/src/FreeImage/Source/LibOpenJPEG/jpt.c

  1/*
  2 * Copyright (c) 2002-2007, Communications and Remote Sensing Laboratory, Universite catholique de Louvain (UCL), Belgium
  3 * Copyright (c) 2002-2007, Professor Benoit Macq
  4 * Copyright (c) 2002-2003, Yannick Verschueren
  5 * Copyright (c) 2005, Herve Drolon, FreeImage Team
  6 * All rights reserved.
  7 *
  8 * Redistribution and use in source and binary forms, with or without
  9 * modification, are permitted provided that the following conditions
 10 * are met:
 11 * 1. Redistributions of source code must retain the above copyright
 12 *    notice, this list of conditions and the following disclaimer.
 13 * 2. Redistributions in binary form must reproduce the above copyright
 14 *    notice, this list of conditions and the following disclaimer in the
 15 *    documentation and/or other materials provided with the distribution.
 16 *
 17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS `AS IS'
 18 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 21 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 25 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 27 * POSSIBILITY OF SUCH DAMAGE.
 28 */
 29
 30#include "opj_includes.h"
 31
 32/*
 33 * Read the information contains in VBAS [JPP/JPT stream message header]
 34 * Store information (7 bits) in value
 35 *
 36 */
 37unsigned int jpt_read_VBAS_info(opj_cio_t *cio, unsigned int value) {
 38	unsigned char elmt;
 39
 40	elmt = cio_read(cio, 1);
 41	while ((elmt >> 7) == 1) {
 42		value = (value << 7);
 43		value |= (elmt & 0x7f);
 44		elmt = cio_read(cio, 1);
 45	}
 46	value = (value << 7);
 47	value |= (elmt & 0x7f);
 48
 49	return value;
 50}
 51
 52/*
 53 * Initialize the value of the message header structure 
 54 *
 55 */
 56void jpt_init_msg_header(opj_jpt_msg_header_t * header) {
 57	header->Id = 0;		/* In-class Identifier    */
 58	header->last_byte = 0;	/* Last byte information  */
 59	header->Class_Id = 0;		/* Class Identifier       */
 60	header->CSn_Id = 0;		/* CSn : index identifier */
 61	header->Msg_offset = 0;	/* Message offset         */
 62	header->Msg_length = 0;	/* Message length         */
 63	header->Layer_nb = 0;		/* Auxiliary for JPP case */
 64}
 65
 66/*
 67 * Re-initialize the value of the message header structure
 68 *
 69 * Only parameters always present in message header
 70 *
 71 */
 72void jpt_reinit_msg_header(opj_jpt_msg_header_t * header) {
 73	header->Id = 0;		/* In-class Identifier    */
 74	header->last_byte = 0;	/* Last byte information  */
 75	header->Msg_offset = 0;	/* Message offset         */
 76	header->Msg_length = 0;	/* Message length         */
 77}
 78
 79/*
 80 * Read the message header for a JPP/JPT - stream
 81 *
 82 */
 83void jpt_read_msg_header(opj_common_ptr cinfo, opj_cio_t *cio, opj_jpt_msg_header_t *header) {
 84	unsigned char elmt, Class = 0, CSn = 0;
 85	jpt_reinit_msg_header(header);
 86
 87	/* ------------- */
 88	/* VBAS : Bin-ID */
 89	/* ------------- */
 90	elmt = cio_read(cio, 1);
 91
 92	/* See for Class and CSn */
 93	switch ((elmt >> 5) & 0x03) {
 94		case 0:
 95			opj_event_msg(cinfo, EVT_ERROR, "Forbidden value encounter in message header !!\n");
 96			break;
 97		case 1:
 98			Class = 0;
 99			CSn = 0;
100			break;
101		case 2:
102			Class = 1;
103			CSn = 0;
104			break;
105		case 3:
106			Class = 1;
107			CSn = 1;
108			break;
109		default:
110			break;
111	}
112
113	/* see information on bits 'c' [p 10 : A.2.1 general, ISO/IEC FCD 15444-9] */
114	if (((elmt >> 4) & 0x01) == 1)
115		header->last_byte = 1;
116
117	/* In-class identifier */
118	header->Id |= (elmt & 0x0f);
119	if ((elmt >> 7) == 1)
120		header->Id = jpt_read_VBAS_info(cio, header->Id);
121
122	/* ------------ */
123	/* VBAS : Class */
124	/* ------------ */
125	if (Class == 1) {
126		header->Class_Id = 0;
127		header->Class_Id = jpt_read_VBAS_info(cio, header->Class_Id);
128	}
129
130	/* ---------- */
131	/* VBAS : CSn */
132	/* ---------- */
133	if (CSn == 1) {
134		header->CSn_Id = 0;
135		header->CSn_Id = jpt_read_VBAS_info(cio, header->CSn_Id);
136	}
137
138	/* ----------------- */
139	/* VBAS : Msg_offset */
140	/* ----------------- */
141	header->Msg_offset = jpt_read_VBAS_info(cio, header->Msg_offset);
142
143	/* ----------------- */
144	/* VBAS : Msg_length */
145	/* ----------------- */
146	header->Msg_length = jpt_read_VBAS_info(cio, header->Msg_length);
147
148	/* ---------- */
149	/* VBAS : Aux */
150	/* ---------- */
151	if ((header->Class_Id & 0x01) == 1) {
152		header->Layer_nb = 0;
153		header->Layer_nb = jpt_read_VBAS_info(cio, header->Layer_nb);
154	}
155}