Added support for MIDI real-time events

platypush/plugins/midi.py

@@ -0,0 +1,95 @@
+import logging
+import rtmidi
+import time
+
+from platypush.message.response import Response
+from platypush.plugins import Plugin
+
+
+class MidiPlugin(Plugin):
+    """
+    Virtual MIDI controller plugin.
+    It requires python-rtmidi - https://pypi.org/project/python-rtmidi/
+    """
+
+    _played_notes = set()
+
+    def __init__(self, device_name='Platypush virtual MIDI output',
+                 *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+        self.device_name = device_name
+        self.midiout = rtmidi.MidiOut()
+        available_ports = self.midiout.get_ports()
+
+        if available_ports:
+            self.midiout.open_port(0)
+            logging.info('Initialized MIDI plugin on port 0')
+        else:
+            self.open_virtual_port(self.device_name)
+            logging.info('Initialized MIDI plugin on virtual device {}'.
+                         format(self.device_name))
+
+
+    def send_message(self, values, *args, **kwargs):
+        """
+        Values is expected to be a list containing the MIDI command code and
+            the command parameters - see reference at
+            https://ccrma.stanford.edu/~craig/articles/linuxmidi/misc/essenmidi.html
+
+        Available MIDI commands:
+             0x80    Note Off
+             0x90    Note On
+             0xA0    Aftertouch
+             0xB0    Continuous controller
+             0xC0    Patch change
+             0xD0    Channel Pressure
+             0xE0    Pitch bend
+             0xF0    Start of system exclusive message
+             0xF1    MIDI Time Code Quarter Frame (Sys Common)
+             0xF2    Song Position Pointer (Sys Common)
+             0xF3    Song Select
+             0xF6    Tune Request (Sys Common)
+             0xF7    End of system exclusive message
+             0xF8    Timing Clock (Sys Realtime)
+             0xFA    Start (Sys Realtime)
+             0xFB    Continue (Sys Realtime)
+             0xFC    Stop (Sys Realtime)
+             0xFE    Active Sensing (Sys Realtime)
+             0xFF    System Reset (Sys Realtime)
+        """
+
+        self.midiout.send_message(values, *args, **kwargs)
+        return Response(output={'status':'ok'})
+
+
+    def play_note(self, note, velocity, duration=0):
+        """
+        Params:
+            - note: MIDI note in range 0-127 with #60 = C4
+            - velocity: MIDI note velocity in range 0-127
+            - duration: Note duration in (float) seconds. Pass 0 if you don't
+              want the note to get off
+        """
+
+        self.send_message([0x90, note, velocity])  # Note on
+        self._played_notes.add(note)
+
+        if duration:
+            time.sleep(duration)
+            self.send_message([0x80, note, 0])  # Note off
+            self._played_notes.remove(note)
+
+
+    def release_note(self, note):
+        self.send_message([0x80, note, 0])  # Note off
+        self._played_notes.remove(note)
+
+
+    def release_all_notes(self):
+        played_notes = self._played_notes.copy()
+        for note in played_notes:
+            self.release_note(note)
+
+# vim:sw=4:ts=4:et:
+

setup.py

@@ -81,6 +81,7 @@ setup(
         'Support for most of the HTTP poll backends': ['python-dateutil'],
         'Support for Last.FM scrobbler plugin': ['pylast'],
         'Support for custom hotword detection': ['snowboy'],
+        'Support for real-time MIDI events': ['rtmidi'],
         'Support for GPIO pins access': ['RPi.GPIO'],
         'Support for MCP3008 analog-to-digital converter plugin': ['adafruit-mcp3008'],
         # 'Support for Leap Motion backend': ['git+ssh://git@github.com:BlackLight/leap-sdk-python3.git', 'redis'],