Get Audio data from recorded video

In my plugin integration, I want to add recorded audio visualization(audio spectrogram) using an external lib like bass .net or naudio. How can I get audio data from a recorded video?

I tried RawVideoSource but it seems to contain only video data.

RawVideoSource rw = new RawVideoSource(camera);
rw.Init();
var rawData= rw.GetNearest(_startTime);

It should be in the rawData.

You might need the description of the “Generic Byte Data”

http://doc.developer.milestonesys.com/html/index.html?base=mipgenericbytedata/main.html&tree=tree_3.html