conversion from stereo stream to mono stream

[marnaoty]

I'm trying to write a code that reads a video/audio file with multiple audio channels and extracts only one channel and write it to another file.

My main problem is when I initialize a new audio frame using:
f = av.audio.frame.AudioFrame(format=...,layout=..., samples=...)
I get NotImplementedError

And in the same time, I cannot update the original frame calling Update_buffer method with half of the samples since I will get something like "ValueError: got 2048 bytes; need 4096 bytes". And of course, also I cannot delete panels !!!

I was searching in the API documentation for anything that may help but I couldn't. Can you give me an advice about this

[WyattBlue]

Here's an example:

import av

input_file = av.open("input_stereo.wav")
audio_stream = input_file.streams.audio[0]

output = av.open("output_mono.wav", mode="w")
out_stream = output.add_stream("pcm_s16le", layout="mono", rate=audio_stream.rate)

for frame in input_file.decode(audio_stream):
    packet = out_stream.encode(frame)
    output.mux(packet)

input_file.close()
output.close()