--- /dev/null
+/*
+ * 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) 1999-2000 Image Power, Inc.
+ * Copyright (c) 1999-2000 The University of British Columbia
+ * Copyright (c) 2001-2003 Michael David Adams
+ *
+ * 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 1.1 2005/05/22 18:33:03 malaterre 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. */
+ assert(!strcmp(mode, "r") || !strcmp(mode, "w") || !strcmp(mode, "r+")
+ || !strcmp(mode, "w+"));
+
+ 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;
+}
git://git.creatis.insa-lyon.fr / gdcm.git / blobdiff