/*****************************************************************************
 * This file is part of Kvazaar HEVC encoder.
 *
 * Copyright (C) 2013-2015 Tampere University of Technology and others (see
 * COPYING file).
 *
 * Kvazaar 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 2.1 of the License, or (at your
 * option) any later version.
 *
 * Kvazaar 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 General Public License along
 * with Kvazaar.  If not, see <http://www.gnu.org/licenses/>.
 ****************************************************************************/

#include "nal.h"

#include "bitstream.h"
#include "strategies/strategies-nal.h"
#include <stdio.h>


/**
 * \brief Write a Network Abstraction Layer (NAL) packet to the output.
 */
void kvz_nal_write(bitstream_t * const bitstream, const uint8_t nal_type,
               const uint8_t temporal_id, const int long_start_code)
{
  uint8_t byte;

  // Some useful constants
  const uint8_t start_code_prefix_one_3bytes = 0x01;
  const uint8_t zero = 0x00;

#ifdef KVZ_DEBUG
  printf("=========== NAL unit  ===========\n");
#endif

  // zero_byte (0x00) shall be present in the byte stream NALU of VPS, SPS
  // and PPS, or the first NALU of an access unit
  if(long_start_code)
    kvz_bitstream_writebyte(bitstream, zero);

  // start_code_prefix_one_3bytes
  kvz_bitstream_writebyte(bitstream, zero);
  kvz_bitstream_writebyte(bitstream, zero);
  kvz_bitstream_writebyte(bitstream, start_code_prefix_one_3bytes);

  // Handle header bits with full bytes instead of using bitstream
  // forbidden_zero_flag(1) + nuh_temporal_id_plus1(3) + nal_unit_type(4)
  uint8_t zero_tid_required_flag = 0;
  
  if ((nal_type >= 16) && (nal_type <= 31)) {
    zero_tid_required_flag = 1;
  }
  uint8_t nal_type_lsb = nal_type - (zero_tid_required_flag << 4);
  
  // forbidden zero (1bit) + reserver zero (1bit) layer_id (6 bits)
  byte = 0; 
  kvz_bitstream_writebyte(bitstream, byte);

  // nal_unit_type (5bits) + temporal_id_plus1 (3 bits)
  byte = (nal_type<<3)+(temporal_id + 1);
  kvz_bitstream_writebyte(bitstream, byte);


#if VERBOSE
  // ToDo: Match with the actual bits
  printf("%-50s u(%d) : %d\n", "zero_tid_required_flag", 1, zero_tid_required_flag);
  printf("%-50s u(%d) : %d\n", "nuh_temporal_id_plus1", 3, temporal_id + 1);
  printf("%-50s u(%d) : %d\n", "nal_unit_type_lsb", 4, nal_type_lsb);
  printf("%-50s u(%d) : %d\n", "nuh_layer_id_plus1", 7, 0);
  printf("%-50s u(%d) : %d\n", "nuh_reserved_zero_bit", 1, 0);
#endif
}

/*!
 \brief Calculate checksums for all colors of the picture.
 \param im The image that checksum is calculated for.
 \param checksum_out Result of the calculation.
 \returns Void
*/
void kvz_image_checksum(const kvz_picture *im, unsigned char checksum_out[][SEI_HASH_MAX_LENGTH], const uint8_t bitdepth)
{
  kvz_array_checksum(im->y, im->height, im->width, im->width, checksum_out[0], bitdepth);

  /* The number of chroma pixels is half that of luma. */
  if (im->chroma_format != KVZ_CSP_400) {
    kvz_array_checksum(im->u, im->height >> 1, im->width >> 1, im->width >> 1, checksum_out[1], bitdepth);
    kvz_array_checksum(im->v, im->height >> 1, im->width >> 1, im->width >> 1, checksum_out[2], bitdepth);
  }
}

/*!
\brief Calculate md5 for all colors of the picture.
\param im The image that md5 is calculated for.
\param checksum_out Result of the calculation.
\returns Void
*/
void kvz_image_md5(const kvz_picture *im, unsigned char checksum_out[][SEI_HASH_MAX_LENGTH], const uint8_t bitdepth)
{
  kvz_array_md5(im->y, im->height, im->width, im->width, checksum_out[0], bitdepth);

  /* The number of chroma pixels is half that of luma. */
  if (im->chroma_format != KVZ_CSP_400) {
    kvz_array_md5(im->u, im->height >> 1, im->width >> 1, im->width >> 1, checksum_out[1], bitdepth);
    kvz_array_md5(im->v, im->height >> 1, im->width >> 1, im->width >> 1, checksum_out[2], bitdepth);
  }
}