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Diffstat (limited to 'kernel/kls_jbig/libjbig/jbig.c')
| -rw-r--r-- | kernel/kls_jbig/libjbig/jbig.c | 3190 |
1 files changed, 3190 insertions, 0 deletions
diff --git a/kernel/kls_jbig/libjbig/jbig.c b/kernel/kls_jbig/libjbig/jbig.c new file mode 100644 index 0000000..6d8afa3 --- /dev/null +++ b/kernel/kls_jbig/libjbig/jbig.c @@ -0,0 +1,3190 @@ +/* + * 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 +#define NDEBUG +#endif + +#include <stdlib.h> +#include <string.h> +#include <assert.h> + +#include "jbig.h" + + +/* optional export of arithmetic coder functions for test purposes */ +#define ARITH static +#ifdef __GNUC__ +#define ARITH_INL static __inline__ +#else +#define ARITH_INL static +#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 */ +}; + +unsigned char *jbg_next_pscdms(unsigned char *p, size_t len); + + +/* + * 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] += ((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] += ((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] = xd >> 24; + buf[5] = (xd >> 16) & 0xff; + buf[6] = (xd >> 8) & 0xff; + buf[7] = xd & 0xff; + buf[8] = yd >> 24; + buf[9] = (yd >> 16) & 0xff; + buf[10] = (yd >> 8) & 0xff; + buf[11] = yd & 0xff; + buf[12] = s->l0 >> 24; + buf[13] = (s->l0 >> 16) & 0xff; + buf[14] = (s->l0 >> 8) & 0xff; + buf[15] = s->l0 & 0xff; + buf[16] = s->mx; + buf[17] = s->my; + buf[18] = s->order; + buf[19] = 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] = yd >> 24; + buf[3] = (yd >> 16) & 0xff; + buf[4] = (yd >> 8) & 0xff; + buf[5] = 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++ = 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++ = 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; +} |