diff options
Diffstat (limited to 'converter/other/jbig/libjbig/jbig_ar.c')
| -rw-r--r-- | converter/other/jbig/libjbig/jbig_ar.c | 138 |
1 files changed, 73 insertions, 65 deletions
diff --git a/converter/other/jbig/libjbig/jbig_ar.c b/converter/other/jbig/libjbig/jbig_ar.c index d23a317d..aad293f2 100644 --- a/converter/other/jbig/libjbig/jbig_ar.c +++ b/converter/other/jbig/libjbig/jbig_ar.c @@ -22,7 +22,7 @@ * 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. */ @@ -106,7 +106,7 @@ static unsigned char nlpstab[113] = { 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; @@ -114,11 +114,12 @@ void arith_encode_init(struct jbg_arenc_state *s, int reuse_st) s->sc = 0; s->ct = 11; s->buffer = -1; /* empty */ - + return; } + void arith_encode_flush(struct jbg_arenc_state *s) { unsigned long temp; @@ -136,15 +137,15 @@ void arith_encode_flush(struct jbg_arenc_state *s) 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); + 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); + s->byte_out(0x00, s->file); } else { if (s->buffer >= 0) - s->byte_out(s->buffer, s->file); + 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); @@ -159,7 +160,7 @@ void arith_encode_flush(struct jbg_arenc_state *s) 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); + s->byte_out(MARKER_STUFF, s->file); } } @@ -167,7 +168,8 @@ void arith_encode_flush(struct jbg_arenc_state *s) } -void arith_encode(struct jbg_arenc_state *s, int cx, int pix) + +void arith_encode(struct jbg_arenc_state *s, int cx, int pix) { register unsigned lsz, ss; register unsigned char *st; @@ -181,9 +183,9 @@ void arith_encode(struct jbg_arenc_state *s, int cx, int pix) #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); + "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) { @@ -225,44 +227,45 @@ void arith_encode(struct jbg_arenc_state *s, int cx, int pix) /* 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? */ + /* 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; + /* 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) */ + /* 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; } + 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; @@ -273,6 +276,8 @@ void arith_decode_init(struct jbg_ardec_state *s, int reuse_st) return; } + + /* * Decode and return one symbol from the provided PSCD byte stream * that starts in s->pscd_ptr and ends in the byte before s->pscd_end. @@ -295,7 +300,7 @@ void arith_decode_init(struct jbg_ardec_state *s, int reuse_st) * decoded. * * s->pscd_ptr == s->pscd_end - 1: - * + * * The decoder has used up all provided PSCD bytes except for the * very last byte, because that has the value 0xff. The decoder can * at this point not yet tell whether this 0xff belongs to a @@ -336,27 +341,27 @@ int arith_decode(struct jbg_ardec_state *s, int cx) while (s->ct <= 8 && s->ct >= 0) { /* first we can move a new byte into s->c */ if (s->pscd_ptr >= s->pscd_end) { - return -1; /* more bytes needed */ + return -1; /* more bytes needed */ } - if (*s->pscd_ptr == 0xff) - if (s->pscd_ptr + 1 >= s->pscd_end) { - return -1; /* final 0xff byte not processed */ - } else { - if (*(s->pscd_ptr + 1) == MARKER_STUFF) { - s->c |= 0xffL << (8 - s->ct); - s->ct += 8; - s->pscd_ptr += 2; - } else { - s->ct = -1; /* start padding with zero bytes */ - if (s->nopadding) { - s->nopadding = 0; - return -2; /* subsequent symbols might depend on zero padding */ - } - } - } + if (*s->pscd_ptr == 0xff) + if (s->pscd_ptr + 1 >= s->pscd_end) { + return -1; /* final 0xff byte not processed */ + } else { + if (*(s->pscd_ptr + 1) == MARKER_STUFF) { + s->c |= 0xffL << (8 - s->ct); + s->ct += 8; + s->pscd_ptr += 2; + } else { + s->ct = -1; /* start padding with zero bytes */ + if (s->nopadding) { + s->nopadding = 0; + return -2; /* subsequent symbols might depend on zero padding */ + } + } + } else { - s->c |= (long)*(s->pscd_ptr++) << (8 - s->ct); - s->ct += 8; + s->c |= (long)*(s->pscd_ptr++) << (8 - s->ct); + s->ct += 8; } } s->c <<= 1; @@ -373,8 +378,8 @@ int arith_decode(struct jbg_ardec_state *s, int cx) #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); + "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)) @@ -383,15 +388,15 @@ int arith_decode(struct jbg_ardec_state *s, int cx) 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 ^= nlpstab[ss]; + pix = 1 - (*st >> 7); + /* Check whether MPS/LPS exchange is necessary + * and chose next probability estimator status */ + *st &= 0x80; + *st ^= nlpstab[ss]; } else { - pix = *st >> 7; - *st &= 0x80; - *st |= nmpstab[ss]; + pix = *st >> 7; + *st &= 0x80; + *st |= nmpstab[ss]; } } else { @@ -415,3 +420,6 @@ int arith_decode(struct jbg_ardec_state *s, int cx) return pix; } + + + |