用于播放固定频率声音的Python库

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的MP3(这可以通过大胆来轻松完成),用python库打开它并重复播放.

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

那有一个python库吗？

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消失了.Python 2(debian,windows)的站点和二进制安装程序可以通过返回机器获得,例如,这里是源代码pyaudiere-0.2.tar.gz.

要在Linux,Windows,OSX上支持Python 2和3,可以使用以下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:

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
)

它是这个AskUbuntu答案的修改版(支持Python 3)版本.

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.

但是:
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,但它不会阻止蚊子.它已经过测试:见这里和这里

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的工作方式。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)