1 /* SPMG/JPEG-LS IMPLEMENTATION V.2.1
2 =====================================
3 These programs are Copyright (c) University of British Columbia. All rights reserved.
4 They may be freely redistributed in their entirety provided that this copyright
5 notice is not removed. THEY MAY NOT BE SOLD FOR PROFIT OR INCORPORATED IN
6 COMMERCIAL PROGRAMS WITHOUT THE WRITTEN PERMISSION OF THE COPYRIGHT HOLDER.
7 Each program is provided as is, without any express or implied warranty,
8 without even the warranty of fitness for a particular purpose.
10 =========================================================
11 THIS SOFTWARE IS BASED ON HP's implementation of jpeg-ls:
12 =========================================================
14 LOCO-I/JPEG-LS IMPLEMENTATION V.0.90
15 -------------------------------------------------------------------------------
16 (c) COPYRIGHT HEWLETT-PACKARD COMPANY, 1995-1999.
17 HEWLETT-PACKARD COMPANY ("HP") DOES NOT WARRANT THE ACCURACY OR
18 COMPLETENESS OF THE INFORMATION GIVEN HERE. ANY USE MADE OF, OR
19 RELIANCE ON, SUCH INFORMATION IS ENTIRELY AT USER'S OWN RISK.
20 BY DOWNLOADING THE LOCO-I/JPEG-LS COMPRESSORS/DECOMPRESSORS
21 ("THE SOFTWARE") YOU AGREE TO BE BOUND BY THE TERMS AND CONDITIONS
22 OF THIS LICENSING AGREEMENT.
23 YOU MAY DOWNLOAD AND USE THE SOFTWARE FOR NON-COMMERCIAL PURPOSES
24 FREE OF CHARGE OR FURTHER OBLIGATION. YOU MAY NOT, DIRECTLY OR
25 INDIRECTLY, DISTRIBUTE THE SOFTWARE FOR A FEE, INCORPORATE THIS
26 SOFTWARE INTO ANY PRODUCT OFFERED FOR SALE, OR USE THE SOFTWARE
27 TO PROVIDE A SERVICE FOR WHICH A FEE IS CHARGED.
28 YOU MAY MAKE COPIES OF THE SOFTWARE AND DISTRIBUTE SUCH COPIES TO
29 OTHER PERSONS PROVIDED THAT SUCH COPIES ARE ACCOMPANIED BY
30 HEWLETT-PACKARD'S COPYRIGHT NOTICE AND THIS AGREEMENT AND THAT
31 SUCH OTHER PERSONS AGREE TO BE BOUND BY THE TERMS OF THIS AGREEMENT.
32 THE SOFTWARE IS NOT OF PRODUCT QUALITY AND MAY HAVE ERRORS OR DEFECTS.
33 THE JPEG-LS STANDARD IS STILL UNDER DEVELOPMENT. THE SOFTWARE IS NOT A
34 FINAL OR FULL IMPLEMENTATION OF THE STANDARD. HP GIVES NO EXPRESS OR
35 IMPLIED WARRANTY OF ANY KIND AND ANY IMPLIED WARRANTIES OF
36 MERCHANTABILITY AND FITNESS FOR PURPOSE ARE DISCLAIMED.
37 HP SHALL NOT BE LIABLE FOR ANY DIRECT, INDIRECT, SPECIAL, INCIDENTAL,
38 OR CONSEQUENTIAL DAMAGES ARISING OUT OF ANY USE OF THE SOFTWARE.
39 -------------------------------------------------------------------------------
44 * Initial code by Alex Jakulin, Aug. 1995
46 * Modified and optimized: Gadiel Seroussi, October 1995
48 * Modified and added Restart marker and input tables by:
49 * David Cheng-Hsiu Chu, and Ismail R. Ismail march 1999
56 extern int zeroLUT[]; /* lookup table to find number of leading zeroes */
58 extern FILE *in, *out;
60 byte negbuff[BUFSIZE+4]; /* byte I/O buffer, allowing for 4 "negative"
64 'buff' is defined as 'rawbuff+4' in bitio.h, so that buff[-4]..buff[-1]
65 are well defined. Those locations are used to "return" data to
66 the byte buffer when flushing the input bit buffer .
70 int fp; /* index into byte buffer */
71 int truebufsize; /* true size of byte buffer ( <= BUFSIZE) */
74 int zeroLUT[256]; /* table to find out number of leading zeros */
77 /* BIT I/O variables */
78 dword reg; /* BIT buffer for input/output */
79 int bits; /* number of bits free in bit buffer (on output) */
80 /* (number of bits free)-8 in bit buffer (on input)*/
83 /****************************************************************************
85 * note: some routines are implemented as preprocessor macros. See bitio.h.
86 ****************************************************************************/
89 void bufiinit(FILE *fil) {
90 /* argument is ignored */
97 byte fillinbuff(FILE *fil)
101 /* remember 4 last bytes of current buffer (for "undo") */
102 for ( i=-4; i<0; i++ )
103 buff[i] = buff[fp+i];
104 truebufsize = fread(buff, 1, BUFSIZE, fil);
105 if ( truebufsize < BUFSIZE )
107 if ( truebufsize <= 0 )
110 { /* second attempt to read past EOF */
111 fprintf(stderr,"*** Premature EOF in compressed file\n");
116 /* One attempt to read past EOF is OK */
120 /* fill buffer with zeros */
121 memset(buff+truebufsize, 0, (BUFSIZE-truebufsize)*sizeof(*buff));
129 /* Initializes the bit input routines */
137 Flush the input bit buffer TO A BYTE BOUNDARY. Return unused whole
138 bytes to the byte buffer
147 filled = 24 - bits; /* how many bits at the MS part of reg
148 have unused data. These correspond to
149 at most filled+2 bits from the input
150 stream, as at most 2 '0' bits might have
151 been dropped by marker processing */
153 dbytes = (filled+2)/8; /* the coorrect number of bytes we need to
154 "unget" is either dbytes or dbytes-1 */
155 /* this solution is more general than what is required here: it
156 will work correctly even if the end of a scan is not followed
157 by a marker, as will necessarily be the case with the standard JPEG
161 bp = buff + fp - dbytes; /* back-in the buffer */
163 for ( i=0; i<dbytes; i++ )
165 if ( bp[i-1]==0xff && (bp[i]&0x80)==0 )
167 treg |= bp[i] << (BITBUFSIZE-7-k);
172 treg |= bp[i] << (BITBUFSIZE-8-k);
180 /* check consistency */
181 if ( filled-k > 7 ) {
182 fprintf(stderr,"bitiflush: inconsistent bits=%d filled=%d k=%d\n",bits,filled,k);
186 if ( treg != (reg<<discard) ) {
187 fprintf(stderr,"bitiflush: inconsistent bits=%d discard=%d reg=%08x treg=%08x\n",bits, discard, reg, treg);
190 if ( reg & (((1<<discard)-1)<<(BITBUFSIZE-discard)) )
191 fprintf(stderr,"bitiflush: Warning: discarding nonzero bits; reg=%08x bits=%d discard=%d\n",reg,bits,discard);
193 fp -= dbytes; /* do the unget */
194 if ( buff[fp-1]==0xff && buff[fp]==0 ) fp++;
203 /* Unpad zeros from byte length */
222 /* creates the bit counting look-up table. */
228 for (i = 0; i < 256; ++i) {
242 /* if using functions instead of macros */
248 assert(no > 0 && no <= 18);
249 temp = reg >> (32 - no);
253 # define GETBITS(n) getbits(n)
255 /* see GETBITS(x,n) in bitio.h */