def _instantiate_library():
'Initialize Portmidi library'
global SINGLETON
SINGLETON = ffi.new('PortMidiStream **')
num = lib.Pm_Initialize()
if num:
raise MidiException(errno=num)
def write_many(self, events):
num = len(events)
cdata = ffi.new('PmEvent []', num)
for i, e in enumerate(events):
cdata[i].message, cdata[i].timestamp = e.message, e.timestamp
ret = lib.Pm_Write(self.stream, cdata, num)
try:
assert(ret == 0)
except AssertionError:
raise MidiException('Error writing PmEvents to stream')
def write_one(self, event):
cdata = ffi.new('PmEvent []', 1)
cdata[0].message = event.message
cdata[0].timestamp = event.timestamp
ret = lib.Pm_Write(self.stream, cdata, 1)
try:
assert(ret == 0)
except AssertionError:
raise MidiException(
'Error writing PmEvent to stream: {}'.format(ret))
def open_stream(self):
pp_stream = ffi.new('PortMidiStream **')
try:
err = lib.Pm_OpenInput(pp_stream,
self.device_id,
self.PNULL,
self.buffer_size,
self.PNULL,
self.PNULL)
self.stream = pp_stream[0]
assert(err == 0)
except AssertionError:
self.stream = None
raise MidiException(text='Invalid Device ID')
def __init__(self, device_id, buffer_size=4096):
'''Initialize a new MIDI Input Stream and open it
If the stream fails to open a MidiException will be raised.
:param device_id
:param buffer_size is the num of PmEvents that can be stored at a time
'''
if not _is_instantiated():
_instantiate_library()
self.buffer_size = buffer_size
self.buffer = ffi.new('PmEvent []', buffer_size)
self.device_id = device_id
self.stream = None
self.open_stream()
def open_stream(self):
'Open portmidi Output Stream and assert that everything went well'
pp_stream = ffi.new('PortMidiStream **')
try:
err = lib.Pm_OpenOutput(pp_stream,
self.device_id,
self.PNULL,
self.buffer_size,
self.PNULL,
self.PNULL,
0)
self.stream = pp_stream[0]
assert(err == 0)
except AssertionError:
self.stream = None
raise MidiException(text='Invalid Device ID')
