Convert audio recording in 'webm' to 'flac' format

[Vishav3]

I am trying to convert audio recording in webm format to 'flac'
Below is my code:

import time
camera = CameraStream(constraints={'audio': True,'video': False})
recorder = AudioRecorder(stream=camera, format='webm')
recorder.recording = True
time.sleep(5)
recorder.recording = False
recorder.audio.autoplay = False
ipd.display(recorder.audio)
with BytesIO(recorder.audio.value) as f:
audioFile = AudioSegment.from_file(f, format='webm')
with BytesIO() as f:
audioFile.export(f, format='flac')
audioBytes = f.getvalue()

I am getting the following error:

Can anyone suggest where I am going wrong?

[maartenbreddels]

Not related to this project, still curious if you managed to solve this.

[pengzhendong]

It seems the ebml header of the webm is not complete (the backend may not recieve the complete header because of the fire and forget). This issue may help: jupyter-widgets/ipywidgets#3981