1 /*
2 * Copyright (C) 2017 Robin Gareus <robin@gareus.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more 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 Street, Fifth Floor, Boston, MA 02110-1301 USA.
17 */
18
19 #include "ardour/raw_midi_parser.h"
20
21 using namespace ARDOUR;
22
RawMidiParser()23 RawMidiParser::RawMidiParser ()
24 {
25 reset ();
26 }
27
28 /* based on AlsaRawMidiIn, some code-dup */
29 bool
process_byte(const uint8_t byte)30 RawMidiParser::process_byte (const uint8_t byte)
31 {
32 if (byte >= 0xf8) {
33 // Realtime
34 if (byte == 0xfd) {
35 return false;
36 }
37 prepare_byte_event (byte);
38 return true;
39 }
40 if (byte == 0xf7) {
41 // Sysex end
42 if (_status_byte == 0xf0) {
43 record_byte (byte);
44 return prepare_buffered_event ();
45 }
46 _total_bytes = 0;
47 _unbuffered_bytes = 0;
48 _expected_bytes = 0;
49 _status_byte = 0;
50 return false;
51 }
52 if (byte >= 0x80) {
53 // Non-realtime status byte
54 if (_total_bytes) {
55 _total_bytes = 0;
56 _unbuffered_bytes = 0;
57 }
58 _status_byte = byte;
59 switch (byte & 0xf0) {
60 case 0x80:
61 case 0x90:
62 case 0xa0:
63 case 0xb0:
64 case 0xe0:
65 // Note On, Note Off, Aftertouch, Control Change, Pitch Wheel
66 _expected_bytes = 3;
67 break;
68 case 0xc0:
69 case 0xd0:
70 // Program Change, Channel Pressure
71 _expected_bytes = 2;
72 break;
73 case 0xf0:
74 switch (byte) {
75 case 0xf0:
76 // Sysex
77 _expected_bytes = 0;
78 break;
79 case 0xf1:
80 case 0xf3:
81 // MTC Quarter Frame, Song Select
82 _expected_bytes = 2;
83 break;
84 case 0xf2:
85 // Song Position
86 _expected_bytes = 3;
87 break;
88 case 0xf4:
89 case 0xf5:
90 // Undefined
91 _expected_bytes = 0;
92 _status_byte = 0;
93 return false;
94 case 0xf6:
95 // Tune Request
96 prepare_byte_event (byte);
97 _expected_bytes = 0;
98 _status_byte = 0;
99 return true;
100 }
101 }
102 record_byte (byte);
103 return false;
104 }
105 // Data byte
106 if (!_status_byte) {
107 // Data bytes without a status will be discarded.
108 _total_bytes++;
109 _unbuffered_bytes++;
110 return false;
111 }
112 if (!_total_bytes) {
113 record_byte (_status_byte);
114 }
115 record_byte (byte);
116 return (_total_bytes == _expected_bytes) ? prepare_buffered_event () : false;
117 }
118