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  • /* The copyright in this software is being made available under the 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) 2010-2019, ITU/ISO/IEC
    
     * All rights reserved.
     *
     * Redistribution and use in source and binary forms, with or without
     * modification, are permitted provided that the following conditions are met:
     *
     *  * Redistributions of source code must retain the above copyright notice,
     *    this list of conditions and the following disclaimer.
     *  * 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.
     *  * Neither the name of the ITU/ISO/IEC nor the names of its contributors may
     *    be used to endorse or promote products derived from this software without
     *    specific prior written permission.
     *
     * 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 HOLDER 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.
     */
    
    #pragma once
    
    #ifndef __ANNEXBWRITE__
    #define __ANNEXBWRITE__
    
    #include <ostream>
    #include "NALwrite.h"
    
    //! \ingroup EncoderLib
    //! \{
    
    /**
     * write all NALunits in au to bytestream out in a manner satisfying
     * AnnexB of AVC.  NALunits are written in the order they are found in au.
     * the zero_byte word is appended to:
     *  - the initial startcode in the access unit,
     *  - any SPS/PPS nal units
     */
    static std::vector<uint32_t> writeAnnexB(std::ostream& out, const AccessUnit& au)
    {
      std::vector<uint32_t> annexBsizes;
    
      for (AccessUnit::const_iterator it = au.begin(); it != au.end(); it++)
      {
        const NALUnitEBSP& nalu = **it;
        uint32_t size = 0; /* size of annexB unit in bytes */
    
        static const uint8_t start_code_prefix[] = {0,0,0,1};
    #if HEVC_VPS
        if (it == au.begin() || nalu.m_nalUnitType == NAL_UNIT_VPS || nalu.m_nalUnitType == NAL_UNIT_SPS || nalu.m_nalUnitType == NAL_UNIT_PPS)
    #else
        if (it == au.begin() || nalu.m_nalUnitType == NAL_UNIT_SPS || nalu.m_nalUnitType == NAL_UNIT_PPS)
    #endif
        {
          /* From AVC, When any of the following conditions are fulfilled, the
           * zero_byte syntax element shall be present:
           *  - the nal_unit_type within the nal_unit() is equal to 7 (sequence
           *    parameter set) or 8 (picture parameter set),
           *  - the byte stream NAL unit syntax structure contains the first NAL
           *    unit of an access unit in decoding order, as specified by subclause
           *    7.4.1.2.3.
           */
          out.write(reinterpret_cast<const char*>(start_code_prefix), 4);
          size += 4;
        }
        else
        {
          out.write(reinterpret_cast<const char*>(start_code_prefix+1), 3);
          size += 3;
        }
        out << nalu.m_nalUnitData.str();
        size += uint32_t(nalu.m_nalUnitData.str().size());
    
        annexBsizes.push_back(size);
      }
    
      if (au.size() > 0)
      {
        out.flush();
      }
    
      return annexBsizes;
    }
    //! \}
    
    #endif