Output video without sound

[O-O1024]

It very strange.

video.set_audio(audio)   # I'm sure audio is not None.
video.write_videofile(
    self.path_vid_out,
    audio=True,
)

I have already call set_audio! But the output videos are without sound.
The values of (audiofile is None), (audio == True), (self.audio is not None) are True, True, False.
So I try to print(self.audio) in the first line of write_videofile()'s body, but the result is None.

Does it caused by decorators.

Specifications

• Python Version: 3.9.13
• MoviePy Version: 1.0.3
• Platform Name: Win10
• Platform Version: Don't know