How can I save the output from AudioRecord?

Question

I'm trying to save a recording using AudioRecord. My recording gets overwritten even if I save the output in a fresh cell. This illustrates the issue:

astream = AudioStream[First@$AudioInputDevices];
sample = AudioRecord[astream];
DialogInput[Print["Record now for 5 s..."]; Pause[5]; 
  Print["Recorded ~ 5 s"]; DialogReturn["Close me"]];
AudioStop[astream];
player = Audio[sample]

My recording is returned as an output as shown. I save it to a new cell.

Now I do a new recording on the same channel:

AudioRecord[astream];(* once again *)

DialogInput[Print["Record again now for 10 s..."]; Pause[10]; 
  Print["Recorded ~ 10 s"]; DialogReturn[]];
AudioStop[astream];
player

Now the recording above looks the same (this does not always happen though; sometimes a fresh audio gadget replaces the one I saved before) but the data has been overwritten with the first 5 s of the new recording.

This looks like a bug to me although I have an intuition as to why this is happening (Dynamic); can anyone suggest a workaround?

A more fundamental issue is that it does not seem to be possible to close the audio stream or to dispose of the resources it is using (without quitting the kernel). That's what's familiar to me from using streams in other programming languages. Is it too much to hope this might be available in future?

Answer 1

A good workflow for recording using AudioStream would be something like this:

(* Create the recording stream *)
astream = AudioStream[First@$AudioInputDevices];
(* Start the recording. AudioRecord just returns its input, so no need to assign it to a variable *)
AudioRecord[astream];
(* Block the kernel for some mount of time *)
DialogInput[Print["Record now for 5 s..."];
Pause[5];
(* End the recording, this way the recording ends after 5 seconds, not after the dialog is closed *)
AudioStop[astream];
Print["Recorded ~ 5 s"];
DialogReturn["Close me"]];
(* Now the stream still exists and it contains the recording. We need to assign the recorded audio to a variable *)
recordedAudio = Audio[sample]
(* Remove the stream and release all its resources *)
RemoveAudioStream[astream]

The result is still stored in the recordedAudio variable. Obviously if you overwrite you'll lose it. You can also save it in a file of your choice by doing something like

Export["myFile.wav", recordedAudio]

If you want to record directly to a specific file, you can use the first code block, but replace the AudioStream call with

AudioRecord[astream, GeneratedAssetLocation ->"myFile.wav"];