/*

 * H.265 video codec.

 * Copyright (c) 2013-2014 struktur AG, Dirk Farin <farin@struktur.de>

 *

 * This file is part of libde265.

 *

 * libde265 is free software: you can redistribute it and/or modify

 * it under the terms of the GNU Lesser General Public License as

 * published by the Free Software Foundation, either version 3 of

 * the License, or (at your option) any later version.

 *

 * libde265 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 Lesser General Public License for more details.

 *

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

 * along with libde265.  If not, see <http://www.gnu.org/licenses/>.

 */

#include "nal.h"

#include "cabac.h"

#include <assert.h>

de265_error nal_header::read(bitreader* reader)

{

  reader->skip_bits(1);

  nal_unit_type = reader->get_bits(6);

  nuh_layer_id  = reader->get_bits(6);

  uint32_t nuh_temporal_id_plus1 = reader->get_bits(3);

  if (nuh_temporal_id_plus1 == 0) {

    return DE265_ERROR_CODED_PARAMETER_OUT_OF_RANGE;

  }

  nuh_temporal_id = nuh_temporal_id_plus1 - 1;

  return DE265_OK;

}

void nal_header::write(CABAC_encoder& out) const

{

  out.skip_bits(1);

  out.write_bits(nal_unit_type,6);

  out.write_bits(nuh_layer_id ,6);

  out.write_bits(nuh_temporal_id+1,3);

}

bool isIDR(uint8_t unit_type)

{

  return (unit_type == NAL_UNIT_IDR_W_RADL ||

          unit_type == NAL_UNIT_IDR_N_LP);

}

bool isBLA(uint8_t unit_type)

{

  return (unit_type == NAL_UNIT_BLA_W_LP ||

          unit_type == NAL_UNIT_BLA_W_RADL ||

          unit_type == NAL_UNIT_BLA_N_LP);

}

bool isCRA(uint8_t unit_type)

{

  return unit_type == NAL_UNIT_CRA_NUT;

}

bool isRAP(uint8_t unit_type)

{

  return isIDR(unit_type) || isBLA(unit_type) || isCRA(unit_type);

}

bool isRASL(uint8_t unit_type)

{

  return (unit_type == NAL_UNIT_RASL_N ||

          unit_type == NAL_UNIT_RASL_R);

}

bool isIRAP(uint8_t unit_type)

{

  return (unit_type >= NAL_UNIT_BLA_W_LP &&

          unit_type <= NAL_UNIT_RESERVED_IRAP_VCL23);

}

bool isRADL(uint8_t unit_type)

{

  return (unit_type == NAL_UNIT_RADL_N ||

          unit_type == NAL_UNIT_RADL_R);

}

bool isReferenceNALU(uint8_t unit_type)

{

  return ( ((unit_type <= NAL_UNIT_RESERVED_VCL_R15) && (unit_type%2 != 0)) ||

           ((unit_type >= NAL_UNIT_BLA_W_LP) &&

            (unit_type <= NAL_UNIT_RESERVED_IRAP_VCL23)) );

}

bool isSublayerNonReference(uint8_t unit_type)

{

  switch (unit_type) {

  case NAL_UNIT_TRAIL_N:

  case NAL_UNIT_TSA_N:

  case NAL_UNIT_STSA_N:

  case NAL_UNIT_RADL_N:

  case NAL_UNIT_RASL_N:

  case NAL_UNIT_RESERVED_VCL_N10:

  case NAL_UNIT_RESERVED_VCL_N12:

  case NAL_UNIT_RESERVED_VCL_N14:

    return true;

  default:

    return false;

  }

}

static const char* NAL_unit_name[] = {

  "TRAIL_N", // 0

  "TRAIL_R",

  "TSA_N",

  "TSA_R",

  "STSA_N",

  "STSA_R",  // 5

  "RADL_N",

  "RADL_R",

  "RASL_N",

  "RASL_R",

  "RESERVED_VCL_N10", // 10

  "RESERVED_VCL_R11",

  "RESERVED_VCL_N12",

  "RESERVED_VCL_R13",

  "RESERVED_VCL_N14",

  "RESERVED_VCL_R15", // 15

  "BLA_W_LP",

  "BLA_W_RADL",

  "BLA_N_LP",

  "IDR_W_RADL",

  "IDR_N_LP",     // 20

  "CRA_NUT",

  "RESERVED_IRAP_VCL22",

  "RESERVED_IRAP_VCL23",

  "RESERVED_VCL24",

  "RESERVED_VCL25", // 25

  "RESERVED_VCL26",

  "RESERVED_VCL27",

  "RESERVED_VCL28",

  "RESERVED_VCL29",

  "RESERVED_VCL30", // 30

  "RESERVED_VCL31",

  "VPS",

  "SPS",

  "PPS",

  "AUD", // 35

  "EOS",

  "EOB",

  "FD",

  "PREFIX_SEI",

  "SUFFIX_SEI", // 40

  "RESERVED_NVCL41",

  "RESERVED_NVCL42",

  "RESERVED_NVCL43",

  "RESERVED_NVCL44",

  "RESERVED_NVCL45", // 45

  "RESERVED_NVCL46",

  "RESERVED_NVCL47"

};

const char* get_NAL_name(uint8_t unit_type)

{

  if (unit_type >= 48) { return "INVALID NAL >= 48"; }

  return NAL_unit_name[unit_type];

}