dotnet

Porcupine Demos for .NET

This project contains .NET Core command line demos for processing real-time audio (i.e. microphone) and audio files using the Porcupine wake word engine.

Porcupine

Made in Vancouver, Canada by Picovoice

Porcupine is a highly-accurate and lightweight wake word engine. It enables building always-listening voice-enabled applications.

Porcupine is:

• using deep neural networks trained in real-world environments.
• compact and computationally-efficient making it perfect for IoT.
• scalable. It can detect multiple always-listening voice commands with no added CPU/memory footprint.
• self-service. Developers can train custom wake phrases using Picovoice Console.

Requirements

• .NET 8.0

Compatibility

• Linux (x86_64)
• macOS (x86_64, arm64)
• Windows (x86_64)
• Raspberry Pi:
  • 3 (32 and 64 bit)
  • 4 (32 and 64 bit)
  • 5 (32 and 64 bit)

Installation

Both demos use Microsoft's .NET Core framework.

Build with the dotnet CLI:

dotnet build -c MicDemo.Release
dotnet build -c FileDemo.Release

AccessKey

Porcupine requires a valid Picovoice AccessKey at initialization. AccessKey acts as your credentials when using Porcupine SDKs. You can get your AccessKey for free. Make sure to keep your AccessKey secret. Signup or Login to Picovoice Console to get your AccessKey.

Usage

NOTE: File path arguments must be absolute paths. The working directory for the following dotnet commands is:

porcupine/demo/dotnet/PorcupineDemo

File Demo

The file demo uses Porcupine to scan for keywords in a wave file. The demo is mainly useful for quantitative performance benchmarking against a corpus of audio data. Porcupine processes a 16kHz, single-channel audio stream. If a stereo file is provided it only processes the first (left) channel. The following processes a file looking for instances of the phrase "Picovoice":

dotnet run -c FileDemo.Release -- \
--input_audio_path ${AUDIO_PATH} \
--access_key ${ACCESS_KEY} \
--keywords picovoice

keywords is a shorthand for using built-in keyword files shipped with the package. The list of default keyword files can be seen in the usage string:

dotnet run -c FileDemo.Release -- --help

To detect multiple phrases concurrently provide them as separate arguments. If the wake word is more than a single word, surround the argument in quotation marks:

dotnet run -c FileDemo.Release -- \
--input_audio_path ${AUDIO_PATH} \
--access_key ${ACCESS_KEY} \
--keywords grasshopper "hey siri"

To detect non-default keywords (e.g. models created using Picovoice Console) use keyword_paths argument:

dotnet run -c FileDemo.Release -- \
--input_audio_path ${AUDIO_PATH} \
--access_key ${ACCESS_KEY} \
--keyword_paths ${KEYWORD_PATH_ONE} ${KEYWORD_PATH_TWO}

The sensitivity of the engine can be tuned per keyword using the sensitivities input argument:

dotnet run -c FileDemo.Release -- \
--input_audio_path ${AUDIO_PATH} \
--access_key ${ACCESS_KEY} \
--keywords grasshopper porcupine \
--sensitivities 0.3 0.6

Sensitivity is the parameter that enables trading miss rate for the false alarm rate. It is a floating point number within [0, 1]. A higher sensitivity reduces the miss rate at the cost of increased false alarm rate.

Microphone Demo

This demo opens an audio stream from a microphone and detects utterances of a given wake word. The following opens the default microphone and detects occurrences of "Picovoice":

dotnet run -c MicDemo.Release -- \
--access_key ${ACCESS_KEY} \
--keywords picovoice

keywords is a shorthand for using default keyword files shipped with the package. The list of default keyword files can be seen in the usage string:

dotnet run -c MicDemo.Release -- --help

To detect multiple phrases concurrently provide them as separate arguments. If the wake word is more than a single word, surround the argument in quotation marks:

dotnet run -c MicDemo.Release -- \
--access_key ${ACCESS_KEY} \
--keywords picovoice "hey siri"

To detect custom keywords (e.g. models created using Picovoice Console) use keyword_paths argument:

dotnet run -c MicDemo.Release -- \
--access_key ${ACCESS_KEY} \
--keyword_paths ${KEYWORD_PATH_ONE} ${KEYWORD_PATH_TWO}

It is possible that the default audio input device is not the one you wish to use. There are a couple of debugging facilities baked into the demo application to solve this. First, type the following into the console:

dotnet run -c MicDemo.Release -- --show_audio_devices

It provides information about various audio input devices on the box. Here is an example output:

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

You can use the device index to specify which microphone to use for the demo. For instance, if you want to use the USB Audio Device in the above example, you can invoke the demo application as below:

dotnet run -c MicDemo.Release -- \
--access_key ${ACCESS_KEY} \
--keywords picovoice
--audio_device_index 0

If the problem persists we suggest storing the recorded audio into a file for inspection. This can be achieved with:

dotnet run -c MicDemo.Release -- \
--access_key ${ACCESS_KEY} \
--keywords picovoice \
--audio_device_index 0 \
--output_path ./test.wav

If after listening to stored file there is no apparent problem detected please open an issue.