AlcPacket.h

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// libflute - FLUTE/ALC library
//
// Copyright (C) 2021 Klaus Kühnhammer (Österreichische Rundfunksender GmbH & Co KG)
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program 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 Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.
//
#pragma once
#include <stddef.h>
#include <stdint.h>
#include <vector>
#include "flute_types.h"
#include "EncodingSymbol.h"
 
namespace LibFlute {
  class AlcPacket {
    public:
      AlcPacket(char* data, size_t len);
 
      AlcPacket(uint16_t tsi, uint16_t toi, FecOti fec_oti, const std::vector<EncodingSymbol>& symbols, size_t max_size, uint32_t fdt_instance_id);
 
      ~AlcPacket();
 
      uint64_t tsi() const { return _tsi; };
 
      uint64_t toi() const { return _toi; };
 
      const FecOti& fec_oti() const { return _fec_oti; };
 
      size_t header_length() const  { return _lct_header.lct_header_len * 4; };
 
      uint32_t fdt_instance_id() const { return _fdt_instance_id; };
 
      FecScheme fec_scheme() const { return _fec_oti.encoding_id; };
 
      ContentEncoding content_encoding() const { return _content_encoding; };
 
      char* data() const { return _buffer; };
 
      size_t size() const { return _len; };
 
    private:
      uint64_t _tsi = 0;
      uint64_t _toi = 0;
 
      uint32_t _fdt_instance_id = 0;
 
      uint32_t _source_block_number = 0;
      uint32_t _encoding_symbol_id = 0;
 
      ContentEncoding _content_encoding = ContentEncoding::NONE;
      FecOti _fec_oti = {};
 
      char* _buffer = nullptr;
      size_t _len;
 
      // RFC5651 5.1 - LCT Header Format
      struct __attribute__((packed)) lct_header_t {
#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
        uint8_t res1:1;
        uint8_t source_packet_indicator:1;
        uint8_t congestion_control_flag:2;
        uint8_t version:4;
 
        uint8_t close_object_flag:1;
        uint8_t close_session_flag:1;
        uint8_t res:2;
        uint8_t half_word_flag:1;
        uint8_t toi_flag:2;
        uint8_t tsi_flag:1;
#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
        uint8_t version:4;
        uint8_t congestion_control_flag:2;
        uint8_t source_packet_indicator:1;
        uint8_t res1:1;
 
        uint8_t tsi_flag:1;
        uint8_t toi_flag:2;
        uint8_t half_word_flag:1;
        uint8_t res2:2;
        uint8_t close_session_flag:1;
        uint8_t close_object_flag:1;
#else
#error "Endianness can not be determined"
#endif
        uint8_t lct_header_len;
        uint8_t codepoint;
      } _lct_header;
      static_assert(sizeof(_lct_header) == 4);
 
      enum HeaderExtension { 
        EXT_NOP  =   0,
        EXT_AUTH =   1,
        EXT_TIME =   2,
        EXT_FTI  =  64,
        EXT_FDT  = 192,
        EXT_CENC = 193
      };
 
  };
};