Source code for sounddevice

# Copyright (c) 2015-2020 Matthias Geier
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"""Play and Record Sound with Python.

API overview:
  * Convenience functions to play and record NumPy arrays:
    `play()`, `rec()`, `playrec()` and the related functions
    `wait()`, `stop()`, `get_status()`, `get_stream()`

  * Functions to get information about the available hardware:
    `query_devices()`, `query_hostapis()`,
    `check_input_settings()`, `check_output_settings()`

  * Module-wide default settings: `default`

  * Platform-specific settings:
    `AsioSettings`, `CoreAudioSettings`, `WasapiSettings`

  * PortAudio streams, using NumPy arrays:
    `Stream`, `InputStream`, `OutputStream`

  * PortAudio streams, using Python buffer objects (NumPy not needed):
    `RawStream`, `RawInputStream`, `RawOutputStream`

  * Miscellaneous functions and classes:
    `sleep()`, `get_portaudio_version()`, `CallbackFlags`,
    `CallbackStop`, `CallbackAbort`

Online documentation:
    https://python-sounddevice.readthedocs.io/

"""
__version__ = '0.4.1'

import atexit as _atexit
import os as _os
import platform as _platform
import sys as _sys
from ctypes.util import find_library as _find_library
from _sounddevice import ffi as _ffi


try:
    for _libname in (
            'portaudio',  # Default name on POSIX systems
            'bin\\libportaudio-2.dll',  # DLL from conda-forge
            'lib/libportaudio.dylib',  # dylib from anaconda
            ):
        _libname = _find_library(_libname)
        if _libname is not None:
            break
    else:
        raise OSError('PortAudio library not found')
    _lib = _ffi.dlopen(_libname)
except OSError:
    if _platform.system() == 'Darwin':
        _libname = 'libportaudio.dylib'
    elif _platform.system() == 'Windows':
        _libname = 'libportaudio' + _platform.architecture()[0] + '.dll'
    else:
        raise
    import _sounddevice_data
    _libname = _os.path.join(
        next(iter(_sounddevice_data.__path__)), 'portaudio-binaries', _libname)
    _lib = _ffi.dlopen(_libname)

_sampleformats = {
    'float32': _lib.paFloat32,
    'int32': _lib.paInt32,
    'int24': _lib.paInt24,
    'int16': _lib.paInt16,
    'int8': _lib.paInt8,
    'uint8': _lib.paUInt8,
}

_initialized = 0
_last_callback = None


[docs]def play(data, samplerate=None, mapping=None, blocking=False, loop=False, **kwargs): """Play back a NumPy array containing audio data. This is a convenience function for interactive use and for small scripts. It cannot be used for multiple overlapping playbacks. This function does the following steps internally: * Call `stop()` to terminate any currently running invocation of `play()`, `rec()` and `playrec()`. * Create an `OutputStream` and a callback function for taking care of the actual playback. * Start the stream. * If ``blocking=True`` was given, wait until playback is done. If not, return immediately. If you need more control (e.g. block-wise gapless playback, multiple overlapping playbacks, ...), you should explicitly create an `OutputStream` yourself. If NumPy is not available, you can use a `RawOutputStream`. Parameters ---------- data : array_like Audio data to be played back. The columns of a two-dimensional array are interpreted as channels, one-dimensional arrays are treated as mono data. The data types *float64*, *float32*, *int32*, *int16*, *int8* and *uint8* can be used. *float64* data is simply converted to *float32* before passing it to PortAudio, because it's not supported natively. mapping : array_like, optional List of channel numbers (starting with 1) where the columns of *data* shall be played back on. Must have the same length as number of channels in *data* (except if *data* is mono, in which case the signal is played back on all given output channels). Each channel number may only appear once in *mapping*. blocking : bool, optional If ``False`` (the default), return immediately (but playback continues in the background), if ``True``, wait until playback is finished. A non-blocking invocation can be stopped with `stop()` or turned into a blocking one with `wait()`. loop : bool, optional Play *data* in a loop. Other Parameters ---------------- samplerate, **kwargs All parameters of `OutputStream` -- except *channels*, *dtype*, *callback* and *finished_callback* -- can be used. Notes ----- If you don't specify the correct sampling rate (either with the *samplerate* argument or by assigning a value to `default.samplerate`), the audio data will be played back, but it might be too slow or too fast! See Also -------- rec, playrec """ ctx = _CallbackContext(loop=loop) ctx.frames = ctx.check_data(data, mapping, kwargs.get('device')) def callback(outdata, frames, time, status): assert len(outdata) == frames ctx.callback_enter(status, outdata) ctx.write_outdata(outdata) ctx.callback_exit() ctx.start_stream(OutputStream, samplerate, ctx.output_channels, ctx.output_dtype, callback, blocking, prime_output_buffers_using_stream_callback=False, **kwargs)
[docs]def rec(frames=None, samplerate=None, channels=None, dtype=None, out=None, mapping=None, blocking=False, **kwargs): """Record audio data into a NumPy array. This is a convenience function for interactive use and for small scripts. This function does the following steps internally: * Call `stop()` to terminate any currently running invocation of `play()`, `rec()` and `playrec()`. * Create an `InputStream` and a callback function for taking care of the actual recording. * Start the stream. * If ``blocking=True`` was given, wait until recording is done. If not, return immediately. If you need more control (e.g. block-wise gapless recording, overlapping recordings, ...), you should explicitly create an `InputStream` yourself. If NumPy is not available, you can use a `RawInputStream`. Parameters ---------- frames : int, sometimes optional Number of frames to record. Not needed if *out* is given. channels : int, optional Number of channels to record. Not needed if *mapping* or *out* is given. The default value can be changed with `default.channels`. dtype : str or numpy.dtype, optional Data type of the recording. Not needed if *out* is given. The data types *float64*, *float32*, *int32*, *int16*, *int8* and *uint8* can be used. For ``dtype='float64'``, audio data is recorded in *float32* format and converted afterwards, because it's not natively supported by PortAudio. The default value can be changed with `default.dtype`. mapping : array_like, optional List of channel numbers (starting with 1) to record. If *mapping* is given, *channels* is silently ignored. blocking : bool, optional If ``False`` (the default), return immediately (but recording continues in the background), if ``True``, wait until recording is finished. A non-blocking invocation can be stopped with `stop()` or turned into a blocking one with `wait()`. Returns ------- numpy.ndarray or type(out) The recorded data. .. note:: By default (``blocking=False``), an array of data is returned which is still being written to while recording! The returned data is only valid once recording has stopped. Use `wait()` to make sure the recording is finished. Other Parameters ---------------- out : numpy.ndarray or subclass, optional If *out* is specified, the recorded data is written into the given array instead of creating a new array. In this case, the arguments *frames*, *channels* and *dtype* are silently ignored! If *mapping* is given, its length must match the number of channels in *out*. samplerate, **kwargs All parameters of `InputStream` -- except *callback* and *finished_callback* -- can be used. Notes ----- If you don't specify a sampling rate (either with the *samplerate* argument or by assigning a value to `default.samplerate`), the default sampling rate of the sound device will be used (see `query_devices()`). See Also -------- play, playrec """ ctx = _CallbackContext() out, ctx.frames = ctx.check_out(out, frames, channels, dtype, mapping) def callback(indata, frames, time, status): assert len(indata) == frames ctx.callback_enter(status, indata) ctx.read_indata(indata) ctx.callback_exit() ctx.start_stream(InputStream, samplerate, ctx.input_channels, ctx.input_dtype, callback, blocking, **kwargs) return out
[docs]def playrec(data, samplerate=None, channels=None, dtype=None, out=None, input_mapping=None, output_mapping=None, blocking=False, **kwargs): """Simultaneous playback and recording of NumPy arrays. This function does the following steps internally: * Call `stop()` to terminate any currently running invocation of `play()`, `rec()` and `playrec()`. * Create a `Stream` and a callback function for taking care of the actual playback and recording. * Start the stream. * If ``blocking=True`` was given, wait until playback/recording is done. If not, return immediately. If you need more control (e.g. block-wise gapless playback and recording, realtime processing, ...), you should explicitly create a `Stream` yourself. If NumPy is not available, you can use a `RawStream`. Parameters ---------- data : array_like Audio data to be played back. See `play()`. channels : int, sometimes optional Number of input channels, see `rec()`. The number of output channels is obtained from *data.shape*. dtype : str or numpy.dtype, optional Input data type, see `rec()`. If *dtype* is not specified, it is taken from *data.dtype* (i.e. `default.dtype` is ignored). The output data type is obtained from *data.dtype* anyway. input_mapping, output_mapping : array_like, optional See the parameter *mapping* of `rec()` and `play()`, respectively. blocking : bool, optional If ``False`` (the default), return immediately (but continue playback/recording in the background), if ``True``, wait until playback/recording is finished. A non-blocking invocation can be stopped with `stop()` or turned into a blocking one with `wait()`. Returns ------- numpy.ndarray or type(out) The recorded data. See `rec()`. Other Parameters ---------------- out : numpy.ndarray or subclass, optional See `rec()`. samplerate, **kwargs All parameters of `Stream` -- except *channels*, *dtype*, *callback* and *finished_callback* -- can be used. Notes ----- If you don't specify the correct sampling rate (either with the *samplerate* argument or by assigning a value to `default.samplerate`), the audio data will be played back, but it might be too slow or too fast! See Also -------- play, rec """ ctx = _CallbackContext() output_frames = ctx.check_data(data, output_mapping, kwargs.get('device')) if dtype is None: dtype = ctx.data.dtype # ignore module defaults out, input_frames = ctx.check_out(out, output_frames, channels, dtype, input_mapping) if input_frames != output_frames: raise ValueError('len(data) != len(out)') ctx.frames = input_frames def callback(indata, outdata, frames, time, status): assert len(indata) == len(outdata) == frames ctx.callback_enter(status, indata) ctx.read_indata(indata) ctx.write_outdata(outdata) ctx.callback_exit() ctx.start_stream(Stream, samplerate, (ctx.input_channels, ctx.output_channels), (ctx.input_dtype, ctx.output_dtype), callback, blocking, prime_output_buffers_using_stream_callback=False, **kwargs) return out
[docs]def wait(ignore_errors=True): """Wait for `play()`/`rec()`/`playrec()` to be finished. Playback/recording can be stopped with a `KeyboardInterrupt`. Returns ------- CallbackFlags or None If at least one buffer over-/underrun happened during the last playback/recording, a `CallbackFlags` object is returned. See Also -------- get_status """ if _last_callback: return _last_callback.wait(ignore_errors)
[docs]def stop(ignore_errors=True): """Stop playback/recording. This only stops `play()`, `rec()` and `playrec()`, but has no influence on streams created with `Stream`, `InputStream`, `OutputStream`, `RawStream`, `RawInputStream`, `RawOutputStream`. """ if _last_callback: # Calling stop() before close() is necessary for older PortAudio # versions, see issue #87: _last_callback.stream.stop(ignore_errors) _last_callback.stream.close(ignore_errors)
[docs]def get_status(): """Get info about over-/underflows in `play()`/`rec()`/`playrec()`. Returns ------- CallbackFlags A `CallbackFlags` object that holds information about the last invocation of `play()`, `rec()` or `playrec()`. See Also -------- wait """ if _last_callback: return _last_callback.status else: raise RuntimeError('play()/rec()/playrec() was not called yet')
[docs]def get_stream(): """Get a reference to the current stream. This applies only to streams created by calls to `play()`, `rec()` or `playrec()`. Returns ------- Stream An `OutputStream`, `InputStream` or `Stream` associated with the last invocation of `play()`, `rec()` or `playrec()`, respectively. """ if _last_callback: return _last_callback.stream else: raise RuntimeError('play()/rec()/playrec() was not called yet')
[docs]def query_devices(device=None, kind=None): """Return information about available devices. Information and capabilities of PortAudio devices. Devices may support input, output or both input and output. To find the default input/output device(s), use `default.device`. Parameters ---------- device : int or str, optional Numeric device ID or device name substring(s). If specified, information about only the given *device* is returned in a single dictionary. kind : {'input', 'output'}, optional If *device* is not specified and *kind* is ``'input'`` or ``'output'``, a single dictionary is returned with information about the default input or output device, respectively. Returns ------- dict or DeviceList A dictionary with information about the given *device* or -- if no arguments were specified -- a `DeviceList` containing one dictionary for each available device. The dictionaries have the following keys: ``'name'`` The name of the device. ``'hostapi'`` The ID of the corresponding host API. Use `query_hostapis()` to get information about a host API. ``'max_input_channels'``, ``'max_output_channels'`` The maximum number of input/output channels supported by the device. See `default.channels`. ``'default_low_input_latency'``, ``'default_low_output_latency'`` Default latency values for interactive performance. This is used if `default.latency` (or the *latency* argument of `playrec()`, `Stream` etc.) is set to ``'low'``. ``'default_high_input_latency'``, ``'default_high_output_latency'`` Default latency values for robust non-interactive applications (e.g. playing sound files). This is used if `default.latency` (or the *latency* argument of `playrec()`, `Stream` etc.) is set to ``'high'``. ``'default_samplerate'`` The default sampling frequency of the device. This is used if `default.samplerate` is not set. Notes ----- The list of devices can also be displayed in a terminal: .. code-block:: sh python3 -m sounddevice Examples -------- The returned `DeviceList` can be indexed and iterated over like any sequence type (yielding the abovementioned dictionaries), but it also has a special string representation which is shown when used in an interactive Python session. Each available device is listed on one line together with the corresponding device ID, which can be assigned to `default.device` or used as *device* argument in `play()`, `Stream` etc. The first character of a line is ``>`` for the default input device, ``<`` for the default output device and ``*`` for the default input/output device. After the device ID and the device name, the corresponding host API name is displayed. In the end of each line, the maximum number of input and output channels is shown. On a GNU/Linux computer it might look somewhat like this: >>> import sounddevice as sd >>> sd.query_devices() 0 HDA Intel: ALC662 rev1 Analog (hw:0,0), ALSA (2 in, 2 out) 1 HDA Intel: ALC662 rev1 Digital (hw:0,1), ALSA (0 in, 2 out) 2 HDA Intel: HDMI 0 (hw:0,3), ALSA (0 in, 8 out) 3 sysdefault, ALSA (128 in, 128 out) 4 front, ALSA (0 in, 2 out) 5 surround40, ALSA (0 in, 2 out) 6 surround51, ALSA (0 in, 2 out) 7 surround71, ALSA (0 in, 2 out) 8 iec958, ALSA (0 in, 2 out) 9 spdif, ALSA (0 in, 2 out) 10 hdmi, ALSA (0 in, 8 out) * 11 default, ALSA (128 in, 128 out) 12 dmix, ALSA (0 in, 2 out) 13 /dev/dsp, OSS (16 in, 16 out) Note that ALSA provides access to some "real" and some "virtual" devices. The latter sometimes have a ridiculously high number of (virtual) inputs and outputs. On macOS, you might get something similar to this: >>> sd.query_devices() 0 Built-in Line Input, Core Audio (2 in, 0 out) > 1 Built-in Digital Input, Core Audio (2 in, 0 out) < 2 Built-in Output, Core Audio (0 in, 2 out) 3 Built-in Line Output, Core Audio (0 in, 2 out) 4 Built-in Digital Output, Core Audio (0 in, 2 out) """ if kind not in ('input', 'output', None): raise ValueError('Invalid kind: {!r}'.format(kind)) if device is None and kind is None: return DeviceList(query_devices(i) for i in range(_check(_lib.Pa_GetDeviceCount()))) device = _get_device_id(device, kind, raise_on_error=True) info = _lib.Pa_GetDeviceInfo(device) if not info: raise PortAudioError('Error querying device {}'.format(device)) assert info.structVersion == 2 name_bytes = _ffi.string(info.name) try: # We don't know beforehand if DirectSound and MME device names use # 'utf-8' or 'mbcs' encoding. Let's try 'utf-8' first, because it more # likely raises an exception on 'mbcs' data than vice versa, see also # https://github.com/spatialaudio/python-sounddevice/issues/72. # All other host APIs use 'utf-8' anyway. name = name_bytes.decode('utf-8') except UnicodeDecodeError: if info.hostApi in ( _lib.Pa_HostApiTypeIdToHostApiIndex(_lib.paDirectSound), _lib.Pa_HostApiTypeIdToHostApiIndex(_lib.paMME)): name = name_bytes.decode('mbcs') else: raise device_dict = { 'name': name, 'hostapi': info.hostApi, 'max_input_channels': info.maxInputChannels, 'max_output_channels': info.maxOutputChannels, 'default_low_input_latency': info.defaultLowInputLatency, 'default_low_output_latency': info.defaultLowOutputLatency, 'default_high_input_latency': info.defaultHighInputLatency, 'default_high_output_latency': info.defaultHighOutputLatency, 'default_samplerate': info.defaultSampleRate, } if kind and device_dict['max_' + kind + '_channels'] < 1: raise ValueError( 'Not an {} device: {!r}'.format(kind, device_dict['name'])) return device_dict
[docs]def query_hostapis(index=None): """Return information about available host APIs. Parameters ---------- index : int, optional If specified, information about only the given host API *index* is returned in a single dictionary. Returns ------- dict or tuple of dict A dictionary with information about the given host API *index* or -- if no *index* was specified -- a tuple containing one dictionary for each available host API. The dictionaries have the following keys: ``'name'`` The name of the host API. ``'devices'`` A list of device IDs belonging to the host API. Use `query_devices()` to get information about a device. ``'default_input_device'``, ``'default_output_device'`` The device ID of the default input/output device of the host API. If no default input/output device exists for the given host API, this is -1. .. note:: The overall default device(s) -- which can be overwritten by assigning to `default.device` -- take(s) precedence over `default.hostapi` and the information in the abovementioned dictionaries. See Also -------- query_devices """ if index is None: return tuple(query_hostapis(i) for i in range(_check(_lib.Pa_GetHostApiCount()))) info = _lib.Pa_GetHostApiInfo(index) if not info: raise PortAudioError('Error querying host API {}'.format(index)) assert info.structVersion == 1 return { 'name': _ffi.string(info.name).decode(), 'devices': [_lib.Pa_HostApiDeviceIndexToDeviceIndex(index, i) for i in range(info.deviceCount)], 'default_input_device': info.defaultInputDevice, 'default_output_device': info.defaultOutputDevice, }
[docs]def check_input_settings(device=None, channels=None, dtype=None, extra_settings=None, samplerate=None): """Check if given input device settings are supported. All parameters are optional, `default` settings are used for any unspecified parameters. If the settings are supported, the function does nothing; if not, an exception is raised. Parameters ---------- device : int or str, optional Device ID or device name substring(s), see `default.device`. channels : int, optional Number of input channels, see `default.channels`. dtype : str or numpy.dtype, optional Data type for input samples, see `default.dtype`. extra_settings : settings object, optional This can be used for host-API-specific input settings. See `default.extra_settings`. samplerate : float, optional Sampling frequency, see `default.samplerate`. """ parameters, dtype, samplesize, samplerate = _get_stream_parameters( 'input', device=device, channels=channels, dtype=dtype, latency=None, extra_settings=extra_settings, samplerate=samplerate) _check(_lib.Pa_IsFormatSupported(parameters, _ffi.NULL, samplerate))
[docs]def check_output_settings(device=None, channels=None, dtype=None, extra_settings=None, samplerate=None): """Check if given output device settings are supported. Same as `check_input_settings()`, just for output device settings. """ parameters, dtype, samplesize, samplerate = _get_stream_parameters( 'output', device=device, channels=channels, dtype=dtype, latency=None, extra_settings=extra_settings, samplerate=samplerate) _check(_lib.Pa_IsFormatSupported(_ffi.NULL, parameters, samplerate))
[docs]def sleep(msec): """Put the caller to sleep for at least *msec* milliseconds. The function may sleep longer than requested so don't rely on this for accurate musical timing. """ _lib.Pa_Sleep(msec)
[docs]def get_portaudio_version(): """Get version information for the PortAudio library. Returns the release number and a textual description of the current PortAudio build, e.g. :: (1899, 'PortAudio V19-devel (built Feb 15 2014 23:28:00)') """ return _lib.Pa_GetVersion(), _ffi.string(_lib.Pa_GetVersionText()).decode()
[docs]class _StreamBase(object): """Direct or indirect base class for all stream classes.""" def __init__(self, kind, samplerate=None, blocksize=None, device=None, channels=None, dtype=None, latency=None, extra_settings=None, callback=None, finished_callback=None, clip_off=None, dither_off=None, never_drop_input=None, prime_output_buffers_using_stream_callback=None, userdata=None, wrap_callback=None): """Base class for PortAudio streams. This class should only be used by library authors who want to create their own custom stream classes. Most users should use the derived classes `Stream`, `InputStream`, `OutputStream`, `RawStream`, `RawInputStream` and `RawOutputStream` instead. This class has the same properties and methods as `Stream`, except for `read_available`/:meth:`~Stream.read` and `write_available`/:meth:`~Stream.write`. It can be created with the same parameters as `Stream`, except that there are three additional parameters and the *callback* parameter also accepts a C function pointer. Parameters ---------- kind : {'input', 'output', 'duplex'} The desired type of stream: for recording, playback or both. callback : Python callable or CData function pointer, optional If *wrap_callback* is ``None`` this can be a function pointer provided by CFFI. Otherwise, it has to be a Python callable. wrap_callback : {'array', 'buffer'}, optional If *callback* is a Python callable, this selects whether the audio data is provided as NumPy array (like in `Stream`) or as Python buffer object (like in `RawStream`). userdata : CData void pointer This is passed to the underlying C callback function on each call and can only be accessed from a *callback* provided as ``CData`` function pointer. Examples -------- A usage example of this class can be seen at https://github.com/spatialaudio/python-rtmixer. """ assert kind in ('input', 'output', 'duplex') assert wrap_callback in ('array', 'buffer', None) if blocksize is None: blocksize = default.blocksize if clip_off is None: clip_off = default.clip_off if dither_off is None: dither_off = default.dither_off if never_drop_input is None: never_drop_input = default.never_drop_input if prime_output_buffers_using_stream_callback is None: prime_output_buffers_using_stream_callback = \ default.prime_output_buffers_using_stream_callback stream_flags = _lib.paNoFlag if clip_off: stream_flags |= _lib.paClipOff if dither_off: stream_flags |= _lib.paDitherOff if never_drop_input: stream_flags |= _lib.paNeverDropInput if prime_output_buffers_using_stream_callback: stream_flags |= _lib.paPrimeOutputBuffersUsingStreamCallback if kind == 'duplex': idevice, odevice = _split(device) ichannels, ochannels = _split(channels) idtype, odtype = _split(dtype) ilatency, olatency = _split(latency) iextra, oextra = _split(extra_settings) iparameters, idtype, isize, isamplerate = _get_stream_parameters( 'input', idevice, ichannels, idtype, ilatency, iextra, samplerate) oparameters, odtype, osize, osamplerate = _get_stream_parameters( 'output', odevice, ochannels, odtype, olatency, oextra, samplerate) self._dtype = idtype, odtype self._device = iparameters.device, oparameters.device self._channels = iparameters.channelCount, oparameters.channelCount self._samplesize = isize, osize if isamplerate != osamplerate: raise ValueError( 'Input and output device must have the same samplerate') else: samplerate = isamplerate else: parameters, self._dtype, self._samplesize, samplerate = \ _get_stream_parameters(kind, device, channels, dtype, latency, extra_settings, samplerate) self._device = parameters.device self._channels = parameters.channelCount if kind == 'input': iparameters = parameters oparameters = _ffi.NULL elif kind == 'output': iparameters = _ffi.NULL oparameters = parameters ffi_callback = _ffi.callback('PaStreamCallback', error=_lib.paAbort) if callback is None: callback_ptr = _ffi.NULL elif kind == 'input' and wrap_callback == 'buffer': @ffi_callback def callback_ptr(iptr, optr, frames, time, status, _): data = _buffer(iptr, frames, self._channels, self._samplesize) return _wrap_callback(callback, data, frames, time, status) elif kind == 'input' and wrap_callback == 'array': @ffi_callback def callback_ptr(iptr, optr, frames, time, status, _): data = _array( _buffer(iptr, frames, self._channels, self._samplesize), self._channels, self._dtype) return _wrap_callback(callback, data, frames, time, status) elif kind == 'output' and wrap_callback == 'buffer': @ffi_callback def callback_ptr(iptr, optr, frames, time, status, _): data = _buffer(optr, frames, self._channels, self._samplesize) return _wrap_callback(callback, data, frames, time, status) elif kind == 'output' and wrap_callback == 'array': @ffi_callback def callback_ptr(iptr, optr, frames, time, status, _): data = _array( _buffer(optr, frames, self._channels, self._samplesize), self._channels, self._dtype) return _wrap_callback(callback, data, frames, time, status) elif kind == 'duplex' and wrap_callback == 'buffer': @ffi_callback def callback_ptr(iptr, optr, frames, time, status, _): ichannels, ochannels = self._channels isize, osize = self._samplesize idata = _buffer(iptr, frames, ichannels, isize) odata = _buffer(optr, frames, ochannels, osize) return _wrap_callback( callback, idata, odata, frames, time, status) elif kind == 'duplex' and wrap_callback == 'array': @ffi_callback def callback_ptr(iptr, optr, frames, time, status, _): ichannels, ochannels = self._channels idtype, odtype = self._dtype isize, osize = self._samplesize idata = _array(_buffer(iptr, frames, ichannels, isize), ichannels, idtype) odata = _array(_buffer(optr, frames, ochannels, osize), ochannels, odtype) return _wrap_callback( callback, idata, odata, frames, time, status) else: # Use cast() to allow CData from different FFI instance: callback_ptr = _ffi.cast('PaStreamCallback*', callback) # CFFI callback object must be kept alive during stream lifetime: self._callback = callback_ptr if userdata is None: userdata = _ffi.NULL self._ptr = _ffi.new('PaStream**') _check(_lib.Pa_OpenStream(self._ptr, iparameters, oparameters, samplerate, blocksize, stream_flags, callback_ptr, userdata), 'Error opening {}'.format(self.__class__.__name__)) # dereference PaStream** --> PaStream* self._ptr = self._ptr[0] self._blocksize = blocksize info = _lib.Pa_GetStreamInfo(self._ptr) if not info: raise PortAudioError('Could not obtain stream info') # TODO: assert info.structVersion == 1 self._samplerate = info.sampleRate if not oparameters: self._latency = info.inputLatency elif not iparameters: self._latency = info.outputLatency else: self._latency = info.inputLatency, info.outputLatency if finished_callback: if isinstance(finished_callback, _ffi.CData): self._finished_callback = finished_callback else: def finished_callback_wrapper(_): return finished_callback() # CFFI callback object is kept alive during stream lifetime: self._finished_callback = _ffi.callback( 'PaStreamFinishedCallback', finished_callback_wrapper) _check(_lib.Pa_SetStreamFinishedCallback(self._ptr, self._finished_callback)) # Avoid confusion if something goes wrong before assigning self._ptr: _ptr = _ffi.NULL @property def samplerate(self): """The sampling frequency in Hertz (= frames per second). In cases where the hardware sampling frequency is inaccurate and PortAudio is aware of it, the value of this field may be different from the *samplerate* parameter passed to `Stream()`. If information about the actual hardware sampling frequency is not available, this field will have the same value as the *samplerate* parameter passed to `Stream()`. """ return self._samplerate @property def blocksize(self): """Number of frames per block. The special value 0 means that the blocksize can change between blocks. See the *blocksize* argument of `Stream`. """ return self._blocksize @property def device(self): """IDs of the input/output device.""" return self._device @property def channels(self): """The number of input/output channels.""" return self._channels @property def dtype(self): """Data type of the audio samples. See Also -------- default.dtype, samplesize """ return self._dtype @property def samplesize(self): """The size in bytes of a single sample. See Also -------- dtype """ return self._samplesize @property def latency(self): """The input/output latency of the stream in seconds. This value provides the most accurate estimate of input/output latency available to the implementation. It may differ significantly from the *latency* value(s) passed to `Stream()`. """ return self._latency @property def active(self): """``True`` when the stream is active, ``False`` otherwise. A stream is active after a successful call to `start()`, until it becomes inactive either as a result of a call to `stop()` or `abort()`, or as a result of an exception raised in the stream callback. In the latter case, the stream is considered inactive after the last buffer has finished playing. See Also -------- stopped """ if self.closed: return False return _check(_lib.Pa_IsStreamActive(self._ptr)) == 1 @property def stopped(self): """``True`` when the stream is stopped, ``False`` otherwise. A stream is considered to be stopped prior to a successful call to `start()` and after a successful call to `stop()` or `abort()`. If a stream callback is cancelled (by raising an exception) the stream is *not* considered to be stopped. See Also -------- active """ if self.closed: return True return _check(_lib.Pa_IsStreamStopped(self._ptr)) == 1 @property def closed(self): """``True`` after a call to `close()`, ``False`` otherwise.""" return self._ptr == _ffi.NULL @property def time(self): """The current stream time in seconds. This is according to the same clock used to generate the timestamps passed with the *time* argument to the stream callback (see the *callback* argument of `Stream`). The time values are monotonically increasing and have unspecified origin. This provides valid time values for the entire life of the stream, from when the stream is opened until it is closed. Starting and stopping the stream does not affect the passage of time as provided here. This time may be used for synchronizing other events to the audio stream, for example synchronizing audio to MIDI. """ time = _lib.Pa_GetStreamTime(self._ptr) if not time: raise PortAudioError('Error getting stream time') return time @property def cpu_load(self): """CPU usage information for the stream. The "CPU Load" is a fraction of total CPU time consumed by a callback stream's audio processing routines including, but not limited to the client supplied stream callback. This function does not work with blocking read/write streams. This may be used in the stream callback function or in the application. It provides a floating point value, typically between 0.0 and 1.0, where 1.0 indicates that the stream callback is consuming the maximum number of CPU cycles possible to maintain real-time operation. A value of 0.5 would imply that PortAudio and the stream callback was consuming roughly 50% of the available CPU time. The value may exceed 1.0. A value of 0.0 will always be returned for a blocking read/write stream, or if an error occurs. """ return _lib.Pa_GetStreamCpuLoad(self._ptr) def __enter__(self): """Start the stream in the beginning of a "with" statement.""" self.start() return self def __exit__(self, *args): """Stop and close the stream when exiting a "with" statement.""" self.stop() self.close() def start(self): """Commence audio processing. See Also -------- stop, abort """ err = _lib.Pa_StartStream(self._ptr) if err != _lib.paStreamIsNotStopped: _check(err, 'Error starting stream') def stop(self, ignore_errors=True): """Terminate audio processing. This waits until all pending audio buffers have been played before it returns. See Also -------- start, abort """ err = _lib.Pa_StopStream(self._ptr) if not ignore_errors: _check(err, 'Error stopping stream') def abort(self, ignore_errors=True): """Terminate audio processing immediately. This does not wait for pending buffers to complete. See Also -------- start, stop """ err = _lib.Pa_AbortStream(self._ptr) if not ignore_errors: _check(err, 'Error aborting stream') def close(self, ignore_errors=True): """Close the stream. If the audio stream is active any pending buffers are discarded as if `abort()` had been called. """ err = _lib.Pa_CloseStream(self._ptr) self._ptr = _ffi.NULL if not ignore_errors: _check(err, 'Error closing stream')
[docs]class RawInputStream(_StreamBase): """Raw stream for recording only. See __init__() and RawStream.""" def __init__(self, samplerate=None, blocksize=None, device=None, channels=None, dtype=None, latency=None, extra_settings=None, callback=None, finished_callback=None, clip_off=None, dither_off=None, never_drop_input=None, prime_output_buffers_using_stream_callback=None): """PortAudio input stream (using buffer objects). This is the same as `InputStream`, except that the *callback* function and :meth:`~RawStream.read` work on plain Python buffer objects instead of on NumPy arrays. NumPy is not necessary for using this. Parameters ---------- dtype : str See `RawStream`. callback : callable User-supplied function to consume audio data in response to requests from an active stream. The callback must have this signature:: callback(indata: buffer, frames: int, time: CData, status: CallbackFlags) -> None The arguments are the same as in the *callback* parameter of `RawStream`, except that *outdata* is missing. See Also -------- RawStream, Stream """ _StreamBase.__init__(self, kind='input', wrap_callback='buffer', **_remove_self(locals())) @property def read_available(self): """The number of frames that can be read without waiting. Returns a value representing the maximum number of frames that can be read from the stream without blocking or busy waiting. """ return _check(_lib.Pa_GetStreamReadAvailable(self._ptr)) def read(self, frames): """Read samples from the stream into a buffer. This is the same as `Stream.read()`, except that it returns a plain Python buffer object instead of a NumPy array. NumPy is not necessary for using this. Parameters ---------- frames : int The number of frames to be read. See `Stream.read()`. Returns ------- data : buffer A buffer of interleaved samples. The buffer contains samples in the format specified by the *dtype* parameter used to open the stream, and the number of channels specified by *channels*. See also `samplesize`. overflowed : bool See `Stream.read()`. """ channels, _ = _split(self._channels) samplesize, _ = _split(self._samplesize) data = _ffi.new('signed char[]', channels * samplesize * frames) err = _lib.Pa_ReadStream(self._ptr, data, frames) if err == _lib.paInputOverflowed: overflowed = True else: _check(err) overflowed = False return _ffi.buffer(data), overflowed
[docs]class RawOutputStream(_StreamBase): """Raw stream for playback only. See __init__() and RawStream.""" def __init__(self, samplerate=None, blocksize=None, device=None, channels=None, dtype=None, latency=None, extra_settings=None, callback=None, finished_callback=None, clip_off=None, dither_off=None, never_drop_input=None, prime_output_buffers_using_stream_callback=None): """PortAudio output stream (using buffer objects). This is the same as `OutputStream`, except that the *callback* function and :meth:`~RawStream.write` work on plain Python buffer objects instead of on NumPy arrays. NumPy is not necessary for using this. Parameters ---------- dtype : str See `RawStream`. callback : callable User-supplied function to generate audio data in response to requests from an active stream. The callback must have this signature:: callback(outdata: buffer, frames: int, time: CData, status: CallbackFlags) -> None The arguments are the same as in the *callback* parameter of `RawStream`, except that *indata* is missing. See Also -------- RawStream, Stream """ _StreamBase.__init__(self, kind='output', wrap_callback='buffer', **_remove_self(locals())) @property def write_available(self): """The number of frames that can be written without waiting. Returns a value representing the maximum number of frames that can be written to the stream without blocking or busy waiting. """ return _check(_lib.Pa_GetStreamWriteAvailable(self._ptr)) def write(self, data): """Write samples to the stream. This is the same as `Stream.write()`, except that it expects a plain Python buffer object instead of a NumPy array. NumPy is not necessary for using this. Parameters ---------- data : buffer or bytes or iterable of int A buffer of interleaved samples. The buffer contains samples in the format specified by the *dtype* argument used to open the stream, and the number of channels specified by *channels*. The length of the buffer is not constrained to a specific range, however high performance applications will want to match this parameter to the *blocksize* parameter used when opening the stream. See also `samplesize`. Returns ------- underflowed : bool See `Stream.write()`. """ try: data = _ffi.from_buffer(data) except AttributeError: pass # from_buffer() not supported except TypeError: pass # input is not a buffer _, samplesize = _split(self._samplesize) _, channels = _split(self._channels) samples, remainder = divmod(len(data), samplesize) if remainder: raise ValueError('len(data) not divisible by samplesize') frames, remainder = divmod(samples, channels) if remainder: raise ValueError('Number of samples not divisible by channels') err = _lib.Pa_WriteStream(self._ptr, data, frames) if err == _lib.paOutputUnderflowed: underflowed = True else: _check(err) underflowed = False return underflowed
[docs]class RawStream(RawInputStream, RawOutputStream): """Raw stream for playback and recording. See __init__().""" def __init__(self, samplerate=None, blocksize=None, device=None, channels=None, dtype=None, latency=None, extra_settings=None, callback=None, finished_callback=None, clip_off=None, dither_off=None, never_drop_input=None, prime_output_buffers_using_stream_callback=None): """PortAudio input/output stream (using buffer objects). This is the same as `Stream`, except that the *callback* function and `read()`/`write()` work on plain Python buffer objects instead of on NumPy arrays. NumPy is not necessary for using this. To open a "raw" input-only or output-only stream use `RawInputStream` or `RawOutputStream`, respectively. If you want to handle audio data as NumPy arrays instead of buffer objects, use `Stream`, `InputStream` or `OutputStream`. Parameters ---------- dtype : str or pair of str The sample format of the buffers provided to the stream callback, `read()` or `write()`. In addition to the formats supported by `Stream` (``'float32'``, ``'int32'``, ``'int16'``, ``'int8'``, ``'uint8'``), this also supports ``'int24'``, i.e. packed 24 bit format. The default value can be changed with `default.dtype`. See also `samplesize`. callback : callable User-supplied function to consume, process or generate audio data in response to requests from an active stream. The callback must have this signature:: callback(indata: buffer, outdata: buffer, frames: int, time: CData, status: CallbackFlags) -> None The arguments are the same as in the *callback* parameter of `Stream`, except that *indata* and *outdata* are plain Python buffer objects instead of NumPy arrays. See Also -------- RawInputStream, RawOutputStream, Stream """ _StreamBase.__init__(self, kind='duplex', wrap_callback='buffer', **_remove_self(locals()))
[docs]class InputStream(RawInputStream): """Stream for input only. See __init__() and Stream.""" def __init__(self, samplerate=None, blocksize=None, device=None, channels=None, dtype=None, latency=None, extra_settings=None, callback=None, finished_callback=None, clip_off=None, dither_off=None, never_drop_input=None, prime_output_buffers_using_stream_callback=None): """PortAudio input stream (using NumPy). This has the same methods and attributes as `Stream`, except :meth:`~Stream.write` and `write_available`. Furthermore, the stream callback is expected to have a different signature (see below). Parameters ---------- callback : callable User-supplied function to consume audio in response to requests from an active stream. The callback must have this signature:: callback(indata: numpy.ndarray, frames: int, time: CData, status: CallbackFlags) -> None The arguments are the same as in the *callback* parameter of `Stream`, except that *outdata* is missing. See Also -------- Stream, RawInputStream """ _StreamBase.__init__(self, kind='input', wrap_callback='array', **_remove_self(locals())) def read(self, frames): """Read samples from the stream into a NumPy array. The function doesn't return until all requested *frames* have been read -- this may involve waiting for the operating system to supply the data (except if no more than `read_available` frames were requested). This is the same as `RawStream.read()`, except that it returns a NumPy array instead of a plain Python buffer object. Parameters ---------- frames : int The number of frames to be read. This parameter is not constrained to a specific range, however high performance applications will want to match this parameter to the *blocksize* parameter used when opening the stream. Returns ------- data : numpy.ndarray A two-dimensional `numpy.ndarray` with one column per channel (i.e. with a shape of ``(frames, channels)``) and with a data type specified by `dtype`. overflowed : bool ``True`` if input data was discarded by PortAudio after the previous call and before this call. """ dtype, _ = _split(self._dtype) channels, _ = _split(self._channels) data, overflowed = RawInputStream.read(self, frames) data = _array(data, channels, dtype) return data, overflowed
[docs]class OutputStream(RawOutputStream): """Stream for output only. See __init__() and Stream.""" def __init__(self, samplerate=None, blocksize=None, device=None, channels=None, dtype=None, latency=None, extra_settings=None, callback=None, finished_callback=None, clip_off=None, dither_off=None, never_drop_input=None, prime_output_buffers_using_stream_callback=None): """PortAudio output stream (using NumPy). This has the same methods and attributes as `Stream`, except :meth:`~Stream.read` and `read_available`. Furthermore, the stream callback is expected to have a different signature (see below). Parameters ---------- callback : callable User-supplied function to generate audio data in response to requests from an active stream. The callback must have this signature:: callback(outdata: numpy.ndarray, frames: int, time: CData, status: CallbackFlags) -> None The arguments are the same as in the *callback* parameter of `Stream`, except that *indata* is missing. See Also -------- Stream, RawOutputStream """ _StreamBase.__init__(self, kind='output', wrap_callback='array', **_remove_self(locals())) def write(self, data): """Write samples to the stream. This function doesn't return until the entire buffer has been consumed -- this may involve waiting for the operating system to consume the data (except if *data* contains no more than `write_available` frames). This is the same as `RawStream.write()`, except that it expects a NumPy array instead of a plain Python buffer object. Parameters ---------- data : array_like A two-dimensional array-like object with one column per channel (i.e. with a shape of ``(frames, channels)``) and with a data type specified by `dtype`. A one-dimensional array can be used for mono data. The array layout must be C-contiguous (see :func:`numpy.ascontiguousarray`). The length of the buffer is not constrained to a specific range, however high performance applications will want to match this parameter to the *blocksize* parameter used when opening the stream. Returns ------- underflowed : bool ``True`` if additional output data was inserted after the previous call and before this call. """ import numpy as np data = np.asarray(data) _, dtype = _split(self._dtype) _, channels = _split(self._channels) if data.ndim > 1 and data.shape[1] != channels: raise ValueError('Number of channels must match') if data.dtype != dtype: raise TypeError('dtype mismatch: {!r} vs {!r}'.format( data.dtype.name, dtype)) if not data.flags.c_contiguous: raise TypeError('data must be C-contiguous') return RawOutputStream.write(self, data)
[docs]class Stream(InputStream, OutputStream): """Stream for input and output. See __init__().""" def __init__(self, samplerate=None, blocksize=None, device=None, channels=None, dtype=None, latency=None, extra_settings=None, callback=None, finished_callback=None, clip_off=None, dither_off=None, never_drop_input=None, prime_output_buffers_using_stream_callback=None): """PortAudio stream for simultaneous input and output (using NumPy). To open an input-only or output-only stream use `InputStream` or `OutputStream`, respectively. If you want to handle audio data as plain buffer objects instead of NumPy arrays, use `RawStream`, `RawInputStream` or `RawOutputStream`. A single stream can provide multiple channels of real-time streaming audio input and output to a client application. A stream provides access to audio hardware represented by one or more devices. Depending on the underlying host API, it may be possible to open multiple streams using the same device, however this behavior is implementation defined. Portable applications should assume that a device may be simultaneously used by at most one stream. The arguments *device*, *channels*, *dtype* and *latency* can be either single values (which will be used for both input and output parameters) or pairs of values (where the first one is the value for the input and the second one for the output). All arguments are optional, the values for unspecified parameters are taken from the `default` object. If one of the values of a parameter pair is ``None``, the corresponding value from `default` will be used instead. The created stream is inactive (see `active`, `stopped`). It can be started with `start()`. Every stream object is also a :ref:`context manager <python:context-managers>`, i.e. it can be used in a :ref:`with statement <python:with>` to automatically call `start()` in the beginning of the statement and `stop()` and `close()` on exit. Parameters ---------- samplerate : float, optional The desired sampling frequency (for both input and output). The default value can be changed with `default.samplerate`. blocksize : int, optional The number of frames passed to the stream callback function, or the preferred block granularity for a blocking read/write stream. The special value ``blocksize=0`` (which is the default) may be used to request that the stream callback will receive an optimal (and possibly varying) number of frames based on host requirements and the requested latency settings. The default value can be changed with `default.blocksize`. .. note:: With some host APIs, the use of non-zero *blocksize* for a callback stream may introduce an additional layer of buffering which could introduce additional latency. PortAudio guarantees that the additional latency will be kept to the theoretical minimum however, it is strongly recommended that a non-zero *blocksize* value only be used when your algorithm requires a fixed number of frames per stream callback. device : int or str or pair thereof, optional Device index(es) or query string(s) specifying the device(s) to be used. The default value(s) can be changed with `default.device`. channels : int or pair of int, optional The number of channels of sound to be delivered to the stream callback or accessed by `read()` or `write()`. It can range from 1 to the value of ``'max_input_channels'`` or ``'max_output_channels'`` in the dict returned by `query_devices()`. By default, the maximum possible number of channels for the selected device is used (which may not be what you want; see `query_devices()`). The default value(s) can be changed with `default.channels`. dtype : str or numpy.dtype or pair thereof, optional The sample format of the `numpy.ndarray` provided to the stream callback, `read()` or `write()`. It may be any of *float32*, *int32*, *int16*, *int8*, *uint8*. See `numpy.dtype`. The *float64* data type is not supported, this is only supported for convenience in `play()`/`rec()`/`playrec()`. The packed 24 bit format ``'int24'`` is only supported in the "raw" stream classes, see `RawStream`. The default value(s) can be changed with `default.dtype`. latency : float or {'low', 'high'} or pair thereof, optional The desired latency in seconds. The special values ``'low'`` and ``'high'`` (latter being the default) select the default low and high latency, respectively (see `query_devices()`). The default value(s) can be changed with `default.latency`. Where practical, implementations should configure their latency based on this parameter, otherwise they may choose the closest viable latency instead. Unless the suggested latency is greater than the absolute upper limit for the device, implementations should round the *latency* up to the next practical value -- i.e. to provide an equal or higher latency wherever possible. Actual latency values for an open stream may be retrieved using the `latency` attribute. .. note:: Specifying the desired latency as 'high' does not guarantee a stable audio stream. For reference, by default Audacity specifies a desired latency of 100ms and achieves robust performance. extra_settings : settings object or pair thereof, optional This can be used for host-API-specific input/output settings. See `default.extra_settings`. callback : callable, optional User-supplied function to consume, process or generate audio data in response to requests from an `active` stream. When a stream is running, PortAudio calls the stream callback periodically. The callback function is responsible for processing and filling input and output buffers, respectively. If no *callback* is given, the stream will be opened in "blocking read/write" mode. In blocking mode, the client can receive sample data using `read()` and write sample data using `write()`, the number of frames that may be read or written without blocking is returned by `read_available` and `write_available`, respectively. The callback must have this signature:: callback(indata: ndarray, outdata: ndarray, frames: int, time: CData, status: CallbackFlags) -> None The first and second argument are the input and output buffer, respectively, as two-dimensional `numpy.ndarray` with one column per channel (i.e. with a shape of ``(frames, channels)``) and with a data type specified by `dtype`. The output buffer contains uninitialized data and the *callback* is supposed to fill it with proper audio data. If no data is available, the buffer should be filled with zeros (e.g. by using ``outdata.fill(0)``). .. note:: In Python, assigning to an identifier merely re-binds the identifier to another object, so this *will not work* as expected:: outdata = my_data # Don't do this! To actually assign data to the buffer itself, you can use indexing, e.g.:: outdata[:] = my_data ... which fills the whole buffer, or:: outdata[:, 1] = my_channel_data ... which only fills one channel. The third argument holds the number of frames to be processed by the stream callback. This is the same as the length of the input and output buffers. The forth argument provides a CFFI structure with timestamps indicating the ADC capture time of the first sample in the input buffer (``time.inputBufferAdcTime``), the DAC output time of the first sample in the output buffer (``time.outputBufferDacTime``) and the time the callback was invoked (``time.currentTime``). These time values are expressed in seconds and are synchronised with the time base used by `time` for the associated stream. The fifth argument is a `CallbackFlags` instance indicating whether input and/or output buffers have been inserted or will be dropped to overcome underflow or overflow conditions. If an exception is raised in the *callback*, it will not be called again. If `CallbackAbort` is raised, the stream will finish as soon as possible. If `CallbackStop` is raised, the stream will continue until all buffers generated by the callback have been played. This may be useful in applications such as soundfile players where a specific duration of output is required. If another exception is raised, its traceback is printed to `sys.stderr`. Exceptions are *not* propagated to the main thread, i.e. the main Python program keeps running as if nothing had happened. .. note:: The *callback* must always fill the entire output buffer, no matter if or which exceptions are raised. If no exception is raised in the *callback*, it automatically continues to be called until `stop()`, `abort()` or `close()` are used to stop the stream. The PortAudio stream callback runs at very high or real-time priority. It is required to consistently meet its time deadlines. Do not allocate memory, access the file system, call library functions or call other functions from the stream callback that may block or take an unpredictable amount of time to complete. With the exception of `cpu_load` it is not permissible to call PortAudio API functions from within the stream callback. In order for a stream to maintain glitch-free operation the callback must consume and return audio data faster than it is recorded and/or played. PortAudio anticipates that each callback invocation may execute for a duration approaching the duration of *frames* audio frames at the stream's sampling frequency. It is reasonable to expect to be able to utilise 70% or more of the available CPU time in the PortAudio callback. However, due to buffer size adaption and other factors, not all host APIs are able to guarantee audio stability under heavy CPU load with arbitrary fixed callback buffer sizes. When high callback CPU utilisation is required the most robust behavior can be achieved by using ``blocksize=0``. finished_callback : callable, optional User-supplied function which will be called when the stream becomes inactive (i.e. once a call to `stop()` will not block). A stream will become inactive after the stream callback raises an exception or when `stop()` or `abort()` is called. For a stream providing audio output, if the stream callback raises `CallbackStop`, or `stop()` is called, the stream finished callback will not be called until all generated sample data has been played. The callback must have this signature:: finished_callback() -> None clip_off : bool, optional See `default.clip_off`. dither_off : bool, optional See `default.dither_off`. never_drop_input : bool, optional See `default.never_drop_input`. prime_output_buffers_using_stream_callback : bool, optional See `default.prime_output_buffers_using_stream_callback`. """ _StreamBase.__init__(self, kind='duplex', wrap_callback='array', **_remove_self(locals()))
[docs]class DeviceList(tuple): """A list with information about all available audio devices. This class is not meant to be instantiated by the user. Instead, it is returned by `query_devices()`. It contains a dictionary for each available device, holding the keys described in `query_devices()`. This class has a special string representation that is shown as return value of `query_devices()` if used in an interactive Python session. It will also be shown when using the :func:`print` function. Furthermore, it can be obtained with :func:`repr` and :class:`str() <str>`. """ __slots__ = () def __repr__(self): idev = _get_device_id(default.device['input'], 'input') odev = _get_device_id(default.device['output'], 'output') digits = len(str(_lib.Pa_GetDeviceCount() - 1)) hostapi_names = [hostapi['name'] for hostapi in query_hostapis()] text = '\n'.join( u'{mark} {idx:{dig}} {name}, {ha} ({ins} in, {outs} out)'.format( mark=(' ', '>', '<', '*')[(idx == idev) + 2 * (idx == odev)], idx=idx, dig=digits, name=info['name'], ha=hostapi_names[info['hostapi']], ins=info['max_input_channels'], outs=info['max_output_channels']) for idx, info in enumerate(self)) return text
[docs]class CallbackFlags(object): """Flag bits for the *status* argument to a stream *callback*. If you experience under-/overflows, you can try to increase the ``latency`` and/or ``blocksize`` settings. You should also avoid anything that could block the callback function for a long time, e.g. extensive computations, waiting for another thread, reading/writing files, network connections, etc. See Also -------- Stream Examples -------- This can be used to collect the errors of multiple *status* objects: >>> import sounddevice as sd >>> errors = sd.CallbackFlags() >>> errors |= status1 >>> errors |= status2 >>> errors |= status3 >>> # and so on ... >>> errors.input_overflow True The values may also be set and cleared by the user: >>> import sounddevice as sd >>> cf = sd.CallbackFlags() >>> cf <sounddevice.CallbackFlags: no flags set> >>> cf.input_underflow = True >>> cf <sounddevice.CallbackFlags: input underflow> >>> cf.input_underflow = False >>> cf <sounddevice.CallbackFlags: no flags set> """ __slots__ = '_flags' def __init__(self, flags=0x0): self._flags = flags def __repr__(self): flags = str(self) if not flags: flags = 'no flags set' return '<sounddevice.CallbackFlags: {}>'.format(flags) def __str__(self): return ', '.join(name.replace('_', ' ') for name in dir(self) if not name.startswith('_') and getattr(self, name)) def __bool__(self): return bool(self._flags) def __ior__(self, other): if not isinstance(other, CallbackFlags): return NotImplemented self._flags |= other._flags return self @property def input_underflow(self): """Input underflow. In a stream opened with ``blocksize=0``, indicates that input data is all silence (zeros) because no real data is available. In a stream opened with a non-zero *blocksize*, it indicates that one or more zero samples have been inserted into the input buffer to compensate for an input underflow. This can only happen in full-duplex streams (including `playrec()`). """ return self._hasflag(_lib.paInputUnderflow) @input_underflow.setter def input_underflow(self, value): self._updateflag(_lib.paInputUnderflow, value) @property def input_overflow(self): """Input overflow. In a stream opened with ``blocksize=0``, indicates that data prior to the first sample of the input buffer was discarded due to an overflow, possibly because the stream callback is using too much CPU time. In a stream opened with a non-zero *blocksize*, it indicates that data prior to one or more samples in the input buffer was discarded. This can happen in full-duplex and input-only streams (including `playrec()` and `rec()`). """ return self._hasflag(_lib.paInputOverflow) @input_overflow.setter def input_overflow(self, value): self._updateflag(_lib.paInputOverflow, value) @property def output_underflow(self): """Output underflow. Indicates that output data (or a gap) was inserted, possibly because the stream callback is using too much CPU time. This can happen in full-duplex and output-only streams (including `playrec()` and `play()`). """ return self._hasflag(_lib.paOutputUnderflow) @output_underflow.setter def output_underflow(self, value): self._updateflag(_lib.paOutputUnderflow, value) @property def output_overflow(self): """Output overflow. Indicates that output data will be discarded because no room is available. This can only happen in full-duplex streams (including `playrec()`), but only when ``never_drop_input=True`` was specified. See `default.never_drop_input`. """ return self._hasflag(_lib.paOutputOverflow) @output_overflow.setter def output_overflow(self, value): self._updateflag(_lib.paOutputOverflow, value) @property def priming_output(self): """Priming output. Some of all of the output data will be used to prime the stream, input data may be zero. This will only take place with some of the host APIs, and only if ``prime_output_buffers_using_stream_callback=True`` was specified. See `default.prime_output_buffers_using_stream_callback`. """ return self._hasflag(_lib.paPrimingOutput) def _hasflag(self, flag): """Check a given flag.""" return bool(self._flags & flag) def _updateflag(self, flag, value): """Set/clear a given flag.""" if value: self._flags |= flag else: self._flags &= ~flag
class _InputOutputPair(object): """Parameter pairs for device, channels, dtype and latency.""" _indexmapping = {'input': 0, 'output': 1} def __init__(self, parent, default_attr): self._pair = [None, None] self._parent = parent self._default_attr = default_attr def __getitem__(self, index): index = self._indexmapping.get(index, index) value = self._pair[index] if value is None: value = getattr(self._parent, self._default_attr)[index] return value def __setitem__(self, index, value): index = self._indexmapping.get(index, index) self._pair[index] = value def __repr__(self): return '[{0[0]!r}, {0[1]!r}]'.format(self)
[docs]class default(object): """Get/set defaults for the *sounddevice* module. The attributes `device`, `channels`, `dtype`, `latency` and `extra_settings` accept single values which specify the given property for both input and output. However, if the property differs between input and output, pairs of values can be used, where the first value specifies the input and the second value specifies the output. All other attributes are always single values. Examples -------- >>> import sounddevice as sd >>> sd.default.samplerate = 48000 >>> sd.default.dtype ['float32', 'float32'] Different values for input and output: >>> sd.default.channels = 1, 2 A single value sets both input and output at the same time: >>> sd.default.device = 5 >>> sd.default.device [5, 5] An attribute can be set to the "factory default" by assigning ``None``: >>> sd.default.samplerate = None >>> sd.default.device = None, 4 Use `reset()` to reset all attributes: >>> sd.default.reset() """ _pairs = 'device', 'channels', 'dtype', 'latency', 'extra_settings' # The class attributes listed in _pairs are only provided here for static # analysis tools and for the docs. They're overwritten in __init__(). device = None, None """Index or query string of default input/output device. If not overwritten, this is queried from PortAudio. If a string is given, the device is selected which contains all space-separated parts in the right order. Each device string contains the name of the corresponding host API in the end. The string comparison is case-insensitive. See Also -------- :func:`query_devices` """ channels = _default_channels = None, None """Number of input/output channels. The maximum number of channels for a given device can be found out with `query_devices()`. """ dtype = _default_dtype = 'float32', 'float32' """Data type used for input/output samples. The types ``'float32'``, ``'int32'``, ``'int16'``, ``'int8'`` and ``'uint8'`` can be used for all streams and functions. Additionally, `play()`, `rec()` and `playrec()` support ``'float64'`` (for convenience, data is merely converted from/to ``'float32'``) and `RawInputStream`, `RawOutputStream` and `RawStream` support ``'int24'`` (packed 24 bit format, which is *not* supported in NumPy!). If NumPy is available, the corresponding `numpy.dtype` objects can be used as well. The floating point representations ``'float32'`` and ``'float64'`` use +1.0 and -1.0 as the maximum and minimum values, respectively. ``'uint8'`` is an unsigned 8 bit format where 128 is considered "ground". """ latency = _default_latency = 'high', 'high' """Suggested input/output latency in seconds. The special values ``'low'`` and ``'high'`` can be used to select the default low/high latency of the chosen device. ``'high'`` is typically more robust (i.e. buffer under-/overflows are less likely), but the latency may be too large for interactive applications. See Also -------- :func:`query_devices` """ extra_settings = _default_extra_settings = None, None """Host-API-specific input/output settings. See Also -------- AsioSettings, CoreAudioSettings, WasapiSettings """ samplerate = None """Sampling frequency in Hertz (= frames per second). See Also -------- :func:`query_devices` """ blocksize = _lib.paFramesPerBufferUnspecified """See the *blocksize* argument of `Stream`.""" clip_off = False """Disable clipping. Set to ``True`` to disable default clipping of out of range samples. """ dither_off = False """Disable dithering. Set to ``True`` to disable default dithering. """ never_drop_input = False """Set behavior for input overflow of full-duplex streams. Set to ``True`` to request that where possible a full duplex stream will not discard overflowed input samples without calling the stream callback. This flag is only valid for full-duplex callback streams (i.e. only `Stream` and `RawStream` and only if *callback* was specified; this includes `playrec()`) and only when used in combination with ``blocksize=0`` (the default). Using this flag incorrectly results in an error being raised. See also http://www.portaudio.com/docs/proposals/001-UnderflowOverflowHandling.html. """ prime_output_buffers_using_stream_callback = False """How to fill initial output buffers. Set to ``True`` to call the stream callback to fill initial output buffers, rather than the default behavior of priming the buffers with zeros (silence). This flag has no effect for input-only (`InputStream` and `RawInputStream`) and blocking read/write streams (i.e. if *callback* wasn't specified). See also http://www.portaudio.com/docs/proposals/020-AllowCallbackToPrimeStream.html. """ def __init__(self): for attr in self._pairs: # __setattr__() must be avoided here vars(self)[attr] = _InputOutputPair(self, '_default_' + attr) def __setattr__(self, name, value): """Only allow setting existing attributes.""" if name in self._pairs: getattr(self, name)._pair[:] = _split(value) elif name in dir(self) and name != 'reset': object.__setattr__(self, name, value) else: raise AttributeError( "'default' object has no attribute " + repr(name)) @property def _default_device(self): return (_lib.Pa_GetDefaultInputDevice(), _lib.Pa_GetDefaultOutputDevice()) @property def hostapi(self): """Index of the default host API (read-only).""" return _check(_lib.Pa_GetDefaultHostApi())
[docs] def reset(self): """Reset all attributes to their "factory default".""" vars(self).clear() self.__init__()
if not hasattr(_ffi, 'I_AM_FAKE'): # This object shadows the 'default' class, except when building the docs. default = default()
[docs]class PortAudioError(Exception): """This exception will be raised on PortAudio errors. Attributes ---------- args A variable length tuple containing the following elements when available: 1) A string describing the error 2) The PortAudio ``PaErrorCode`` value 3) A 3-tuple containing the host API index, host error code, and the host error message (which may be an empty string) """ def __str__(self): errormsg = self.args[0] if self.args else '' if len(self.args) > 1: errormsg = '{} [PaErrorCode {}]'.format(errormsg, self.args[1]) if len(self.args) > 2: host_api, hosterror_code, hosterror_text = self.args[2] hostname = query_hostapis(host_api)['name'] errormsg = "{}: '{}' [{} error {}]".format( errormsg, hosterror_text, hostname, hosterror_code) return errormsg
[docs]class CallbackStop(Exception): """Exception to be raised by the user to stop callback processing. If this is raised in the stream callback, the callback will not be invoked anymore (but all pending audio buffers will be played). See Also -------- CallbackAbort, :meth:`Stream.stop`, Stream """
[docs]class CallbackAbort(Exception): """Exception to be raised by the user to abort callback processing. If this is raised in the stream callback, all pending buffers are discarded and the callback will not be invoked anymore. See Also -------- CallbackStop, :meth:`Stream.abort`, Stream """
[docs]class AsioSettings(object): def __init__(self, channel_selectors): """ASIO-specific input/output settings. Objects of this class can be used as *extra_settings* argument to `Stream()` (and variants) or as `default.extra_settings`. Parameters ---------- channel_selectors : list of int Support for opening only specific channels of an ASIO device. *channel_selectors* is a list of integers specifying the (zero-based) channel numbers to use. The length of *channel_selectors* must match the corresponding *channels* parameter of `Stream()` (or variants), otherwise a crash may result. The values in the *channel_selectors* array must specify channels within the range of supported channels. Examples -------- Setting output channels when calling `play()`: >>> import sounddevice as sd >>> asio_out = sd.AsioSettings(channel_selectors=[12, 13]) >>> sd.play(..., extra_settings=asio_out) Setting default output channels: >>> sd.default.extra_settings = asio_out >>> sd.play(...) Setting input channels as well: >>> asio_in = sd.AsioSettings(channel_selectors=[8]) >>> sd.default.extra_settings = asio_in, asio_out >>> sd.playrec(..., channels=1, ...) """ if isinstance(channel_selectors, int): raise TypeError('channel_selectors must be a list or tuple') # int array must be kept alive! self._selectors = _ffi.new('int[]', channel_selectors) self._streaminfo = _ffi.new('PaAsioStreamInfo*', dict( size=_ffi.sizeof('PaAsioStreamInfo'), hostApiType=_lib.paASIO, version=1, flags=_lib.paAsioUseChannelSelectors, channelSelectors=self._selectors))
[docs]class CoreAudioSettings(object): def __init__(self, channel_map=None, change_device_parameters=False, fail_if_conversion_required=False, conversion_quality='max'): """Mac Core Audio-specific input/output settings. Objects of this class can be used as *extra_settings* argument to `Stream()` (and variants) or as `default.extra_settings`. Parameters ---------- channel_map : sequence of int, optional Support for opening only specific channels of a Core Audio device. Note that *channel_map* is treated differently between input and output channels. For input devices, *channel_map* is a list of integers specifying the (zero-based) channel numbers to use. For output devices, *channel_map* must have the same length as the number of output channels of the device. Specify unused channels with -1, and a 0-based index for any desired channels. See the example below. For additional information, see the `PortAudio documentation`__. __ https://app.assembla.com/spaces/portaudio/git/source/ master/src/hostapi/coreaudio/notes.txt change_device_parameters : bool, optional If ``True``, allows PortAudio to change things like the device's frame size, which allows for much lower latency, but might disrupt the device if other programs are using it, even when you are just querying the device. ``False`` is the default. fail_if_conversion_required : bool, optional In combination with the above flag, ``True`` causes the stream opening to fail, unless the exact sample rates are supported by the device. conversion_quality : {'min', 'low', 'medium', 'high', 'max'}, optional This sets Core Audio's sample rate conversion quality. ``'max'`` is the default. Example ------- This example assumes a device having 6 input and 6 output channels. Input is from the second and fourth channels, and output is to the device's third and fifth channels: >>> import sounddevice as sd >>> ca_in = sd.CoreAudioSettings(channel_map=[1, 3]) >>> ca_out = sd.CoreAudioSettings(channel_map=[-1, -1, 0, -1, 1, -1]) >>> sd.playrec(..., channels=2, extra_settings=(ca_in, ca_out)) """ conversion_dict = { 'min': _lib.paMacCoreConversionQualityMin, 'low': _lib.paMacCoreConversionQualityLow, 'medium': _lib.paMacCoreConversionQualityMedium, 'high': _lib.paMacCoreConversionQualityHigh, 'max': _lib.paMacCoreConversionQualityMax, } # Minimal checking on channel_map to catch errors that might # otherwise go unnoticed: if isinstance(channel_map, int): raise TypeError('channel_map must be a list or tuple') try: self._flags = conversion_dict[conversion_quality.lower()] except (KeyError, AttributeError) as e: raise ValueError('conversion_quality must be one of ' + repr(list(conversion_dict))) from e if change_device_parameters: self._flags |= _lib.paMacCoreChangeDeviceParameters if fail_if_conversion_required: self._flags |= _lib.paMacCoreFailIfConversionRequired # this struct must be kept alive! self._streaminfo = _ffi.new('PaMacCoreStreamInfo*') _lib.PaMacCore_SetupStreamInfo(self._streaminfo, self._flags) if channel_map is not None: # this array must be kept alive! self._channel_map = _ffi.new('SInt32[]', channel_map) if len(self._channel_map) == 0: raise TypeError('channel_map must not be empty') _lib.PaMacCore_SetupChannelMap(self._streaminfo, self._channel_map, len(self._channel_map))
[docs]class WasapiSettings(object): def __init__(self, exclusive=False): """WASAPI-specific input/output settings. Objects of this class can be used as *extra_settings* argument to `Stream()` (and variants) or as `default.extra_settings`. They can also be used in `check_input_settings()` and `check_output_settings()`. Parameters ---------- exclusive : bool Exclusive mode allows to deliver audio data directly to hardware bypassing software mixing. Examples -------- Setting exclusive mode when calling `play()`: >>> import sounddevice as sd >>> wasapi_exclusive = sd.WasapiSettings(exclusive=True) >>> sd.play(..., extra_settings=wasapi_exclusive) Setting exclusive mode as default: >>> sd.default.extra_settings = wasapi_exclusive >>> sd.play(...) """ flags = 0x0 if exclusive: flags |= _lib.paWinWasapiExclusive self._streaminfo = _ffi.new('PaWasapiStreamInfo*', dict( size=_ffi.sizeof('PaWasapiStreamInfo'), hostApiType=_lib.paWASAPI, version=1, flags=flags, ))
class _CallbackContext(object): """Helper class for re-use in play()/rec()/playrec() callbacks.""" blocksize = None data = None out = None frame = 0 input_channels = output_channels = None input_dtype = output_dtype = None input_mapping = output_mapping = None silent_channels = None def __init__(self, loop=False): import threading try: import numpy assert numpy # avoid "imported but unused" message (W0611) except ImportError as e: raise ImportError( 'NumPy must be installed for play()/rec()/playrec()') from e self.loop = loop self.event = threading.Event() self.status = CallbackFlags() def check_data(self, data, mapping, device): """Check data and output mapping.""" import numpy as np data = np.asarray(data) if data.ndim < 2: data = data.reshape(-1, 1) frames, channels = data.shape dtype = _check_dtype(data.dtype) mapping_is_explicit = mapping is not None mapping, channels = _check_mapping(mapping, channels) if data.shape[1] == 1: pass # No problem, mono data is duplicated into arbitrary channels elif data.shape[1] != len(mapping): raise ValueError( 'number of output channels != size of output mapping') # Apparently, some PortAudio host APIs duplicate mono streams to the # first two channels, which is unexpected when specifying mapping=[1]. # In this case, we play silence on the second channel, but only if the # device actually supports a second channel: if (mapping_is_explicit and np.array_equal(mapping, [0]) and query_devices(device, 'output')['max_output_channels'] >= 2): channels = 2 silent_channels = np.setdiff1d(np.arange(channels), mapping) if len(mapping) + len(silent_channels) != channels: raise ValueError('each channel may only appear once in mapping') self.data = data self.output_channels = channels self.output_dtype = dtype self.output_mapping = mapping self.silent_channels = silent_channels return frames def check_out(self, out, frames, channels, dtype, mapping): """Check out, frames, channels, dtype and input mapping.""" import numpy as np if out is None: if frames is None: raise TypeError('frames must be specified') if channels is None: channels = default.channels['input'] if channels is None: if mapping is None: raise TypeError( 'Unable to determine number of input channels') else: channels = len(np.atleast_1d(mapping)) if dtype is None: dtype = default.dtype['input'] out = np.empty((frames, channels), dtype, order='C') else: frames, channels = out.shape dtype = out.dtype dtype = _check_dtype(dtype) mapping, channels = _check_mapping(mapping, channels) if out.shape[1] != len(mapping): raise ValueError( 'number of input channels != size of input mapping') self.out = out self.input_channels = channels self.input_dtype = dtype self.input_mapping = mapping return out, frames def callback_enter(self, status, data): """Check status and blocksize.""" self.status |= status self.blocksize = min(self.frames - self.frame, len(data)) def read_indata(self, indata): # We manually iterate over each channel in mapping because # numpy.take(..., out=...) has a bug: # https://github.com/numpy/numpy/pull/4246. # Note: using indata[:blocksize, mapping] (a.k.a. 'fancy' indexing) # would create unwanted copies (and probably memory allocations). for target, source in enumerate(self.input_mapping): # If out.dtype is 'float64', 'float32' data is "upgraded" here: self.out[self.frame:self.frame + self.blocksize, target] = \ indata[:self.blocksize, source] def write_outdata(self, outdata): # 'float64' data is cast to 'float32' here: outdata[:self.blocksize, self.output_mapping] = \ self.data[self.frame:self.frame + self.blocksize] outdata[:self.blocksize, self.silent_channels] = 0 if self.loop and self.blocksize < len(outdata): self.frame = 0 outdata = outdata[self.blocksize:] self.blocksize = min(self.frames, len(outdata)) self.write_outdata(outdata) else: outdata[self.blocksize:] = 0 def callback_exit(self): if not self.blocksize: raise CallbackAbort self.frame += self.blocksize def finished_callback(self): self.event.set() # Drop temporary audio buffers to free memory self.data = None self.out = None # Drop CFFI objects to avoid reference cycles self.stream._callback = None self.stream._finished_callback = None def start_stream(self, StreamClass, samplerate, channels, dtype, callback, blocking, **kwargs): stop() # Stop previous playback/recording self.stream = StreamClass(samplerate=samplerate, channels=channels, dtype=dtype, callback=callback, finished_callback=self.finished_callback, **kwargs) self.stream.start() global _last_callback _last_callback = self if blocking: self.wait() def wait(self, ignore_errors=True): """Wait for finished_callback. Can be interrupted with a KeyboardInterrupt. """ try: self.event.wait() finally: self.stream.close(ignore_errors) return self.status if self.status else None def _remove_self(d): """Return a copy of d without the 'self' entry.""" d = d.copy() del d['self'] return d def _check_mapping(mapping, channels): """Check mapping, obtain channels.""" import numpy as np if mapping is None: mapping = np.arange(channels) else: mapping = np.array(mapping, copy=True) mapping = np.atleast_1d(mapping) if mapping.min() < 1: raise ValueError('channel numbers must not be < 1') channels = mapping.max() mapping -= 1 # channel numbers start with 1 return mapping, channels def _check_dtype(dtype): """Check dtype.""" import numpy as np dtype = np.dtype(dtype).name if dtype in _sampleformats: pass elif dtype == 'float64': dtype = 'float32' else: raise TypeError('Unsupported data type: ' + repr(dtype)) return dtype def _get_stream_parameters(kind, device, channels, dtype, latency, extra_settings, samplerate): """Get parameters for one direction (input or output) of a stream.""" assert kind in ('input', 'output') if device is None: device = default.device[kind] if channels is None: channels = default.channels[kind] if dtype is None: dtype = default.dtype[kind] if latency is None: latency = default.latency[kind] if extra_settings is None: extra_settings = default.extra_settings[kind] if samplerate is None: samplerate = default.samplerate device = _get_device_id(device, kind, raise_on_error=True) info = query_devices(device) if channels is None: channels = info['max_' + kind + '_channels'] try: # If NumPy is available, get canonical dtype name dtype = _sys.modules['numpy'].dtype(dtype).name except Exception: pass # NumPy not available or invalid dtype (e.g. 'int24') or ... try: sampleformat = _sampleformats[dtype] except KeyError as e: raise ValueError('Invalid ' + kind + ' sample format') from e samplesize = _check(_lib.Pa_GetSampleSize(sampleformat)) if latency in ('low', 'high'): latency = info['default_' + latency + '_' + kind + '_latency'] if samplerate is None: samplerate = info['default_samplerate'] parameters = _ffi.new('PaStreamParameters*', ( device, channels, sampleformat, latency, extra_settings._streaminfo if extra_settings else _ffi.NULL)) return parameters, dtype, samplesize, samplerate def _wrap_callback(callback, *args): """Invoke callback function and check for custom exceptions.""" args = args[:-1] + (CallbackFlags(args[-1]),) try: callback(*args) except CallbackStop: return _lib.paComplete except CallbackAbort: return _lib.paAbort return _lib.paContinue def _buffer(ptr, frames, channels, samplesize): """Create a buffer object from a pointer to some memory.""" return _ffi.buffer(ptr, frames * channels * samplesize) def _array(buffer, channels, dtype): """Create NumPy array from a buffer object.""" import numpy as np data = np.frombuffer(buffer, dtype=dtype) data.shape = -1, channels return data
[docs]def _split(value): """Split input/output value into two values. This can be useful for generic code that allows using the same value for input and output but also a pair of two separate values. """ if isinstance(value, (str, bytes)): # iterable, but not meant for splitting return value, value try: invalue, outvalue = value except TypeError: invalue = outvalue = value except ValueError as e: raise ValueError('Only single values and pairs are allowed') from e return invalue, outvalue
def _check(err, msg=''): """Raise PortAudioError for below-zero error codes.""" if err >= 0: return err errormsg = _ffi.string(_lib.Pa_GetErrorText(err)).decode() if msg: errormsg = '{}: {}'.format(msg, errormsg) if err == _lib.paUnanticipatedHostError: # (gh82) We grab the host error info here rather than inside # PortAudioError since _check should only ever be called after a # failing API function call. This way we can avoid any potential issues # in scenarios where multiple APIs are being used simultaneously. info = _lib.Pa_GetLastHostErrorInfo() host_api = _lib.Pa_HostApiTypeIdToHostApiIndex(info.hostApiType) hosterror_text = _ffi.string(info.errorText).decode() hosterror_info = host_api, info.errorCode, hosterror_text raise PortAudioError(errormsg, err, hosterror_info) raise PortAudioError(errormsg, err) def _get_device_id(id_or_query_string, kind, raise_on_error=False): """Return device ID given space-separated substrings.""" assert kind in ('input', 'output', None) if id_or_query_string is None: id_or_query_string = default.device idev, odev = _split(id_or_query_string) if kind == 'input': id_or_query_string = idev elif kind == 'output': id_or_query_string = odev else: if idev == odev: id_or_query_string = idev else: raise ValueError('Input and output device are different: {!r}' .format(id_or_query_string)) if isinstance(id_or_query_string, int): return id_or_query_string device_list = [] for id, info in enumerate(query_devices()): if not kind or info['max_' + kind + '_channels'] > 0: hostapi_info = query_hostapis(info['hostapi']) device_list.append((id, info['name'], hostapi_info['name'])) query_string = id_or_query_string.lower() substrings = query_string.split() matches = [] exact_device_matches = [] for id, device_string, hostapi_string in device_list: full_string = device_string + ', ' + hostapi_string pos = 0 for substring in substrings: pos = full_string.lower().find(substring, pos) if pos < 0: break pos += len(substring) else: matches.append((id, full_string)) if device_string.lower() == query_string: exact_device_matches.append(id) if kind is None: kind = 'input/output' # Just used for error messages if not matches: if raise_on_error: raise ValueError( 'No ' + kind + ' device matching ' + repr(id_or_query_string)) else: return -1 if len(matches) > 1: if len(exact_device_matches) == 1: return exact_device_matches[0] if raise_on_error: raise ValueError('Multiple ' + kind + ' devices found for ' + repr(id_or_query_string) + ':\n' + '\n'.join('[{}] {}'.format(id, name) for id, name in matches)) else: return -1 return matches[0][0]
[docs]def _initialize(): """Initialize PortAudio. This temporarily forwards messages from stderr to ``/dev/null`` (where supported). In most cases, this doesn't have to be called explicitly, because it is automatically called with the ``import sounddevice`` statement. """ old_stderr = None try: stdio = _ffi.dlopen(None) except OSError: pass else: for stderr_name in 'stderr', '__stderrp': try: old_stderr = getattr(stdio, stderr_name) except _ffi.error: continue else: devnull = stdio.fopen(_os.devnull.encode(), b'w') setattr(stdio, stderr_name, devnull) break try: _check(_lib.Pa_Initialize(), 'Error initializing PortAudio') global _initialized _initialized += 1 finally: if old_stderr is not None: setattr(stdio, stderr_name, old_stderr) stdio.fclose(devnull)
[docs]def _terminate(): """Terminate PortAudio. In most cases, this doesn't have to be called explicitly. """ global _initialized _check(_lib.Pa_Terminate(), 'Error terminating PortAudio') _initialized -= 1
def _exit_handler(): assert _initialized >= 0 # We cleanup any open streams here since older versions of portaudio don't # manage this (see github issue #1) if _last_callback: # NB: calling stop() first is required; without it portaudio hangs when # calling close() _last_callback.stream.stop() _last_callback.stream.close() while _initialized: _terminate() _atexit.register(_exit_handler) _initialize() if __name__ == '__main__': print(query_devices())