Leopard Speech-to-Text
.NET Quick Start

Platforms

• Linux (x86_64)
• macOS (x86_64, arm64)
• Windows (x86_64)
• Raspberry Pi (3, 4, 5)

Requirements

• Picovoice Account & AccessKey

.NET Framework 4.6.1+ / .NET Standard 2.0+ / .NET Core 3.0+:

• Windows (x86_64)

.NET Standard 2.0+ / .NET Core 3.0+:

• Linux (x86_64)
• macOS (x86_64)

.NET Core 3.0+:

• Raspberry Pi (3, 4)

.NET 6.0+:

• macOS (arm64)

Picovoice Account & AccessKey

Signup or Login to Picovoice Console to get your AccessKey. Make sure to keep your AccessKey secret.

Quick Start

Setup

1. Install .NET.

2. Install the Leopard Speech-to-Text NuGet package in Visual Studio or using the .NET CLI:

dotnet add package Leopard

Usage

Create an instance of the engine:

using Pv;

const string accessKey = "${ACCESS_KEY}";

Leopard leopard = Leopard.Create(accessKey);

Transcribe an audio file by providing an absolute path to the file:

LeopardTranscript result = leopard.ProcessFile("${AUDIO_FILE_PATH}");

Transcribe raw audio data (sample rate of 16 kHz, 16-bit linearly encoded and 1 channel):

short[] GetAudioData()
{
   // ...
}

LeopardTranscript result = leopard.Process(GetAudioData());

Model File

The Leopard Speech-to-Text .NET SDK comes preloaded with a default English language model (.pv file). Default models for other supported languages can be found in the Leopard Speech-to-Text GitHub repository.

Create custom language models using the Picovoice Console. Here you can train language models with custom vocabulary and boost words in the existing vocabulary.

To switch from the default English model, pass in a .pv file to the .Create() constructor:

Leopard leopard = Leopard.Create(accessKey, modelPath: "${MODEL_PATH}");

Word Metadata

Along with the transcript, Leopard Speech-to-Text returns metadata for each transcribed word. Available metadata items are:

• Start Time: Indicates when the word started in the transcribed audio. Value is in seconds.
• End Time: Indicates when the word ended in the transcribed audio. Value is in seconds.
• Confidence: Leopard Speech-to-Text's confidence that the transcribed word is accurate. It is a number within [0, 1].
• Speaker Tag: If speaker diarization is enabled on initialization, the speaker tag is a non-negative integer identifying unique speakers, with 0 reserved for unknown speakers. If speaker diarization is not enabled, the value will always be -1.

Demo

For the Leopard Speech-to-Text .NET SDK, we offer demo applications that demonstrate how to use the Speech-to-Text engine on audio files.

Setup

1. Clone the Leopard Speech-to-Text repository from GitHub:

git clone --recurse-submodules https://github.com/Picovoice/leopard.git

2. Build the demo:

cd leopard/demo/dotnet/Leopard
dotnet build -c FileDemo.Release

Usage

Use the --help flag to see the usage options for the demo:

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

Run the following command to transcribe an audio file:

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

For more information on our Leopard Speech-to-Text demos for .NET, head over to our GitHub repository.

Resources