openjpeg/libopenjpeg/jpt.c

156 lines
4.6 KiB
C

/*
* Copyright (c) 2004, Yannick Verschueren
* Copyright (c) 2005, HervŽ Drolon, FreeImage Team
* Copyright (c) 2002-2005, Communications and remote sensing Laboratory, Universite catholique de Louvain, Belgium
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS `AS IS'
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "opj_includes.h"
/*
* Read the information contains in VBAS [JPP/JPT stream message header]
* Store information (7 bits) in value
*
*/
unsigned int jpt_read_VBAS_info(opj_cio_t *cio, unsigned int value) {
unsigned char elmt;
elmt = cio_read(cio, 1);
while ((elmt >> 7) == 1) {
value = (value << 7);
value |= (elmt & 0x7f);
elmt = cio_read(cio, 1);
}
value = (value << 7);
value |= (elmt & 0x7f);
return value;
}
/*
* Initialize the value of the message header structure
*
*/
void jpt_init_msg_header(opj_jpt_msg_header_t * header) {
header->Id = 0; /* In-class Identifier */
header->last_byte = 0; /* Last byte information */
header->Class_Id = 0; /* Class Identifier */
header->CSn_Id = 0; /* CSn : index identifier */
header->Msg_offset = 0; /* Message offset */
header->Msg_length = 0; /* Message length */
header->Layer_nb = 0; /* Auxiliary for JPP case */
}
/*
* Re-initialize the value of the message header structure
*
* Only parameters always present in message header
*
*/
void jpt_reinit_msg_header(opj_jpt_msg_header_t * header) {
header->Id = 0; /* In-class Identifier */
header->last_byte = 0; /* Last byte information */
header->Msg_offset = 0; /* Message offset */
header->Msg_length = 0; /* Message length */
}
/*
* Read the message header for a JPP/JPT - stream
*
*/
void jpt_read_msg_header(opj_common_ptr cinfo, opj_cio_t *cio, opj_jpt_msg_header_t *header) {
unsigned char elmt, Class = 0, CSn = 0;
jpt_reinit_msg_header(header);
/* ------------- */
/* VBAS : Bin-ID */
/* ------------- */
elmt = cio_read(cio, 1);
/* See for Class and CSn */
switch ((elmt >> 5) & 0x03) {
case 0:
opg_event_msg(cinfo, EVT_ERROR, "Forbidden value encounter in message header !!\n");
break;
case 1:
Class = 0;
CSn = 0;
break;
case 2:
Class = 1;
CSn = 0;
break;
case 3:
Class = 1;
CSn = 1;
break;
default:
break;
}
/* see information on bits 'c' [p 10 : A.2.1 general, ISO/IEC FCD 15444-9] */
if (((elmt >> 4) & 0x01) == 1)
header->last_byte = 1;
/* In-class identifier */
header->Id |= (elmt & 0x0f);
if ((elmt >> 7) == 1)
header->Id = jpt_read_VBAS_info(cio, header->Id);
/* ------------ */
/* VBAS : Class */
/* ------------ */
if (Class == 1) {
header->Class_Id = 0;
header->Class_Id = jpt_read_VBAS_info(cio, header->Class_Id);
}
/* ---------- */
/* VBAS : CSn */
/* ---------- */
if (CSn == 1) {
header->CSn_Id = 0;
header->CSn_Id = jpt_read_VBAS_info(cio, header->CSn_Id);
}
/* ----------------- */
/* VBAS : Msg_offset */
/* ----------------- */
header->Msg_offset = jpt_read_VBAS_info(cio, header->Msg_offset);
/* ----------------- */
/* VBAS : Msg_length */
/* ----------------- */
header->Msg_length = jpt_read_VBAS_info(cio, header->Msg_length);
/* ---------- */
/* VBAS : Aux */
/* ---------- */
if ((header->Class_Id & 0x01) == 1) {
header->Layer_nb = 0;
header->Layer_nb = jpt_read_VBAS_info(cio, header->Layer_nb);
}
}