Source code for sounddevice

# Copyright (c) 2015-2016 Matthias Geier
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.

"""Play and Record Sound with Python.

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

"""
__version__ = "0.3.3"

import atexit as _atexit
from cffi import FFI as _FFI
import os as _os
import platform as _platform
import sys as _sys

_ffi = _FFI()
_ffi.cdef("""
int Pa_GetVersion( void );
const char* Pa_GetVersionText( void );
typedef int PaError;
typedef enum PaErrorCode
{
    paNoError = 0,
    paNotInitialized = -10000,
    paUnanticipatedHostError,
    paInvalidChannelCount,
    paInvalidSampleRate,
    paInvalidDevice,
    paInvalidFlag,
    paSampleFormatNotSupported,
    paBadIODeviceCombination,
    paInsufficientMemory,
    paBufferTooBig,
    paBufferTooSmall,
    paNullCallback,
    paBadStreamPtr,
    paTimedOut,
    paInternalError,
    paDeviceUnavailable,
    paIncompatibleHostApiSpecificStreamInfo,
    paStreamIsStopped,
    paStreamIsNotStopped,
    paInputOverflowed,
    paOutputUnderflowed,
    paHostApiNotFound,
    paInvalidHostApi,
    paCanNotReadFromACallbackStream,
    paCanNotWriteToACallbackStream,
    paCanNotReadFromAnOutputOnlyStream,
    paCanNotWriteToAnInputOnlyStream,
    paIncompatibleStreamHostApi,
    paBadBufferPtr
} PaErrorCode;
const char *Pa_GetErrorText( PaError errorCode );
PaError Pa_Initialize( void );
PaError Pa_Terminate( void );
typedef int PaDeviceIndex;
/* not implemented: paNoDevice */
/* not implemented: paUseHostApiSpecificDeviceSpecification */
typedef int PaHostApiIndex;
PaHostApiIndex Pa_GetHostApiCount( void );
PaHostApiIndex Pa_GetDefaultHostApi( void );
typedef enum PaHostApiTypeId
{
    paInDevelopment=0,
    paDirectSound=1,
    paMME=2,
    paASIO=3,
    paSoundManager=4,
    paCoreAudio=5,
    paOSS=7,
    paALSA=8,
    paAL=9,
    paBeOS=10,
    paWDMKS=11,
    paJACK=12,
    paWASAPI=13,
    paAudioScienceHPI=14
} PaHostApiTypeId;
typedef struct PaHostApiInfo
{
    int structVersion;
    PaHostApiTypeId type;
    const char *name;
    int deviceCount;
    PaDeviceIndex defaultInputDevice;
    PaDeviceIndex defaultOutputDevice;
} PaHostApiInfo;
const PaHostApiInfo * Pa_GetHostApiInfo( PaHostApiIndex hostApi );
PaHostApiIndex Pa_HostApiTypeIdToHostApiIndex( PaHostApiTypeId type );
PaDeviceIndex Pa_HostApiDeviceIndexToDeviceIndex( PaHostApiIndex hostApi,
        int hostApiDeviceIndex );
typedef struct PaHostErrorInfo{
    PaHostApiTypeId hostApiType;
    long errorCode;
    const char *errorText;
}PaHostErrorInfo;
const PaHostErrorInfo* Pa_GetLastHostErrorInfo( void );
PaDeviceIndex Pa_GetDeviceCount( void );
PaDeviceIndex Pa_GetDefaultInputDevice( void );
PaDeviceIndex Pa_GetDefaultOutputDevice( void );
typedef double PaTime;
typedef unsigned long PaSampleFormat;
#define paFloat32        0x00000001
#define paInt32          0x00000002
#define paInt24          0x00000004
#define paInt16          0x00000008
#define paInt8           0x00000010
#define paUInt8          0x00000020
#define paCustomFormat   0x00010000
#define paNonInterleaved 0x80000000
typedef struct PaDeviceInfo
{
    int structVersion;
    const char *name;
    PaHostApiIndex hostApi;
    int maxInputChannels;
    int maxOutputChannels;
    PaTime defaultLowInputLatency;
    PaTime defaultLowOutputLatency;
    PaTime defaultHighInputLatency;
    PaTime defaultHighOutputLatency;
    double defaultSampleRate;
} PaDeviceInfo;
const PaDeviceInfo* Pa_GetDeviceInfo( PaDeviceIndex device );
typedef struct PaStreamParameters
{
    PaDeviceIndex device;
    int channelCount;
    PaSampleFormat sampleFormat;
    PaTime suggestedLatency;
    void *hostApiSpecificStreamInfo;
} PaStreamParameters;
/* not implemented: paFormatIsSupported */
PaError Pa_IsFormatSupported( const PaStreamParameters *inputParameters,
                              const PaStreamParameters *outputParameters,
                              double sampleRate );
typedef void PaStream;
#define paFramesPerBufferUnspecified 0
typedef unsigned long PaStreamFlags;
#define   paNoFlag         0
#define   paClipOff        0x00000001
#define   paDitherOff      0x00000002
#define   paNeverDropInput 0x00000004
#define   paPrimeOutputBuffersUsingStreamCallback 0x00000008
#define   paPlatformSpecificFlags 0xFFFF0000
typedef struct PaStreamCallbackTimeInfo{
    PaTime inputBufferAdcTime;
    PaTime currentTime;
    PaTime outputBufferDacTime;
} PaStreamCallbackTimeInfo;
typedef unsigned long PaStreamCallbackFlags;
#define paInputUnderflow  0x00000001
#define paInputOverflow   0x00000002
#define paOutputUnderflow 0x00000004
#define paOutputOverflow  0x00000008
#define paPrimingOutput   0x00000010
typedef enum PaStreamCallbackResult
{
    paContinue=0,
    paComplete=1,
    paAbort=2
} PaStreamCallbackResult;
typedef int PaStreamCallback(
    const void *input, void *output,
    unsigned long frameCount,
    const PaStreamCallbackTimeInfo* timeInfo,
    PaStreamCallbackFlags statusFlags,
    void *userData );
PaError Pa_OpenStream( PaStream** stream,
                       const PaStreamParameters *inputParameters,
                       const PaStreamParameters *outputParameters,
                       double sampleRate,
                       unsigned long framesPerBuffer,
                       PaStreamFlags streamFlags,
                       PaStreamCallback *streamCallback,
                       void *userData );
/* not implemented: Pa_OpenDefaultStream */
PaError Pa_CloseStream( PaStream *stream );
typedef void PaStreamFinishedCallback( void *userData );
PaError Pa_SetStreamFinishedCallback( PaStream *stream,
    PaStreamFinishedCallback* streamFinishedCallback );
PaError Pa_StartStream( PaStream *stream );
PaError Pa_StopStream( PaStream *stream );
PaError Pa_AbortStream( PaStream *stream );
PaError Pa_IsStreamStopped( PaStream *stream );
PaError Pa_IsStreamActive( PaStream *stream );
typedef struct PaStreamInfo
{
    int structVersion;
    PaTime inputLatency;
    PaTime outputLatency;
    double sampleRate;
} PaStreamInfo;
const PaStreamInfo* Pa_GetStreamInfo( PaStream *stream );
PaTime Pa_GetStreamTime( PaStream *stream );
double Pa_GetStreamCpuLoad( PaStream* stream );
PaError Pa_ReadStream( PaStream* stream,
                       void *buffer,
                       unsigned long frames );
PaError Pa_WriteStream( PaStream* stream,
                        const void *buffer,
                        unsigned long frames );
signed long Pa_GetStreamReadAvailable( PaStream* stream );
signed long Pa_GetStreamWriteAvailable( PaStream* stream );
/* not implemented: Pa_GetStreamHostApiType */
PaError Pa_GetSampleSize( PaSampleFormat format );
void Pa_Sleep( long msec );
""")

try:
    _lib = _ffi.dlopen('portaudio')
except OSError:
    if _platform.system() == 'Darwin':
        _libname = 'libportaudio.dylib'
    elif _platform.system() == 'Windows':
        _libname = 'libportaudio' + _platform.architecture()[0] + '.dll'
    else:
        raise
    _lib = _ffi.dlopen(_os.path.join(
        _os.path.dirname(_os.path.abspath(__file__)),
        '_sounddevice_data',
        _libname
    ))

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

_last_callback = None


[docs]def play(data, samplerate=None, mapping=None, blocking=False, loop=False, **kwargs): """Play back an array of audio data. 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 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). Each channel 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 :func:`stop` or turned into a blocking one with :func:`wait`. loop : bool, optional Play `data` in a loop. Other Parameters ---------------- samplerate, **kwargs All parameters of :class:`OutputStream` (except `channels`, `dtype`, `callback` and `finished_callback`) can be used. 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. 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 :attr:`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 :attr:`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 :func:`stop` or turned into a blocking one with :func:`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 :func:`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 :class:`InputStream` (except `callback` and `finished_callback`) can be used. See Also -------- play, playrec """ ctx = _CallbackContext() 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 ctx.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. Parameters ---------- data : array_like Audio data to be played back. See :func:`play`. channels : int, sometimes optional Number of input channels, see :func:`rec`. The number of output channels is obtained from `data.shape`. dtype : str or numpy.dtype, optional Input data type, see :func:`rec`. If `dtype` is not specified, it is taken from `data.dtype` (i.e. :attr:`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 :func:`rec` and :func:`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 :func:`stop` or turned into a blocking one with :func:`wait`. Returns ------- numpy.ndarray or type(out) The recorded data. See :func:`rec`. Other Parameters ---------------- out : numpy.ndarray or subclass, optional See :func:`rec`. samplerate, **kwargs All parameters of :class:`Stream` (except `channels`, `dtype`, `callback` and `finished_callback`) can be used. 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 input_frames = ctx.check_out(out, output_frames, channels, dtype, input_mapping) if input_frames != output_frames: raise PortAudioError("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 ctx.out
[docs]def wait(): """Wait for :func:`play`/:func:`rec`/:func:`playrec` to be finished. Playback/recording can be stopped with a :class:`KeyboardInterrupt`. Returns ------- CallbackFlags or None If at least one buffer over-/underrun happened during the last playback/recording, a :class:`CallbackFlags` object is returned. See Also -------- get_status """ if _last_callback: return _last_callback.wait()
[docs]def stop(ignore_errors=True): """Stop playback/recording. This only stops :func:`play`, :func:`rec` and :func:`playrec`, but has no influence on streams created with :class:`Stream`, :class:`InputStream`, :class:`OutputStream`, :class:`RawStream`, :class:`RawInputStream`, :class:`RawOutputStream`. """ if _last_callback: _last_callback.stream.close(ignore_errors)
[docs]def get_status(): """Get information about over-/underflows in play()/rec()/playrec(). Returns ------- CallbackFlags A :class:`CallbackFlags` object that holds information about the last invocation of :func:`play`, :func:`rec` or :func:`playrec`. See Also -------- wait """ if _last_callback: return _last_callback.status 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, use :attr:`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 `device` was specified -- a :class:`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 :func:`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 :attr:`default.channels`. ``'default_low_input_latency'``, ``'default_low_output_latency'`` Default latency values for interactive performance. This is used if :attr:`default.latency` (or the `latency` argument of :func:`playrec`, :class:`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 :attr:`default.latency` (or the `latency` argument of :func:`playrec`, :class:`Stream` etc.) is set to ``'high'``. ``'default_samplerate'`` The default sampling frequency of the device. This is used if :attr:`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 :class:`DeviceList` can be indexed and iterated over like a normal :class:`tuple` (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 :attr:`default.device` or used as `device` argument in :func:`play`, :class:`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 Mac OS X, 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: {0!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 {0}".format(device)) assert info.structVersion == 2 if info.hostApi == _lib.Pa_HostApiTypeIdToHostApiIndex(_lib.paDirectSound): encoding = 'mbcs' else: encoding = 'utf-8' device_dict = { 'name': _ffi.string(info.name).decode(encoding, 'replace'), '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 {0} device: {1!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 :func:`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 :attr:`default.device` -- take(s) precedence over :attr:`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 {0}".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, samplerate=None): """Check if given input device settings are supported. All parameters are optional, :obj:`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, see :attr:`default.device`. channels : int, optional Number of input channels, see :attr:`default.channels`. dtype : str or numpy.dtype, optional Data type for input samples, see :attr:`default.dtype`. samplerate : float, optional Sampling frequency, see :attr:`default.samplerate`. """ parameters, dtype, samplesize, samplerate = _get_stream_parameters( 'input', device=device, channels=channels, dtype=dtype, latency=None, samplerate=samplerate) _check(_lib.Pa_IsFormatSupported(parameters, _ffi.NULL, samplerate))
[docs]def check_output_settings(device=None, channels=None, dtype=None, samplerate=None): """Check if given output device settings are supported. Same as :func:`check_input_settings`, just for output device settings. """ parameters, dtype, samplesize, samplerate = _get_stream_parameters( 'output', device=device, channels=channels, dtype=dtype, latency=None, 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()
class _StreamBase(object): """Base class for Raw{Input,Output}Stream.""" def __init__(self, kind, samplerate, blocksize, device, channels, dtype, latency, callback_wrapper, finished_callback, clip_off, dither_off, never_drop_input, prime_output_buffers_using_stream_callback): 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) iparameters, idtype, isize, isamplerate = _get_stream_parameters( 'input', idevice, ichannels, idtype, ilatency, samplerate) oparameters, odtype, osize, osamplerate = _get_stream_parameters( 'output', odevice, ochannels, odtype, olatency, 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 PortAudioError( "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, 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 if callback_wrapper: self._callback = _ffi.callback( "PaStreamCallback", callback_wrapper, error=_lib.paAbort) else: self._callback = _ffi.NULL self._ptr = _ffi.new("PaStream**") _check(_lib.Pa_OpenStream(self._ptr, iparameters, oparameters, samplerate, blocksize, stream_flags, self._callback, _ffi.NULL), "Error opening {0}".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: def finished_callback_wrapper(_): return finished_callback() 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 :class:`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 :class:`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 :class:`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 :class:`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 :meth:`start`, until it becomes inactive either as a result of a call to :meth:`.stop` or :meth:`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 """ 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 :meth:`start` and after a successful call to :meth:`.stop` or :meth:`abort`. If a stream callback is cancelled (by raising an exception) the stream is *not* considered to be stopped. See Also -------- active """ return _check(_lib.Pa_IsStreamStopped(self._ptr)) == 1 @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 :class:`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 __del__(self): """Close stream at garbage collection.""" self.close() 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): """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 err != _lib.paStreamIsStopped: _check(err, "Error stopping stream") def abort(self): """Terminate audio processing immediately. This does not wait for pending buffers to complete. See Also -------- start, stop """ err = _lib.Pa_AbortStream(self._ptr) if err != _lib.paStreamIsStopped: _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 :meth:`abort` had been called. """ err = _lib.Pa_CloseStream(self._ptr) 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, callback=None, finished_callback=None, clip_off=None, dither_off=None, never_drop_input=None, prime_output_buffers_using_stream_callback=None): """Open a "raw" input stream. This is the same as :class:`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 to use this. Parameters ---------- dtype : str See :class:`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 :class:`RawStream`, except that `outdata` is missing. See Also -------- RawStream, Stream """ def callback_wrapper(iptr, optr, frames, time, status, _): data = _buffer(iptr, frames, self._channels, self._samplesize) return _wrap_callback(callback, data, frames, time, status) _StreamBase.__init__( self, 'input', samplerate, blocksize, device, channels, dtype, latency, callback and callback_wrapper, finished_callback, clip_off, dither_off, never_drop_input, prime_output_buffers_using_stream_callback) @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 :meth:`Stream.read`, except that it returns a plain Python buffer object instead of a NumPy array. NumPy is not necessary to use this. Parameters ---------- frames : int The number of frames to be read. See :meth:`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 :attr:`Stream.samplesize`. overflowed : bool See :meth:`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, callback=None, finished_callback=None, clip_off=None, dither_off=None, never_drop_input=None, prime_output_buffers_using_stream_callback=None): """Open a "raw" output stream. This is the same as :class:`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 to use this. Parameters ---------- dtype : str See :class:`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 :class:`RawStream`, except that `indata` is missing. See Also -------- RawStream, Stream """ def callback_wrapper(iptr, optr, frames, time, status, _): data = _buffer(optr, frames, self._channels, self._samplesize) return _wrap_callback(callback, data, frames, time, status) _StreamBase.__init__( self, 'output', samplerate, blocksize, device, channels, dtype, latency, callback and callback_wrapper, finished_callback, clip_off, dither_off, never_drop_input, prime_output_buffers_using_stream_callback) @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 :meth:`Stream.write`, except that it expects a plain Python buffer object instead of a NumPy array. NumPy is not necessary to use 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 :attr:`Stream.samplesize`. Returns ------- underflowed : bool See :meth:`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, callback=None, finished_callback=None, clip_off=None, dither_off=None, never_drop_input=None, prime_output_buffers_using_stream_callback=None): """Open a "raw" input/output stream. This is the same as :class:`Stream`, except that the `callback` function and :meth:`read`/:meth:`write` work on plain Python buffer objects instead of on NumPy arrays. NumPy is not necessary to use this. To open "raw" input-only or output-only stream use :class:`RawInputStream` or :class:`RawOutputStream`, respectively. If you want to handle audio data as NumPy arrays instead of buffer objects, use :class:`Stream`, :class:`InputStream` or :class:`OutputStream`. Parameters ---------- dtype : str or pair of str The sample format of the buffers provided to the stream callback, :meth:`read` or :meth:`write`. In addition to the formats supported by :class:`Stream` (``'float32'``, ``'int32'``, ``'int16'``, ``'int8'``, ``'uint8'``), this also supports ``'int24'``, i.e. packed 24 bit format. The default value can be changed with :attr:`default.dtype`. See also :attr:`Stream.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 :class:`Stream`, except that `indata` and `outdata` are plain Python buffer objects instead of NumPy arrays. See Also -------- RawInputStream, RawOutputStream, Stream """ def callback_wrapper(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) _StreamBase.__init__( self, 'duplex', samplerate, blocksize, device, channels, dtype, latency, callback and callback_wrapper, finished_callback, clip_off, dither_off, never_drop_input, prime_output_buffers_using_stream_callback)
[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, callback=None, finished_callback=None, clip_off=None, dither_off=None, never_drop_input=None, prime_output_buffers_using_stream_callback=None): """Open an input stream. This has the same methods and attributes as :class:`Stream`, except :meth:`~Stream.write` and :attr:`~Stream.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 :class:`Stream`, except that `outdata` is missing. See Also -------- Stream, RawInputStream """ def callback_wrapper(iptr, optr, frames, time, status, _): buffer = _buffer(iptr, frames, self._channels, self._samplesize) data = _array(buffer, self._channels, self._dtype) return _wrap_callback(callback, data, frames, time, status) _StreamBase.__init__( self, 'input', samplerate, blocksize, device, channels, dtype, latency, callback and callback_wrapper, finished_callback, clip_off, dither_off, never_drop_input, prime_output_buffers_using_stream_callback) 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 :attr:`read_available` frames were requested). This is the same as :meth:`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 :class:`numpy.ndarray` with one column per channel (i.e. with a shape of `(frames, channels)`) and with a data type specified by :attr:`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, callback=None, finished_callback=None, clip_off=None, dither_off=None, never_drop_input=None, prime_output_buffers_using_stream_callback=None): """Open an output stream. This has the same methods and attributes as :class:`Stream`, except :meth:`~Stream.read` and :attr:`~Stream.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 :class:`Stream`, except that `indata` is missing. See Also -------- Stream, RawOutputStream """ def callback_wrapper(iptr, optr, frames, time, status, _): buffer = _buffer(optr, frames, self._channels, self._samplesize) data = _array(buffer, self._channels, self._dtype) return _wrap_callback(callback, data, frames, time, status) _StreamBase.__init__( self, 'output', samplerate, blocksize, device, channels, dtype, latency, callback and callback_wrapper, finished_callback, clip_off, dither_off, never_drop_input, prime_output_buffers_using_stream_callback) 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 :attr:`write_available` frames). This is the same as :meth:`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 :attr:`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: {0!r} vs {1!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, callback=None, finished_callback=None, clip_off=None, dither_off=None, never_drop_input=None, prime_output_buffers_using_stream_callback=None): """Open a stream for input and output. To open an input-only or output-only stream use :class:`InputStream` or :class:`OutputStream`, respectively. If you want to handle audio data as buffer objects instead of NumPy arrays, use :class:`RawStream`, :class:`RawInputStream` or :class:`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 :attr:`default` object. If one of the values of a parameter pair is ``None``, the corresponding value from :attr:`default` will be used instead. The created stream is inactive (see :attr:`active`, :attr:`stopped`). It can be started with :meth:`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 :meth:`start` in the beginning of the statement and :meth:`stop` and :meth:`close` on exit. Parameters ---------- samplerate : float, optional The desired sampling frequency (for both input and output). The default value can be changed with :attr:`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 :attr:`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 :attr:`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 :meth:`read` or :meth:`write`. It can range from 1 to the value of ``'max_input_channels'``/``'max_output_channels'`` in the dict returned by :func:`query_devices`. By default, the maximum possible number of channels for the selected device is used (which may not be what you want; see :func:`query_devices`). The default value(s) can be changed with :attr:`default.channels`. dtype : str or numpy.dtype or pair thereof, optional The sample format of the :class:`numpy.ndarray` provided to the stream callback, :meth:`read` or :meth:`write`. It may be any of `float32`, `int32`, `int16`, `int8`, `uint8`. See :class:`numpy.dtype`. The `float64` data type is not supported, this is only supported for convenience in :func:`play`/:func:`rec`/:func:`playrec`. The packed 24 bit format ``'int24'`` is only supported in the "raw" stream classes, see :class:`RawStream`. The default value(s) can be changed with :attr:`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 :func:`query_devices`). The default value(s) can be changed with :attr:`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 :attr:`latency` attribute. callback : callable, optional User-supplied function to consume, process or generate audio data in response to requests from an :attr:`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 :meth:`read` and write sample data using :meth:`write`, the number of frames that may be read or written without blocking is returned by :attr:`read_available` and :attr:`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 :class:`numpy.ndarray` with one column per channel (i.e. with a shape of *(frames, channels)*) and with a data type specified by :attr:`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 :attr:`time` for the associated stream. The fifth argument is a :class:`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 :class:`CallbackAbort` is raised, the stream will finish as soon as possible. If :class:`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 :obj:`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 :meth:`.stop`, :meth:`abort` or :meth:`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 :attr:`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 :meth:`.stop` will not block). A stream will become inactive after the stream callback raises an exception or when :meth:`.stop` or :meth:`.abort` is called. For a stream providing audio output, if the stream callback raises :class:`CallbackStop`, or :meth:`.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 :attr:`default.clip_off`. dither_off : bool, optional See :attr:`default.dither_off`. never_drop_input : bool, optional See :attr:`default.never_drop_input`. prime_output_buffers_using_stream_callback : bool, optional See :attr:`default.prime_output_buffers_using_stream_callback`. """ def callback_wrapper(iptr, optr, frames, time, status, _): ichannels, ochannels = self._channels idtype, odtype = self._dtype isize, osize = self._samplesize ibuffer = _buffer(iptr, frames, ichannels, isize) obuffer = _buffer(optr, frames, ochannels, osize) idata = _array(ibuffer, ichannels, idtype) odata = _array(obuffer, ochannels, odtype) return _wrap_callback(callback, idata, odata, frames, time, status) _StreamBase.__init__( self, 'duplex', samplerate, blocksize, device, channels, dtype, latency, callback and callback_wrapper, finished_callback, clip_off, dither_off, never_drop_input, prime_output_buffers_using_stream_callback)
[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 :func:`query_devices`. It contains a dictionary for each available device, holding the keys described in :func:`query_devices`. This class has a special string representation that is shown as return value of :func:`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, odev = [ dev if isinstance(dev, int) else _get_device_id(dev, kind) for kind, dev in zip(('input', 'output'), default.device) ] digits = len(str(_lib.Pa_GetDeviceCount() - 1)) hostapi_names = [hostapi['name'] for hostapi in query_hostapis()] return '\n'.join( "{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))
[docs]class CallbackFlags(object): """Flag bits for the `status` argument to a stream `callback`. 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 """ __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: {0}>".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) __nonzero__ = __bool__ # For Python 2.x 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. """ return self._hasflag(_lib.paInputUnderflow) @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. Otherwise indicates that data prior to one or more samples in the input buffer was discarded. """ return self._hasflag(_lib.paInputOverflow) @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. """ return self._hasflag(_lib.paOutputUnderflow) @property def output_overflow(self): """Output overflow. Indicates that output data will be discarded because no room is available. """ return self._hasflag(_lib.paOutputOverflow) @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. """ return self._hasflag(_lib.paPrimingOutput) def _hasflag(self, flag): """Helper function to check a given flag.""" return bool(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 :attr:`device`, :attr:`channels`, :attr:`dtype` and :attr:`latency` 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 :meth:`reset` to reset all attributes: >>> sd.default.reset() """ # The class attributes device, channels, dtype and latency 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 :func:`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, :func:`play`, :func:`rec` and :func:`playrec` support ``'float64'`` (for convenience, data is merely converted from/to ``'float32'``) and :class:`RawInputStream`, :class:`RawOutputStream` and :class:`RawStream` support ``'int24'`` (packed 24 bit format -- *not* supported in NumPy!). If NumPy is available, the corresponding :class:`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` """ samplerate = None """Sampling frequency in Hertz (= frames per second). See Also -------- :func:`query_devices` """ blocksize = _lib.paFramesPerBufferUnspecified """See the `blocksize` argument of :class:`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 :class:`Stream` and :class:`RawStream` and only if `callback` was specified; this includes :func:`playrec`) and only when used in combination with `blocksize=0` (the default). Using this flag incorrectly results in an error being raised. """ 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 (:class:`InputStream` and :class:`RawInputStream`) and blocking read/write streams (i.e. if `callback` wasn't specified). """ def __init__(self): # __setattr__() must be avoided here vars(self)['device'] = _InputOutputPair(self, '_default_device') vars(self)['channels'] = _InputOutputPair(self, '_default_channels') vars(self)['dtype'] = _InputOutputPair(self, '_default_dtype') vars(self)['latency'] = _InputOutputPair(self, '_default_latency') def __setattr__(self, name, value): """Only allow setting existing attributes.""" if name in ('device', 'channels', 'dtype', 'latency'): 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."""
[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 """
class _CallbackContext(object): """Helper class for re-use in play()/rec()/playrec() callbacks.""" blocksize = None data = 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: raise ImportError( "NumPy must be installed for play()/rec()/playrec()") 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 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() 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): """Wait for finished_callback. Can be interrupted with a KeyboardInterrupt. """ try: self.event.wait() finally: self.stream.close() return self.status if self.status else None def _check_mapping(mapping, channels): """Check mapping, obtain channels.""" import numpy as np if mapping is None: mapping = np.arange(channels) else: 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, samplerate): """Get parameters for one direction (input or output) of a stream.""" 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 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: raise ValueError("Invalid " + kind + " sample format") 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, _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 def _split(value): """Split input/output value into two values.""" if isinstance(value, str): # iterable, but not meant for splitting return value, value try: invalue, outvalue = value except TypeError: invalue = outvalue = value except ValueError: raise ValueError("Only single values and pairs are allowed") return invalue, outvalue def _check(err, msg=""): """Raise error for non-zero error codes.""" if err < 0: msg += ": " if msg else "" if err == _lib.paUnanticipatedHostError: info = _lib.Pa_GetLastHostErrorInfo() hostapi = _lib.Pa_HostApiTypeIdToHostApiIndex(info.hostApiType) msg += "Unanticipated host API {0} error {1}: {2!r}".format( hostapi, info.errorCode, _ffi.string(info.errorText).decode()) else: msg += _ffi.string(_lib.Pa_GetErrorText(err)).decode() raise PortAudioError(msg) return 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: {0!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('[{0}] {1}'.format(id, name) for id, name in matches)) else: return -1 return matches[0][0] def _initialize(): """Initialize PortAudio.""" _check(_lib.Pa_Initialize(), "Error initializing PortAudio") _atexit.register(_lib.Pa_Terminate) def _terminate(): """Terminate PortAudio.""" _atexit.unregister(_lib.Pa_Terminate) _check(_lib.Pa_Terminate(), "Error terminating PortAudio") def _ignore_stderr(): """Try to forward PortAudio messages from stderr to /dev/null.""" ffi = _FFI() ffi.cdef(""" /* from stdio.h */ FILE* fopen(const char* path, const char* mode); int fclose(FILE* fp); FILE* stderr; /* GNU C library */ FILE* __stderrp; /* Mac OS X */ """) try: stdio = ffi.dlopen(None) devnull = stdio.fopen(_os.devnull.encode(), b'w') except OSError: return try: stdio.stderr = devnull except KeyError: try: stdio.__stderrp = devnull except KeyError: stdio.fclose(devnull) _ignore_stderr() _initialize() if __name__ == '__main__': print(query_devices())