Extract BWF metadata?

[ginwakeup]

Hello,

I have a process that reads an AAF which contains embedded BWF timecode, but it disappears when I write the Mob Essence this disk like this:

wav_output = os.path.join(audio_output, "{}.wav".format(clip_name))

data = source_mob.essence.open("r").read()
audio_file = aaf2.audio.wave.Wave_write(output_name)

audio_file.setnchannels(channels)
audio_file.setframerate(sample_rate)
audio_file.setsampwidth(sample_size)

map(audio_file.writeframesraw, data )

Is there a way to retain the BWF metadata, which I believe is stored in the file header?

Even if I use writeframesraw which is supposed to save the header, it's not there when I check the file using BWFMetaEdit.

[ginwakeup]

Or, alternatively, if I am parsing the AAF and I find the TimelineMobSlot containing the Timecode data, how do I read it?

It seems like the value is invalid (checking the Start.data field)

The length is 5184000 which does not represent the expected timecode