/*
 * The copyright in this software is being made available under the 2-clauses
 * BSD License, included below. This software may be subject to other third
 * party and contributor rights, including patent rights, and no such rights
 * are granted under this license.
 *
 * Copyright (c) 2002-2014, Universite catholique de Louvain (UCL), Belgium
 * Copyright (c) 2002-2014, Professor Benoit Macq
 * Copyright (c) 2002-2003, Yannick Verschueren
 * Copyright (c) 2005, Herve Drolon, FreeImage Team
 * 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
 *
 */
static 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
 *
 */
static 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:
        opj_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);
    }
}