Source code for jack

# Copyright (c) 2014-2015 Matthias Geier
#
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# in the Software without restriction, including without limitation the rights
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# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
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#
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# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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# THE SOFTWARE.

"""JACK Client for Python.

http://jackclient-python.rtfd.org/

"""
__version__ = "0.4.0"

import errno as _errno
import platform as _platform
from cffi import FFI as _FFI

_ffi = _FFI()
_ffi.cdef("""

/* types.h */

typedef uint64_t jack_uuid_t;
typedef uint32_t jack_nframes_t;
typedef uint64_t jack_time_t;
typedef struct _jack_port jack_port_t;
typedef struct _jack_client jack_client_t;
typedef uint32_t jack_port_id_t;
typedef uint32_t jack_port_type_id_t;
enum JackOptions {
    JackNullOption = 0x00,
    JackNoStartServer = 0x01,
    JackUseExactName = 0x02,
    JackServerName = 0x04,
    JackLoadName = 0x08,
    JackLoadInit = 0x10,
    JackSessionID = 0x20
};
typedef enum JackOptions jack_options_t;
enum JackStatus {
    JackFailure = 0x01,
    JackInvalidOption = 0x02,
    JackNameNotUnique = 0x04,
    JackServerStarted = 0x08,
    JackServerFailed = 0x10,
    JackServerError = 0x20,
    JackNoSuchClient = 0x40,
    JackLoadFailure = 0x80,
    JackInitFailure = 0x100,
    JackShmFailure = 0x200,
    JackVersionError = 0x400,
    JackBackendError = 0x800,
    JackClientZombie = 0x1000
};
typedef enum JackStatus jack_status_t;
typedef int (*JackProcessCallback)(jack_nframes_t nframes, void* arg);
typedef int (*JackGraphOrderCallback)(void* arg);
typedef int (*JackXRunCallback)(void* arg);
typedef int (*JackBufferSizeCallback)(jack_nframes_t nframes, void* arg);
typedef int (*JackSampleRateCallback)(jack_nframes_t nframes, void* arg);
typedef void (*JackPortRegistrationCallback)(jack_port_id_t port, int /* register */, void* arg);
typedef void (*JackClientRegistrationCallback)(const char* name, int /* register */, void* arg);
typedef void (*JackPortConnectCallback)(jack_port_id_t a, jack_port_id_t b, int connect, void* arg);
typedef int (*JackPortRenameCallback)(jack_port_id_t port, const char* old_name, const char* new_name, void* arg);
typedef void (*JackFreewheelCallback)(int starting, void* arg);
/* not implemented: JackShutdownCallback (only JackInfoShutdownCallback is used) */
typedef void (*JackInfoShutdownCallback)(jack_status_t code, const char* reason, void* arg);
/* JACK_DEFAULT_AUDIO_TYPE: see _AUDIO */
/* JACK_DEFAULT_MIDI_TYPE: see _MIDI */
/* not implemented: jack_default_audio_sample_t (hard-coded as float) */
enum JackPortFlags {
    JackPortIsInput = 0x1,
    JackPortIsOutput = 0x2,
    JackPortIsPhysical = 0x4,
    JackPortCanMonitor = 0x8,
    JackPortIsTerminal = 0x10,
};
typedef enum {
    JackTransportStopped = 0,
    JackTransportRolling = 1,
    JackTransportLooping = 2,  /* deprecated */
    JackTransportStarting = 3,
    JackTransportNetStarting = 4,
} jack_transport_state_t;
typedef uint64_t jack_unique_t;
typedef enum {
    JackPositionBBT = 0x10,
    JackPositionTimecode = 0x20,
    JackBBTFrameOffset = 0x40,
    JackAudioVideoRatio = 0x80,
    JackVideoFrameOffset = 0x100,
} jack_position_bits_t;
/* _jack_position: see below in "packed" section */
typedef struct _jack_position jack_position_t;
typedef void (*JackTimebaseCallback)(jack_transport_state_t state, jack_nframes_t nframes, jack_position_t *pos, int new_pos, void *arg);
/* deprecated: jack_transport_bits_t */
/* deprecated: jack_transport_info_t */

/* jack.h */

void jack_get_version(int* major_ptr, int* minor_ptr, int* micro_ptr, int* proto_ptr);
const char* jack_get_version_string();
jack_client_t* jack_client_open(const char* client_name, jack_options_t options, jack_status_t* status, ...);
/* deprecated: jack_client_new */
int jack_client_close(jack_client_t* client);
int jack_client_name_size(void);
char* jack_get_client_name(jack_client_t* client);
char* jack_get_uuid_for_client_name(jack_client_t* client, const char* client_name);
char* jack_get_client_name_by_uuid(jack_client_t* client, const char* client_uuid);
/* deprecated: jack_internal_client_new */
/* deprecated: jack_internal_client_close */
int jack_activate(jack_client_t* client);
int jack_deactivate(jack_client_t* client);
int jack_get_client_pid(const char* name);
/* not implemented: jack_client_thread_id */
int jack_is_realtime(jack_client_t* client);
/* deprecated: jack_thread_wait */
/* not implemented: jack_cycle_wait */
/* not implemented: jack_cycle_signal */
/* not implemented: jack_set_process_thread */
/* not implemented: jack_set_thread_init_callback */
/* not implemented (jack_on_info_shutdown is used): jack_on_shutdown */
void jack_on_info_shutdown(jack_client_t* client, JackInfoShutdownCallback shutdown_callback, void* arg);
int jack_set_process_callback(jack_client_t* client, JackProcessCallback process_callback, void* arg);
int jack_set_freewheel_callback(jack_client_t* client, JackFreewheelCallback freewheel_callback, void* arg);
int jack_set_buffer_size_callback(jack_client_t* client, JackBufferSizeCallback bufsize_callback, void* arg);
int jack_set_sample_rate_callback(jack_client_t* client, JackSampleRateCallback srate_callback, void* arg);
int jack_set_client_registration_callback(jack_client_t* client, JackClientRegistrationCallback registration_callback, void* arg);
int jack_set_port_registration_callback(jack_client_t* client, JackPortRegistrationCallback registration_callback, void* arg);
int jack_set_port_connect_callback(jack_client_t* client, JackPortConnectCallback connect_callback, void* arg);
int jack_set_port_rename_callback(jack_client_t* client, JackPortRenameCallback rename_callback, void* arg);
int jack_set_graph_order_callback(jack_client_t* client, JackGraphOrderCallback graph_callback, void*);
int jack_set_xrun_callback(jack_client_t* client, JackXRunCallback xrun_callback, void* arg);
/* TODO: jack_set_latency_callback */
int jack_set_freewheel(jack_client_t* client, int onoff);
int jack_set_buffer_size(jack_client_t* client, jack_nframes_t nframes);
jack_nframes_t jack_get_sample_rate(jack_client_t*);
jack_nframes_t jack_get_buffer_size(jack_client_t*);
/* deprecated: jack_engine_takeover_timebase */
float jack_cpu_load(jack_client_t* client);
jack_port_t* jack_port_register(jack_client_t* client, const char* port_name, const char* port_type, unsigned long flags, unsigned long buffer_size);
int jack_port_unregister(jack_client_t* client, jack_port_t* port);
void* jack_port_get_buffer(jack_port_t* port, jack_nframes_t);
jack_uuid_t jack_port_uuid(const jack_port_t* port);
const char* jack_port_name(const jack_port_t* port);
const char* jack_port_short_name(const jack_port_t* port);
int jack_port_flags(const jack_port_t* port);
const char* jack_port_type(const jack_port_t* port);
/* not implemented: jack_port_type_id */
int jack_port_is_mine(const jack_client_t* client, const jack_port_t* port);
int jack_port_connected(const jack_port_t* port);
int jack_port_connected_to(const jack_port_t* port, const char* port_name);
const char** jack_port_get_connections(const jack_port_t* port);
const char** jack_port_get_all_connections(const jack_client_t* client, const jack_port_t* port);
/* deprecated: jack_port_tie */
/* deprecated: jack_port_untie */
int jack_port_set_name(jack_port_t* port, const char* port_name);
/* TODO: jack_port_set_alias */
/* TODO: jack_port_unset_alias */
/* TODO: jack_port_get_aliases */
int jack_port_request_monitor(jack_port_t *port, int onoff);
/* not implemented (use jack_port_request_monitor): jack_port_request_monitor_by_name */
/* TODO: jack_port_ensure_monitor */
/* TODO: jack_port_monitoring_input */
int jack_connect(jack_client_t* client, const char* source_port, const char* destination_port);
int jack_disconnect(jack_client_t* client, const char* source_port, const char* destination_port);
int jack_port_disconnect(jack_client_t* client, jack_port_t* port);
int jack_port_name_size(void);
/* not implemented: jack_port_type_size */
/* not implemented: jack_port_type_get_buffer_size */
/* TODO: jack_port_set_latency */
/* TODO: jack_port_get_latency_range */
/* TODO: jack_port_set_latency_range */
/* TODO: jack_recompute_total_latencies */
/* TODO: jack_port_get_latency */
/* TODO: jack_port_get_total_latency */
/* TODO: jack_recompute_total_latency */
const char** jack_get_ports(jack_client_t* client, const char* port_name_pattern, const char* type_name_pattern, unsigned long flags);
jack_port_t* jack_port_by_name(jack_client_t* client, const char* port_name);
jack_port_t* jack_port_by_id(jack_client_t* client, jack_port_id_t port_id);
jack_nframes_t jack_frames_since_cycle_start(const jack_client_t*);
jack_nframes_t jack_frame_time(const jack_client_t*);
jack_nframes_t jack_last_frame_time(const jack_client_t* client);
/* TODO: jack_get_cycle_times */
/* TODO: jack_frames_to_time */
/* TODO: jack_time_to_frames */
/* TODO: jack_get_time */
void jack_set_error_function(void (*func)(const char*));
void jack_set_info_function(void (*func)(const char*));
void jack_free(void* ptr);

/* ringbuffer.h */

typedef struct {
    char* buf;
    size_t len;
} jack_ringbuffer_data_t;
typedef struct {
    char* buf;
    volatile size_t write_ptr;
    volatile size_t read_ptr;
    size_t size;
    size_t size_mask;
    int mlocked;
} jack_ringbuffer_t;
jack_ringbuffer_t* jack_ringbuffer_create(size_t sz);
void jack_ringbuffer_free(jack_ringbuffer_t* rb);
void jack_ringbuffer_get_read_vector(const jack_ringbuffer_t* rb, jack_ringbuffer_data_t* vec);
void jack_ringbuffer_get_write_vector(const jack_ringbuffer_t* rb, jack_ringbuffer_data_t* vec);
size_t jack_ringbuffer_read(jack_ringbuffer_t* rb, char* dest, size_t cnt);
size_t jack_ringbuffer_peek(jack_ringbuffer_t* rb, char* dest, size_t cnt);
void jack_ringbuffer_read_advance(jack_ringbuffer_t* rb, size_t cnt);
size_t jack_ringbuffer_read_space(const jack_ringbuffer_t* rb);
int jack_ringbuffer_mlock(jack_ringbuffer_t* rb);
void jack_ringbuffer_reset(jack_ringbuffer_t* rb);
void jack_ringbuffer_reset_size (jack_ringbuffer_t* rb, size_t sz);
/* Note: "char*" was changed to "unsigned char*" to support iterables of int */
size_t jack_ringbuffer_write(jack_ringbuffer_t* rb, const unsigned char* src, size_t cnt);
void jack_ringbuffer_write_advance(jack_ringbuffer_t* rb, size_t cnt);
size_t jack_ringbuffer_write_space(const jack_ringbuffer_t* rb);

/* transport.h */

/* TODO: jack_release_timebase */
/* TODO: jack_set_sync_callback */
/* TODO: jack_set_sync_timeout */
int jack_set_timebase_callback(jack_client_t* client, int conditional, JackTimebaseCallback timebase_callback, void* arg);
int  jack_transport_locate(jack_client_t* client, jack_nframes_t frame);
jack_transport_state_t jack_transport_query(const jack_client_t* client, jack_position_t* pos);
jack_nframes_t jack_get_current_transport_frame(const jack_client_t* client);
/* TODO: jack_transport_reposition */
void jack_transport_start(jack_client_t* client);
void jack_transport_stop(jack_client_t* client);
/* deprecated: jack_get_transport_info */
/* deprecated: jack_set_transport_info */

/* statistics.h */

float jack_get_xrun_delayed_usecs(jack_client_t* client);

/* midiport.h */

typedef unsigned char jack_midi_data_t;
typedef struct _jack_midi_event {
    jack_nframes_t time;
    size_t size;
    jack_midi_data_t* buffer;
} jack_midi_event_t;
uint32_t jack_midi_get_event_count(void* port_buffer);
int jack_midi_event_get(jack_midi_event_t* event, void* port_buffer, uint32_t event_index);
void jack_midi_clear_buffer(void* port_buffer);
/* not implemented: jack_midi_reset_buffer */
size_t jack_midi_max_event_size(void* port_buffer);
jack_midi_data_t* jack_midi_event_reserve(void* port_buffer, jack_nframes_t time, size_t data_size);
int jack_midi_event_write(void* port_buffer, jack_nframes_t time, const jack_midi_data_t* data, size_t data_size);
uint32_t jack_midi_get_lost_event_count(void* port_buffer);
""")

# Packed structure
_ffi.cdef("""
struct _jack_position {
    jack_unique_t unique_1;
    jack_time_t usecs;
    jack_nframes_t frame_rate;
    jack_nframes_t frame;
    jack_position_bits_t valid;
    int32_t bar;
    int32_t beat;
    int32_t tick;
    double bar_start_tick;
    float beats_per_bar;
    float beat_type;
    double ticks_per_beat;
    double beats_per_minute;
    double frame_time;
    double next_time;
    jack_nframes_t bbt_offset;
    float audio_frames_per_video_frame;
    jack_nframes_t video_offset;
    int32_t padding[7];
    jack_unique_t unique_2;
};
""", packed=True)

if _platform.system() == 'Windows':
    if _platform.architecture()[0] == '64bit':
        _lib = _ffi.dlopen("libjack64")
    else:
        _lib = _ffi.dlopen("libjack")
else:
    _lib = _ffi.dlopen("jack")

_AUDIO = b"32 bit float mono audio"
_MIDI = b"8 bit raw midi"

STOPPED = _lib.JackTransportStopped
"""Transport halted."""
ROLLING = _lib.JackTransportRolling
"""Transport playing."""
STARTING = _lib.JackTransportStarting
"""Waiting for sync ready."""
NETSTARTING = _lib.JackTransportNetStarting
"""Waiting for sync ready on the network."""

_SUCCESS = 0
_FAILURE = 1


[docs]class Client(object): """A client that can connect to the JACK audio server.""" def __init__(self, name, use_exact_name=False, no_start_server=False, servername=None, session_id=None): """Create a new JACK client. Parameters ---------- name : str The desired client name of at most :func:`client_name_size` characters. The name scope is local to each server. Unless forbidden by the `use_exact_name` option, the server will modify this name to create a unique variant, if needed. Other Parameters ---------------- use_exact_name : bool Whether an error should be raised if `name` is not unique. See :attr:`Status.name_not_unique`. no_start_server : bool Do not automatically start the JACK server when it is not already running. This option is always selected if ``JACK_NO_START_SERVER`` is defined in the calling process environment. servername : str Selects from among several possible concurrent server instances. Server names are unique to each user. If unspecified, use ``"default"`` unless ``JACK_DEFAULT_SERVER`` is defined in the process environment. session_id : str Pass a SessionID Token. This allows the sessionmanager to identify the client again. """ status = _ffi.new("jack_status_t*") args = [name.encode(), _lib.JackNullOption, status] if use_exact_name: args[1] |= _lib.JackUseExactName if no_start_server: args[1] |= _lib.JackNoStartServer if servername: args[1] |= _lib.JackServerName args.append(_ffi.new("char[]", servername.encode())) if session_id: args[1] |= _lib.JackSessionID args.append(_ffi.new("char[]", session_id.encode())) self._ptr = _lib.jack_client_open(*args) self._status = Status(status[0]) if not self._ptr: raise JackError(str(self.status)) self._inports = Ports(self, _AUDIO, _lib.JackPortIsInput) self._outports = Ports(self, _AUDIO, _lib.JackPortIsOutput) self._midi_inports = Ports(self, _MIDI, _lib.JackPortIsInput) self._midi_outports = Ports(self, _MIDI, _lib.JackPortIsOutput) self._keepalive = [] self._position = _ffi.new("jack_position_t*") # Avoid confusion if something goes wrong before opening the client: _ptr = _ffi.NULL def __enter__(self): self.activate() return self def __exit__(self, *args): self.deactivate() self.close() def __del__(self): """Close JACK client on garbage collection.""" self.close() @property def name(self): """The name of the JACK client (read-only).""" return _ffi.string(_lib.jack_get_client_name(self._ptr)).decode() @property def samplerate(self): """The sample rate of the JACK system (read-only).""" return _lib.jack_get_sample_rate(self._ptr) @property def blocksize(self): """The JACK block size (must be a power of two). The current maximum size that will ever be passed to the process callback. It should only be queried *before* :meth:`activate` has been called. This size may change, clients that depend on it must register a callback with :meth:`set_blocksize_callback` so they will be notified if it does. Changing the blocksize stops the JACK engine process cycle, then calls all registered callback functions (see :meth:`set_blocksize_callback`) before restarting the process cycle. This will cause a gap in the audio flow, so it should only be done at appropriate stopping points. """ return _lib.jack_get_buffer_size(self._ptr) @blocksize.setter def blocksize(self, blocksize): _check(_lib.jack_set_buffer_size(self._ptr, blocksize), "Error setting JACK blocksize") @property def status(self): """JACK client status. See :class:`Status`.""" return self._status @property def realtime(self): """Whether JACK is running with ``-R`` (``--realtime``).""" return bool(_lib.jack_is_realtime(self._ptr)) @property def frames_since_cycle_start(self): """Time since start of audio block. The estimated time in frames that has passed since the JACK server began the current process cycle. """ return _lib.jack_frames_since_cycle_start(self._ptr) @property def frame_time(self): """The estimated current time in frames. This is intended for use in other threads (not the process callback). The return value can be compared with the value of :attr:`last_frame_time` to relate time in other threads to JACK time. """ return _lib.jack_frame_time(self._ptr) @property def last_frame_time(self): """The precise time at the start of the current process cycle. This may only be used from the process callback (see :meth:`set_process_callback`), and can be used to interpret timestamps generated by :attr:`frame_time` in other threads with respect to the current process cycle. This is the only jack time function that returns exact time: when used during the process callback it always returns the same value (until the next process callback, where it will return that value + :attr:`blocksize`, etc). The return value is guaranteed to be monotonic and linear in this fashion unless an xrun occurs (see :meth:`set_xrun_callback`). If an xrun occurs, clients must check this value again, as time may have advanced in a non-linear way (e.g. cycles may have been skipped). """ return _lib.jack_last_frame_time(self._ptr) @property def inports(self): """A list of audio input :class:`Ports`. New ports can be created and added to this list with the :meth:`~Ports.register` method. When :meth:`~OwnPort.unregister` is called on one of the items in this list, this port is removed from the list. The :meth:`~Ports.clear` method can be used to unregister all audio input ports at once. See Also -------- Ports, OwnPort """ return self._inports @property def outports(self): """A list of audio output :class:`Ports`. New ports can be created and added to this list with the :meth:`~Ports.register` method. When :meth:`~OwnPort.unregister` is called on one of the items in this list, this port is removed from the list. The :meth:`~Ports.clear` method can be used to unregister all audio output ports at once. See Also -------- Ports, OwnPort """ return self._outports @property def midi_inports(self): """A list of MIDI input :class:`Ports`. New MIDI ports can be created and added to this list with the :meth:`~Ports.register` method. When :meth:`~OwnPort.unregister` is called on one of the items in this list, this port is removed from the list. The :meth:`~Ports.clear` method can be used to unregister all MIDI input ports at once. See Also -------- Ports, OwnMidiPort """ return self._midi_inports @property def midi_outports(self): """A list of MIDI output :class:`Ports`. New MIDI ports can be created and added to this list with the :meth:`~Ports.register` method. When :meth:`~OwnPort.unregister` is called on one of the items in this list, this port is removed from the list. The :meth:`~Ports.clear` method can be used to unregister all MIDI output ports at once. See Also -------- Ports, OwnMidiPort """ return self._midi_outports
[docs] def owns(self, port): """Check if a given port belongs to `self`. Parameters ---------- port : str or Port Full port name or :class:`Port`, :class:`MidiPort`, :class:`OwnPort` or :class:`OwnMidiPort` object. """ port = self._get_port_ptr(port) return bool(_lib.jack_port_is_mine(self._ptr, port))
[docs] def activate(self): """Activate JACK client. Tell the JACK server that the program is ready to start processing audio. """ _check(_lib.jack_activate(self._ptr), "Error activating JACK client")
[docs] def deactivate(self, ignore_errors=True): """De-activate JACK client. Tell the JACK server to remove `self` from the process graph. Also, disconnect all ports belonging to it, since inactive clients have no port connections. """ err = _lib.jack_deactivate(self._ptr) if not ignore_errors: _check(err, "Error deactivating JACK client")
[docs] def cpu_load(self): """Return the current CPU load estimated by JACK. This is a running average of the time it takes to execute a full process cycle for all clients as a percentage of the real time available per cycle determined by the :attr:`blocksize` and :attr:`samplerate`. """ return _lib.jack_cpu_load(self._ptr)
[docs] def close(self, ignore_errors=True): """Close the JACK client.""" if self._ptr: err = _lib.jack_client_close(self._ptr) self._ptr = _ffi.NULL if not ignore_errors: _check(err, "Error closing JACK client")
[docs] def connect(self, source, destination): """Establish a connection between two ports. When a connection exists, data written to the source port will be available to be read at the destination port. Audio ports can obviously not be connected with MIDI ports. Parameters ---------- source : str or Port One end of the connection. Must be an output port. destination : str or Port The other end of the connection. Must be an input port. See Also -------- OwnPort.connect """ if isinstance(source, Port): source = source.name if isinstance(destination, Port): destination = destination.name err = _lib.jack_connect(self._ptr, source.encode(), destination.encode()) if err == _errno.EEXIST: raise JackError("Connection {0!r} -> {1!r} " "already exists".format(source, destination)) _check(err, "Error connecting {0!r} -> {1!r}".format(source, destination))
[docs] def disconnect(self, source, destination): """Remove a connection between two ports. Parameters ---------- source, destination : str or Port See :meth:`connect`. """ if isinstance(source, Port): source = source.name if isinstance(destination, Port): destination = destination.name _check(_lib.jack_disconnect( self._ptr, source.encode(), destination.encode()), "Couldn't disconnect {0!r} -> {1!r}".format(source, destination))
[docs] def transport_start(self): """Start JACK transport.""" _lib.jack_transport_start(self._ptr)
[docs] def transport_stop(self): """Stop JACK transport.""" _lib.jack_transport_stop(self._ptr)
@property def transport_state(self): """JACK transport state. This is one of :attr:`STOPPED`, :attr:`ROLLING`, :attr:`STARTING`, :attr:`NETSTARTING`. See Also -------- transport_query """ return TransportState(_lib.jack_transport_query(self._ptr, _ffi.NULL))
[docs] def transport_locate(self, frame): """Reposition the JACK transport to a new frame number. Parameters ---------- frame : int Frame number. """ _check(_lib.jack_transport_locate(self._ptr, frame), "Error locating JACK transport")
[docs] def transport_query(self): """Query the current transport state and position. This is a convenience function that does the same as :meth:`transport_query_struct` but it only returns the valid fields in an easy-to-use ``dict``. Returns ------- state : TransportState The transport state can take following values: :attr:`STOPPED`, :attr:`ROLLING`, :attr:`STARTING` and :attr:`NETSTARTING`. position : dict A dictionary containing only the valid fields of the structure returned by :meth:`transport_query_struct`. See Also -------- :attr:`transport_state` """ state, pos = self.transport_query_struct() return TransportState(state), position2dict(pos)
[docs] def transport_query_struct(self): """Query the current transport state and position. This function is realtime-safe, and can be called from any thread. If called from the process thread, the returned position corresponds to the first frame of the current cycle and the state returned is valid for the entire cycle. Returns ------- state : int The transport state can take following values: :attr:`STOPPED`, :attr:`ROLLING`, :attr:`STARTING` and :attr:`NETSTARTING`. position : jack_position_t See the `JACK transport documentation`__ for the available fields. __ http://jackaudio.org/files/docs/html/ structjack__position__t.html See Also -------- transport_query, transport_reposition_struct """ state = _lib.jack_transport_query(self._ptr, self._position) return state, self._position
[docs] def transport_reposition_struct(self, position): """Request a new transport position. May be called at any time by any client. The new position takes effect in two process cycles. If there are slow-sync clients and the transport is already rolling, it will enter the :attr:`STARTING` state and begin invoking their sync callbacks (see :meth:`set_sync_callback`) until ready. This function is realtime-safe. Parameters ---------- position : jack_position_t Requested new transport position. This is the same structure as returned by :meth:`transport_query_struct`. See Also -------- transport_query_struct, transport_locate """ _check(_lib.jack_transport_reposition(self._ptr, position), "Error re-positioning transport")
[docs] def set_freewheel(self, onoff): """Start/Stop JACK's "freewheel" mode. When in "freewheel" mode, JACK no longer waits for any external event to begin the start of the next process cycle. As a result, freewheel mode causes "faster than realtime" execution of a JACK graph. If possessed, real-time scheduling is dropped when entering freewheel mode, and if appropriate it is reacquired when stopping. IMPORTANT: on systems using capabilities to provide real-time scheduling (i.e. Linux kernel 2.4), if onoff is zero, this function must be called from the thread that originally called :meth:`activate`. This restriction does not apply to other systems (e.g. Linux kernel 2.6 or OS X). Parameters ---------- onoff : bool If ``True``, freewheel mode starts. Otherwise freewheel mode ends. See Also -------- set_freewheel_callback """ _check(_lib.jack_set_freewheel(self._ptr, onoff), "Error setting freewheel mode")
[docs] def set_shutdown_callback(self, callback): """Register shutdown callback. Register a function (and optional argument) to be called if and when the JACK server shuts down the client thread. The function must be written as if it were an asynchonrous POSIX signal handler -- use only async-safe functions, and remember that it is executed from another thread. A typical function might set a flag or write to a pipe so that the rest of the application knows that the JACK client thread has shut down. .. note:: Clients do not need to call this. It exists only to help more complex clients understand what is going on. It should be called before :meth:`activate`. .. note:: The `callback` should typically signal another thread to correctly finish cleanup by calling :meth:`close` (since :meth:`close` cannot be called directly in the context of the thread that calls the shutdown callback). Parameters ---------- callback : callable User-supplied function that is called whenever the JACK daemon is shutdown. It must have this signature:: callback(status: Status, reason: str) -> None The argument `status` is of type :class:`jack.Status`. .. note:: After server shutdown, the client is *not* deallocated by JACK, the user (that's you!) is responsible to properly use :meth:`close` to release client ressources. .. warning:: :meth:`close` cannot be safely used inside the shutdown callback and has to be called outside of the callback context. """ @self._callback("JackInfoShutdownCallback") def callback_wrapper(code, reason, _): callback(Status(code), _ffi.string(reason).decode()) _lib.jack_on_info_shutdown(self._ptr, callback_wrapper, _ffi.NULL)
[docs] def set_process_callback(self, callback): """Register process callback. Tell the JACK server to call `callback` whenever there is work be done. The code in the supplied function must be suitable for real-time execution. That means that it cannot call functions that might block for a long time. This includes malloc, free, printf, pthread_mutex_lock, sleep, wait, poll, select, pthread_join, pthread_cond_wait, etc, etc. .. warning:: Most Python interpreters use a `global interpreter lock (GIL)`__, which violates the above real-time requirement. Furthermore, Python's `garbage collector`__ might become active at an inconvenient time and block the process callback for some time. Because of this, Python is not really suitable for real-time processing. If you want to implement a *reliable* real-time audio/MIDI application, you should use a different programming language, such as C or C++. If you can live with some random audio drop-outs now and then, feel free to continue using Python! __ http://en.wikipedia.org/wiki/Global_Interpreter_Lock __ http://en.wikipedia.org/wiki/Garbage_collection_(computer_science) .. note:: This function cannot be called while the client is activated (after :meth:`activate` has been called). Parameters ---------- callback : callable User-supplied function that is called by the engine anytime there is work to be done. It must have this signature:: callback(frames: int) -> None The argument `frames` specifies the number of frames that have to be processed in the current audio block. It will be the same number as :attr:`blocksize` and it will be a power of two. As long as the client is active, the `callback` will be called once in each process cycle. However, if an exception is raised inside of a `callback`, it will not be called anymore. The exception :class:`CallbackExit` can be used to silently prevent further callback invocations, all other exceptions will print an error message to *stderr*. """ @self._callback("JackProcessCallback", error=_FAILURE) def callback_wrapper(frames, _): try: callback(frames) except CallbackExit: return _FAILURE return _SUCCESS _check(_lib.jack_set_process_callback( self._ptr, callback_wrapper, _ffi.NULL), "Error setting process callback")
[docs] def set_freewheel_callback(self, callback): """Register freewheel callback. Tell the JACK server to call `callback` whenever we enter or leave "freewheel" mode. The argument to the callback will be ``True`` if JACK is entering freewheel mode, and ``False`` otherwise. All "notification events" are received in a separated non RT thread, the code in the supplied function does not need to be suitable for real-time execution. .. note:: This function cannot be called while the client is activated (after :meth:`activate` has been called). Parameters ---------- callback : callable User-supplied function that is called whenever JACK starts or stops freewheeling. It must have this signature:: callback(starting: bool) -> None The argument `starting` is ``True`` if we start to freewheel, ``False`` otherwise. See Also -------- set_freewheel """ @self._callback("JackFreewheelCallback") def callback_wrapper(starting, _): callback(bool(starting)) _check(_lib.jack_set_freewheel_callback( self._ptr, callback_wrapper, _ffi.NULL), "Error setting freewheel callback")
[docs] def set_blocksize_callback(self, callback): """Register blocksize callback. Tell JACK to call `callback` whenever the size of the the buffer that will be passed to the process callback is about to change. Clients that depend on knowing the buffer size must supply a `callback` before activating themselves. All "notification events" are received in a separated non RT thread, the code in the supplied function does not need to be suitable for real-time execution. .. note:: This function cannot be called while the client is activated (after :meth:`activate` has been called). Parameters ---------- callback : callable User-supplied function that is invoked whenever the JACK engine buffer size changes. It must have this signature:: callback(blocksize: int) -> None The argument `blocksize` is the new buffer size. The `callback` is supposed to raise :class:`CallbackExit` on error. .. note:: Although this function is called in the JACK process thread, the normal process cycle is suspended during its operation, causing a gap in the audio flow. So, the `callback` can allocate storage, touch memory not previously referenced, and perform other operations that are not realtime safe. See Also -------- :attr:`blocksize` """ @self._callback("JackBufferSizeCallback", error=_FAILURE) def callback_wrapper(blocksize, _): try: callback(blocksize) except CallbackExit: return _FAILURE return _SUCCESS _check(_lib.jack_set_buffer_size_callback( self._ptr, callback_wrapper, _ffi.NULL), "Error setting blocksize callback")
[docs] def set_samplerate_callback(self, callback): """Register samplerate callback. Tell the JACK server to call `callback` whenever the system sample rate changes. All "notification events" are received in a separated non RT thread, the code in the supplied function does not need to be suitable for real-time execution. .. note:: This function cannot be called while the client is activated (after :meth:`activate` has been called). Parameters ---------- callback : callable User-supplied function that is called when the engine sample rate changes. It must have this signature:: callback(samplerate: int) -> None The argument `samplerate` is the new engine sample rate. The `callback` is supposed to raise :class:`CallbackExit` on error. See Also -------- :attr:`samplerate` """ @self._callback("JackSampleRateCallback", error=_FAILURE) def callback_wrapper(samplerate, _): try: callback(samplerate) except CallbackExit: return _FAILURE return _SUCCESS _check(_lib.jack_set_sample_rate_callback( self._ptr, callback_wrapper, _ffi.NULL), "Error setting samplerate callback")
[docs] def set_client_registration_callback(self, callback): """Register client registration callback. Tell the JACK server to call `callback` whenever a client is registered or unregistered. All "notification events" are received in a separated non RT thread, the code in the supplied function does not need to be suitable for real-time execution. .. note:: This function cannot be called while the client is activated (after :meth:`activate` has been called). Parameters ---------- callback : callable User-supplied function that is called whenever a client is registered or unregistered. It must have this signature:: callback(name: str, register: bool) -> None The first argument contains the client name, the second argument is ``True`` if the client is being registered and ``False`` if the client is being unregistered. """ @self._callback("JackClientRegistrationCallback") def callback_wrapper(name, register, _): callback(_ffi.string(name).decode(), bool(register)) _check(_lib.jack_set_client_registration_callback( self._ptr, callback_wrapper, _ffi.NULL), "Error setting client registration callback")
[docs] def set_port_registration_callback(self, callback): """Register port registration callback. Tell the JACK server to call `callback` whenever a port is registered or unregistered. All "notification events" are received in a separated non RT thread, the code in the supplied function does not need to be suitable for real-time execution. .. note:: This function cannot be called while the client is activated (after :meth:`activate` has been called). Parameters ---------- callback : callable User-supplied function function that is called whenever a port is registered or unregistered. It must have this signature:: callback(port: Port, register: bool) -> None The first argument is a :class:`Port`, :class:`MidiPort`, :class:`OwnPort` or :class:`OwnMidiPort` object, the second argument is ``True`` if the port is being registered, ``False`` if the port is being unregistered. See Also -------- Ports.register """ @self._callback("JackPortRegistrationCallback") def callback_wrapper(port, register, _): port = self._wrap_port_ptr(_lib.jack_port_by_id(self._ptr, port)) callback(port, bool(register)) _check(_lib.jack_set_port_registration_callback( self._ptr, callback_wrapper, _ffi.NULL), "Error setting port registration callback")
[docs] def set_port_connect_callback(self, callback): """Register port connect callback. Tell the JACK server to call `callback` whenever a port is connected or disconnected. All "notification events" are received in a separated non RT thread, the code in the supplied function does not need to be suitable for real-time execution. .. note:: This function cannot be called while the client is activated (after :meth:`activate` has been called). Parameters ---------- callback : callable User-supplied function that is called whenever a port is connected or disconnected. It must have this signature:: callback(a: Port, b: Port, connect: bool) -> None The first and second arguments contain :class:`Port`, :class:`MidiPort`, :class:`OwnPort` or :class:`OwnMidiPort` objects of the ports which are connected or disconnected. The third argument is ``True`` if the ports were connected and ``False`` if the ports were disconnected. See Also -------- Client.connect, OwnPort.connect """ @self._callback("JackPortConnectCallback") def callback_wrapper(a, b, connect, _): a = self._wrap_port_ptr(_lib.jack_port_by_id(self._ptr, a)) b = self._wrap_port_ptr(_lib.jack_port_by_id(self._ptr, b)) callback(a, b, bool(connect)) _check(_lib.jack_set_port_connect_callback( self._ptr, callback_wrapper, _ffi.NULL), "Error setting port connect callback")
[docs] def set_port_rename_callback(self, callback): """Register port rename callback. Tell the JACK server to call `callback` whenever a port is renamed. All "notification events" are received in a separated non RT thread, the code in the supplied function does not need to be suitable for real-time execution. .. note:: This function cannot be called while the client is activated (after :meth:`activate` has been called). Parameters ---------- callback : callable User-supplied function that is called whenever the port name has been changed. It must have this signature:: callback(port: Port, old: str, new: str) -> None The first argument is the port that has been renamed (a :class:`Port`, :class:`MidiPort`, :class:`OwnPort` or :class:`OwnMidiPort` object); the second and third argument is the old and new name, respectively. The `callback` is supposed to raise :class:`CallbackExit` on error. See Also -------- :attr:`Port.shortname` Notes ----- The port rename callback is not available in JACK 1! See `this mailing list posting`__ and `this commit message`__. __ http://comments.gmane.org/gmane.comp.audio.jackit/28888 __ https://github.com/jackaudio/jack1/commit/ 94c819accfab2612050e875c24cf325daa0fd26d """ @self._callback("JackPortRenameCallback", error=_FAILURE) def callback_wrapper(port, old_name, new_name, _): port = self._wrap_port_ptr(_lib.jack_port_by_id(self._ptr, port)) try: callback(port, _ffi.string(old_name).decode(), _ffi.string(new_name).decode()) except CallbackExit: return _FAILURE return _SUCCESS _check(_lib.jack_set_port_rename_callback( self._ptr, callback_wrapper, _ffi.NULL), "Error setting port rename callback")
[docs] def set_graph_order_callback(self, callback): """Register graph order callback. Tell the JACK server to call `callback` whenever the processing graph is reordered. All "notification events" are received in a separated non RT thread, the code in the supplied function does not need to be suitable for real-time execution. .. note:: This function cannot be called while the client is activated (after :meth:`activate` has been called). Parameters ---------- callback : callable User-supplied function that is called whenever the processing graph is reordered. It must have this signature:: callback() -> None The `callback` is supposed to raise :class:`CallbackExit` on error. """ @self._callback("JackGraphOrderCallback", error=_FAILURE) def callback_wrapper(_): try: callback() except CallbackExit: return _FAILURE return _SUCCESS _check(_lib.jack_set_graph_order_callback( self._ptr, callback_wrapper, _ffi.NULL), "Error setting graph order callback")
[docs] def set_xrun_callback(self, callback): """Register xrun callback. Tell the JACK server to call `callback` whenever there is an xrun. All "notification events" are received in a separated non RT thread, the code in the supplied function does not need to be suitable for real-time execution. .. note:: This function cannot be called while the client is activated (after :meth:`activate` has been called). Parameters ---------- callback : callable User-supplied function that is called whenever an xrun has occured. It must have this signature:: callback(delayed_usecs: float) -> None The callback argument is the delay in microseconds due to the most recent XRUN occurrence. The `callback` is supposed to raise :class:`CallbackExit` on error. """ @self._callback("JackXRunCallback", error=_FAILURE) def callback_wrapper(_): try: callback(_lib.jack_get_xrun_delayed_usecs(self._ptr)) except CallbackExit: return _FAILURE return _SUCCESS _check(_lib.jack_set_xrun_callback( self._ptr, callback_wrapper, _ffi.NULL), "Error setting xrun callback")
[docs] def set_timebase_callback(self, callback=None, conditional=False): """Register as timebase master for the JACK subsystem. The timebase master registers a callback that updates extended position information such as beats or timecode whenever necessary. Without this extended information, there is no need for this function. There is never more than one master at a time. When a new client takes over, the former callback is no longer called. Taking over the timebase may be done conditionally, so that `callback` is not registered if there was a master already. Parameters ---------- callback : callable Realtime function that returns extended position information. Its output affects all of the following process cycle. This realtime function must not wait. It is called immediately after the process callback (see :meth:`set_process_callback`) in the same thread whenever the transport is rolling, or when any client has requested a new position in the previous cycle. The first cycle after :meth:`set_timebase_callback()` is also treated as a new position, or the first cycle after :meth:`activate()` if the client had been inactive. The `callback` must have this signature:: callback(state: int, blocksize: int, pos: jack_position_t, new_pos: bool) -> None `state` The current transport state. See :attr:`transport_state`. `blocksize` The number of frames in the current period. See :attr:`blocksize`. `pos` The position structure for the next cycle; `pos.frame` will be its frame number. If `new_pos` is ``False``, this structure contains extended position information from the current cycle. If `new_pos` is ``True``, it contains whatever was set by the requester. The `callback`'s task is to update the extended information here. See :meth:`transport_query_struct` for details about `jack_position_t`. `new_pos` ``True`` for a newly requested `pos`, or for the first cycle after the timebase callback is defined. .. note:: The `pos` argument must not be used to set `pos.frame`. To change position, use :meth:`transport_reposition_struct()` or :meth:`transport_locate()`. These functions are realtime-safe, the timebase callback can call them directly. conditional : bool Set to ``True`` for a conditional request. Returns ------- bool ``True`` if the timebase callback was registered. ``False`` if a conditional request failed because another timebase master is already registered. """ if callback is None: return lambda cb: self.set_timebase_callback(cb, conditional) @self._callback("JackTimebaseCallback") def callback_wrapper(state, blocksize, pos, new_pos, _): callback(state, blocksize, pos, bool(new_pos)) err = _lib.jack_set_timebase_callback(self._ptr, conditional, callback_wrapper, _ffi.NULL) # Because of a bug in JACK2 version <= 1.9.10, we also check for -1. # See https://github.com/jackaudio/jack2/pull/123 if conditional and err in (_errno.EBUSY, -1): return False _check(err, "Error setting timebase callback") return True
[docs] def get_uuid_for_client_name(self, name): """Get the session ID for a client name. The session manager needs this to reassociate a client name to the session ID. """ uuid = _ffi.gc(_lib.jack_get_uuid_for_client_name( self._ptr, name.encode()), _lib.jack_free) if not uuid: raise JackError("Unable to get session ID for {0!r}".format(name)) return _ffi.string(uuid).decode()
[docs] def get_client_name_by_uuid(self, uuid): """Get the client name for a session ID. In order to snapshot the graph connections, the session manager needs to map session IDs to client names. """ name = _ffi.gc(_lib.jack_get_client_name_by_uuid( self._ptr, uuid.encode()), _lib.jack_free) if not name: raise JackError("Unable to get client name for {0!r}".format(uuid)) return _ffi.string(name).decode()
[docs] def get_port_by_name(self, name): """Get port by name. Given a full port name, this returns a :class:`Port`, :class:`MidiPort`, :class:`OwnPort` or :class:`OwnMidiPort` object. """ port_ptr = _lib.jack_port_by_name(self._ptr, name.encode()) if not port_ptr: raise JackError("Port {0!r} not available".format(name)) return self._wrap_port_ptr(port_ptr)
[docs] def get_all_connections(self, port): """Return a list of ports which the given port is connected to. This differs from :attr:`OwnPort.connections` (also available on :class:`OwnMidiPort`) in two important respects: 1) You may not call this function from code that is executed in response to a JACK event. For example, you cannot use it in a graph order callback. 2) You need not be the owner of the port to get information about its connections. """ port = self._get_port_ptr(port) names = _ffi.gc(_lib.jack_port_get_all_connections(self._ptr, port), _lib.jack_free) return self._port_list_from_pointers(names)
[docs] def get_ports(self, name_pattern="", is_audio=False, is_midi=False, is_input=False, is_output=False, is_physical=False, can_monitor=False, is_terminal=False): """Return a list of selected ports. Parameters ---------- name_pattern : str A regular expression used to select ports by name. If empty, no selection based on name will be carried out. is_audio, is_midi : bool Select audio/MIDI ports. If neither of them is ``True``, both types of ports are selected. is_input, is_output, is_physical, can_monitor, is_terminal : bool Select ports by their flags. If none of them are ``True``, no selection based on flags will be carried out. Returns ------- list of Port/MidiPort/OwnPort/OwnMidiPort All ports that satisfy the given conditions. """ if is_audio and not is_midi: type_pattern = _AUDIO elif is_midi and not is_audio: type_pattern = _MIDI else: type_pattern = b"" flags = 0x0 if is_input: flags |= _lib.JackPortIsInput if is_output: flags |= _lib.JackPortIsOutput if is_physical: flags |= _lib.JackPortIsPhysical if can_monitor: flags |= _lib.JackPortCanMonitor if is_terminal: flags |= _lib.JackPortIsTerminal names = _ffi.gc(_lib.jack_get_ports( self._ptr, name_pattern.encode(), type_pattern, flags), _lib.jack_free) return self._port_list_from_pointers(names)
def _callback(self, cdecl, **kwargs): """Wrapper for ffi.callback() that keeps callback alive.""" def callback_decorator(python_callable): function_ptr = _ffi.callback(cdecl, python_callable, **kwargs) self._keepalive.append(function_ptr) return function_ptr return callback_decorator def _register_port(self, name, porttype, is_terminal, is_physical, flags): """Create a new port.""" if is_terminal: flags |= _lib.JackPortIsTerminal if is_physical: flags |= _lib.JackPortIsPhysical port_ptr = _lib.jack_port_register(self._ptr, name.encode(), porttype, flags, 0) if not port_ptr: raise JackError( "{0!r}: port registration failed".format(name)) return self._wrap_port_ptr(port_ptr) def _port_list_from_pointers(self, names): """Get list of Port objects from char**.""" ports = [] if names: idx = 0 while True: name = names[idx] if not name: break ports.append(self.get_port_by_name(_ffi.string(name).decode())) idx += 1 return ports def _get_port_ptr(self, port): """Get port pointer from Port object or string or port pointer.""" if isinstance(port, Port): port = port._ptr elif isinstance(port, str): port = self.get_port_by_name(port)._ptr return port def _wrap_port_ptr(self, ptr): """Create appropriate port object for a given port pointer.""" porttype = _ffi.string(_lib.jack_port_type(ptr)) if porttype == _AUDIO: port = OwnPort(ptr, self) if self.owns(ptr) else Port(ptr) elif porttype == _MIDI: port = OwnMidiPort(ptr, self) if self.owns(ptr) else MidiPort(ptr) else: assert False return port
[docs]class Port(object): """A JACK audio port. This class cannot be instantiated directly. Instead, instances of this class are returned from :meth:`Client.get_port_by_name`, :meth:`Client.get_ports`, :meth:`Client.get_all_connections` and :attr:`OwnPort.connections`. In addition, instances of this class are available in the callbacks which are set with :meth:`Client.set_port_registration_callback`, :meth:`Client.set_port_connect_callback` or :meth:`Client.set_port_rename_callback`. Note, however, that if the used :class:`Client` owns the respective port, instances of :class:`OwnPort` (instead of :class:`Port`) will be created. In case of MIDI ports, instances of :class:`MidiPort` or :class:`OwnMidiPort` are created. Besides being the type of non-owned JACK audio ports, this class also serves as base class for all other port classes (:class:`OwnPort`, :class:`MidiPort` and :class:`OwnMidiPort`). New JACK audio/MIDI ports can be created with the :meth:`~Ports.register` method of :attr:`Client.inports`, :attr:`Client.outports`, :attr:`Client.midi_inports` and :attr:`Client.midi_outports`. """ def __init__(self, port_ptr): self._ptr = port_ptr def __repr__(self): return "jack.{0.__class__.__name__}('{0.name}')".format(self) def __eq__(self, other): """Ports are equal if their underlying port pointers are.""" return self._ptr == other._ptr def __ne__(self, other): """This should be implemented whenever __eq__() is implemented.""" return not self.__eq__(other) @property def name(self): """Full name of the JACK port (read-only).""" return _ffi.string(_lib.jack_port_name(self._ptr)).decode() @property def shortname(self): """Short name of the JACK port, not including "client_name:". Must be unique among all ports owned by a client. May be modified at any time. If the resulting full name (including the "client_name:" prefix) is longer than :func:`port_name_size`, it will be truncated. """ return _ffi.string(_lib.jack_port_short_name(self._ptr)).decode() @shortname.setter def shortname(self, shortname): _check(_lib.jack_port_set_name(self._ptr, shortname.encode()), "Error setting port name") @property def uuid(self): """The UUID of the JACK port.""" return _lib.jack_port_uuid(self._ptr) is_audio = property(lambda self: True, doc="This is always ``True``.") is_midi = property(lambda self: False, doc="This is always ``False``.") @property def is_input(self): """Can the port receive data?""" return self._hasflag(_lib.JackPortIsInput) @property def is_output(self): """Can data be read from this port?""" return self._hasflag(_lib.JackPortIsOutput) @property def is_physical(self): """Does it correspond to some kind of physical I/O connector?""" return self._hasflag(_lib.JackPortIsPhysical) @property def can_monitor(self): """Does a call to :meth:`request_monitor` make sense?""" return self._hasflag(_lib.JackPortCanMonitor) @property def is_terminal(self): """Is the data consumed/generated?""" return self._hasflag(_lib.JackPortIsTerminal)
[docs] def request_monitor(self, onoff): """Set input monitoring. If :attr:`can_monitor` is ``True``, turn input monitoring on or off. Otherwise, do nothing. Parameters ---------- onoff : bool If ``True``, switch monitoring on; if ``False``, switch it off. """ _check(_lib.jack_port_request_monitor(self._ptr, onoff), "Unable to switch monitoring on/off")
def _hasflag(self, flag): """Helper method for is_*().""" return bool(_lib.jack_port_flags(self._ptr) & flag)
[docs]class MidiPort(Port): """A JACK MIDI port. This class is derived from :class:`Port` and has exactly the same attributes and methods. This class cannot be instantiated directly (see :class:`Port`). New JACK audio/MIDI ports can be created with the :meth:`~Ports.register` method of :attr:`Client.inports`, :attr:`Client.outports`, :attr:`Client.midi_inports` and :attr:`Client.midi_outports`. See Also -------- Port, OwnMidiPort """ is_audio = property(lambda self: False, doc="This is always ``False``.") is_midi = property(lambda self: True, doc="This is always ``True``.")
[docs]class OwnPort(Port): """A JACK audio port owned by a :class:`Client` object. This class is derived from :class:`Port`. :class:`OwnPort` objects can do everything that :class:`Port` objects can, plus a lot more. This class cannot be instantiated directly (see :class:`Port`). New JACK audio/MIDI ports can be created with the :meth:`~Ports.register` method of :attr:`Client.inports`, :attr:`Client.outports`, :attr:`Client.midi_inports` and :attr:`Client.midi_outports`. """ def __init__(self, port_ptr, client): Port.__init__(self, port_ptr) self._client = client @property def number_of_connections(self): """Number of connections to or from port.""" return _lib.jack_port_connected(self._ptr) @property def connections(self): """List of ports which the port is connected to.""" names = _ffi.gc(_lib.jack_port_get_connections(self._ptr), _lib.jack_free) return self._client._port_list_from_pointers(names)
[docs] def is_connected_to(self, port): """Am I *directly* connected to `port`? Parameters ---------- port : str or Port Full port name or port object. """ if isinstance(port, Port): port = port.name return bool(_lib.jack_port_connected_to(self._ptr, port.encode()))
[docs] def connect(self, port): """Connect to given port. Parameters ---------- port : str or Port Full port name or port object. See Also -------- Client.connect """ if not isinstance(port, Port): port = self._client.get_port_by_name(port) if self.is_output: source = self if not port.is_input: raise ValueError("Input port expected") destination = port elif self.is_input: destination = self if not port.is_output: raise ValueError("Output port expected") source = port else: assert False self._client.connect(source.name, destination.name)
[docs] def disconnect(self, other=None): """Disconnect this port. Parameters ---------- other : str or Port Port to disconnect from. By default, disconnect from all connected ports. """ if other is None: _check(_lib.jack_port_disconnect(self._client._ptr, self._ptr), "Error disconnecting {0!r}".format(self.name)) else: if self.is_output: args = self, other elif self.is_input: args = other, self self._client.disconnect(*args)
[docs] def unregister(self): """Unregister port. Remove the port from the client, disconnecting any existing connections. This also removes the port from :attr:`Client.inports`, :attr:`Client.outports`, :attr:`Client.midi_inports` or :attr:`Client.midi_outports`. """ if self.is_audio: listname = "" elif self.is_midi: listname = "midi_" if self.is_input: listname += "inports" elif self.is_output: listname += "outports" ports = getattr(self._client, listname) ports._portlist.remove(self) _check(_lib.jack_port_unregister(self._client._ptr, self._ptr), "Error unregistering {0!r}".format(self.name))
[docs] def get_buffer(self): """Get buffer for audio data. This returns a buffer holding the memory area associated with the specified port. For an output port, it will be a memory area that can be written to; for an input port, it will be an area containing the data from the port's connection(s), or zero-filled. If there are multiple inbound connections, the data will be mixed appropriately. Caching output ports is DEPRECATED in JACK 2.0, due to some new optimization (like "pipelining"). Port buffers have to be retrieved in each callback for proper functioning. """ blocksize = self._client.blocksize return _ffi.buffer(_lib.jack_port_get_buffer(self._ptr, blocksize), blocksize * _ffi.sizeof("float"))
[docs] def get_array(self): """Get audio buffer as NumPy array. Make sure to ``import numpy`` before calling this, otherwise the first call might take a long time. See Also -------- get_buffer """ import numpy as np return np.frombuffer(self.get_buffer(), dtype=np.float32)
[docs]class OwnMidiPort(MidiPort, OwnPort): """A JACK MIDI port owned by a :class:`Client` object. This class is derived from :class:`OwnPort` and :class:`MidiPort`, which are themselves derived from :class:`Port`. It has the same attributes and methods as :class:`OwnPort`, but :meth:`get_buffer` and :meth:`get_array` are disabled. Instead, it has methods for sending and receiving MIDI events (to be used from within the process callback -- see :meth:`Client.set_process_callback`). This class cannot be instantiated directly (see :class:`Port`). New JACK audio/MIDI ports can be created with the :meth:`~Ports.register` method of :attr:`Client.inports`, :attr:`Client.outports`, :attr:`Client.midi_inports` and :attr:`Client.midi_outports`. """ def __init__(self, *args, **kwargs): OwnPort.__init__(self, *args, **kwargs) self._event = _ffi.new("jack_midi_event_t*")
[docs] def get_buffer(self): """Not available for MIDI ports.""" raise NotImplementedError("get_buffer() not available on MIDI ports")
[docs] def get_array(self): """Not available for MIDI ports.""" raise NotImplementedError("get_array() not available on MIDI ports")
@property def max_event_size(self): """Get the size of the largest event that can be stored by the port. This returns the current space available, taking into account events already stored in the port. """ return _lib.jack_midi_max_event_size( _lib.jack_port_get_buffer(self._ptr, self._client.blocksize)) @property def lost_midi_events(self): """Get the number of events that could not be written to the port. This being a non-zero value implies that the port is full. Currently the only way this can happen is if events are lost on port mixdown. """ return _lib.jack_midi_get_lost_event_count( _lib.jack_port_get_buffer(self._ptr, self._client.blocksize))
[docs] def incoming_midi_events(self): """Return generator for incoming MIDI events. JACK MIDI is normalised, the MIDI events yielded by this generator are guaranteed to be complete MIDI events (the status byte will always be present, and no realtime events will be interspersed with the events). Yields ------ time : int Time (in samples) relative to the beginning of the current audio block. event : buffer The actual MIDI event data. """ event = self._event buf = _lib.jack_port_get_buffer(self._ptr, self._client.blocksize) for i in range(_lib.jack_midi_get_event_count(buf)): err = _lib.jack_midi_event_get(event, buf, i) # TODO: proper error handling if this ever happens: assert not err, err yield event.time, _ffi.buffer(event.buffer, event.size)
[docs] def clear_buffer(self): """Clear an event buffer. This should be called at the beginning of each process cycle before calling :meth:`reserve_midi_event` or :meth:`write_midi_event`. This function may not be called on an input port. """ _lib.jack_midi_clear_buffer( _lib.jack_port_get_buffer(self._ptr, self._client.blocksize))
[docs] def write_midi_event(self, time, event): """Create an outgoing MIDI event. Clients must write normalised MIDI data to the port - no running status and no (one-byte) realtime messages interspersed with other messages (realtime messages are fine when they occur on their own, like other messages). Events must be written in order, sorted by their sample offsets. JACK will not sort the events for you, and will refuse to store out-of-order events. Parameters ---------- time : int Time (in samples) relative to the beginning of the current audio block. event : bytes or buffer or sequence of int The actual MIDI event data. .. note:: Buffer objects are only supported for CFFI >= 0.9. Raises ------ JackError If MIDI event couldn't be written. """ try: event = _ffi.from_buffer(event) except AttributeError: pass # from_buffer() not supported except TypeError: pass # input is not a buffer _check(_lib.jack_midi_event_write( _lib.jack_port_get_buffer(self._ptr, self._client.blocksize), time, event, len(event)), "Error writing MIDI event")
[docs] def reserve_midi_event(self, time, size): """Get a buffer where an outgoing MIDI event can be written to. Clients must write normalised MIDI data to the port - no running status and no (one-byte) realtime messages interspersed with other messages (realtime messages are fine when they occur on their own, like other messages). Events must be written in order, sorted by their sample offsets. JACK will not sort the events for you, and will refuse to store out-of-order events. Parameters ---------- time : int Time (in samples) relative to the beginning of the current audio block. size : int Number of bytes to reserve. Returns ------- buffer A buffer object where MIDI data bytes can be written to. If no space could be reserved, an empty buffer is returned. """ buf = _lib.jack_midi_event_reserve( _lib.jack_port_get_buffer(self._ptr, self._client.blocksize), time, size) return _ffi.buffer(buf, size if buf else 0)
[docs]class Ports(object): """A list of input/output ports. This class is not meant to be instantiated directly. It is only used as :attr:`Client.inports`, :attr:`Client.outports`, :attr:`Client.midi_inports` and :attr:`Client.midi_outports`. The ports can be accessed by indexing or by iteration. New ports can be added with :meth:`register`, existing ports can be removed by calling their :meth:`~OwnPort.unregister` method. """ def __init__(self, client, porttype, flag): self._client = client self._type = porttype self._flag = flag self._portlist = [] def __len__(self): return self._portlist.__len__() def __getitem__(self, name): return self._portlist.__getitem__(name) # No __setitem__! def __iter__(self): return self._portlist.__iter__() def __repr__(self): return self._portlist.__repr__()
[docs] def register(self, shortname, is_terminal=False, is_physical=False): """Create a new input/output port. The new :class:`OwnPort` or :class:`OwnMidiPort` object is automatically added to :attr:`Client.inports`, :attr:`Client.outports`, :attr:`Client.midi_inports` or :attr:`Client.midi_outports`. Parameters ---------- shortname : str Each port has a short name. The port's full name contains the name of the client concatenated with a colon (:) followed by its short name. The :func:`port_name_size` is the maximum length of this full name. Exceeding that will cause the port registration to fail. The port name must be unique among all ports owned by this client. If the name is not unique, the registration will fail. is_terminal : bool For an input port: If ``True``, the data received by the port will not be passed on or made available at any other port. For an output port: If ``True``, the data available at the port does not originate from any other port Audio synthesizers, I/O hardware interface clients, HDR systems are examples of clients that would set this flag for their ports. is_physical : bool If ``True`` the port corresponds to some kind of physical I/O connector. Returns ------- Port A new :class:`OwnPort` or :class:`OwnMidiPort` instance. """ port = self._client._register_port( shortname, self._type, is_terminal, is_physical, self._flag) self._portlist.append(port) return port
[docs] def clear(self): """Unregister all ports in the list. See Also -------- OwnPort.unregister """ while self._portlist: self._portlist[0].unregister()
[docs]class RingBuffer(object): """JACK's lock-free ringbuffer.""" def __init__(self, size): """Create a lock-free ringbuffer. A ringbuffer is a good way to pass data between threads (e.g. between the main program and the process callback), when streaming realtime data to slower media, like audio file playback or recording. The key attribute of a ringbuffer is that it can be safely accessed by two threads simultaneously -- one reading from the buffer and the other writing to it -- without using any synchronization or mutual exclusion primitives. For this to work correctly, there can only be a single reader and a single writer thread. Their identities cannot be interchanged. Parameters ---------- size : int Size in bytes. JACK will allocate a buffer of at least this size (rounded up to the next power of 2), but one byte is reserved for internal use. Use :attr:`write_space` to determine the actual size available for writing. """ ptr = _lib.jack_ringbuffer_create(size) if not ptr: raise JackError("Could not create RingBuffer") self._ptr = _ffi.gc(ptr, _lib.jack_ringbuffer_free) @property def write_space(self): """The number of bytes available for writing.""" return _lib.jack_ringbuffer_write_space(self._ptr)
[docs] def write(self, data): """Write data into the ringbuffer. Parameters ---------- data : buffer or bytes or iterable of int Bytes to be written to the ringbuffer. Returns ------- int The number of bytes written, which could be less than the length of `data` if there was no more space left (see :attr:`write_space`). See Also -------- :attr:`write_space`, :attr:`write_buffers` """ try: data = _ffi.from_buffer(data) except AttributeError: pass # from_buffer() not supported except TypeError: pass # input is not a buffer return _lib.jack_ringbuffer_write(self._ptr, data, len(data))
@property def write_buffers(self): """Contains two buffer objects that can be written to directly. Two are needed because the space available for writing may be split across the end of the ringbuffer. Either of them could be 0 length. This can be used as a no-copy version of :meth:`write`. When finished with writing, :meth:`write_advance` should be used. .. note:: After an operation that changes the write pointer (:meth:`write`, :meth:`write_advance`, :meth:`reset`), the buffers are no longer valid and one should use this property again to get new ones. """ vectors = _ffi.new("jack_ringbuffer_data_t[2]") _lib.jack_ringbuffer_get_write_vector(self._ptr, vectors) return ( _ffi.buffer(vectors[0].buf, vectors[0].len), _ffi.buffer(vectors[1].buf, vectors[1].len) )
[docs] def write_advance(self, size): """Advance the write pointer. After data has been written to the ringbuffer using :attr:`write_buffers`, use this method to advance the buffer pointer, making the data available for future read operations. Parameters ---------- size : int The number of bytes to advance. """ _lib.jack_ringbuffer_write_advance(self._ptr, size)
@property def read_space(self): """The number of bytes available for reading.""" return _lib.jack_ringbuffer_read_space(self._ptr)
[docs] def read(self, size): """Read data from the ringbuffer. Parameters ---------- size : int Number of bytes to read. Returns ------- buffer A buffer object containing the requested data. If no more data is left (see :attr:`read_space`), a smaller (or even empty) buffer is returned. See Also -------- peek, :attr:`read_space`, :attr:`read_buffers` """ data = _ffi.new("unsigned char[]", size) size = _lib.jack_ringbuffer_read(self._ptr, data, size) return _ffi.buffer(data, size)
[docs] def peek(self, size): """Peek at data from the ringbuffer. Opposed to :meth:`read` this function does not move the read pointer. Thus it's a convenient way to inspect data in the ringbuffer in a continuous fashion. The price is that the data is copied into a newly allocated buffer. For "raw" non-copy inspection of the data in the ringbuffer use :attr:`read_buffers`. Parameters ---------- size : int Number of bytes to peek. Returns ------- buffer A buffer object containing the requested data. If no more data is left (see :attr:`read_space`), a smaller (or even empty) buffer is returned. See Also -------- read, :attr:`read_space`, :attr:`read_buffers` """ data = _ffi.new("unsigned char[]", size) size = _lib.jack_ringbuffer_peek(self._ptr, data, size) return _ffi.buffer(data, size)
@property def read_buffers(self): """Contains two buffer objects that can be read directly. Two are needed because the data to be read may be split across the end of the ringbuffer. Either of them could be 0 length. This can be used as a no-copy version of :meth:`peek` or :meth:`read`. When finished with reading, :meth:`read_advance` should be used. .. note:: After an operation that changes the read pointer (:meth:`read`, :meth:`read_advance`, :meth:`reset`), the buffers are no longer valid and one should use this property again to get new ones. """ vectors = _ffi.new("jack_ringbuffer_data_t[2]") _lib.jack_ringbuffer_get_read_vector(self._ptr, vectors) return ( _ffi.buffer(vectors[0].buf, vectors[0].len), _ffi.buffer(vectors[1].buf, vectors[1].len) )
[docs] def read_advance(self, size): """Advance the read pointer. After data has been read from the ringbuffer using :attr:`read_buffers` or :meth:`peek`, use this method to advance the buffer pointers, making that space available for future write operations. Parameters ---------- size : int The number of bytes to advance. """ _lib.jack_ringbuffer_read_advance(self._ptr, size)
[docs] def mlock(self): """Lock a ringbuffer data block into memory. Uses the ``mlock()`` system call. This prevents the ringbuffer's memory from being paged to the swap area. .. note:: This is not a realtime operation. """ _check(_lib.jack_ringbuffer_mlock(self._ptr), "Error mlocking the RingBuffer data")
[docs] def reset(self, size=None): """Reset the read and write pointers, making an empty buffer. .. note:: This is not thread safe. Parameters ---------- size : int, optional The new size for the ringbuffer. Must be less than allocated size. """ if size is None: _lib.jack_ringbuffer_reset(self._ptr) else: _lib.jack_ringbuffer_reset_size(self._ptr, size)
@property def size(self): """The number of bytes in total used by the buffer. See Also -------- :attr:`read_space`, :attr:`write_space` """ return self._ptr.size
[docs]class Status(object): """Representation of the JACK status bits.""" __slots__ = '_code' def __init__(self, code): self._code = code def __repr__(self): flags = ", ".join(name for name in dir(self) if not name.startswith('_') and getattr(self, name)) if not flags: flags = "no flags set" return "<jack.Status 0x{0:X}: {1}>".format(self._code, flags) @property def failure(self): """Overall operation failed.""" return self._hasflag(_lib.JackFailure) @property def invalid_option(self): """The operation contained an invalid or unsupported option.""" return self._hasflag(_lib.JackInvalidOption) @property def name_not_unique(self): """The desired client name was not unique. With the `use_exact_name` option of :class:`Client`, this situation is fatal. Otherwise, the name is modified by appending a dash and a two-digit number in the range "-01" to "-99". :attr:`Client.name` will return the exact string that was used. If the specified `name` plus these extra characters would be too long, the open fails instead. """ return self._hasflag(_lib.JackNameNotUnique) @property def server_started(self): """The JACK server was started for this :class:`Client`. Otherwise, it was running already. """ return self._hasflag(_lib.JackServerStarted) @property def server_failed(self): """Unable to connect to the JACK server.""" return self._hasflag(_lib.JackServerFailed) @property def server_error(self): """Communication error with the JACK server.""" return self._hasflag(_lib.JackServerError) @property def no_such_client(self): """Requested client does not exist.""" return self._hasflag(_lib.JackNoSuchClient) @property def load_failure(self): """Unable to load internal client.""" return self._hasflag(_lib.JackLoadFailure) @property def init_failure(self): """Unable to initialize client.""" return self._hasflag(_lib.JackInitFailure) @property def shm_failure(self): """Unable to access shared memory.""" return self._hasflag(_lib.JackShmFailure) @property def version_error(self): """Client's protocol version does not match.""" return self._hasflag(_lib.JackVersionError) @property def backend_error(self): """Backend error.""" return self._hasflag(_lib.JackBackendError) @property def client_zombie(self): """Client zombified failure.""" return self._hasflag(_lib.JackClientZombie) def _hasflag(self, flag): """Helper function for Status properties.""" return bool(self._code & flag)
[docs]class TransportState(object): """Representation of the JACK transport state. See Also -------- :attr:`Client.transport_state`, :meth:`Client.transport_query` """ __slots__ = '_code' def __init__(self, code): self._code = code def __eq__(self, other): return self._code == other def __repr__(self): return "jack." + { _lib.JackTransportStopped: 'STOPPED', _lib.JackTransportRolling: 'ROLLING', _lib.JackTransportStarting: 'STARTING', _lib.JackTransportNetStarting: 'NETSTARTING', }[self._code]
[docs]class JackError(Exception): """Exception for all kinds of JACK-related errors.""" pass
[docs]class CallbackExit(Exception): """To be raised in a callback function to signal failure. See Also -------- :meth:`Client.set_process_callback` :meth:`Client.set_blocksize_callback` :meth:`Client.set_samplerate_callback` :meth:`Client.set_port_rename_callback` :meth:`Client.set_graph_order_callback` :meth:`Client.set_xrun_callback` """ pass
[docs]def position2dict(pos): """Convert CFFI position struct to a dict.""" assert pos.unique_1 == pos.unique_2 keys = ['usecs', 'frame_rate', 'frame'] if pos.valid & _lib.JackPositionBBT: keys += ['bar', 'beat', 'tick', 'bar_start_tick', 'beats_per_bar', 'beat_type', 'ticks_per_beat', 'beats_per_minute'] if pos.valid & _lib.JackPositionTimecode: keys += ['frame_time', 'next_time'] if pos.valid & _lib.JackBBTFrameOffset: keys += ['bbt_offset'] if pos.valid & _lib.JackAudioVideoRatio: keys += ['audio_frames_per_video_frame'] if pos.valid & _lib.JackVideoFrameOffset: keys += ['video_offset'] return dict((k, getattr(pos, k)) for k in keys)
[docs]def version(): """Get tuple of major/minor/micro/protocol version.""" v = _ffi.new("int[4]") _lib.jack_get_version(v+0, v+1, v+2, v+3) return tuple(v)
[docs]def version_string(): """Get human-readable JACK version.""" return _ffi.string(_lib.jack_get_version_string()).decode()
[docs]def client_name_size(): """Return the maximum number of characters in a JACK client name. This includes the final NULL character. This value is a constant. """ return _lib.jack_client_name_size()
[docs]def port_name_size(): """Maximum length of port names. The maximum number of characters in a full JACK port name including the final NULL character. This value is a constant. A port's full name contains the owning client name concatenated with a colon (:) followed by its short name and a NULL character. """ return _lib.jack_port_name_size()
[docs]def set_error_function(callback=None): """Set the callback for error message display. Set it to ``None`` to restore the default error callback function (which prints the error message plus a newline to stderr). The `callback` function must have this signature:: callback(message: str) -> None """ _set_error_or_info_function(callback, _lib.jack_set_error_function)
[docs]def set_info_function(callback=None): """Set the callback for info message display. Set it to ``None`` to restore default info callback function (which prints the info message plus a newline to stderr). The `callback` function must have this signature:: callback(message: str) -> None """ _set_error_or_info_function(callback, _lib.jack_set_info_function)
[docs]def client_pid(name): """Return PID of a JACK client. Parameters ---------- name : str Name of the JACK client whose PID shall be returned. Returns ------- int PID of `name`. If not available, 0 will be returned. """ return _lib.jack_get_client_pid(name.encode())
def _set_error_or_info_function(callback, setter): """Helper for set_error_function() and set_info_function().""" if callback is None: callback_wrapper = _ffi.NULL else: @_ffi.callback("void (*)(const char*)") def callback_wrapper(msg): callback(_ffi.string(msg).decode()) _keepalive[setter] = callback_wrapper setter(callback_wrapper) _keepalive = {} def _check(error_code, msg): """Check error code and raise JackError if non-zero.""" if error_code: raise JackError("{0} ({1})".format(msg, error_code))