lily/midi-chunk.cc

   1 /*
   2   midi-chunk.cc -- implement Midi_chunk
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2007 Han-Wen Nienhuys <hanwen@lilypond.org>
   7
   8 */
   9
  10 #include "midi-chunk.hh"
  11
  12 #include "midi-item.hh"
  13 #include "std-string.hh"
  14 #include "string-convert.hh"
  15
  16 Midi_track::Midi_track ()
  17 {
  18   //                4D 54 72 6B     MTrk
  19   //                00 00 00 3B     chunk length (59)
  20   //        00      FF 58 04 04 02 18 08    time signature
  21   //        00      FF 51 03 07 A1 20       tempo
  22
  23   // FF 59 02 sf mi  Key Signature
  24   //         sf = -7:  7 flats
  25   //         sf = -1:  1 flat
  26   //         sf = 0:  key of C
  27   //         sf = 1:  1 sharp
  28   //         sf = 7: 7 sharps
  29   //         mi = 0:  major key
  30   //         mi = 1:  minor key
  31
  32   number_ = 0;
  33
  34   char const *data_str0 = ""
  35     //        "00" "ff58" "0404" "0218" "08"
  36     //  "00" "ff51" "0307" "a120"
  37     // why a key at all, in midi?
  38     // key: C
  39     //  "00" "ff59" "02" "00" "00"
  40     // key: F (scsii-menuetto)
  41     //                            "00" "ff59" "02" "ff" "00"
  42     ;
  43
  44   string data_string;
  45   // only for format 0 (currently using format 1)?
  46   data_string += String_convert::hex2bin (data_str0);
  47
  48   char const *footer_str0 = "00" "ff2f" "00";
  49   string footer_string = String_convert::hex2bin (footer_str0);
  50
  51   set ("MTrk", data_string, footer_string);
  52 }
  53
  54 void
  55 Midi_track::add (int delta_ticks, Midi_item *midi)
  56 {
  57   assert (delta_ticks >= 0);
  58
  59   Midi_event *e = new Midi_event (delta_ticks, midi);
  60   events_.push_back (e);
  61 }
  62
  63 string
  64 Midi_track::data_string () const
  65 {
  66   string str = Midi_chunk::data_string ();
  67
  68   for (vector<Midi_event*>::const_iterator i (events_.begin ());
  69        i != events_.end (); i ++)
  70     {
  71       str += (*i)->to_string ();
  72     }
  73   return str;
  74 }
  75
  76
  77 Midi_track::~Midi_track ()
  78 {
  79   junk_pointers (events_);
  80 }
  81
  82 /****************************************************************
  83   event
  84 */
  85 Midi_event::Midi_event (int delta_ticks, Midi_item *midi)
  86 {
  87   delta_ticks_ = delta_ticks;
  88   midi_ = midi;
  89 }
  90
  91 string
  92 Midi_event::to_string () const
  93 {
  94   string delta_string = int2midi_varint_string (delta_ticks_);
  95   string midi_string = midi_->to_string ();
  96   assert (midi_string.length ());
  97   return delta_string + midi_string;
  98 }
  99 /****************************************************************
 100  header
 101 */
 102
 103 Midi_header::Midi_header (int format, int tracks, int clocks_per_4)
 104 {
 105   string str;
 106
 107   string format_string = String_convert::int2hex (format, 4, '0');
 108   str += String_convert::hex2bin (format_string);
 109
 110   string tracks_string = String_convert::int2hex (tracks, 4, '0');
 111   str += String_convert::hex2bin (tracks_string);
 112
 113   string tempo_string = String_convert::int2hex (clocks_per_4, 4, '0');
 114   str += String_convert::hex2bin (tempo_string);
 115
 116   set ("MThd", str, "");
 117 }
 118
 119
 120 /****************************************************************
 121    chunk
 122  */
 123 Midi_chunk::~Midi_chunk ()
 124 {
 125
 126 }
 127
 128 void
 129 Midi_chunk::set (string header_string, string data_string, string footer_string)
 130 {
 131   data_string_ = data_string;
 132   footer_string_ = footer_string;
 133   header_string_ = header_string;
 134 }
 135
 136 string
 137 Midi_chunk::data_string () const
 138 {
 139   return data_string_;
 140 }
 141
 142 string
 143 Midi_chunk::to_string () const
 144 {
 145   string str = header_string_;
 146   string dat = data_string ();
 147   string length_string = String_convert::int2hex (dat.length ()
 148                                                   + footer_string_.length (), 8, '0');
 149   length_string = String_convert::hex2bin (length_string);
 150
 151   str += length_string;
 152   str += dat;
 153   str += footer_string_;
 154
 155   return str;
 156 }
 157