/*
* Copyright (c) 2018-2019, Arm Limited and affiliates.
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef MIDIMESSAGE_H
#define MIDIMESSAGE_H
#include <stdint.h>
#define MAX_MIDI_MESSAGE_SIZE 256 // Max message size. SysEx can be up to 65536 but 256 should be fine for most usage
// MIDI Message Format
//
// [ msg(4) | channel(4) ] [ 0 | n(7) ] [ 0 | m(7) ]
//
// MIDI Data Messages (Channel Specific)
//
// Message msg n m
// ---------------------------------------------
// Note Off 0x8 Key Velocity
// Note On 0x9 Key Velocity
// Polyphonic Aftertouch 0xA Key Pressure
// Control Change 0xB Controller Value
// Program Change 0xC Program -
// Channel Aftertouch 0xD Pressure -
// Pitch Wheel 0xE LSB MSB
#define CABLE_NUM (0<<4)
/**
* \defgroup drivers_MIDIMessage MIDIMessage class
* \ingroup drivers-internal-api-usb
* @{
*/
/** A MIDI message container */
class MIDIMessage {
public:
MIDIMessage() : data(new uint8_t[MAX_MIDI_MESSAGE_SIZE + 1]), length(0) {}
MIDIMessage(uint8_t *buf) : data(new uint8_t[MAX_MIDI_MESSAGE_SIZE + 1]), length(0)
{
for (int i = 0; i < 4; i++) {
data[i] = buf[i];
}
}
/**
* Copy constructor
*/
MIDIMessage(const MIDIMessage &other)
{
*this = other;
}
/**
* Assignment operator
*/
MIDIMessage &operator=(const MIDIMessage &other)
{
length = other.length;
for (int i = 0; i < length; i++) {
data[i] = other.data[i];
}
return *this;
}
~MIDIMessage()
{
delete[] data;
}
/**
* Set this MIDIMessage to a raw MIDI message
*
* @param buf is a true MIDI message (not USBMidi message)
* @param buf_len size of message
*/
void from_raw(uint8_t *buf, int buf_len)
{
length = buf_len + 1;
if (length > MAX_MIDI_MESSAGE_SIZE) {
// Message is too big
length = 0;
return;
}
// first byte keeped for retro-compatibility
data[0] = CABLE_NUM | 0x08;
for (int i = 0; i < buf_len; i++) {
data[i + 1] = buf[i];
}
}
// create messages
/** Create a NoteOff message
* @param key Key ID
* @param velocity Key velocity (0-127, default = 127)
* @param channel Key channel (0-15, default 0)
* @returns A MIDIMessage
*/
static MIDIMessage NoteOff(int key, int velocity = 127, int channel = 0)
{
MIDIMessage msg;
msg.data[0] = CABLE_NUM | 0x08;
msg.data[1] = 0x80 | (channel & 0x0F);
msg.data[2] = key & 0x7F;
msg.data[3] = velocity & 0x7F;
msg.length = 4;
return msg;
}
/** Create a NoteOn message
* @param key Key ID
* @param velocity Key velocity (0-127, default = 127)
* @param channel Key channel (0-15, default 0)
* @returns A MIDIMessage
*/
static MIDIMessage NoteOn(int key, int velocity = 127, int channel = 0)
{
MIDIMessage msg;
msg.data[0] = CABLE_NUM | 0x09;
msg.data[1] = 0x90 | (channel & 0x0F);
msg.data[2] = key & 0x7F;
msg.data[3] = velocity & 0x7F;
msg.length = 4;
return msg;
}
/** Create a PolyPhonic Aftertouch message
* @param key Key ID
* @param pressure Aftertouch pressure (0-127)
* @param channel Key channel (0-15, default 0)
* @returns A MIDIMessage
*/
static MIDIMessage PolyphonicAftertouch(int key, int pressure, int channel = 0)
{
MIDIMessage msg;
msg.data[0] = CABLE_NUM | 0x0A;
msg.data[1] = 0xA0 | (channel & 0x0F);
msg.data[2] = key & 0x7F;
msg.data[3] = pressure & 0x7F;
msg.length = 4;
return msg;
}
/** Create a Control Change message
* @param control Controller ID
* @param value Controller value (0-127)
* @param channel Controller channel (0-15, default 0)
* @returns A MIDIMessage
*/
static MIDIMessage ControlChange(int control, int value, int channel = 0)
{
MIDIMessage msg;
msg.data[0] = CABLE_NUM | 0x0B;
msg.data[1] = 0xB0 | (channel & 0x0F);
msg.data[2] = control & 0x7F;
msg.data[3] = value & 0x7F;
msg.length = 4;
return msg;
}
/** Create a Program Change message
* @param program Program ID
* @param channel Channel (0-15, default 0)
* @returns A MIDIMessage
*/
static MIDIMessage ProgramChange(int program, int channel = 0)
{
MIDIMessage msg;
msg.data[0] = CABLE_NUM | 0x0C;
msg.data[1] = 0xC0 | (channel & 0x0F);
msg.data[2] = program & 0x7F;
msg.data[3] = 0x00;
msg.length = 4;
return msg;
}
/** Create a Channel Aftertouch message
* @param pressure Pressure
* @param channel Key channel (0-15, default 0)
* @returns A MIDIMessage
*/
static MIDIMessage ChannelAftertouch(int pressure, int channel = 0)
{
MIDIMessage msg;
msg.data[0] = CABLE_NUM | 0x0D;
msg.data[1] = 0xD0 | (channel & 0x0F);
msg.data[2] = pressure & 0x7F;
msg.data[3] = 0x00;
msg.length = 4;
return msg;
}
/** Create a Pitch Wheel message
* @param pitch Pitch (-8192 - 8191, default = 0)
* @param channel Channel (0-15, default 0)
* @returns A MIDIMessage
*/
static MIDIMessage PitchWheel(int pitch = 0, int channel = 0)
{
MIDIMessage msg;
int p = pitch + 8192; // 0 - 16383, 8192 is center
msg.data[0] = CABLE_NUM | 0x0E;
msg.data[1] = 0xE0 | (channel & 0x0F);
msg.data[2] = p & 0x7F;
msg.data[3] = (p >> 7) & 0x7F;
msg.length = 4;
return msg;
}
/** Create an All Notes Off message
* @param channel Channel (0-15, default 0)
* @returns A MIDIMessage
*/
static MIDIMessage AllNotesOff(int channel = 0)
{
return ControlChange(123, 0, channel);
}
/** Create a SysEx message
* @param data SysEx data (including 0xF0 .. 0xF7)
* @param len SysEx data length
* @returns A MIDIMessage
*/
static MIDIMessage SysEx(uint8_t *data, int len)
{
MIDIMessage msg;
msg.from_raw(data, len);
return msg;
}
// decode messages
/** MIDI Message Types */
enum MIDIMessageType {
ErrorType,
NoteOffType,
NoteOnType,
PolyphonicAftertouchType,
ControlChangeType,
ProgramChangeType,
ChannelAftertouchType,
PitchWheelType,
ResetAllControllersType,
AllNotesOffType,
SysExType
};
/** Read the message type
*
* @returns MIDIMessageType
*/
MIDIMessageType type()
{
MIDIMessageType message_type;
uint8_t min_size;
switch ((data[1] >> 4) & 0xF) {
case 0x8:
// message, channel
// key
// velocity
min_size = 3;
message_type = NoteOffType;
break;
case 0x9:
// message, channel
// key
// velocity
min_size = 3;
message_type = NoteOnType;
break;
case 0xA:
// message, channel
// key
// pressure
min_size = 3;
message_type = PolyphonicAftertouchType;
break;
case 0xB:
// message, channel
// controller
min_size = 2;
if ((data[2] & 0x7F) < 120) { // standard controllers
message_type = ControlChangeType;
} else if ((data[2] & 0x7F) == 121) {
message_type = ResetAllControllersType;
} else if ((data[2] & 0x7F) == 123) {
message_type = AllNotesOffType;
} else {
message_type = ErrorType; // unsupported atm
}
break;
case 0xC:
// message, channel
// program
min_size = 2;
message_type = ProgramChangeType;
break;
case 0xD:
// message, channel
// pressure
min_size = 2;
message_type = ChannelAftertouchType;
break;
case 0xE:
// message, channel
// pitch lsb
// pitch msb
min_size = 3;
message_type = PitchWheelType;
break;
case 0xF:
min_size = 2;
message_type = SysExType;
break;
default:
message_type = ErrorType;
break;
}
if (length < min_size) {
// too small to be a valid message
message_type = ErrorType;
}
return message_type;
}
/**
* Read the channel number
*
* @return channel number or -1 on error
*/
int channel()
{
return (data[1] & 0x0F);
}
/**
* Read the key ID
*
* @return key ID or -1 on error
*/
int key()
{
MIDIMessageType msg_type = type();
if ((msg_type != NoteOffType) &&
(msg_type != NoteOnType) &&
(msg_type != PolyphonicAftertouchType)) {
return -1;
}
return data[2] & 0x7F;
}
/**
* Read the velocity
*
* @return velocity or -1 on error
*/
int velocity()
{
MIDIMessageType msg_type = type();
if ((msg_type != NoteOffType) &&
(msg_type != NoteOnType)) {
return -1;
}
return data[3] & 0x7F;
}
/**
* Read the controller value
*
* @return controller value or -1 on error
*/
int value()
{
MIDIMessageType msg_type = type();
if ((msg_type != ControlChangeType) &&
(msg_type != ResetAllControllersType) &&
(msg_type != AllNotesOffType)) {
return -1;
}
return data[3] & 0x7F;
}
/**
* Read the aftertouch pressure
*
* @return aftertouch pressure or -1 on error
*/
int pressure()
{
MIDIMessageType msg_type = type();
if ((msg_type != PolyphonicAftertouchType) &&
(msg_type != ChannelAftertouchType)) {
return -1;
}
if (type() == PolyphonicAftertouchType) {
return data[3] & 0x7F;
} else {
return data[2] & 0x7F;
}
}
/**
* Read the controller number
*
* @return controller number or -1 on error
*/
int controller()
{
MIDIMessageType msg_type = type();
if ((msg_type != ControlChangeType) &&
(msg_type != ResetAllControllersType) &&
(msg_type != AllNotesOffType)) {
return -1;
}
return data[2] & 0x7F;
}
/**
* Read the program number
*
* @return program number or -1 on error
*/
int program()
{
MIDIMessageType msg_type = type();
if (msg_type != ProgramChangeType) {
return -1;
}
return data[2] & 0x7F;
}
/**
* Read the pitch value
*
* @return pitch value or -1 on error
*/
int pitch()
{
MIDIMessageType msg_type = type();
if (msg_type != PitchWheelType) {
return -1;
}
int p = ((data[3] & 0x7F) << 7) | (data[2] & 0x7F);
return p - 8192; // 0 - 16383, 8192 is center
}
uint8_t *data;
uint16_t length;
};
/** @}*/
#endif
