Question

我家里有蚊子问题。这通常不会涉及程序员的社区;然而，我看到一些设备声称通过播放17Khz音调来阻止这些讨厌的生物。我想用我的笔记本电脑做这件事。

一种方法是创建一个具有单一固定频率音调（This can easily done by audacity），opening it with a python library并重复播放的MP3。

第二种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

是否有python库？

Answer 1

PyAudiere是解决此问题的简单跨平台解决方案：

>>> 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消失了。 {2}的The site和二进制安装程序（debian，windows）可通过返回机器获得，例如here's source code pyaudiere-0.2.tar.gz。

要在Linux，Windows，OSX上支持Python 2和3，可以使用pyaudio module代替：

#!/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()

示例：

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this AskUbuntu answer的修改版（支持Python 3）。

Answer 2

模块winsound包含在Python中，所以没有外部库可以安装，它应该做你想要的（而不是其他）。

 import winsound
 winsound.Beep(17000, 100)

它非常简单易用，但仅适用于Windows。

但：
对这个问题的完整答案应该注意，虽然这种方法会产生声音，但它不能阻止蚊子。它已经过测试：请参阅here和here

Answer 3

我将代码放在这里，这有助于程序员弄清代码的工作原理

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的Python binding（Simple Direct Media Library）。

用于播放固定频率声音的Python库

5 个答案: