Sideband/sbapp/plyer/platforms/win/audio.py

399 lines
9.6 KiB
Python

'''
Documentation:
http://docs.microsoft.com/en-us/windows/desktop/Multimedia
.. versionadded:: 1.4.0
'''
from os.path import join
from ctypes import windll
from ctypes import (
sizeof, c_void_p, c_ulonglong, c_ulong,
c_wchar_p, byref, Structure, create_string_buffer
)
from ctypes.wintypes import DWORD, UINT
from sbapp.plyer.facades import Audio
from sbapp.plyer.platforms.win.storagepath import WinStoragePath
# DWORD_PTR i.e. ULONG_PTR, 32/64bit
ULONG_PTR = c_ulonglong if sizeof(c_void_p) == 8 else c_ulong
# device specific symbols
MCI_OPEN = 0x803
MCI_OPEN_TYPE = 0x2000
MCI_OPEN_ELEMENT = 512
MCI_RECORD = 0x80F
MCI_STOP = 0x808
MCI_SAVE = 0x813
MCI_PLAY = 0x806
MCI_CLOSE = 0x804
# recorder specific symbols
MCI_FROM = 4
MCI_TO = 8
MCI_WAIT = 2
MCI_SAVE_FILE = 256
class MCI_OPEN_PARMS(Structure):
'''
Struct for MCI_OPEN message parameters.
.. versionadded:: 1.4.0
'''
_fields_ = [
('mciOpenParms', ULONG_PTR),
('wDeviceID', UINT),
('lpstrDeviceType', c_wchar_p),
('lpstrElementName', c_wchar_p),
('lpstrAlias', c_wchar_p)
]
class MCI_RECORD_PARMS(Structure):
'''
Struct for MCI_RECORD message parameters.
http://docs.microsoft.com/en-us/windows/desktop/Multimedia/mci-record-parms
.. versionadded:: 1.4.0
'''
_fields_ = [
('dwCallback', ULONG_PTR),
('dwFrom', DWORD),
('dwTo', DWORD)
]
class MCI_SAVE_PARMS(Structure):
'''
Struct for MCI_SAVE message parameters.
http://docs.microsoft.com/en-us/windows/desktop/Multimedia/mci-save-parms
.. versionadded:: 1.4.0
'''
_fields_ = [
('dwCallback', ULONG_PTR),
('lpfilename', c_wchar_p)
]
class MCI_PLAY_PARMS(Structure):
'''
Struct for MCI_PLAY message parameters.
http://docs.microsoft.com/en-us/windows/desktop/Multimedia/mci-play-parms
.. versionadded:: 1.4.0
'''
_fields_ = [
('dwCallback', ULONG_PTR),
('dwFrom', DWORD),
('dwTo', DWORD)
]
def send_command(device, msg, flags, params):
'''
Generic mciSendCommandW() wrapper with error handler.
All parameters are required as for mciSendCommandW().
In case of no `params` passed, use `None`, that value
won't be dereferenced.
.. versionadded:: 1.4.0
'''
multimedia = windll.winmm
send_command_w = multimedia.mciSendCommandW
get_error = multimedia.mciGetErrorStringW
# error text buffer
# by API specification 128 is max, however the API sometimes
# kind of does not respect the documented bounds and returns
# more characters than buffer length...?!
error_len = 128
# big enough to prevent API accidentally segfaulting
error_text = create_string_buffer(error_len * 2)
# open a recording device with a new file
error_code = send_command_w(
device, # device ID
msg,
flags,
# reference to parameters structure or original value
# in case of params=False/0/None/...
byref(params) if params else params
)
# handle error messages if any
if error_code:
# device did not open, raise an exception
get_error(error_code, byref(error_text), error_len)
error_text = error_text.raw.replace(b'\x00', b'').decode('utf-8')
# either it can close already open device or it will fail because
# the device is in non-closable state, but the end result is the same
# and it makes no sense to parse MCI_CLOSE's error in this case
send_command_w(device, MCI_CLOSE, 0, None)
raise Exception(error_code, error_text)
# return params struct because some commands write into it
# to pass some values out of the local function scope
return params
class WinRecorder:
'''
Generic wrapper for MCI_RECORD handling the filenames and device closing
in the same approach like it is used for other platforms.
.. versionadded:: 1.4.0
'''
def __init__(self, device, filename):
self._device = device
self._filename = filename
@property
def device(self):
'''
Public property returning device ID.
.. versionadded:: 1.4.0
'''
return self._device
@property
def filename(self):
'''
Public property returning filename for current recording.
.. versionadded:: 1.4.0
'''
return self._filename
def record(self):
'''
Start recording a WAV sound.
.. versionadded:: 1.4.0
'''
send_command(
device=self.device,
msg=MCI_RECORD,
flags=0,
params=None
)
def stop(self):
'''
Stop recording and save the data to a file path
self.filename. Wait until the file is written.
Close the device afterwards.
.. versionadded:: 1.4.0
'''
# stop the recording first
send_command(
device=self.device,
msg=MCI_STOP,
flags=MCI_WAIT,
params=None
)
# choose filename for the WAV file
save_params = MCI_SAVE_PARMS()
save_params.lpfilename = self.filename
# save the sound data to a file and wait
# until it ends writing to the file
send_command(
device=self.device,
msg=MCI_SAVE,
flags=MCI_SAVE_FILE | MCI_WAIT,
params=save_params
)
# close the recording device
send_command(
device=self.device,
msg=MCI_CLOSE,
flags=0,
params=None
)
class WinPlayer:
'''
Generic wrapper for MCI_PLAY handling the device closing.
.. versionadded:: 1.4.0
'''
def __init__(self, device):
self._device = device
@property
def device(self):
'''
Public property returning device ID.
.. versionadded:: 1.4.0
'''
return self._device
def play(self):
'''
Start playing a WAV sound.
.. versionadded:: 1.4.0
'''
play_params = MCI_PLAY_PARMS()
play_params.dwFrom = 0
send_command(
device=self.device,
msg=MCI_PLAY,
flags=MCI_FROM,
params=play_params
)
def stop(self):
'''
Stop playing a WAV sound and close the device.
.. versionadded:: 1.4.0
'''
send_command(
device=self.device,
msg=MCI_STOP,
flags=MCI_WAIT,
params=None
)
# close the playing device
send_command(
device=self.device,
msg=MCI_CLOSE,
flags=0,
params=None
)
class WinAudio(Audio):
'''
Windows implementation of audio recording and audio playing.
.. versionadded:: 1.4.0
'''
def __init__(self, file_path=None):
# default path unless specified otherwise
default_path = join(
WinStoragePath().get_music_dir(),
'audio.wav'
)
super().__init__(file_path or default_path)
self._recorder = None
self._player = None
self._current_file = None
def _start(self):
'''
Start recording a WAV sound in the background asynchronously.
.. versionadded:: 1.4.0
'''
# clean everything before recording in case
# there is a different device open
self._stop()
# create structure and set device parameters
open_params = MCI_OPEN_PARMS()
open_params.lpstrDeviceType = 'waveaudio'
open_params.lpstrElementName = ''
# open a new device for recording
open_params = send_command(
device=0, # device ID before opening
msg=MCI_OPEN,
# empty filename in lpstrElementName
# device type in lpstrDeviceType
flags=MCI_OPEN_ELEMENT | MCI_OPEN_TYPE,
params=open_params
)
# get recorder with device id and path for saving
self._recorder = WinRecorder(
device=open_params.wDeviceID,
filename=self._file_path
)
self._recorder.record()
# Setting the currently recorded file as current file
# for using it as a parameter in audio player
self._current_file = self._recorder.filename
def _stop(self):
'''
Stop recording or playing of a WAV sound.
.. versionadded:: 1.4.0
'''
if self._recorder:
self._recorder.stop()
self._recorder = None
if self._player:
self._player.stop()
self._player = None
def _play(self):
'''
Play a WAV sound from a file. Prioritize latest recorded file before
default file path from WinAudio.
.. versionadded:: 1.4.0
'''
# create structure and set device parameters
open_params = MCI_OPEN_PARMS()
open_params.lpstrDeviceType = 'waveaudio'
open_params.lpstrElementName = self._current_file or self._file_path
# open a new device for playing
open_params = send_command(
device=0, # device ID before opening
msg=MCI_OPEN,
# existing filename in lpstrElementName
# device type in lpstrDeviceType
flags=MCI_OPEN_ELEMENT | MCI_OPEN_TYPE,
params=open_params
)
# get recorder with device id and path for saving
self._player = WinPlayer(device=open_params.wDeviceID)
self._player.play()
def instance():
'''
Instance for facade proxy.
'''
return WinAudio()