/* * 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 #else #define NDEBUG #endif #include #include #include #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] += ((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; }