https://www.facebook.com/tokoik/posts/1496161427092706

for_tokoi_2017-03-25.hxx

struct frame_type final
{
  size_t get_frame_size() const
  { return sizeof( frame_type ) - 1 + data_size; }
　　
  some_type1 some_header1;
  some_type2 some_header2;
  size_t data_size = 0;
  array< uint8_t, 0 > data;
};

struct video_type final
{
  size_t frames_size = 0;
  array< frame_type, 0 > frames;
  
  frame_type& operator[]( const size_t target_frame_number )
  {
    const auto current_frame_address =
      reinterpret_cast< uint8_t* >( &frames[ 0 ] )
      ;
    
    for
    ( size_t current_frame_number = 0
    ; current_frame_number < target_frame_number
    ; ++current_frame_number
    )
    {
      const frame_type& current_frame = 
      current_frame_address +=
        + reinterpret_cast< const frame_type* >( current_frame_address )->get_frame_size()
        ;
    }
    
    return *current_frame;
  }
};