mqc.h revision ac3d58cff7c80b0ef56bf55130d91da17cbaa3c4 
1/*
2 * The copyright in this software is being made available under the 2-clauses
3 * BSD License, included below. This software may be subject to other third
4 * party and contributor rights, including patent rights, and no such rights
5 * are granted under this license.
6 *
7 * Copyright (c) 2002-2014, Universite catholique de Louvain (UCL), Belgium
8 * Copyright (c) 2002-2014, Professor Benoit Macq
9 * Copyright (c) 2001-2003, David Janssens
10 * Copyright (c) 2002-2003, Yannick Verschueren
11 * Copyright (c) 2003-2007, Francois-Olivier Devaux
12 * Copyright (c) 2003-2014, Antonin Descampe
13 * Copyright (c) 2005, Herve Drolon, FreeImage Team
14 * Copyright (c) 2008, Jerome Fimes, Communications & Systemes <jerome.fimes@c-s.fr>
15 * All rights reserved.
16 *
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions
19 * are met:
20 * 1. Redistributions of source code must retain the above copyright
21 *    notice, this list of conditions and the following disclaimer.
22 * 2. Redistributions in binary form must reproduce the above copyright
23 *    notice, this list of conditions and the following disclaimer in the
24 *    documentation and/or other materials provided with the distribution.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS `AS IS'
27 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
30 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 * POSSIBILITY OF SUCH DAMAGE.
37 */
38
39#ifndef __MQC_H
40#define __MQC_H
41/**
42@file mqc.h
43@brief Implementation of an MQ-Coder (MQC)
44
45The functions in MQC.C have for goal to realize the MQ-coder operations. The functions
46in MQC.C are used by some function in T1.C.
47*/
48
49/** @defgroup MQC MQC - Implementation of an MQ-Coder */
50/*@{*/
51
52/**
53This struct defines the state of a context.
54*/
55typedef struct opj_mqc_state {
56	/** the probability of the Least Probable Symbol (0.75->0x8000, 1.5->0xffff) */
57	OPJ_UINT32 qeval;
58	/** the Most Probable Symbol (0 or 1) */
59	OPJ_UINT32 mps;
60	/** next state if the next encoded symbol is the MPS */
61	struct opj_mqc_state *nmps;
62	/** next state if the next encoded symbol is the LPS */
63	struct opj_mqc_state *nlps;
64} opj_mqc_state_t;
65
66#define MQC_NUMCTXS 19
67
68/**
69MQ coder
70*/
71typedef struct opj_mqc {
72	OPJ_UINT32 c;
73	OPJ_UINT32 a;
74	OPJ_UINT32 ct;
75	OPJ_BYTE *bp;
76	OPJ_BYTE *start;
77	OPJ_BYTE *end;
78	opj_mqc_state_t *ctxs[MQC_NUMCTXS];
79	opj_mqc_state_t **curctx;
80#ifdef MQC_PERF_OPT
81	unsigned char *buffer;
82#endif
83} opj_mqc_t;
84
85/** @name Exported functions */
86/*@{*/
87/* ----------------------------------------------------------------------- */
88/**
89Create a new MQC handle
90@return Returns a new MQC handle if successful, returns NULL otherwise
91*/
92opj_mqc_t* opj_mqc_create(void);
93/**
94Destroy a previously created MQC handle
95@param mqc MQC handle to destroy
96*/
97void opj_mqc_destroy(opj_mqc_t *mqc);
98/**
99Return the number of bytes written/read since initialisation
100@param mqc MQC handle
101@return Returns the number of bytes already encoded
102*/
103OPJ_UINT32 opj_mqc_numbytes(opj_mqc_t *mqc);
104/**
105Reset the states of all the context of the coder/decoder
106(each context is set to a state where 0 and 1 are more or less equiprobable)
107@param mqc MQC handle
108*/
109void opj_mqc_resetstates(opj_mqc_t *mqc);
110/**
111Set the state of a particular context
112@param mqc MQC handle
113@param ctxno Number that identifies the context
114@param msb The MSB of the new state of the context
115@param prob Number that identifies the probability of the symbols for the new state of the context
116*/
117void opj_mqc_setstate(opj_mqc_t *mqc, OPJ_UINT32 ctxno, OPJ_UINT32 msb, OPJ_INT32 prob);
118/**
119Initialize the encoder
120@param mqc MQC handle
121@param bp Pointer to the start of the buffer where the bytes will be written
122*/
123void opj_mqc_init_enc(opj_mqc_t *mqc, OPJ_BYTE *bp);
124/**
125Set the current context used for coding/decoding
126@param mqc MQC handle
127@param ctxno Number that identifies the context
128*/
129#define opj_mqc_setcurctx(mqc, ctxno)	(mqc)->curctx = &(mqc)->ctxs[(OPJ_UINT32)(ctxno)]
130/**
131Encode a symbol using the MQ-coder
132@param mqc MQC handle
133@param d The symbol to be encoded (0 or 1)
134*/
135void opj_mqc_encode(opj_mqc_t *mqc, OPJ_UINT32 d);
136/**
137Flush the encoder, so that all remaining data is written
138@param mqc MQC handle
139*/
140void opj_mqc_flush(opj_mqc_t *mqc);
141/**
142BYPASS mode switch, initialization operation.
143JPEG 2000 p 505.
144<h2>Not fully implemented and tested !!</h2>
145@param mqc MQC handle
146*/
147void opj_mqc_bypass_init_enc(opj_mqc_t *mqc);
148/**
149BYPASS mode switch, coding operation.
150JPEG 2000 p 505.
151<h2>Not fully implemented and tested !!</h2>
152@param mqc MQC handle
153@param d The symbol to be encoded (0 or 1)
154*/
155void opj_mqc_bypass_enc(opj_mqc_t *mqc, OPJ_UINT32 d);
156/**
157BYPASS mode switch, flush operation
158<h2>Not fully implemented and tested !!</h2>
159@param mqc MQC handle
160@return Returns 1 (always)
161*/
162OPJ_UINT32 opj_mqc_bypass_flush_enc(opj_mqc_t *mqc);
163/**
164RESET mode switch
165@param mqc MQC handle
166*/
167void opj_mqc_reset_enc(opj_mqc_t *mqc);
168/**
169RESTART mode switch (TERMALL)
170@param mqc MQC handle
171@return Returns 1 (always)
172*/
173OPJ_UINT32 opj_mqc_restart_enc(opj_mqc_t *mqc);
174/**
175RESTART mode switch (TERMALL) reinitialisation
176@param mqc MQC handle
177*/
178void opj_mqc_restart_init_enc(opj_mqc_t *mqc);
179/**
180ERTERM mode switch (PTERM)
181@param mqc MQC handle
182*/
183void opj_mqc_erterm_enc(opj_mqc_t *mqc);
184/**
185SEGMARK mode switch (SEGSYM)
186@param mqc MQC handle
187*/
188void opj_mqc_segmark_enc(opj_mqc_t *mqc);
189/**
190Initialize the decoder
191@param mqc MQC handle
192@param bp Pointer to the start of the buffer from which the bytes will be read
193@param len Length of the input buffer
194*/
195OPJ_BOOL opj_mqc_init_dec(opj_mqc_t *mqc, OPJ_BYTE *bp, OPJ_UINT32 len);
196/**
197Decode a symbol
198@param mqc MQC handle
199@return Returns the decoded symbol (0 or 1)
200*/
201OPJ_INT32 opj_mqc_decode(opj_mqc_t * const mqc);
202/* ----------------------------------------------------------------------- */
203/*@}*/
204
205/*@}*/
206
207#endif /* __MQC_H */
208