diff options
Diffstat (limited to 'src/libjasper/jpc/jpc_mqdec.c')
| -rw-r--r-- | src/libjasper/jpc/jpc_mqdec.c | 306 |
1 files changed, 306 insertions, 0 deletions
diff --git a/src/libjasper/jpc/jpc_mqdec.c b/src/libjasper/jpc/jpc_mqdec.c new file mode 100644 index 0000000..74e6b33 --- /dev/null +++ b/src/libjasper/jpc/jpc_mqdec.c @@ -0,0 +1,306 @@ +/* + * 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__ + */ + +/* + * MQ Arithmetic Decoder + * + * $Id: jpc_mqdec.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_types.h" +#include "jasper/jas_malloc.h" +#include "jasper/jas_math.h" +#include "jasper/jas_debug.h" + +#include "jpc_mqdec.h" + +/******************************************************************************\ +* Local macros. +\******************************************************************************/ + +#if defined(DEBUG) +#define MQDEC_CALL(n, x) \ + ((jas_getdbglevel() >= (n)) ? ((void)(x)) : ((void)0)) +#else +#define MQDEC_CALL(n, x) +#endif + +/******************************************************************************\ +* Local function prototypes. +\******************************************************************************/ + +static void jpc_mqdec_bytein(jpc_mqdec_t *mqdec); + +/******************************************************************************\ +* Code for creation and destruction of a MQ decoder. +\******************************************************************************/ + +/* Create a MQ decoder. */ +jpc_mqdec_t *jpc_mqdec_create(int maxctxs, jas_stream_t *in) +{ + jpc_mqdec_t *mqdec; + + /* There must be at least one context. */ + assert(maxctxs > 0); + + /* Allocate memory for the MQ decoder. */ + if (!(mqdec = jas_malloc(sizeof(jpc_mqdec_t)))) { + goto error; + } + mqdec->in = in; + mqdec->maxctxs = maxctxs; + /* Allocate memory for the per-context state information. */ + if (!(mqdec->ctxs = jas_malloc(mqdec->maxctxs * sizeof(jpc_mqstate_t *)))) { + goto error; + } + /* Set the current context to the first context. */ + mqdec->curctx = mqdec->ctxs; + + /* If an input stream has been associated with the MQ decoder, + initialize the decoder state from the stream. */ + if (mqdec->in) { + jpc_mqdec_init(mqdec); + } + /* Initialize the per-context state information. */ + jpc_mqdec_setctxs(mqdec, 0, 0); + + return mqdec; + +error: + /* Oops... Something has gone wrong. */ + if (mqdec) { + jpc_mqdec_destroy(mqdec); + } + return 0; +} + +/* Destroy a MQ decoder. */ +void jpc_mqdec_destroy(jpc_mqdec_t *mqdec) +{ + if (mqdec->ctxs) { + jas_free(mqdec->ctxs); + } + jas_free(mqdec); +} + +/******************************************************************************\ +* Code for initialization of a MQ decoder. +\******************************************************************************/ + +/* Initialize the state of a MQ decoder. */ + +void jpc_mqdec_init(jpc_mqdec_t *mqdec) +{ + int c; + + mqdec->eof = 0; + mqdec->creg = 0; + /* Get the next byte from the input stream. */ + if ((c = jas_stream_getc(mqdec->in)) == EOF) { + /* We have encountered an I/O error or EOF. */ + c = 0xff; + mqdec->eof = 1; + } + mqdec->inbuffer = c; + mqdec->creg += mqdec->inbuffer << 16; + jpc_mqdec_bytein(mqdec); + mqdec->creg <<= 7; + mqdec->ctreg -= 7; + mqdec->areg = 0x8000; +} + +/* Set the input stream for a MQ decoder. */ + +void jpc_mqdec_setinput(jpc_mqdec_t *mqdec, jas_stream_t *in) +{ + mqdec->in = in; +} + +/* Initialize one or more contexts. */ + +void jpc_mqdec_setctxs(jpc_mqdec_t *mqdec, int numctxs, jpc_mqctx_t *ctxs) +{ + jpc_mqstate_t **ctx; + int n; + + ctx = mqdec->ctxs; + n = JAS_MIN(mqdec->maxctxs, numctxs); + while (--n >= 0) { + *ctx = &jpc_mqstates[2 * ctxs->ind + ctxs->mps]; + ++ctx; + ++ctxs; + } + n = mqdec->maxctxs - numctxs; + while (--n >= 0) { + *ctx = &jpc_mqstates[0]; + ++ctx; + } +} + +/* Initialize a context. */ + +void jpc_mqdec_setctx(jpc_mqdec_t *mqdec, int ctxno, jpc_mqctx_t *ctx) +{ + jpc_mqstate_t **ctxi; + ctxi = &mqdec->ctxs[ctxno]; + *ctxi = &jpc_mqstates[2 * ctx->ind + ctx->mps]; +} + +/******************************************************************************\ +* Code for decoding a bit. +\******************************************************************************/ + +/* Decode a bit. */ + +int jpc_mqdec_getbit_func(register jpc_mqdec_t *mqdec) +{ + int bit; + JAS_DBGLOG(100, ("jpc_mqdec_getbit_func(%p)\n", mqdec)); + MQDEC_CALL(100, jpc_mqdec_dump(mqdec, stderr)); + bit = jpc_mqdec_getbit_macro(mqdec); + MQDEC_CALL(100, jpc_mqdec_dump(mqdec, stderr)); + JAS_DBGLOG(100, ("ctx = %d, decoded %d\n", mqdec->curctx - + mqdec->ctxs, bit)); + return bit; +} + +/* Apply MPS_EXCHANGE algorithm (with RENORMD). */ +int jpc_mqdec_mpsexchrenormd(register jpc_mqdec_t *mqdec) +{ + int ret; + register jpc_mqstate_t *state = *mqdec->curctx; + jpc_mqdec_mpsexchange(mqdec->areg, state->qeval, mqdec->curctx, ret); + jpc_mqdec_renormd(mqdec->areg, mqdec->creg, mqdec->ctreg, mqdec->in, + mqdec->eof, mqdec->inbuffer); + return ret; +} + +/* Apply LPS_EXCHANGE algorithm (with RENORMD). */ +int jpc_mqdec_lpsexchrenormd(register jpc_mqdec_t *mqdec) +{ + int ret; + register jpc_mqstate_t *state = *mqdec->curctx; + jpc_mqdec_lpsexchange(mqdec->areg, state->qeval, mqdec->curctx, ret); + jpc_mqdec_renormd(mqdec->areg, mqdec->creg, mqdec->ctreg, mqdec->in, + mqdec->eof, mqdec->inbuffer); + return ret; +} + +/******************************************************************************\ +* Support code. +\******************************************************************************/ + +/* Apply the BYTEIN algorithm. */ +static void jpc_mqdec_bytein(jpc_mqdec_t *mqdec) +{ + int c; + unsigned char prevbuf; + + if (!mqdec->eof) { + if ((c = jas_stream_getc(mqdec->in)) == EOF) { + mqdec->eof = 1; + c = 0xff; + } + prevbuf = mqdec->inbuffer; + mqdec->inbuffer = c; + if (prevbuf == 0xff) { + if (c > 0x8f) { + mqdec->creg += 0xff00; + mqdec->ctreg = 8; + } else { + mqdec->creg += c << 9; + mqdec->ctreg = 7; + } + } else { + mqdec->creg += c << 8; + mqdec->ctreg = 8; + } + } else { + mqdec->creg += 0xff00; + mqdec->ctreg = 8; + } +} + +/******************************************************************************\ +* Code for debugging. +\******************************************************************************/ + +/* Dump a MQ decoder to a stream for debugging. */ + +void jpc_mqdec_dump(jpc_mqdec_t *mqdec, FILE *out) +{ + fprintf(out, "MQDEC A = %08lx, C = %08lx, CT=%08lx, ", + (unsigned long) mqdec->areg, (unsigned long) mqdec->creg, + (unsigned long) mqdec->ctreg); + fprintf(out, "CTX = %d, ", mqdec->curctx - mqdec->ctxs); + fprintf(out, "IND %d, MPS %d, QEVAL %x\n", *mqdec->curctx - + jpc_mqstates, (*mqdec->curctx)->mps, (*mqdec->curctx)->qeval); +} |