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livetrax/libs/evoral/evoral/midi_util.h

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3.6 KiB
C++

/*
* Copyright (C) 2008-2014 David Robillard <d@drobilla.net>
* Copyright (C) 2009-2014 Paul Davis <paul@linuxaudiosystems.com>
* Copyright (C) 2009 Hans Baier <hansfbaier@googlemail.com>
* Copyright (C) 2013 John Emmas <john@creativepost.co.uk>
* Copyright (C) 2015-2016 Robin Gareus <robin@gareus.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef EVORAL_MIDI_UTIL_H
#define EVORAL_MIDI_UTIL_H
#include <iostream>
#include <stdint.h>
#include <string>
#include <sys/types.h>
#include <assert.h>
#include "evoral/visibility.h"
#include "evoral/midi_events.h"
namespace Evoral {
/** Return the size of the given event including the status byte,
* or -1 if unknown (e.g. sysex)
*/
static inline int
midi_event_size(uint8_t status)
{
// if we have a channel event
if (status >= 0x80 && status < 0xF0) {
status &= 0xF0; // mask off the channel
}
switch (status) {
case MIDI_CMD_NOTE_OFF:
case MIDI_CMD_NOTE_ON:
case MIDI_CMD_NOTE_PRESSURE:
case MIDI_CMD_CONTROL:
case MIDI_CMD_BENDER:
case MIDI_CMD_COMMON_SONG_POS:
return 3;
case MIDI_CMD_PGM_CHANGE:
case MIDI_CMD_CHANNEL_PRESSURE:
case MIDI_CMD_COMMON_MTC_QUARTER:
case MIDI_CMD_COMMON_SONG_SELECT:
return 2;
case MIDI_CMD_COMMON_TUNE_REQUEST:
case MIDI_CMD_COMMON_SYSEX_END:
case MIDI_CMD_COMMON_CLOCK:
case MIDI_CMD_COMMON_START:
case MIDI_CMD_COMMON_CONTINUE:
case MIDI_CMD_COMMON_STOP:
case MIDI_CMD_COMMON_SENSING:
case MIDI_CMD_COMMON_RESET:
return 1;
case MIDI_CMD_COMMON_SYSEX:
std::cerr << "event size called for sysex\n";
return -1;
}
std::cerr << "event size called for unknown status byte " << std::hex << (int) status << "\n";
return -1;
}
/** Return the size of the given event including the status byte,
* or -1 if event is illegal.
*/
static inline int
midi_event_size(const uint8_t* buffer)
{
uint8_t status = buffer[0];
// Mask off channel if applicable
if (status >= 0x80 && status < 0xF0) {
status &= 0xF0;
}
// see http://www.midi.org/techspecs/midimessages.php
if (status == MIDI_CMD_COMMON_SYSEX) {
int end;
for (end = 1; buffer[end] != MIDI_CMD_COMMON_SYSEX_END; end++) {
if ((buffer[end] & 0x80) != 0) {
return -1;
}
}
assert(buffer[end] == MIDI_CMD_COMMON_SYSEX_END);
return end + 1;
} else {
return midi_event_size(status);
}
}
/** Return true iff the given buffer is a valid MIDI event.
* \a len must be exactly correct for the contents of \a buffer
*/
static inline bool
midi_event_is_valid(const uint8_t* buffer, size_t len)
{
uint8_t status = buffer[0];
if (status < 0x80) {
return false;
}
const int size = midi_event_size(buffer);
if (size < 0 || (size_t)size != len) {
return false;
}
if (status < 0xf0) {
/* Channel messages: all start with status byte followed by
* non status bytes.
*/
for (size_t i = 1; i < len; ++i) {
if ((buffer[i] & 0x80) != 0) {
return false; // Non-status byte has MSb set
}
}
}
return true;
}
} // namespace Evoral
#endif // EVORAL_MIDI_UTIL_H