package VOC_data is

type sound_bytes is range 0 .. 255;
 for sound_bytes'size use 8;
max_block_length:constant:=20000;
subtype block_lengths is integer range 0 .. max_block_length;
subtype sound_indices is integer range 1 .. max_block_length;
type sounds is array(sound_indices range <>) of sound_bytes;

type block_types  is (terminator,voice_data,voice_continuation,
                      silence,marker,text,start_repeat,end_repeat);
 for block_types use (terminator=>0,voice_data=>1,voice_continuation=>2,
                      silence=>3,marker=>4,text=>5,start_repeat=>6,
                      end_repeat=>7);
 for block_types'size use 8;

subtype sample_rates is natural range 3906 .. integer'last;
type pack_types is (unpacked,halved,thirds,quartered);
 for pack_types use (unpacked=>0,halved=>1,thirds=>2,quartered=>3);
type markers is range 1 .. 16#FFFE#;
type repeat_counts is range 1 .. 16#FFFF#;

type blocks(block_type   : block_types:=terminator) is record
  block_length : block_lengths:=1;
  case block_type is
    when terminator =>
      null;
    when voice_data | voice_continuation =>
      sample_rate  : sample_rates;
      packing      : pack_types;
      data         : sounds(1 .. max_block_length);
    when silence =>
      silence_interval : duration;
    when marker =>
      mark         : markers;
    when text =>
      text_string : string(1 .. max_block_length);
    when start_repeat =>
      count        : repeat_counts;
    when end_repeat =>
      null;
  end case;
end record;

end VOC_data;