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Question

我正在使用python处理音频信号。我想记录一个信号并保持其SPL级别。我正在使用pyaudio Library来做到这一点。这是我找到的例子。但是，我发现信号大约比它应该大18db。有没有办法改变文件wav中记录的信号幅度？第二个问题是对于wav文件，数据以带符号的16位编码。我的印象是负值是使用两个补码编码的，任何人都可以确认吗？

非常感谢！

enter code here def record(output_file_name, rec_device_id=None):
# Sampling = Data is recorded per batches of 1024 bits
CHUNK = 1024
FORMAT = pyaudio.paInt16
CHANNELS = 1
# Sampling = 48kHz
RATE = 48000
RECORD_SECONDS = 5
WAVE_OUTPUT_FILENAME = output_file_name

p = pyaudio.PyAudio()
stream = p.open(format=FORMAT,
                channels=CHANNELS,
                rate=RATE,
                input=True,
                frames_per_buffer=CHUNK,
                    input_device_index=rec_device_id)
# Sampling = 48kHz
print("*** recording start ***")

frames = []

rms=np.zeros(RATE / CHUNK * RECORD_SECONDS+1)
for i in range(0, int(RATE / CHUNK * RECORD_SECONDS)):
    data = stream.read(CHUNK)
    #print("*** data ***",data)
    #decoded = struct.unpack('h',data)
    print("*** decoded ***",decoded)
    frames.append(data)
    rms[i] = audioop.rms(data, 2)

print("*** recording done ***")
print("*** rms ***",rms)

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

wf = wave.open(output_file_name,  'wb')
wf.setnchannels(CHANNELS)
wf.setsampwidth(p.get_sample_size(FORMAT))
wf.setframerate(RATE)
wf.writeframes(b''.join(frames))
wf.close()