uvg266/src/nal.c

/*****************************************************************************
 * 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/>.
 ****************************************************************************/

/*
 * \file
 */

#include "nal.h"
#include "strategyselector.h"

#include <stdlib.h>
#include <string.h>
#include <assert.h>

#include "config.h"
#include "bitstream.h"
#include "cabac.h"
#include "encoder.h"

/**
 * \brief Write a Network Abstraction Layer (NAL) packet to the output.
 */
void 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;

  // 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)
    bitstream_writebyte(bitstream, zero);

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

  // Handle header bits with full bytes instead of using bitstream
  // forbidden_zero_flag(1) + nal_unit_type(6) + 1bit of nuh_layer_id
  byte = nal_type << 1;
  bitstream_writebyte(bitstream, byte);

  // 5bits of nuh_layer_id + nuh_temporal_id_plus1(3)
  byte = (temporal_id + 1) & 7;
  bitstream_writebyte(bitstream, byte);
}

/*!
 \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 image_checksum(const image* im, unsigned char checksum_out[][SEI_HASH_MAX_LENGTH])
{
  array_checksum(im->y, im->height, im->width, im->width, checksum_out[0]);

  /* The number of chroma pixels is half that of luma. */
  array_checksum(im->u, im->height >> 1, im->width >> 1, im->width >> 1, checksum_out[1]);
  array_checksum(im->v, im->height >> 1, im->width >> 1, im->width >> 1, checksum_out[2]);
}