[ 7]);
- y = (((long) s->buffer[ 8] << 24) | ((long) s->buffer[ 9] << 16) |
- ((long) s->buffer[10] << 8) | (long) s->buffer[11]);
- if (s->dl != 0 && ((s->xd << (s->d - s->dl + 1)) != x &&
- (s->yd << (s->d - s->dl + 1)) != y))
- return JBG_ENOCONT;
- s->xd = x;
- s->yd = y;
- s->l0 = (((long) s->buffer[12] << 24) | ((long) s->buffer[13] << 16) |
- ((long) s->buffer[14] << 8) | (long) s->buffer[15]);
- /* ITU-T T.85 trick not directly supported by decoder; for full
- * T.85 compatibility with respect to all NEWLEN marker scenarios,
- * preprocess BIE with jbg_newlen() before passing it to the decoder. */
- if (s->yd == 0xffffffff)
- return JBG_EIMPL;
- if (!s->planes || !s->xd || !s->yd || !s->l0)
- return JBG_EINVAL;
- /* prevent uint32 overflow: s->l0 * 2 ^ s->d < 2 ^ 32 */
- if (s->d > 31 || (s->d != 0 && s->l0 >= (1UL << (32 - s->d))))
- return JBG_EIMPL;
- s->mx = s->buffer[16];
- if (s->mx > 127)
- return JBG_EINVAL;
- s->my = s->buffer[17];
- #if 0
- if (s->my > 0)
- return JBG_EIMPL;
- #endif
- s->order = s->buffer[18];
- if (iindex[s->order & 7][0] < 0)
- return JBG_EINVAL;
- /* HITOLO and SEQ currently not yet implemented */
- if (s->dl != s->d && (s->order & JBG_HITOLO || s->order & JBG_SEQ))
- return JBG_EIMPL;
- s->options = s->buffer[19];
- /* calculate number of stripes that will be required */
- s->stripes = jbg_stripes(s->l0, s->yd, s->d);
-
- /* some initialization */
- s->ii[iindex[s->order & 7][STRIPE]] = 0;
- s->ii[iindex[s->order & 7][LAYER]] = s->dl;
- s->ii[iindex[s->order & 7][PLANE]] = 0;
- if (s->dl == 0) {
- s->s = (struct jbg_ardec_state **)
- checked_malloc(s->planes, sizeof(struct jbg_ardec_state *));
- s->tx = (int **) checked_malloc(s->planes, sizeof(int *));
- s->ty = (int **) checked_malloc(s->planes, sizeof(int *));
- s->reset = (int **) checked_malloc(s->planes, sizeof(int *));
- s->lntp = (int **) checked_malloc(s->planes, sizeof(int *));
- s->lhp[0] = (unsigned char **)
- checked_malloc(s->planes, sizeof(unsigned char *));
- s->lhp[1] = (unsigned char **)
- checked_malloc(s->planes, sizeof(unsigned char *));
- for (i = 0; i < s->planes; i++) {
- s->s[i] = (struct jbg_ardec_state *)
- checked_malloc(s->d - s->dl + 1, sizeof(struct jbg_ardec_state));
- s->tx[i] = (int *) checked_malloc(s->d - s->dl + 1, sizeof(int));
- s->ty[i] = (int *) checked_malloc(s->d - s->dl + 1, sizeof(int));
- s->reset[i] = (int *) checked_malloc(s->d - s->dl + 1, sizeof(int));
- s->lntp[i] = (int *) checked_malloc(s->d - s->dl + 1, sizeof(int));
- s->lhp[ s->d & 1][i] = (unsigned char *)
- checked_malloc(s->yd, jbg_ceil_half(s->xd, 3));
- s->lhp[(s->d-1) & 1][i] = (unsigned char *)
- checked_malloc(jbg_ceil_half(s->yd, 1), jbg_ceil_half(s->xd, 1+3));
- }
- } else {
- for (i = 0; i < s->planes; i++) {
- s->s[i] = (struct jbg_ardec_state *)
- checked_realloc(s->s[i], s->d - s->dl + 1,
- sizeof(struct jbg_ardec_state));
- s->tx[i] = (int *) checked_realloc(s->tx[i],
- s->d - s->dl + 1, sizeof(int));
- s->ty[i] = (int *) checked_realloc(s->ty[i],
- s->d - s->dl + 1, sizeof(int));
- s->reset[i] = (int *) checked_realloc(s->reset[i],
- s->d - s->dl + 1, sizeof(int));
- s->lntp[i] = (int *) checked_realloc(s->lntp[i],
- s->d - s->dl + 1, sizeof(int));
- s->lhp[ s->d & 1][i] = (unsigned char *)
- checked_realloc(s->lhp[ s->d & 1][i],
- s->yd, jbg_ceil_half(s->xd, 3));
- s->lhp[(s->d-1) & 1][i] = (unsigned char *)
- checked_realloc(s->lhp[(s->d-1) & 1][i],
- jbg_ceil_half(s->yd, 1), jbg_ceil_half(s->xd, 1+3));
- }
- }
- for (i = 0; i < s->planes; i++)
- for (j = 0; j <= s->d - s->dl; j++)
- arith_decode_init(s->s[i] + j, 0);
- if (s->dl == 0 || (s->options & JBG_DPON && !(s->options & JBG_DPPRIV)))
- s->dppriv = jbg_dptable;
- s->comment_skip = 0;
- s->buf_len = 0;
- s->x = 0;
- s->i = 0;
- s->pseudo = 1;
- s->at_moves = 0;
- }
- /* read in DPTABLE */
- if (s->bie_len < 20 + 1728 &&
- (s->options & (JBG_DPON | JBG_DPPRIV | JBG_DPLAST)) ==
- (JBG_DPON | JBG_DPPRIV)) {
- assert(s->bie_len >= 20);
- while (s->bie_len < 20 + 1728 && *cnt < len)
- s->buffer[s->bie_len++ - 20] = data[(*cnt)++];
- if (s->bie_len < 20 + 1728)
- return JBG_EAGAIN;
- if (!s->dppriv || s->dppriv == jbg_dptable)
- s->dppriv = (char *) checked_malloc(1728, sizeof(char));
- jbg_dppriv2int(s->dppriv, s->buffer);
- }
- /*
- * BID processing loop
- */
-
- while (*cnt < len) {
- /* process floating marker segments */
- /* skip COMMENT contents */
- if (s->comment_skip) {
- if (s->comment_skip <= len - *cnt) {
- *cnt += s->comment_skip;
- s->comment_skip = 0;
- } else {
- s->comment_skip -= len - *cnt;
- *cnt = len;
- }
- continue;
- }
- /* load complete marker segments into s->buffer for processing */
- if (s->buf_len > 0) {
- assert(s->buffer[0] == MARKER_ESC);
- while (s->buf_len < 2 && *cnt < len)
- s->buffer[s->buf_len++] = data[(*cnt)++];
- if (s->buf_len < 2) continue;
- switch (s->buffer[1]) {
- case MARKER_COMMENT: required_length = 6; break;
- case MARKER_ATMOVE: required_length = 8; break;
- case MARKER_NEWLEN: required_length = 6; break;
- case MARKER_ABORT:
- case MARKER_SDNORM:
- case MARKER_SDRST: required_length = 2; break;
- case MARKER_STUFF:
- /* forward stuffed 0xff to arithmetic decoder */
- s->buf_len = 0;
- decode_pscd(s, s->buffer, 2);
- continue;
- default:
- return JBG_EMARKER;
- }
- while (s->buf_len < required_length && *cnt < len)
- s->buffer[s->buf_len++] = data[(*cnt)++];
- if (s->buf_len < required_length) continue;
- /* now the buffer is filled with exactly one marker segment */
- switch (s->buffer[1]) {
- case MARKER_COMMENT:
- s->comment_skip =
- (((long) s->buffer[2] << 24) | ((long) s->buffer[3] << 16) |
- ((long) s->buffer[4] << 8) | (long) s->buffer[5]);
- break;
- case MARKER_ATMOVE:
- if (s->at_moves < JBG_ATMOVES_MAX) {
- s->at_line[s->at_moves] =
- (((long) s->buffer[2] << 24) | ((long) s->buffer[3] << 16) |
- ((long) s->buffer[4] << 8) | (long) s->buffer[5]);
- s->at_tx[s->at_moves] = (signed char) s->buffer[6];
- s->at_ty[s->at_moves] = s->buffer[7];
- if (s->at_tx[s->at_moves] < - (int) s->mx ||
- s->at_tx[s->at_moves] > (int) s->mx ||
- s->at_ty[s->at_moves] > (int) s->my ||
- (s->at_ty[s->at_moves] == 0 && s->at_tx[s->at_moves] < 0))
- return JBG_EINVAL;
- if (s->at_ty[s->at_moves] != 0)
- return JBG_EIMPL;
- s->at_moves++;
- } else
- return JBG_EIMPL;
- break;
- case MARKER_NEWLEN:
- y = (((long) s->buffer[2] << 24) | ((long) s->buffer[3] << 16) |
- ((long) s->buffer[4] << 8) | (long) s->buffer[5]);
- if (y > s->yd || !(s->options & JBG_VLENGTH))
- return JBG_EINVAL;
- s->yd = y;
- /* calculate again number of stripes that will be required */
- s->stripes = jbg_stripes(s->l0, s->yd, s->d);
- break;
- case MARKER_ABORT:
- return JBG_EABORT;
-
- case MARKER_SDNORM:
- case MARKER_SDRST:
- /* decode final pixels based on trailing zero bytes */
- decode_pscd(s, s->buffer, 2);
- arith_decode_init(s->s[s->ii[iindex[s->order & 7][PLANE]]] +
- s->ii[iindex[s->order & 7][LAYER]] - s->dl,
- s->ii[iindex[s->order & 7][STRIPE]] != s->stripes - 1
- && s->buffer[1] != MARKER_SDRST);
-
- s->reset[s->ii[iindex[s->order & 7][PLANE]]]
- [s->ii[iindex[s->order & 7][LAYER]] - s->dl] =
- (s->buffer[1] == MARKER_SDRST);
-
- /* prepare for next SDE */
- s->x = 0;
- s->i = 0;
- s->pseudo = 1;
- s->at_moves = 0;
-
- /* increment layer/stripe/plane loop variables */
- /* start and end value for each loop: */
- is[iindex[s->order & 7][STRIPE]] = 0;
- ie[iindex[s->order & 7][STRIPE]] = s->stripes - 1;
- is[iindex[s->order & 7][LAYER]] = s->dl;
- ie[iindex[s->order & 7][LAYER]] = s->d;
- is[iindex[s->order & 7][PLANE]] = 0;
- ie[iindex[s->order & 7][PLANE]] = s->planes - 1;
- i = 2; /* index to innermost loop */
- do {
- j = 0; /* carry flag */
- if (++s->ii[i] > ie[i]) {
- /* handling overflow of loop variable */
- j = 1;
- if (i > 0)
- s->ii[i] = is[i];
- }
- } while (--i >= 0 && j);
- s->buf_len = 0;
-
- /* check whether this have been all SDEs */
- if (j) {
- #ifdef DEBUG
- fprintf(stderr, "This was the final SDE in this BIE, "
- "%d bytes left.\n", len - *cnt);
- #endif
- s->bie_len = 0;
- return JBG_EOK;
- }
- /* check whether we have to abort because of xmax/ymax */
- if (iindex[s->order & 7][LAYER] == 0 && i < 0) {
- /* LAYER is the outermost loop and we have just gone to next layer */
- if (jbg_ceil_half(s->xd, s->d - s->ii[0]) > s->xmax ||
- jbg_ceil_half(s->yd, s->d - s->ii[0]) > s->ymax) {
- s->xmax = 4294967295UL;
- s->ymax = 4294967295UL;
- return JBG_EOK_INTR;
- }
- if (s->ii[0] > (unsigned long) s->dmax) {
- s->dmax = 256;
- return JBG_EOK_INTR;
- }
- }
- break;
- }
- s->buf_len = 0;
- } else if (data[*cnt] == MARKER_ESC)
- s->buffer[s->buf_len++] = data[(*cnt)++];
- else {
- /* we have found PSCD bytes */
- *cnt += decode_pscd(s, data + *cnt, len - *cnt);
- if (*cnt < len && data[*cnt] != 0xff) {
- #ifdef DEBUG
- fprintf(stderr, "PSCD was longer than expected, unread bytes "
- "%02x %02x %02x %02x ...\n", data[*cnt], data[*cnt+1],
- data[*cnt+2], data[*cnt+3]);
- #endif
- return JBG_EINVAL;
- }
-
- }
- } /* of BID processing loop 'while (*cnt < len) ...' */
- return JBG_EAGAIN;
- }
- /*
- * After jbg_dec_in() returned JBG_EOK or JBG_EOK_INTR, you can call this
- * function in order to find out the width of the image.
- */
- long jbg_dec_getwidth(const struct jbg_dec_state *s)
- {
- if (s->d < 0)
- return -1;
- if (iindex[s->order & 7][LAYER] == 0) {
- if (s->ii[0] < 1)
- return -1;
- else
- return jbg_ceil_half(s->xd, s->d - (s->ii[0] - 1));
- }
- return s->xd;
- }
- /*
- * After jbg_dec_in() returned JBG_EOK or JBG_EOK_INTR, you can call this
- * function in order to find out the height of the image.
- */
- long jbg_dec_getheight(const struct jbg_dec_state *s)
- {
- if (s->d < 0)
- return -1;
- if (iindex[s->order & 7][LAYER] == 0) {
- if (s->ii[0] < 1)
- return -1;
- else
- return jbg_ceil_half(s->yd, s->d - (s->ii[0] - 1));
- }
-
- return s->yd;
- }
- /*
- * After jbg_dec_in() returned JBG_EOK or JBG_EOK_INTR, you can call this
- * function in order to get a pointer to the image.
- */
- unsigned char *jbg_dec_getimage(const struct jbg_dec_state *s, int plane)
- {
- if (s->d < 0)
- return NULL;
- if (iindex[s->order & 7][LAYER] == 0) {
- if (s->ii[0] < 1)
- return NULL;
- else
- return s->lhp[(s->ii[0] - 1) & 1][plane];
- }
-
- return s->lhp[s->d & 1][plane];
- }
- /*
- * After jbg_dec_in() returned JBG_EOK or JBG_EOK_INTR, you can call
- * this function in order to find out the size in bytes of one
- * bitplane of the image.
- */
- long jbg_dec_getsize(const struct jbg_dec_state *s)
- {
- if (s->d < 0)
- return -1;
- if (iindex[s->order & 7][LAYER] == 0) {
- if (s->ii[0] < 1)
- return -1;
- else
- return
- jbg_ceil_half(s->xd, s->d - (s->ii[0] - 1) + 3) *
- jbg_ceil_half(s->yd, s->d - (s->ii[0] - 1));
- }
-
- return jbg_ceil_half(s->xd, 3) * s->yd;
- }
- /*
- * After jbg_dec_in() returned JBG_EOK or JBG_EOK_INTR, you can call
- * this function in order to find out the size of the image that you
- * can retrieve with jbg_merge_planes().
- */
- long jbg_dec_getsize_merged(const struct jbg_dec_state *s)
- {
- if (s->d < 0)
- return -1;
- if (iindex[s->order & 7][LAYER] == 0) {
- if (s->ii[0] < 1)
- return -1;
- else
- return
- jbg_ceil_half(s->xd, s->d - (s->ii[0] - 1)) *
- jbg_ceil_half(s->yd, s->d - (s->ii[0] - 1)) *
- ((s->planes + 7) / 8);
- }
-
- return s->xd * s->yd * ((s->planes + 7) / 8);
- }
- /*
- * The destructor function which releases any resources obtained by the
- * other decoder functions.
- */
- void jbg_dec_free(struct jbg_dec_state *s)
- {
- int i;
- extern char jbg_dptable[];
- if (s->d < 0 || s->s == NULL)
- return;
- s->d = -2;
- for (i = 0; i < s->planes; i++) {
- checked_free(s->s[i]);
- checked_free(s->tx[i]);
- checked_free(s->ty[i]);
- checked_free(s->reset[i]);
- checked_free(s->lntp[i]);
- checked_free(s->lhp[0][i]);
- checked_free(s->lhp[1][i]);
- }
-
- checked_free(s->s);
- checked_free(s->tx);
- checked_free(s->ty);
- checked_free(s->reset);
- checked_free(s->lntp);
- checked_free(s->lhp[0]);
- checked_free(s->lhp[1]);
- if (s->dppriv && s->dppriv != jbg_dptable)
- checked_free(s->dppriv);
- s->s = NULL;
- return;
- }
- /*
- * Split bigendian integer pixel field into separate bit planes. In the
- * src array, every pixel is represented by a ((has_planes + 7) / 8) byte
- * long word, most significant byte first. While has_planes describes
- * the number of used bits per pixel in the source image, encode_plane
- * is the number of most significant bits among those that we
- * actually transfer to dest.
- */
- void jbg_split_planes(unsigned long x, unsigned long y, int has_planes,
- int encode_planes,
- const unsigned char *src, unsigned char **dest,
- int use_graycode)
- {
- unsigned long bpl = jbg_ceil_half(x, 3); /* bytes per line in dest plane */
- unsigned long line, i;
- unsigned k = 8;
- int p;
- unsigned prev; /* previous *src byte shifted by 8 bit to the left */
- register int bits, msb = has_planes - 1;
- int bitno;
- /* sanity checks */
- if (encode_planes > has_planes)
- encode_planes = has_planes;
- use_graycode = use_graycode != 0 && encode_planes > 1;
-
- for (p = 0; p < encode_planes; p++)
- memset(dest[p], 0, bpl * y);
-
- for (line = 0; line < y; line++) { /* lines loop */
- for (i = 0; i * 8 < x; i++) { /* dest bytes loop */
- for (k = 0; k < 8 && i * 8 + k < x; k++) { /* pixel loop */
- prev = 0;
- for (p = 0; p < encode_planes; p++) { /* bit planes loop */
- /* calculate which bit in *src do we want */
- bitno = (msb - p) & 7;
- /* put this bit with its left neighbor right adjusted into bits */
- bits = (prev | *src) >> bitno;
- /* go to next *src byte, but keep old */
- if (bitno == 0)
- prev = *src++ << 8;
- /* make space for inserting new bit */
- dest[p][bpl * line + i] <<= 1;
- /* insert bit, if requested apply Gray encoding */
- dest[p][bpl * line + i] |= (bits ^ (use_graycode & (bits>>1))) & 1;
- /*
- * Theorem: Let b(n),...,b(1),b(0) be the digits of a
- * binary word and let g(n),...,g(1),g(0) be the digits of the
- * corresponding Gray code word, then g(i) = b(i) xor b(i+1).
- */
- }
- /* skip unused *src bytes */
- for (;p < has_planes; p++)
- if (((msb - p) & 7) == 0)
- src++;
- }
- }
- for (p = 0; p < encode_planes; p++) /* right padding loop */
- dest[p][bpl * (line + 1) - 1] <<= 8 - k;
- }
-
- return;
- }
- /*
- * Merge the separate bit planes decoded by the JBIG decoder into an
- * integer pixel field. This is essentially the counterpart to
- * jbg_split_planes().
- */
- void jbg_dec_merge_planes(const struct jbg_dec_state *s, int use_graycode,
- void (*data_out)(unsigned char *start, size_t len,
- void *file), void *file)
- {
- #define BUFLEN 4096
- int bpp;
- unsigned long bpl, line, i;
- unsigned k = 8;
- int p;
- unsigned char buf[BUFLEN];
- unsigned char *bp = buf;
- unsigned char **src;
- unsigned long x, y;
- unsigned v;
- /* sanity check */
- use_graycode = use_graycode != 0;
-
- x = jbg_dec_getwidth(s);
- y = jbg_dec_getheight(s);
- if (x <= 0 || y <= 0)
- return;
- bpp = (s->planes + 7) / 8; /* bytes per pixel in dest image */
- bpl = jbg_ceil_half(x, 3); /* bytes per line in src plane */
- if (iindex[s->order & 7][LAYER] == 0)
- if (s->ii[0] < 1)
- return;
- else
- src = s->lhp[(s->ii[0] - 1) & 1];
- else
- src = s->lhp[s->d & 1];
-
- for (line = 0; line < y; line++) { /* lines loop */
- for (i = 0; i * 8 < x; i++) { /* src bytes loop */
- for (k = 0; k < 8 && i * 8 + k < x; k++) { /* pixel loop */
- v = 0;
- for (p = 0; p < s->planes;) { /* dest bytes loop */
- do {
- v = (v << 1) |
- (((src[p][bpl * line + i] >> (7 - k)) & 1) ^
- (use_graycode & v));
- } while ((s->planes - ++p) & 7);
- *bp++ = v;
- if (bp - buf == BUFLEN) {
- data_out(buf, BUFLEN, file);
- bp = buf;
- }
- }
- }
- }
- }
-
- if (bp - buf > 0)
- data_out(buf, bp - buf, file);
-
- return;
- }
- /*
- * Given a pointer p to the first byte of either a marker segment or a
- * PSCD, as well as the length len of the remaining data, return
- * either the pointer to the first byte of the next marker segment or
- * PSCD, or p+len if this was the last one, or NULL if some error was
- * encountered.
- */
- unsigned char *jbg_next_pscdms(unsigned char *p, size_t len)
- {
- unsigned char *pp;
- unsigned long l;
- if (len < 2)
- return NULL;
- if (p[0] != MARKER_ESC || p[1] == MARKER_STUFF) {
- do {
- while (p[0] == MARKER_ESC && p[1] == MARKER_STUFF) {
- p += 2;
- len -= 2;
- if (len < 2) return NULL;
- }
- pp = (unsigned char *) memchr(p, MARKER_ESC, len - 1);
- if (!pp) return NULL;
- l = pp - p;
- assert(l < len);
- p += l;
- len -= l;
- } while (p[1] == MARKER_STUFF);
- } else {
- switch (p[1]) {
- case MARKER_SDNORM:
- case MARKER_SDRST:
- case MARKER_ABORT:
- return p + 2;
- case MARKER_NEWLEN:
- if (len < 6) return NULL;
- return p + 6;
- case MARKER_ATMOVE:
- if (len < 8) return NULL;
- return p + 8;
- case MARKER_COMMENT:
- if (len < 6) return NULL;
- l = (((long) p[2] << 24) | ((long) p[3] << 16) |
- ((long) p[4] << 8) | (long) p[5]);
- if (len - 6 < l) return NULL;
- return p + 6 + l;
- default:
- return NULL;
- }
- }
- return p;
- }
- /*
- * Scan a complete BIE for a NEWLEN marker segment, then read the new
- * YD value found in it and use it to overwrite the one in the BIE
- * header. Use this procedure if a BIE initially declares an
- * unreasonably high provisional YD value (e.g., 0xffffffff) or
- * depends on the fact that section 6.2.6.2 of ITU-T T.82 says that a
- * NEWLEN marker segment "could refer to a line in the immediately
- * preceding stripe due to an unexpected termination of the image or
- * the use of only such stripe". ITU-T.85 explicitely suggests the
- * use of this for fax machines that start transmission before having
- * encountered the end of the page. None of this is necessary for
- * BIEs produced by JBIG-KIT, which normally does not use NEWLEN.
- */
- int jbg_newlen(unsigned char *bie, size_t len)
- {
- unsigned char *p = bie + 20;
- int i;
- if (len < 20)
- return JBG_EAGAIN;
- if ((bie[19] & (JBG_DPON | JBG_DPPRIV | JBG_DPLAST))
- == (JBG_DPON | JBG_DPPRIV))
- p += 1728; /* skip DPTABLE */
- if (p >= bie + len)
- return JBG_EAGAIN;
- while ((p = jbg_next_pscdms(p, len - (p - bie)))) {
- if (p == bie + len)
- return JBG_EOK;
- else if (p[0] == MARKER_ESC)
- switch (p[1]) {
- case MARKER_NEWLEN:
- /* overwrite YD in BIH with YD from NEWLEN */
- for (i = 0; i < 4; i++) {
- bie[8+i] = p[2+i];
- }
- return JBG_EOK;
- case MARKER_ABORT:
- return JBG_EABORT;
- }
- }
- return JBG_EINVAL;
- }