PyAudio - 如何将波形文件混合成连续流

Question

我想编写一个非常基本的应用程序，将麦克风的音频传递给扬声器。在https://people.csail.mit.edu/hubert/pyaudio/中描述的pyaudio非常简单。

def passthrough(): 
    WIDTH = 2 
    CHANNELS = 1 
    RATE = 44100 

    p = pyaudio.PyAudio() 

    def callback(in_data, frame_count, time_info, status): 

     return (in_data, pyaudio.paContinue) 

    stream = p.open(format=p.get_format_from_width(WIDTH), 
        channels=CHANNELS, 
        rate=RATE, 
        input=True, 
        output=True, 
        stream_callback=callback) 

    stream.start_stream() 

    while stream.is_active(): 
     time.sleep(0.1) 

    stream.stop_stream() 
    stream.close() 

    p.terminate() 

但是现在我尝试在发生事件时将波形文件混合到此流中。这就是我现在被卡住的地方。播放波形文件似乎也很容易。

def play_wave(wav_file): 
    wf = wave.open(wav_file, 'rb') 

    sample_width=wf.getsampwidth() 
    channels=wf.getnchannels() 
    rate=wf.getframerate() 
    second=sample_width*channels*rate 

    def callback(in_data, frame_count, time_info, status): 
     data = wf.readframes(frame_count) 
     return (data, pyaudio.paContinue) 

    p = pyaudio.PyAudio() 

    stream = p.open(format=p.get_format_from_width(sample_width), 
       channels=channels, 
       rate=int(rate), 
       output=True, 
       stream_callback=callback) 
    stream.start_stream() 

    while stream.is_active(): 
     time.sleep(0.1) 

    stream.stop_stream() 
    stream.close() 
    wf.close() 

    p.terminate() 

在这个时候，我有两个问题。

1. 怎样波输出混合到连续流
2. 我怎样才能触发1.基于事件

希望有人能照亮黑暗的地下室，我在现在的。

编辑：假设波形文件具有相同数量的通道和相同的速率，所以不需要转换。

Answer 1

把吞吐量（）函数移动到线程后，它就像所期望的那样工作。当我昨天尝试这个时，我只是搞砸了线程启动（在run（）方法中代替init）。

所以这里是完整的工作代码。

import pyaudio 
import wave 
import threading 
import time 

class AudioPass(threading.Thread): 
    def __init__(self): 
     threading.Thread.__init__(self) 
    def run(self): 
     self.passthrough() 
    def passthrough(self): 
     WIDTH = 2 
     CHANNELS = 1 
     RATE = 44100 

     p = pyaudio.PyAudio() 

     def callback(in_data, frame_count, time_info, status): 

      return (in_data, pyaudio.paContinue) 

     stream = p.open(format=p.get_format_from_width(WIDTH), 
         channels=CHANNELS, 
         rate=RATE, 
         input=True, 
         output=True, 
         stream_callback=callback) 

     stream.start_stream() 

     while stream.is_active(): 
      time.sleep(0.1) 

     stream.stop_stream() 
     stream.close() 

     p.terminate() 


def play_wave(wav_file): 
    wf = wave.open(wav_file, 'rb') 

    sample_width=wf.getsampwidth() 
    channels=wf.getnchannels() 
    rate=wf.getframerate() 
    second=sample_width*channels*rate 

    def callback(in_data, frame_count, time_info, status): 
     data = wf.readframes(frame_count) 
     return (data, pyaudio.paContinue) 

    p = pyaudio.PyAudio() 

    stream = p.open(format=p.get_format_from_width(sample_width), 
       channels=channels, 
       rate=int(rate), 
       output=True, 
       stream_callback=callback) 
    stream.start_stream() 

    while stream.is_active(): 
     time.sleep(0.1) 

    stream.stop_stream() 
    stream.close() 
    wf.close() 

    p.terminate() 

thread = AudioPass() 
thread.start() 
play_wave('C:/bell.wav') 

后来我也将尝试另一种方式colleauge今天建议，如果它确实表现得很好，我会把这里作为替代，太。使用线程方式很好，因为我可以对流和wav文件使用不同的速率。

Answer 2

一位同事提供了下面的解决方案，这是一个非常原始的方法，但它的工作原理和理解这种pyaudio的工作原理是很好的。

import time 
import pyaudio 
import numpy 
WIDTH = 2 
CHANNELS = 1 
RATE = 44100 
p = pyaudio.PyAudio() 
SINE_WAVE_FREQUENCY = 440.0 # In Hz 
SINE_WAVE_DURATION = 5.0 # In seconds 
SINE_WAVE_VOLUME = 0.5 
SINE_WAVE = (numpy.sin(2 * numpy.pi * numpy.arange(RATE * SINE_WAVE_DURATION) * SINE_WAVE_FREQUENCY/RATE)).astype(numpy.float32) * SINE_WAVE_VOLUME 
def loopback(in_data, frame_count, time_info, status): 
     return (in_data, pyaudio.paContinue) 
stream = p.open(format=p.get_format_from_width(WIDTH), channels=CHANNELS, rate=RATE, input=True, output=True, stream_callback=loopback) 
stream.start_stream() 
def playsine(): 
     sinestream = p.open(format=pyaudio.paFloat32, channels=1, rate=RATE, output=True) 
     sinestream.write(SINE_WAVE) 
     sinestream.stop_stream() 
     sinestream.close() 
while True: 
     input("Press enter to play a sine wave") 
     playsine()