libs/evoral/evoral/midi_util.h

   1 /* This file is part of Evoral.
   2  * Copyright(C) 2008 David Robillard <http://drobilla.net>
   3  * Copyright(C) 2000-2008 Paul Davis
   4  *
   5  * Evoral is free software; you can redistribute it and/or modify it under the
   6  * terms of the GNU General Public License as published by the Free Software
   7  * Foundation; either version 2 of the License, or(at your option) any later
   8  * version.
   9  *
  10  * Evoral is distributed in the hope that it will be useful, but WITHOUT ANY
  11  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  12  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for details.
  13  *
  14  * You should have received a copy of the GNU General Public License along
  15  * with this program; if not, write to the Free Software Foundation, Inc.,
  16  * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  17  */
  18
  19 #ifndef EVORAL_MIDI_UTIL_H
  20 #define EVORAL_MIDI_UTIL_H
  21
  22 #include <iostream>
  23
  24 #include <stdint.h>
  25 #include <stdbool.h>
  26 #include <string>
  27 #include <sys/types.h>
  28 #include <assert.h>
  29 #include "evoral/midi_events.h"
  30
  31 namespace Evoral {
  32
  33
  34 /** Return the size of the given event including the status byte,
  35  * or -1 if unknown (e.g. sysex)
  36  */
  37 static inline int
  38 midi_event_size(uint8_t status)
  39 {
  40         // if we have a channel event
  41         if (status >= 0x80 && status < 0xF0) {
  42                 status &= 0xF0; // mask off the channel
  43         }
  44
  45         switch (status) {
  46         case MIDI_CMD_NOTE_OFF:
  47         case MIDI_CMD_NOTE_ON:
  48         case MIDI_CMD_NOTE_PRESSURE:
  49         case MIDI_CMD_CONTROL:
  50         case MIDI_CMD_BENDER:
  51         case MIDI_CMD_COMMON_SONG_POS:
  52                 return 3;
  53
  54         case MIDI_CMD_PGM_CHANGE:
  55         case MIDI_CMD_CHANNEL_PRESSURE:
  56         case MIDI_CMD_COMMON_MTC_QUARTER:
  57         case MIDI_CMD_COMMON_SONG_SELECT:
  58                 return 2;
  59
  60         case MIDI_CMD_COMMON_TUNE_REQUEST:
  61         case MIDI_CMD_COMMON_SYSEX_END:
  62         case MIDI_CMD_COMMON_CLOCK:
  63         case MIDI_CMD_COMMON_START:
  64         case MIDI_CMD_COMMON_CONTINUE:
  65         case MIDI_CMD_COMMON_STOP:
  66         case MIDI_CMD_COMMON_SENSING:
  67         case MIDI_CMD_COMMON_RESET:
  68                 return 1;
  69
  70         case MIDI_CMD_COMMON_SYSEX:
  71                 std::cerr << "event size called for sysex\n";
  72                 return -1;
  73         }
  74
  75         std::cerr << "event size called for unknown status byte " << std::hex << (int) status << "\n";
  76         return -1;
  77 }
  78
  79 /** Return the size of the given event including the status byte,
  80  * or -1 if event is illegal.
  81  */
  82 static inline int
  83 midi_event_size(const uint8_t* buffer)
  84 {
  85         uint8_t status = buffer[0];
  86
  87         // Mask off channel if applicable
  88         if (status >= 0x80 && status < 0xF0) {
  89                 status &= 0xF0;
  90         }
  91
  92         // see http://www.midi.org/techspecs/midimessages.php
  93         if (status == MIDI_CMD_COMMON_SYSEX) {
  94                 int end;
  95
  96                 for (end = 1; buffer[end] != MIDI_CMD_COMMON_SYSEX_END; end++) {
  97                         assert((buffer[end] & 0x80) == 0);
  98                 }
  99                 assert(buffer[end] == MIDI_CMD_COMMON_SYSEX_END);
 100                 return end + 1;
 101         } else {
 102                 return midi_event_size(status);
 103         }
 104 }
 105
 106 /** Return true iff the given buffer is a valid MIDI event.
 107  * \a len must be exactly correct for the contents of \a buffer
 108  */
 109 static inline bool
 110 midi_event_is_valid(const uint8_t* buffer, size_t len)
 111 {
 112         uint8_t status = buffer[0];
 113         if (status < 0x80) {
 114                 return false;
 115         }
 116         const int size = midi_event_size(buffer);
 117         if (size < 0 || (size_t)size != len) {
 118                 return false;
 119         }
 120         return true;
 121 }
 122
 123 std::string midi_note_name (uint8_t noteval);
 124
 125 } // namespace Evoral
 126
 127 #endif // EVORAL_MIDI_UTIL_H
 128