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libremidi API

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Classes and Structs

Struct chunking_parameters
Struct Documentation
struct libremidi::chunking_parameters

Used to determine how large sent messages will be chunked.

Public Members

std::chrono::milliseconds interval = {}
int32_t size = {}
std::function<bool(std::chrono::microseconds, int)> wait = chunking_parameters::default_wait

Will be called by the chunking code to allow the API user to wait.

By default just calls sleep. Arguments are: the time that must be waited, the bytes currently written. Return false if you want to abort the transfer, and true otherwise.

Public Static Functions

static inline bool default_wait(std::chrono::microseconds time_to_wait, int written_bytes)
Struct driver_error
Inheritance Relationships
Base Type
Struct Documentation
struct libremidi::driver_error : public libremidi::midi_exception

Public Functions

inline ~driver_error() override

Public Static Attributes

static constexpr auto code = midi_error::DRIVER_ERROR
Struct invalid_device_error
Inheritance Relationships
Base Type
Struct Documentation
struct libremidi::invalid_device_error : public libremidi::midi_exception

Public Functions

inline ~invalid_device_error() override

Public Static Attributes

static constexpr auto code = midi_error::INVALID_DEVICE
Struct invalid_parameter_error
Inheritance Relationships
Base Type
Struct Documentation
struct libremidi::invalid_parameter_error : public libremidi::midi_exception

Public Functions

inline ~invalid_parameter_error() override

Public Static Attributes

static constexpr auto code = midi_error::INVALID_PARAMETER
Struct invalid_use_error
Inheritance Relationships
Base Type
Struct Documentation
struct libremidi::invalid_use_error : public libremidi::midi_exception

Public Functions

inline ~invalid_use_error() override

Public Static Attributes

static constexpr auto code = midi_error::INVALID_USE
Struct memory_error
Inheritance Relationships
Base Type
Struct Documentation
struct libremidi::memory_error : public libremidi::midi_exception

Public Functions

inline ~memory_error() override

Public Static Attributes

static constexpr auto code = midi_error::MEMORY_ERROR
Struct message
Struct Documentation
struct libremidi::message

Public Functions

message() noexcept = default
inline message(const midi_bytes &src_bytes, double src_timestamp)
template<typename ...Args>
inline message(Args... args) noexcept
inline bool uses_channel(int channel) const
inline int get_channel() const
inline bool is_meta_event() const
inline meta_event_type get_meta_event_type() const
inline message_type get_message_type() const
inline bool is_note_on_or_off() const
inline auto size() const
inline auto &front() const
inline auto &back() const
inline auto &operator[](int i) const
inline auto &front()
inline auto &back()
inline auto &operator[](int i)
template<typename ...Args>
inline auto assign(Args&&... args)
template<typename ...Args>
inline auto insert(Args&&... args)
inline auto clear()
inline auto begin() const
inline auto end() const
inline auto begin()
inline auto end()
inline auto cbegin() const
inline auto cend() const
inline auto cbegin()
inline auto cend()
inline auto rbegin() const
inline auto rend() const
inline auto rbegin()
inline auto rend()

Public Members

midi_bytes bytes
double timestamp = {}

Public Static Functions

static inline uint8_t make_command(const message_type type, const int channel) noexcept
static inline message note_on(uint8_t channel, uint8_t note, uint8_t velocity) noexcept
static inline message note_off(uint8_t channel, uint8_t note, uint8_t velocity) noexcept
static inline message control_change(uint8_t channel, uint8_t control, uint8_t value) noexcept
static inline message program_change(uint8_t channel, uint8_t value) noexcept
static inline message pitch_bend(uint8_t channel, int value) noexcept
static inline message pitch_bend(uint8_t channel, uint8_t lsb, uint8_t msb) noexcept
static inline message poly_pressure(uint8_t channel, uint8_t note, uint8_t value) noexcept
static inline message aftertouch(uint8_t channel, uint8_t value) noexcept
Struct meta_events
Struct Documentation
struct libremidi::meta_events

Public Static Functions

static inline message end_of_track()
static inline message channel(int channel)
static inline message tempo(int mpqn)
static inline message time_signature(int numerator, int denominator)
static inline message key_signature(int keyIndex, bool isMinor)
static inline message song_position(int positionInBeats) noexcept
Struct midi_exception
Inheritance Relationships
Base Type

  • public runtime_error

Derived Types
Struct Documentation
struct libremidi::midi_exception : public runtime_error

Base exception class for MIDI problems.

Subclassed by libremidi::driver_error, libremidi::invalid_device_error, libremidi::invalid_parameter_error, libremidi::invalid_use_error, libremidi::memory_error, libremidi::no_devices_found_error, libremidi::system_error, libremidi::thread_error

Public Functions

inline ~midi_exception() override
Struct no_devices_found_error
Inheritance Relationships
Base Type
Struct Documentation
struct libremidi::no_devices_found_error : public libremidi::midi_exception

Public Functions

inline ~no_devices_found_error() override

Public Static Attributes

static constexpr auto code = midi_error::NO_DEVICES_FOUND
Struct observer::callbacks
Nested Relationships

This struct is a nested type of Class observer.

Struct Documentation
struct libremidi::observer::callbacks

Public Members

std::function<void(int, std::string)> input_added
std::function<void(int, std::string)> input_removed
std::function<void(int, std::string)> output_added
std::function<void(int, std::string)> output_removed
Struct system_error
Inheritance Relationships
Base Type
Struct Documentation
struct libremidi::system_error : public libremidi::midi_exception

Public Functions

inline ~system_error() override

Public Static Attributes

static constexpr auto code = midi_error::SYSTEM_ERROR
Struct thread_error
Inheritance Relationships
Base Type
Struct Documentation
struct libremidi::thread_error : public libremidi::midi_exception

Public Functions

inline ~thread_error() override

Public Static Attributes

static constexpr auto code = midi_error::THREAD_ERROR
Struct track_event
Struct Documentation
struct libremidi::track_event

Public Members

int tick = 0
int track = 0
message m
Class midi_in
Class Documentation
class libremidi::midi_in

A realtime MIDI input class.

This class provides a common, platform-independent API for realtime MIDI input. It allows access to a single MIDI input port. Incoming MIDI messages are either saved to a queue for retrieval using the getMessage() function or immediately passed to a user-specified callback function. Create multiple instances of this class to connect to more than one MIDI device at the same time. With the OS-X, Linux ALSA, and JACK MIDI APIs, it is also possible to open a virtual input port to which other MIDI software clients can connect.

by Gary P. Scavone, 2003-2017.

Public Types

using message_callback = std::function<void(const message &message)>

User callback function type definition.

Public Functions

inline midi_in(libremidi::API api = API::UNSPECIFIED, std::string_view clientName = "RtMidi Input Client", unsigned int queueSizeLimit = 100)

Default constructor that allows an optional api, client name and queue size.

An exception will be thrown if a MIDI system initialization error occurs. The queue size defines the maximum number of messages that can be held in the MIDI queue (when not using a callback function). If the queue size limit is reached, incoming messages will be ignored.

If no API argument is specified and multiple API support has been compiled, the default order of use is ALSA, JACK (Linux) and CORE, JACK (OS-X).

Parameters

  • api: An optional API id can be specified.

  • clientName: An optional client name can be specified. This will be used to group the ports that are created by the application.

  • queueSizeLimit: An optional size of the MIDI input queue can be specified.

inline ~midi_in()

If a MIDI connection is still open, it will be closed by the destructor.

inline libremidi::API get_current_api() const noexcept

Returns the MIDI API specifier for the current instance of RtMidiIn.

inline void open_port(unsigned int portNumber, std::string_view portName)

Open a MIDI input connection given by enumeration number.

Parameters

  • portNumber: A port number greater than 0 can be specified. Otherwise, the default or first port found is opened.

  • portName: A name for the application port that is used to connect to portId can be specified.

inline void open_port()
inline void open_port(unsigned int port)
inline void open_virtual_port(std::string_view portName)

Create a virtual input port, with optional name, to allow software connections (OS X, JACK and ALSA only).

This function creates a virtual MIDI input port to which other software applications can connect. This type of functionality is currently only supported by the Macintosh OS-X, any JACK, and Linux ALSA APIs (the function returns an error for the other APIs).

Parameters

  • portName: An optional name for the application port that is used to connect to portId can be specified.

inline void open_virtual_port()
inline void set_callback(message_callback callback)

Set a callback function to be invoked for incoming MIDI messages.

The callback function will be called whenever an incoming MIDI message is received. While not absolutely necessary, it is best to set the callback function before opening a MIDI port to avoid leaving some messages in the queue.

Parameters

  • callback: A callback function must be given.

  • userData: Optionally, a pointer to additional data can be passed to the callback function whenever it is called.

inline void cancel_callback()

Cancel use of the current callback function (if one exists).

Subsequent incoming MIDI messages will be written to the queue and can be retrieved with the getMessage function.

inline void close_port()

Close an open MIDI connection (if one exists).

inline bool is_port_open() const noexcept

Returns true if a port is open and false if not.

Note that this only applies to connections made with the openPort() function, not to virtual ports.

inline unsigned int get_port_count()

Return the number of available MIDI input ports.

Return

This function returns the number of MIDI ports of the selected API.

inline std::string get_port_name(unsigned int portNumber = 0)

Return a string identifier for the specified MIDI input port number.

Return

The name of the port with the given Id is returned. An empty string is returned if an invalid port specifier is provided. User code should assume a UTF-8 encoding.

inline void ignore_types(bool midiSysex = true, bool midiTime = true, bool midiSense = true)

Specify whether certain MIDI message types should be queued or ignored during input.

By default, MIDI timing and active sensing messages are ignored during message input because of their relative high data rates. MIDI sysex messages are ignored by default as well. Variable values of “true” imply that the respective message type will be ignored.

inline message get_message()

Fill the user-provided vector with the data bytes for the next available MIDI message in the input queue and return the event delta-time in seconds.

This function returns immediately whether a new message is available or not. A valid message is indicated by a non-zero vector size. An exception is thrown if an error occurs during message retrieval or an input connection was not previously established.

inline bool get_message(message&)
inline void set_error_callback(midi_error_callback errorCallback)

Set an error callback function to be invoked when an error has occured.

The callback function will be called whenever an error has occured. It is best to set the error callback function before opening a port.

inline void set_client_name(std::string_view clientName)
inline void set_port_name(std::string_view portName)
Class midi_out
Class Documentation
class libremidi::midi_out

A realtime MIDI output class.

This class provides a common, platform-independent API for MIDI output. It allows one to probe available MIDI output ports, to connect to one such port, and to send MIDI bytes immediately over the connection. Create multiple instances of this class to connect to more than one MIDI device at the same time. With the OS-X, Linux ALSA and JACK MIDI APIs, it is also possible to open a virtual port to which other MIDI software clients can connect.

by Gary P. Scavone, 2003-2017.

Public Functions

inline midi_out(libremidi::API api, std::string_view clientName)

Default constructor that allows an optional client name.

An exception will be thrown if a MIDI system initialization error occurs.

If no API argument is specified and multiple API support has been compiled, the default order of use is ALSA, JACK (Linux) and CORE, JACK (OS-X).

inline midi_out()
inline ~midi_out()

The destructor closes any open MIDI connections.

inline libremidi::API get_current_api() noexcept

Returns the MIDI API specifier for the current instance of RtMidiOut.

inline void open_port(unsigned int portNumber, std::string_view portName)

Open a MIDI output connection.

An optional port number greater than 0 can be specified. Otherwise, the default or first port found is opened. An exception is thrown if an error occurs while attempting to make the port connection.

inline void open_port()
inline void open_port(unsigned int port)
inline void close_port()

Close an open MIDI connection (if one exists).

inline bool is_port_open() const noexcept

Returns true if a port is open and false if not.

Note that this only applies to connections made with the openPort() function, not to virtual ports.

inline void open_virtual_port(std::string_view portName)

Create a virtual output port, with optional name, to allow software connections (OS X, JACK and ALSA only).

This function creates a virtual MIDI output port to which other software applications can connect. This type of functionality is currently only supported by the Macintosh OS-X, Linux ALSA and JACK APIs (the function does nothing with the other APIs). An exception is thrown if an error occurs while attempting to create the virtual port.

inline void open_virtual_port()
inline unsigned int get_port_count()

Return the number of available MIDI output ports.

inline std::string get_port_name(unsigned int portNumber = 0)

Return a string identifier for the specified MIDI port type and number.

Return

The name of the port with the given Id is returned. An empty string is returned if an invalid port specifier is provided. User code should assume a UTF-8 encoding.

inline void send_message(const std::vector<unsigned char> &message)

Immediately send a single message out an open MIDI output port.

An exception is thrown if an error occurs during output or an output connection was not previously established.

inline void send_message(const libremidi::message &message)
inline void send_message(const unsigned char *message, size_t size)

Immediately send a single message out an open MIDI output port.

An exception is thrown if an error occurs during output or an output connection was not previously established.

Parameters

  • message: A pointer to the MIDI message as raw bytes

  • size: Length of the MIDI message in bytes

inline void set_error_callback(midi_error_callback errorCallback) noexcept

Set an error callback function to be invoked when an error has occured.

The callback function will be called whenever an error has occured. It is best to set the error callback function before opening a port.

inline void set_client_name(std::string_view clientName)
inline void set_port_name(std::string_view portName)
inline void set_chunking_parameters(std::optional<chunking_parameters> parameters)

For large messages, chunk their content and wait. Setting a null optional will disable chunking.

Class observer
Nested Relationships
Class Documentation
class libremidi::observer

The callbacks will be called whenever a device is added or removed for a given API.

Public Functions

inline observer(libremidi::API, callbacks)
inline ~observer()
struct callbacks

Public Members

std::function<void(int, std::string)> input_added
std::function<void(int, std::string)> input_removed
std::function<void(int, std::string)> output_added
std::function<void(int, std::string)> output_removed
Class reader
Class Documentation
class libremidi::reader

Public Functions

inline reader(bool useAbsolute = false)
inline ~reader()
inline void parse(const std::vector<uint8_t> &buffer)
inline double get_end_time()

Public Members

float ticksPerBeat = {}
float startingTempo = {}
std::vector<midi_track> tracks
Class writer
Class Documentation
class libremidi::writer

Public Functions

inline writer(int ticks)
inline ~writer()
inline size_t get_num_tracks()
inline void add_event(int tick, int track, message m)
inline void add_event(int track, track_event m)
inline void add_track()
inline void write(std::ostream &out)
inline const std::vector<midi_track> &get_tracks()

Enums

Enum API
Enum Documentation
enum libremidi::API

MIDI API specifier arguments.

Values:

enumerator UNSPECIFIED

Search for a working compiled API.

enumerator MACOSX_CORE

Macintosh OS-X Core Midi API.

enumerator LINUX_ALSA

The Advanced Linux Sound Architecture API.

enumerator LINUX_ALSA_SEQ
enumerator LINUX_ALSA_RAW

Raw ALSA API.

enumerator UNIX_JACK

The JACK Low-Latency MIDI Server API.

enumerator WINDOWS_MM

The Microsoft Multimedia MIDI API.

enumerator WINDOWS_UWP

The Microsoft WinRT MIDI API.

enumerator EMSCRIPTEN_WEBMIDI

Web MIDI API through Emscripten

enumerator DUMMY

A compilable but non-functional API.

Enum message_type
Enum Documentation
enum libremidi::message_type

Values:

enumerator INVALID
enumerator NOTE_OFF
enumerator NOTE_ON
enumerator POLY_PRESSURE
enumerator CONTROL_CHANGE
enumerator PROGRAM_CHANGE
enumerator AFTERTOUCH
enumerator PITCH_BEND
enumerator SYSTEM_EXCLUSIVE
enumerator TIME_CODE
enumerator SONG_POS_POINTER
enumerator SONG_SELECT
enumerator RESERVED1
enumerator RESERVED2
enumerator TUNE_REQUEST
enumerator EOX
enumerator TIME_CLOCK
enumerator RESERVED3
enumerator START
enumerator CONTINUE
enumerator STOP
enumerator RESERVED4
enumerator ACTIVE_SENSING
enumerator SYSTEM_RESET
Enum meta_event_type
Enum Documentation
enum libremidi::meta_event_type

Values:

enumerator SEQUENCE_NUMBER
enumerator TEXT
enumerator COPYRIGHT
enumerator TRACK_NAME
enumerator INSTRUMENT
enumerator LYRIC
enumerator MARKER
enumerator CUE
enumerator PATCH_NAME
enumerator DEVICE_NAME
enumerator CHANNEL_PREFIX
enumerator MIDI_PORT
enumerator END_OF_TRACK
enumerator TEMPO_CHANGE
enumerator SMPTE_OFFSET
enumerator TIME_SIGNATURE
enumerator KEY_SIGNATURE
enumerator PROPRIETARY
enumerator UNKNOWN
Enum midi_error
Enum Documentation
enum libremidi::midi_error

Defines various error types.

Values:

enumerator WARNING

A non-critical error.

enumerator UNSPECIFIED

The default, unspecified error type.

enumerator NO_DEVICES_FOUND

No devices found on system.

enumerator INVALID_DEVICE

An invalid device ID was specified.

enumerator MEMORY_ERROR

An error occured during memory allocation.

enumerator INVALID_PARAMETER

An invalid parameter was specified to a function.

enumerator INVALID_USE

The function was called incorrectly.

enumerator DRIVER_ERROR

A system driver error occured.

enumerator SYSTEM_ERROR

A system error occured.

enumerator THREAD_ERROR

A thread error occured.

Functions

Function libremidi::available_apis
Function Documentation

Warning

doxygenfunction: Unable to resolve function “libremidi::available_apis” with arguments () in doxygen xml output for project “libremidi” from directory: ./doxyoutput/xml. Potential matches: 

- std::vector<libremidi::API> available_apis() noexcept
Function libremidi::clamp
Function Documentation
inline constexpr uint8_t libremidi::clamp(uint8_t val, uint8_t min, uint8_t max)
Template Function libremidi::for_all_backends
Function Documentation
template<typename F>
auto libremidi::for_all_backends(F &&f)
Template Function libremidi::for_backend
Function Documentation
template<typename F>
auto libremidi::for_backend(libremidi::API api, F &&f)
Function libremidi::get_version
Function Documentation

Warning

doxygenfunction: Unable to resolve function “libremidi::get_version” with arguments () in doxygen xml output for project “libremidi” from directory: ./doxyoutput/xml. Potential matches: 

- std::string get_version() noexcept
Template Function libremidi::make_tl
Function Documentation
template<typename unused, typename ...Args>
constexpr auto libremidi::make_tl(unused, Args...)
Function libremidi::open_midi_in
Function Documentation
inline std::unique_ptr<midi_in_api> libremidi::open_midi_in(libremidi::API api, std::string_view clientName, unsigned int queueSizeLimit)
Function libremidi::open_midi_observer
Function Documentation
inline std::unique_ptr<observer_api> libremidi::open_midi_observer(libremidi::API api, observer::callbacks &&cb)
Function libremidi::open_midi_out
Function Documentation
inline std::unique_ptr<midi_out_api> libremidi::open_midi_out(libremidi::API api, std::string_view clientName)
Function libremidi::parseEvent
Function Documentation
inline track_event libremidi::parseEvent(int tick, int track, uint8_t const *&dataStart, message_type lastEventTypeByte)
Function libremidi::util::read_bytes
Function Documentation
inline void libremidi::util::read_bytes(midi_bytes &buffer, uint8_t const *&data, int num)
Function libremidi::util::read_uint16_be
Function Documentation
inline uint16_t libremidi::util::read_uint16_be(uint8_t const *&data)
Function libremidi::util::read_uint24_be
Function Documentation
inline uint32_t libremidi::util::read_uint24_be(uint8_t const *&data)
Function libremidi::util::read_uint32_be
Function Documentation
inline uint32_t libremidi::util::read_uint32_be(uint8_t const *&data)
Function libremidi::util::read_variable_length
Function Documentation
inline uint32_t libremidi::util::read_variable_length(uint8_t const *&data)
Function libremidi::util::write_double_be
Function Documentation
inline std::ostream &libremidi::util::write_double_be(std::ostream &out, double value)
Function libremidi::util::write_float_be
Function Documentation
inline std::ostream &libremidi::util::write_float_be(std::ostream &out, float value)
Function libremidi::util::write_int16_be
Function Documentation
inline std::ostream &libremidi::util::write_int16_be(std::ostream &out, int16_t value)
Function libremidi::util::write_int32_be
Function Documentation
inline std::ostream &libremidi::util::write_int32_be(std::ostream &out, int32_t value)
Function libremidi::util::write_uint16_be
Function Documentation
inline std::ostream &libremidi::util::write_uint16_be(std::ostream &out, uint16_t value)
Function libremidi::util::write_uint32_be
Function Documentation
inline std::ostream &libremidi::util::write_uint32_be(std::ostream &out, uint32_t value)
Function libremidi::util::write_variable_length
Function Documentation
inline void libremidi::util::write_variable_length(uint32_t aValue, std::vector<uint8_t> &outdata)

Variables

Variable libremidi::available_backends
Variable Documentation
static constexpr auto libremidi::available_backends = make_tl(0, dummy_backend{})

Defines

Define LIBREMIDI_DUMMY
Define Documentation

Warning

doxygendefine: Cannot find define “LIBREMIDI_DUMMY” in doxygen xml output for project “libremidi” from directory: ./doxyoutput/xml

Define LIBREMIDI_EXPORT
Define Documentation
LIBREMIDI_EXPORT
Define LIBREMIDI_INLINE
Define Documentation
LIBREMIDI_INLINE
Define LIBREMIDI_VERSION
Define Documentation
LIBREMIDI_VERSION

Typedefs

Typedef libremidi::midi_bytes
Typedef Documentation
using libremidi::midi_bytes = std::vector<unsigned char>
Typedef libremidi::midi_error_callback
Typedef Documentation
using libremidi::midi_error_callback = std::function<void(midi_error type, std::string_view errorText)>

Error callback function.

Note that class behaviour is undefined after a critical error (not a warning) is reported.

Parameters

  • type: Type of error.

  • errorText: Error description.

Typedef libremidi::midi_track
Typedef Documentation
typedef std::vector<track_event> libremidi::midi_track

Indices and tables