python - 用于播放固定频率声音的 Python 库

Question

我家有蚊子问题。这通常与程序员社区无关；然而，我见过一些声称通过播放 17Khz 音调来阻止这些讨厌的生物的设备。我想用我的笔记本电脑来做这个。

一种方法是创建一个带有单一固定频率音调的 MP3（这可以通过 audacity 轻松完成），使用 python 库打开它并重复播放。

第二个是使用计算机内置扬声器播放声音。我正在寻找类似于 QBasic Sound的东西：

SOUND 17000, 100

有没有一个python库？

Answer 1

PyAudiere是一个简单的跨平台解决方案：

>>> import audiere
>>> d = audiere.open_device()
>>> t = d.create_tone(17000) # 17 KHz
>>> t.play() # non-blocking call
>>> import time
>>> time.sleep(5)
>>> t.stop()

pyaudiere.org 不见了。Python 2（debian、windows）的站点和二进制安装程序可通过 Wayback 机器获得，例如，这里的源代码pyaudiere-0.2.tar.gz。

为了在 Linux、Windows、OSX 上同时支持 Python 2 和 3，可以使用pyaudio模块：

#!/usr/bin/env python
"""Play a fixed frequency sound."""
from __future__ import division
import math

from pyaudio import PyAudio # sudo apt-get install python{,3}-pyaudio

try:
    from itertools import izip
except ImportError: # Python 3
    izip = zip
    xrange = range

def sine_tone(frequency, duration, volume=1, sample_rate=22050):
    n_samples = int(sample_rate * duration)
    restframes = n_samples % sample_rate

    p = PyAudio()
    stream = p.open(format=p.get_format_from_width(1), # 8bit
                    channels=1, # mono
                    rate=sample_rate,
                    output=True)
    s = lambda t: volume * math.sin(2 * math.pi * frequency * t / sample_rate)
    samples = (int(s(t) * 0x7f + 0x80) for t in xrange(n_samples))
    for buf in izip(*[samples]*sample_rate): # write several samples at a time
        stream.write(bytes(bytearray(buf)))

    # fill remainder of frameset with silence
    stream.write(b'\x80' * restframes)

    stream.stop_stream()
    stream.close()
    p.terminate()

例子：

sine_tone(
    # see http://www.phy.mtu.edu/~suits/notefreqs.html
    frequency=440.00, # Hz, waves per second A4
    duration=3.21, # seconds to play sound
    volume=.01, # 0..1 how loud it is
    # see http://en.wikipedia.org/wiki/Bit_rate#Audio
    sample_rate=22050 # number of samples per second
)

它是此 AskUbuntu 答案的修改（以支持 Python 3）版本。

Answer 2

模块winsound包含在 Python 中，因此无需安装外部库，它应该可以满足您的需求（仅此而已）。

 import winsound
 winsound.Beep(17000, 100)

它非常简单易用，但仅适用于 Windows。

但是：
这个问题的完整答案应该注意，虽然这种方法会产生声音，但它不会阻止蚊子。它已经过测试：请参见此处和此处

Answer 3

我把我的代码放在这里是因为它可以帮助程序员清楚代码是如何工作的。解释在代码本身中：

#!/usr/bin/env python3
import pyaudio
import struct
import math

FORMAT = pyaudio.paInt16
CHANNELS = 2
RATE = 44100

p = pyaudio.PyAudio()


def data_for_freq(frequency: float, time: float = None):
    """get frames for a fixed frequency for a specified time or
    number of frames, if frame_count is specified, the specified
    time is ignored"""
    frame_count = int(RATE * time)

    remainder_frames = frame_count % RATE
    wavedata = []

    for i in range(frame_count):
        a = RATE / frequency  # number of frames per wave
        b = i / a
        # explanation for b
        # considering one wave, what part of the wave should this be
        # if we graph the sine wave in a
        # displacement vs i graph for the particle
        # where 0 is the beginning of the sine wave and
        # 1 the end of the sine wave
        # which part is "i" is denoted by b
        # for clarity you might use
        # though this is redundant since math.sin is a looping function
        # b = b - int(b)

        c = b * (2 * math.pi)
        # explanation for c
        # now we map b to between 0 and 2*math.PI
        # since 0 - 2*PI, 2*PI - 4*PI, ...
        # are the repeating domains of the sin wave (so the decimal values will
        # also be mapped accordingly,
        # and the integral values will be multiplied
        # by 2*PI and since sin(n*2*PI) is zero where n is an integer)
        d = math.sin(c) * 32767
        e = int(d)
        wavedata.append(e)

    for i in range(remainder_frames):
        wavedata.append(0)

    number_of_bytes = str(len(wavedata))  
    wavedata = struct.pack(number_of_bytes + 'h', *wavedata)

    return wavedata


def play(frequency: float, time: float):
    """
    play a frequency for a fixed time!
    """
    frames = data_for_freq(frequency, time)
    stream = p.open(format=FORMAT, channels=CHANNELS, rate=RATE, output=True)
    stream.write(frames)
    stream.stop_stream()
    stream.close()


if __name__ == "__main__":
    play(400, 1)

Answer 4

我简化了 jfs 对 Python3.6+ 的回答并做了一些小的改进：

import math
from pyaudio import PyAudio, paUInt8

def generate_sine_wave(frequency, duration, volume=0.2, sample_rate=22050):
    ''' Generate a tone at the given frequency.

        Limited to unsigned 8-bit samples at a given sample_rate.
        The sample rate should be at least double the frequency.
    '''
    if sample_rate < (frequency * 2):
        print('Warning: sample_rate must be at least double the frequency '
              f'to accurately represent it:\n    sample_rate {sample_rate}'
              f' ≯ {frequency*2} (frequency {frequency}*2)')

    num_samples = int(sample_rate * duration)
    rest_frames = num_samples % sample_rate

    pa = PyAudio()
    stream = pa.open(
        format=paUInt8,
        channels=1,  # mono
        rate=sample_rate,
        output=True,
    )

    # make samples
    s = lambda i: volume * math.sin(2 * math.pi * frequency * i / sample_rate)
    samples = (int(s(i) * 0x7F + 0x80) for i in range(num_samples))

    # write several samples at a time
    for buf in zip( *([samples] * sample_rate) ):
        stream.write(bytes(buf))

    # fill remainder of frameset with silence
    stream.write(b'\x80' * rest_frames)

    stream.stop_stream()
    stream.close()
    pa.terminate()

generate_sine_wave(
    # see http://www.phy.mtu.edu/~suits/notefreqs.html
    frequency=523.25,   # Hz, waves per second C6
    duration=1.2,       # seconds to play sound
    volume=0.25,        # 0..1 how loud it is
    sample_rate=22050,  # number of samples per second: 11025, 22050, 44100
)

Answer 5

您可以使用SDL（简单直接媒体库）的Python 绑定。