13
0
livetrax/libs/evoral/evoral/midi_util.h
Paul Davis 07c08e4673 fix incorrect test for valid MIDI events.
Only channel messages have the form <statusbyte>{<nonstatusbyte>..}
2014-12-31 10:32:50 -05:00

142 lines
3.5 KiB
C++

/* This file is part of Evoral.
* Copyright(C) 2008 David Robillard <http://drobilla.net>
* Copyright(C) 2000-2008 Paul Davis
*
* Evoral 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.
*
* Evoral 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 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 St, 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;
}
LIBEVORAL_API std::string midi_note_name (uint8_t noteval);
} // namespace Evoral
#endif // EVORAL_MIDI_UTIL_H