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Diffstat (limited to 'src/libjasper/jpc/jpc_bs.c')
| -rw-r--r-- | src/libjasper/jpc/jpc_bs.c | 440 |
1 files changed, 440 insertions, 0 deletions
diff --git a/src/libjasper/jpc/jpc_bs.c b/src/libjasper/jpc/jpc_bs.c new file mode 100644 index 0000000..0471665 --- /dev/null +++ b/src/libjasper/jpc/jpc_bs.c @@ -0,0 +1,440 @@ +/* + * 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 1.1 2008/10/17 06:15:00 scuri 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; +} |