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- /*
- * Copyright (c) 1999-2000, Image Power, Inc. and the University of
- * British Columbia.
- * Copyright (c) 2001-2003 Michael David Adams.
- * All rights reserved.
- */
- /* __START_OF_JASPER_LICENSE__
- *
- * JasPer License Version 2.0
- *
- * Copyright (c) 2001-2006 Michael David Adams
- * Copyright (c) 1999-2000 Image Power, Inc.
- * Copyright (c) 1999-2000 The University of British Columbia
- *
- * All rights reserved.
- *
- * Permission is hereby granted, free of charge, to any person (the
- * "User") obtaining a copy of this software and associated documentation
- * files (the "Software"), to deal in the Software without restriction,
- * including without limitation the rights to use, copy, modify, merge,
- * publish, distribute, and/or sell copies of the Software, and to permit
- * persons to whom the Software is furnished to do so, subject to the
- * following conditions:
- *
- * 1. The above copyright notices and this permission notice (which
- * includes the disclaimer below) shall be included in all copies or
- * substantial portions of the Software.
- *
- * 2. The name of a copyright holder shall not be used to endorse or
- * promote products derived from the Software without specific prior
- * written permission.
- *
- * THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL PART OF THIS
- * LICENSE. NO USE OF THE SOFTWARE IS AUTHORIZED HEREUNDER EXCEPT UNDER
- * THIS DISCLAIMER. THE SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS
- * "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
- * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
- * PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. IN NO
- * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL
- * INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING
- * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
- * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
- * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. NO ASSURANCES ARE
- * PROVIDED BY THE COPYRIGHT HOLDERS THAT THE SOFTWARE DOES NOT INFRINGE
- * THE PATENT OR OTHER INTELLECTUAL PROPERTY RIGHTS OF ANY OTHER ENTITY.
- * EACH COPYRIGHT HOLDER DISCLAIMS ANY LIABILITY TO THE USER FOR CLAIMS
- * BROUGHT BY ANY OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL
- * PROPERTY RIGHTS OR OTHERWISE. AS A CONDITION TO EXERCISING THE RIGHTS
- * GRANTED HEREUNDER, EACH USER HEREBY ASSUMES SOLE RESPONSIBILITY TO SECURE
- * ANY OTHER INTELLECTUAL PROPERTY RIGHTS NEEDED, IF ANY. THE SOFTWARE
- * IS NOT FAULT-TOLERANT AND IS NOT INTENDED FOR USE IN MISSION-CRITICAL
- * SYSTEMS, SUCH AS THOSE USED IN THE OPERATION OF NUCLEAR FACILITIES,
- * AIRCRAFT NAVIGATION OR COMMUNICATION SYSTEMS, AIR TRAFFIC CONTROL
- * SYSTEMS, DIRECT LIFE SUPPORT MACHINES, OR WEAPONS SYSTEMS, IN WHICH
- * THE FAILURE OF THE SOFTWARE OR SYSTEM COULD LEAD DIRECTLY TO DEATH,
- * PERSONAL INJURY, OR SEVERE PHYSICAL OR ENVIRONMENTAL DAMAGE ("HIGH
- * RISK ACTIVITIES"). THE COPYRIGHT HOLDERS SPECIFICALLY DISCLAIM ANY
- * EXPRESS OR IMPLIED WARRANTY OF FITNESS FOR HIGH RISK ACTIVITIES.
- *
- * __END_OF_JASPER_LICENSE__
- */
- /*
- * Bit Stream Class
- *
- * $Id: jpc_bs.c,v 1.2 2008-05-26 09:40:52 vp153 Exp $
- */
- /******************************************************************************\
- * Includes.
- \******************************************************************************/
- #include <assert.h>
- #include <stdlib.h>
- #include <stdarg.h>
- #include "jasper/jas_malloc.h"
- #include "jasper/jas_math.h"
- #include "jasper/jas_debug.h"
- #include "jpc_bs.h"
- /******************************************************************************\
- * Local function prototypes.
- \******************************************************************************/
- static jpc_bitstream_t *jpc_bitstream_alloc(void);
- /******************************************************************************\
- * Code for opening and closing bit streams.
- \******************************************************************************/
- /* Open a bit stream from a stream. */
- jpc_bitstream_t *jpc_bitstream_sopen(jas_stream_t *stream, char *mode)
- {
- jpc_bitstream_t *bitstream;
- /* Ensure that the open mode is valid. */
- #if 1
- /* This causes a string literal too long error (with c99 pedantic mode). */
- assert(!strcmp(mode, "r") || !strcmp(mode, "w") || !strcmp(mode, "r+")
- || !strcmp(mode, "w+"));
- #endif
- if (!(bitstream = jpc_bitstream_alloc())) {
- return 0;
- }
- /* By default, do not close the underlying (character) stream, upon
- the close of the bit stream. */
- bitstream->flags_ = JPC_BITSTREAM_NOCLOSE;
- bitstream->stream_ = stream;
- bitstream->openmode_ = (mode[0] == 'w') ? JPC_BITSTREAM_WRITE :
- JPC_BITSTREAM_READ;
- /* Mark the data buffer as empty. */
- bitstream->cnt_ = (bitstream->openmode_ == JPC_BITSTREAM_READ) ? 0 : 8;
- bitstream->buf_ = 0;
- return bitstream;
- }
- /* Close a bit stream. */
- int jpc_bitstream_close(jpc_bitstream_t *bitstream)
- {
- int ret = 0;
- /* Align to the next byte boundary while considering the effects of
- bit stuffing. */
- if (jpc_bitstream_align(bitstream)) {
- ret = -1;
- }
- /* If necessary, close the underlying (character) stream. */
- if (!(bitstream->flags_ & JPC_BITSTREAM_NOCLOSE) && bitstream->stream_) {
- if (jas_stream_close(bitstream->stream_)) {
- ret = -1;
- }
- bitstream->stream_ = 0;
- }
- jas_free(bitstream);
- return ret;
- }
- /* Allocate a new bit stream. */
- static jpc_bitstream_t *jpc_bitstream_alloc()
- {
- jpc_bitstream_t *bitstream;
- /* Allocate memory for the new bit stream object. */
- if (!(bitstream = jas_malloc(sizeof(jpc_bitstream_t)))) {
- return 0;
- }
- /* Initialize all of the data members. */
- bitstream->stream_ = 0;
- bitstream->cnt_ = 0;
- bitstream->flags_ = 0;
- bitstream->openmode_ = 0;
- return bitstream;
- }
- /******************************************************************************\
- * Code for reading/writing from/to bit streams.
- \******************************************************************************/
- /* Get a bit from a bit stream. */
- int jpc_bitstream_getbit_func(jpc_bitstream_t *bitstream)
- {
- int ret;
- JAS_DBGLOG(1000, ("jpc_bitstream_getbit_func(%p)\n", bitstream));
- ret = jpc_bitstream_getbit_macro(bitstream);
- JAS_DBGLOG(1000, ("jpc_bitstream_getbit_func -> %d\n", ret));
- return ret;
- }
- /* Put a bit to a bit stream. */
- int jpc_bitstream_putbit_func(jpc_bitstream_t *bitstream, int b)
- {
- int ret;
- JAS_DBGLOG(1000, ("jpc_bitstream_putbit_func(%p, %d)\n", bitstream, b));
- ret = jpc_bitstream_putbit_macro(bitstream, b);
- JAS_DBGLOG(1000, ("jpc_bitstream_putbit_func() -> %d\n", ret));
- return ret;
- }
- /* Get one or more bits from a bit stream. */
- long jpc_bitstream_getbits(jpc_bitstream_t *bitstream, int n)
- {
- long v;
- int u;
- /* We can reliably get at most 31 bits since ISO/IEC 9899 only
- guarantees that a long can represent values up to 2^31-1. */
- assert(n >= 0 && n < 32);
- /* Get the number of bits requested from the specified bit stream. */
- v = 0;
- while (--n >= 0) {
- if ((u = jpc_bitstream_getbit(bitstream)) < 0) {
- return -1;
- }
- v = (v << 1) | u;
- }
- return v;
- }
- /* Put one or more bits to a bit stream. */
- int jpc_bitstream_putbits(jpc_bitstream_t *bitstream, int n, long v)
- {
- int m;
- /* We can reliably put at most 31 bits since ISO/IEC 9899 only
- guarantees that a long can represent values up to 2^31-1. */
- assert(n >= 0 && n < 32);
- /* Ensure that only the bits to be output are nonzero. */
- assert(!(v & (~JAS_ONES(n))));
- /* Put the desired number of bits to the specified bit stream. */
- m = n - 1;
- while (--n >= 0) {
- if (jpc_bitstream_putbit(bitstream, (v >> m) & 1) == EOF) {
- return EOF;
- }
- v <<= 1;
- }
- return 0;
- }
- /******************************************************************************\
- * Code for buffer filling and flushing.
- \******************************************************************************/
- /* Fill the buffer for a bit stream. */
- int jpc_bitstream_fillbuf(jpc_bitstream_t *bitstream)
- {
- int c;
- /* Note: The count has already been decremented by the caller. */
- assert(bitstream->openmode_ & JPC_BITSTREAM_READ);
- assert(bitstream->cnt_ <= 0);
- if (bitstream->flags_ & JPC_BITSTREAM_ERR) {
- bitstream->cnt_ = 0;
- return -1;
- }
- if (bitstream->flags_ & JPC_BITSTREAM_EOF) {
- bitstream->buf_ = 0x7f;
- bitstream->cnt_ = 7;
- return 1;
- }
- bitstream->buf_ = (bitstream->buf_ << 8) & 0xffff;
- if ((c = jas_stream_getc((bitstream)->stream_)) == EOF) {
- bitstream->flags_ |= JPC_BITSTREAM_EOF;
- return 1;
- }
- bitstream->cnt_ = (bitstream->buf_ == 0xff00) ? 6 : 7;
- bitstream->buf_ |= c & ((1 << (bitstream->cnt_ + 1)) - 1);
- return (bitstream->buf_ >> bitstream->cnt_) & 1;
- }
- /******************************************************************************\
- * Code related to flushing.
- \******************************************************************************/
- /* Does the bit stream need to be aligned to a byte boundary (considering
- the effects of bit stuffing)? */
- int jpc_bitstream_needalign(jpc_bitstream_t *bitstream)
- {
- if (bitstream->openmode_ & JPC_BITSTREAM_READ) {
- /* The bit stream is open for reading. */
- /* If there are any bits buffered for reading, or the
- previous byte forced a stuffed bit, alignment is
- required. */
- if ((bitstream->cnt_ < 8 && bitstream->cnt_ > 0) ||
- ((bitstream->buf_ >> 8) & 0xff) == 0xff) {
- return 1;
- }
- } else if (bitstream->openmode_ & JPC_BITSTREAM_WRITE) {
- /* The bit stream is open for writing. */
- /* If there are any bits buffered for writing, or the
- previous byte forced a stuffed bit, alignment is
- required. */
- if ((bitstream->cnt_ < 8 && bitstream->cnt_ >= 0) ||
- ((bitstream->buf_ >> 8) & 0xff) == 0xff) {
- return 1;
- }
- } else {
- /* This should not happen. Famous last words, eh? :-) */
- assert(0);
- return -1;
- }
- return 0;
- }
- /* How many additional bytes would be output if we align the bit stream? */
- int jpc_bitstream_pending(jpc_bitstream_t *bitstream)
- {
- if (bitstream->openmode_ & JPC_BITSTREAM_WRITE) {
- /* The bit stream is being used for writing. */
- #if 1
- /* XXX - Is this really correct? Check someday... */
- if (bitstream->cnt_ < 8) {
- return 1;
- }
- #else
- if (bitstream->cnt_ < 8) {
- if (((bitstream->buf_ >> 8) & 0xff) == 0xff) {
- return 2;
- }
- return 1;
- }
- #endif
- return 0;
- } else {
- /* This operation should not be invoked on a bit stream that
- is being used for reading. */
- return -1;
- }
- }
- /* Align the bit stream to a byte boundary. */
- int jpc_bitstream_align(jpc_bitstream_t *bitstream)
- {
- int ret;
- if (bitstream->openmode_ & JPC_BITSTREAM_READ) {
- ret = jpc_bitstream_inalign(bitstream, 0, 0);
- } else if (bitstream->openmode_ & JPC_BITSTREAM_WRITE) {
- ret = jpc_bitstream_outalign(bitstream, 0);
- } else {
- abort();
- }
- return ret;
- }
- /* Align a bit stream in the input case. */
- int jpc_bitstream_inalign(jpc_bitstream_t *bitstream, int fillmask,
- int filldata)
- {
- int n;
- int v;
- int u;
- int numfill;
- int m;
- numfill = 7;
- m = 0;
- v = 0;
- if (bitstream->cnt_ > 0) {
- n = bitstream->cnt_;
- } else if (!bitstream->cnt_) {
- n = ((bitstream->buf_ & 0xff) == 0xff) ? 7 : 0;
- } else {
- n = 0;
- }
- if (n > 0) {
- if ((u = jpc_bitstream_getbits(bitstream, n)) < 0) {
- return -1;
- }
- m += n;
- v = (v << n) | u;
- }
- if ((bitstream->buf_ & 0xff) == 0xff) {
- if ((u = jpc_bitstream_getbits(bitstream, 7)) < 0) {
- return -1;
- }
- v = (v << 7) | u;
- m += 7;
- }
- if (m > numfill) {
- v >>= m - numfill;
- } else {
- filldata >>= numfill - m;
- fillmask >>= numfill - m;
- }
- if (((~(v ^ filldata)) & fillmask) != fillmask) {
- /* The actual fill pattern does not match the expected one. */
- return 1;
- }
- return 0;
- }
- /* Align a bit stream in the output case. */
- int jpc_bitstream_outalign(jpc_bitstream_t *bitstream, int filldata)
- {
- int n;
- int v;
- /* Ensure that this bit stream is open for writing. */
- assert(bitstream->openmode_ & JPC_BITSTREAM_WRITE);
- /* Ensure that the first bit of fill data is zero. */
- /* Note: The first bit of fill data must be zero. If this were not
- the case, the fill data itself could cause further bit stuffing to
- be required (which would cause numerous complications). */
- assert(!(filldata & (~0x3f)));
- if (!bitstream->cnt_) {
- if ((bitstream->buf_ & 0xff) == 0xff) {
- n = 7;
- v = filldata;
- } else {
- n = 0;
- v = 0;
- }
- } else if (bitstream->cnt_ > 0 && bitstream->cnt_ < 8) {
- n = bitstream->cnt_;
- v = filldata >> (7 - n);
- } else {
- n = 0;
- v = 0;
- return 0;
- }
- /* Write the appropriate fill data to the bit stream. */
- if (n > 0) {
- if (jpc_bitstream_putbits(bitstream, n, v)) {
- return -1;
- }
- }
- if (bitstream->cnt_ < 8) {
- assert(bitstream->cnt_ >= 0 && bitstream->cnt_ < 8);
- assert((bitstream->buf_ & 0xff) != 0xff);
- /* Force the pending byte of output to be written to the
- underlying (character) stream. */
- if (jas_stream_putc(bitstream->stream_, bitstream->buf_ & 0xff) == EOF) {
- return -1;
- }
- bitstream->cnt_ = 8;
- bitstream->buf_ = (bitstream->buf_ << 8) & 0xffff;
- }
- return 0;
- }
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