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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/***************************************************************************
 *            iso11172-1.h
 *
 *  Wed Aug 31 13:48:30 CEST 2005
 *  Copyright  2005 Bent Bisballe Nyeng
 *  deva@aasimon.org
 ****************************************************************************/

/*
 *  This file is part of MIaV.
 *
 *  MIaV 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.
 *
 *  MIaV 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 MIaV; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
 */

/*
 *  This file contains symbols used to create an ISO11172-1 compatible multiplexed 
 *  MPEG stream.
 */

#include "config.h"
#ifndef __MIAV_ISO11172_1_H__
#define __MIAV_ISO11172_1_H__

#define CLOCK_90KHZ 90000

namespace ISO11172_1 {
  ////////////////////////////////////////////////////
  // Types
  ////////////////////////////////////////////////////
  // 64 bits (8 bytes)
  typedef struct {
    unsigned long long int marker_bit3:1;
    unsigned long long int system_clock_reference3:15;
    unsigned long long int marker_bit2:1;
    unsigned long long int system_clock_reference2:15;
    unsigned long long int marker_bit1:1;
    unsigned long long int system_clock_reference1:3;
    unsigned long long int padding:4;
    unsigned long long int stuffing_byte:8;
    unsigned long long int packet_length:16;
  } packet_header;

  typedef struct {
    unsigned long long int marker_bit5:1;
    unsigned long long int mux_rate:22;
    unsigned long long int marker_bit4:1;
    unsigned long long int marker_bit3:1;
    unsigned long long int system_clock_reference3:15;
    unsigned long long int marker_bit2:1;
    unsigned long long int system_clock_reference2:15;
    unsigned long long int marker_bit1:1;
    unsigned long long int system_clock_reference1:3;
    unsigned long long int padding:4;
  } pack_header;

  typedef struct {
    unsigned long long int reserved_byte:8;
    unsigned long long int video_bound:5;
    unsigned long long int marker_bit3:1;
    unsigned long long int system_video_clock_flag:1;
    unsigned long long int system_audio_clock_flag:1;
    unsigned long long int CSPS_flag:1;
    unsigned long long int fixed_flag:1;
    unsigned long long int audio_bound:6;
    unsigned long long int marker_bit2:1;
    unsigned long long int rate_bound:22;
    unsigned long long int marker_bit1:1;
    unsigned long long int header_length:16;
  } system_header;

  typedef struct {
    unsigned long int STD_buffer_size_bound:13;
    unsigned long int STD_buffer_bound_scale:1;
    unsigned long int market_bits:2;
    unsigned long int stream_id:8;
  } stream_description;

  ////////////////////////////////////////////////////
  // Constants
  ////////////////////////////////////////////////////
  const char pack_start_code[]          = "\x00\x00\x01\xBA";
  const char system_header_start_code[] = "\x00\x00\x01\xBB";
  const char packet_start_code_prefix[] = "\x00\x00\x01";
  const char stream_id_video1[]         = "\xE3";
  const char stream_id_video2[]         = "\xE4";
  const char stream_id_video3[]         = "\xE5";
  const char stream_id_video4[]         = "\xE6";
  const char stream_id_video5[]         = "\xE7";
  const char stream_id_video6[]         = "\xE8";
  const char stream_id_video7[]         = "\xE9";
  const char stream_id_video8[]         = "\xEA";
  const char stream_id_audio1[]         = "\xC0";
  const char stream_id_audio2[]         = "\xC1";
  const char stream_id_audio3[]         = "\xC2";
  const char stream_id_audio4[]         = "\xC3";
  const char stream_id_audio5[]         = "\xC4";
  const char stream_id_audio6[]         = "\xC5";
  const char stream_id_audio7[]         = "\xC6";
  const char stream_id_audio8[]         = "\xC7";
  const char stream_id_padding[]        = "\xBE";
  const char end_code[]                 = "\x00\x00\x01\xB9";

  ////////////////////////////////////////////////////
  // Methods
  ////////////////////////////////////////////////////
  /**
   * SCR stands for System Clock Reference
   */
  inline unsigned int SCR(unsigned int previous_SCR,
                          unsigned int pack_header_size,
                          unsigned int packets_per_pack,
                          unsigned int packet_data_size,
                          unsigned int Rmux)
  {
    // To prevent a crash when doing division.
    if(Rmux == 0) Rmux = 1;
    return previous_SCR + (unsigned int)((double)(pack_header_size + 
                                                  (packets_per_pack * packet_data_size)) * 
                                         (double)CLOCK_90KHZ / (double)Rmux);
  }

  /**
   * Calculates Rmux according to subclause A.5.4
   * mux stands for multiplexing and R for Rate,
   * so Rmux is the rate of the multiplexing.
   */
  inline unsigned int Rmux(unsigned int video_data_rate,
                           unsigned int audio_data_rate,
                           unsigned int packet_header_size,
                           unsigned int pack_header_size,
                           unsigned int packets_per_pack,
                           unsigned int packet_data_size)
  {
    // To prevent a crash when doing division.
    if(packets_per_pack == 0) packets_per_pack = 1;
    if(packet_data_size == 0) packet_data_size = 1;
    
    return (unsigned int)(
                          ((double)video_data_rate + (double)audio_data_rate) *
                          (1.0 + ((double)packet_header_size + (double)pack_header_size / (double)packets_per_pack) 
                           / (double)packet_data_size)
                          );
  }

  
};

#endif/*__MIAV_ISO11172_1_H__*/