recording audio in raw or pcm format using python

Question

I am trying to use porcupine on my Jetson Nano as a wake word. In order to do this I need to record audio in pcm format(which I believe is raw format) using python. I also need the sample rate to be 16,000 and 16bit linearly encoded on single channel. My input device index is 11. So, How would I be able to record audio in this format using python?

Answer 1

It looks like there is a demo already setup for this from porcupine's side.

Checkout their demo here - it's a lot of code so I won't paste it all.

Essentially it requires installing the pvporcupinedemo package:

$ sudo pip3 install pvporcupinedemo

And then running the demo script (located in the Python demo) to start running the processing:

$ porcupine_demo_mic --access_key ${ACCESS_KEY} --keywords picovoice

There are various arguments to this script, which can be found documented in the repo itself.

The demo explicitly states that this should work for the Jetson Nano:

Runs on Linux (x86_64), Mac (x86_64 and arm64), Windows (x86_64), Raspberry Pi (all variants), NVIDIA Jetson (Nano), and BeagleBone.

To make sure the demo detects your microphone, you can run the detect mic script flag:

$ porcupine_demo_mic --show_audio_devices

And you should see something like:

index: 0, device name: USB Audio Device
index: 1, device name: MacBook Air Microphone

Then you can determine which mic is correct, and use the index as an argument to the demo, e.g. for the "USB Audio Device":

$ porcupine_demo_mic --access_key ${ACCESS_KEY} --keywords picovoice --audio_device_index 0

I would then go ahead and start picking apart the code in their demo to modify it as required.