Source code for psychopy.sound.backend_pygame

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import numpy
from os import path
from psychopy import logging
from psychopy.constants import (STARTED, PLAYING, PAUSED, FINISHED, STOPPED,
                                NOT_STARTED, FOREVER)
from ._base import _SoundBase
from .exceptions import DependencyError

try:
    import pygame
    from pygame import mixer, sndarray
except ImportError as err:
    # convert this import error to our own, pygame probably not installed
    raise DependencyError(repr(err))


def getDevices(kind=None):
    """Get audio playback and recording devices via the backend's audio API.

    Queries the system for available audio playback and recording devices,
    returning names and capabilities.

    Parameters
    ----------
    kind : str or None
        Audio device types to query from the system. Values can be 'input' or
        'output' for recording and playback, respectively. If `None`, only
        playback devices are returned.

    Returns
    -------
    dict
        A `dict` of `dict` of installed playback/capture devices and their
        properties. Keys are device names and values are properties stored in a
        `dict`. Properties are guaranteed to contain the following keys and
        values:

            * `name` - Human readable name of the device i.e. "High Definition
              Audio". This is the same as the value's key used to access the
              property.
            * `id` - Enumerated device ID.

    """
    # Just some values to keep the prefs dialog from crashing
    if kind.startswith('out') or None:
        return {'Default Playback Device':
                    {'name': 'Default Playback Device', 'id': 0}}
    elif kind.startswith('in'):
        return {'Default Recording Device':
                    {'name': 'Default Recording Device', 'id': 0}}
    else:
        raise ValueError("Invalid value for argument `kind`.")

    # # This code here will be usable when we update to Pygame 2.x, for now we
    # # just return some values indicating the default audio device is being
    # # used.
    #
    # # 0 = playback, 1 = recording
    # if kind.startswith('out') or None:
    #     devType = 0
    # elif kind.startswith('in'):
    #     devType = 1
    # else:
    #     raise ValueError('Invalid value for `kind`.')
    #
    # # query the number of devices of `kind` from SDL
    # devCount = sdl2.get_num_audio_devices(devType)
    #
    # # DEBUG: make sure we have an integer
    # assert isinstance(devCount, (int,))
    #
    # # build the dictionary of audio devices
    # devs = dict()
    # for devIdx in range(devCount):
    #     # create new entry in output dict
    #     devName = str(sdl2.get_audio_device_name(devIdx, 0), encoding="utf-8")
    #     devs[devName] = dict()
    #     devs['name'] = devName  # redundant?
    #     devs['id'] = devIdx
    #
    #     # query additional information from SDL2 about device


def init(rate=22050, bits=16, stereo=True, buffer=1024):
    """If you need a specific format for sounds you need to run this init
    function. Run this *before creating your visual.Window*.

    The format cannot be changed once initialised or once a Window has been
    created.

    If a Sound object is created before this function is run it will be
    executed with default format (signed 16bit stereo at 22KHz).

    For more details see pygame help page for the mixer.
    """
    global Sound, audioDriver
    Sound = SoundPygame
    audioDriver = 'n/a'
    if stereo == True:
        stereoChans = 2
    else:
        stereoChans = 0
    if bits == 16:
        # for pygame bits are signed for 16bit, signified by the minus
        bits = -16
    # defaults: 22050Hz, 16bit, stereo,
    mixer.init(rate, bits, stereoChans, buffer)
    sndarray.use_arraytype("numpy")
    setRate, setBits, setStereo = mixer.get_init()
    if setRate != rate:
        logging.warn('Requested sound sample rate was not poossible')
    if setBits != bits:
        logging.warn('Requested sound depth (bits) was not possible')
    if setStereo != 2 and stereo == True:
        logging.warn('Requested stereo setting was not possible')


[docs]class SoundPygame(_SoundBase): """Create a sound object, from one of many ways. :parameters: value: can be a number, string or an array: * If it's a number between 37 and 32767 then a tone will be generated at that frequency in Hz. * It could be a string for a note ('A', 'Bfl', 'B', 'C', 'Csh', ...). Then you may want to specify which octave as well * Or a string could represent a filename in the current location, or mediaLocation, or a full path combo * Or by giving an Nx2 numpy array of floats (-1:1) you can specify the sound yourself as a waveform secs: duration (only relevant if the value is a note name or a frequency value) octave: is only relevant if the value is a note name. Middle octave of a piano is 4. Most computers won't output sounds in the bottom octave (1) and the top octave (8) is generally painful sampleRate(=44100): If a sound has already been created or if the bits(=16): Pygame uses the same bit depth for all sounds once initialised """ def __init__(self, value="C", secs=0.5, octave=4, sampleRate=44100, bits=16, name='', autoLog=True, loops=0, stereo=True, hamming=False): """ Parameters ---------- value : int, str or array_like * If it's a number between 37 and 32767 then a tone will be generated at that frequency in Hz. * It could be a string for a note ('A', 'Bfl', 'B', 'C', 'Csh', ...). Then you may want to specify which octave as well. * Or a string could represent a filename in the current location, or mediaLocation, or a full path combo. * Or by giving an Nx2 numpy array of floats (-1:1) you can specify the sound yourself as a waveform. secs : float Duration of sound in seconds (only relevant if the value is a note name or a frequency value). octave : """ self.name = name # only needed for autoLogging self.autoLog = autoLog if stereo == True: stereoChans = 2 else: stereoChans = 0 if bits == 16: # for pygame bits are signed for 16bit, signified by the minus bits = -16 # check initialisation if not mixer.get_init(): pygame.mixer.init(sampleRate, bits, stereoChans, 3072) inits = mixer.get_init() if inits is None: init() inits = mixer.get_init() self.sampleRate, self.format, self.isStereo = inits if hamming: logging.warning("Hamming was requested using the 'pygame' sound " "library but hamming is not supported there.") self.hamming = False # try to create sound self._snd = None # distinguish the loops requested from loops actual because of # infinite tones (which have many loops but none requested) # -1 for infinite or a number of loops self.requestedLoops = self.loops = int(loops) self.setSound(value=value, secs=secs, octave=octave, hamming=False)
[docs] def play(self, fromStart=True, log=True, loops=None, when=None): """Starts playing the sound on an available channel. :Parameters: fromStart : bool Not yet implemented. log : bool Whether or not to log the playback event. loops : int How many times to repeat the sound after it plays once. If `loops` == -1, the sound will repeat indefinitely until stopped. when: not used but included for compatibility purposes :Notes: If no sound channels are available, it will not play and return None. This runs off a separate thread i.e. your code won't wait for the sound to finish before continuing. You need to use a psychopy.core.wait() command if you want things to pause. If you call play() whiles something is already playing the sounds will be played over each other. """ if loops is None: loops = self.loops self._snd.play(loops=loops) self.status = STARTED if log and self.autoLog: logging.exp("Sound %s started" % (self.name), obj=self) return self
[docs] def stop(self, log=True): """Stops the sound immediately """ self._snd.stop() self.status = STOPPED if log and self.autoLog: logging.exp("Sound %s stopped" % (self.name), obj=self)
[docs] def fadeOut(self, mSecs): """fades out the sound (when playing) over mSecs. Don't know why you would do this in psychophysics but it's easy and fun to include as a possibility :) """ self._snd.fadeout(mSecs) self.status = STOPPED
[docs] def getDuration(self): """Gets the duration of the current sound in secs """ return self._snd.get_length()
[docs] def getVolume(self): """Returns the current volume of the sound (0.0:1.0) """ return self._snd.get_volume()
[docs] def setVolume(self, newVol, log=True): """Sets the current volume of the sound (0.0:1.0) """ self._snd.set_volume(newVol) if log and self.autoLog: msg = "Set Sound %s volume=%.3f" logging.exp(msg % (self.name, newVol), obj=self) return self.getVolume()
def _setSndFromFile(self, fileName): # load the file if not path.isfile(fileName): msg = "Sound file %s could not be found." % fileName logging.error(msg) raise ValueError(msg) self.fileName = fileName # in case a tone with inf loops had been used before self.loops = self.requestedLoops try: self._snd = mixer.Sound(self.fileName) except Exception: msg = "Sound file %s could not be opened using pygame for sound." logging.error(msg % fileName) raise ValueError(msg % fileName) def _setSndFromArray(self, thisArray): # get a mixer.Sound object from an array of floats (-1:1) # make stereo if mono if (self.isStereo == 2 and (len(thisArray.shape) == 1 or thisArray.shape[1] < 2)): tmp = numpy.ones((len(thisArray), 2)) tmp[:, 0] = thisArray tmp[:, 1] = thisArray thisArray = tmp # get the format right if self.format == -16: thisArray = (thisArray * 2**15).astype(numpy.int16) elif self.format == 16: thisArray = ((thisArray + 1) * 2**15).astype(numpy.uint16) elif self.format == -8: thisArray = (thisArray * 2**7).astype(numpy.Int8) elif self.format == 8: thisArray = ((thisArray + 1) * 2**7).astype(numpy.uint8) self._snd = sndarray.make_sound(thisArray)

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