/*****************************************************************************

* Copyright (C) 2013-2020 MulticoreWare, Inc

*

* Authors: Steve Borho <steve@borho.org>

*

* This program is free software; you can redistribute it and/or modify

* it under the terms of the GNU General Public License as published by

* the Free Software Foundation; either version 2 of the License, or

* (at your option) any later version.

*

* This program is distributed in the hope that it will be useful,

* but WITHOUT ANY WARRANTY; without even the implied warranty of

* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

* GNU General Public License for more details.

*

* You should have received a copy of the GNU General Public License

* along with this program; if not, write to the Free Software

* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02111, USA.

*

* This program is also available under a commercial proprietary license.

* For more information, contact us at license @ x265.com.

*****************************************************************************/

#include "common.h"

#include "bitstream.h"

#include "slice.h"

#include "sei.h"

using namespace X265_NS;

/* x265's identifying GUID */

const uint8_t SEIuserDataUnregistered::m_uuid_iso_iec_11578[16] = {

    0x2C, 0xA2, 0xDE, 0x09, 0xB5, 0x17, 0x47, 0xDB,

    0xBB, 0x55, 0xA4, 0xFE, 0x7F, 0xC2, 0xFC, 0x4E

};

/* marshal a single SEI message sei, storing the marshalled representation

* in bitstream bs */

void SEI::writeSEImessages(Bitstream& bs, const SPS& sps, NalUnitType nalUnitType, NALList& list, int isNested)

{

    if (!isNested)

        bs.resetBits();

    BitCounter counter;

    m_bitIf = &counter;

    writeSEI(sps);

    /* count the size of the payload and return the size in bits */

    X265_CHECK(0 == (counter.getNumberOfWrittenBits() & 7), "payload unaligned\n");

    uint32_t payloadData = counter.getNumberOfWrittenBits() >> 3;

    // set bitstream

    m_bitIf = &bs;

    uint32_t payloadType = m_payloadType;

    for (; payloadType >= 0xff; payloadType -= 0xff)

        WRITE_CODE(0xff, 8, "payload_type");

    WRITE_CODE(payloadType, 8, "payload_type");

    uint32_t payloadSize = payloadData;

    for (; payloadSize >= 0xff; payloadSize -= 0xff)

        WRITE_CODE(0xff, 8, "payload_size");

    WRITE_CODE(payloadSize, 8, "payload_size");

    // virtual writeSEI method, write to bs 

    writeSEI(sps);

    if (!isNested)

    {

        if (nalUnitType != NAL_UNIT_UNSPECIFIED)

            bs.writeByteAlignment();

        list.serialize(nalUnitType, bs);

    }

}

void SEI::writeByteAlign()

{

    // TODO: expose bs.writeByteAlignment() as virtual function

    if (m_bitIf->getNumberOfWrittenBits() % 8 != 0)

    {

        WRITE_FLAG(1, "bit_equal_to_one");

        while (m_bitIf->getNumberOfWrittenBits() % 8 != 0)

        {

            WRITE_FLAG(0, "bit_equal_to_zero");

        }

    }

}

void SEI::setSize(uint32_t size)

{

    m_payloadSize = size;

}

/* charSet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/" */

char* SEI::base64Decode(char encodedString[], int base64EncodeLength)

{

    char* decodedString;

    decodedString = (char*)malloc(sizeof(char) * ((base64EncodeLength / 4) * 3));

    int i, j, k = 0;

    // stores the bitstream

    int bitstream = 0;

    // countBits stores current number of bits in bitstream

    int countBits = 0;

    // selects 4 characters from encodedString at a time. Find the position of each encoded character in charSet and stores in bitstream

    for (i = 0; i < base64EncodeLength; i += 4)

    {

        bitstream = 0, countBits = 0;

        for (j = 0; j < 4; j++)

        {

            // make space for 6 bits

            if (encodedString[i + j] != '=')

            {

                bitstream = bitstream << 6;

                countBits += 6;

            }

            // Finding the position of each encoded character in charSet and storing in bitstream, use OR '|' operator to store bits

            if (encodedString[i + j] >= 'A' && encodedString[i + j] <= 'Z')

                bitstream = bitstream | (encodedString[i + j] - 'A');

            else if (encodedString[i + j] >= 'a' && encodedString[i + j] <= 'z')

                bitstream = bitstream | (encodedString[i + j] - 'a' + 26);

            else if (encodedString[i + j] >= '0' && encodedString[i + j] <= '9')

                bitstream = bitstream | (encodedString[i + j] - '0' + 52);

            // '+' occurs in 62nd position in charSet

            else if (encodedString[i + j] == '+')

                bitstream = bitstream | 62;

            // '/' occurs in 63rd position in charSet

            else if (encodedString[i + j] == '/')

                bitstream = bitstream | 63;

            // to delete appended bits during encoding

            else

            {

                bitstream = bitstream >> 2;

                countBits -= 2;

            }

        }

        while (countBits != 0)

        {

            countBits -= 8;

            decodedString[k++] = (bitstream >> countBits) & 255;

        }

    }

    return decodedString;

}