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livetrax/libs/ardour/raw_midi_parser.cc

118 lines
2.7 KiB
C++

/*
* Copyright (C) 2017 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.
*/
#include "ardour/raw_midi_parser.h"
using namespace ARDOUR;
RawMidiParser::RawMidiParser ()
{
reset ();
}
/* based on AlsaRawMidiIn, some code-dup */
bool
RawMidiParser::process_byte (const uint8_t byte)
{
if (byte >= 0xf8) {
// Realtime
if (byte == 0xfd) {
return false;
}
prepare_byte_event (byte);
return true;
}
if (byte == 0xf7) {
// Sysex end
if (_status_byte == 0xf0) {
record_byte (byte);
return prepare_buffered_event ();
}
_total_bytes = 0;
_unbuffered_bytes = 0;
_expected_bytes = 0;
_status_byte = 0;
return false;
}
if (byte >= 0x80) {
// Non-realtime status byte
if (_total_bytes) {
_total_bytes = 0;
_unbuffered_bytes = 0;
}
_status_byte = byte;
switch (byte & 0xf0) {
case 0x80:
case 0x90:
case 0xa0:
case 0xb0:
case 0xe0:
// Note On, Note Off, Aftertouch, Control Change, Pitch Wheel
_expected_bytes = 3;
break;
case 0xc0:
case 0xd0:
// Program Change, Channel Pressure
_expected_bytes = 2;
break;
case 0xf0:
switch (byte) {
case 0xf0:
// Sysex
_expected_bytes = 0;
break;
case 0xf1:
case 0xf3:
// MTC Quarter Frame, Song Select
_expected_bytes = 2;
break;
case 0xf2:
// Song Position
_expected_bytes = 3;
break;
case 0xf4:
case 0xf5:
// Undefined
_expected_bytes = 0;
_status_byte = 0;
return false;
case 0xf6:
// Tune Request
prepare_byte_event (byte);
_expected_bytes = 0;
_status_byte = 0;
return true;
}
}
record_byte (byte);
return false;
}
// Data byte
if (!_status_byte) {
// Data bytes without a status will be discarded.
_total_bytes++;
_unbuffered_bytes++;
return false;
}
if (!_total_bytes) {
record_byte (_status_byte);
}
record_byte (byte);
return (_total_bytes == _expected_bytes) ? prepare_buffered_event () : false;
}