OpusSharp 1.6.5

OpusSharp

OpusSharp aims to be a cross-platform, pure and ported C# compatible version of the native opus codec/library. The core library uses the native compiled DLL's/binaries. Windows, Android, Linux, macOS and iOS are supported. OpusSharp compiles the opus binaries using a github actions file which is available here.

Encoder Example

Simple encoder example for initializing and encoding. You of course can use short[] or float[] arrays to encode as well.

using OpusSharp.Core;

byte[] someAudioData = ...;
var frameSizeMs = 20;
var sampleRate = 48000;
var channels = 1;
var samplesPerFrame = sampleRate / (1000 / frameSizeMs) * channels; //960 samples per frame.
var encoder = new OpusEncoder(sampleRate, channels, OpusPredefinedValues.OPUS_APPLICATION_VOIP);

byte[] encodedAudio = new byte[1000] //1000 bytes for an encoded buffer should be enough according to the opus documentation.
var encodedBytes = encoder.Encode(someAudioData, samplesPerFrame, encodedAudio, encodedAudio.Length);

//We can use encodedBytes to trim any excess data from the encodedAudio buffer before sending over the network or writing to a file.

Decoder Example

Simple decoder example for initializing and decoding. You of course can use short[] or float[] arrays to encode as well.

using OpusSharp.Core;

byte[] someEncodedAudio = ...;
var frameSizeMs = 20;
var sampleRate = 48000;
var channels = 1;
var samplesPerFrame = sampleRate / (1000 / frameSizeMs) * channels; //960 samples per frame.
var decoder = new OpusDecoder(sampleRate, channels);

var decoded = new byte[1920]; //We get 1920 bytes from doing this calculation because 16/8 (16 bit audio, 1 byte is 8 bits) equals 2 multiplied by samplesPerFrame gets us bytes per frame. 16/(sizeof(byte) * 8) * samplesPerFrame
var decodedSamples = decoder.Decode(someEncodedAudio, someEncodedAudio.Length, decoded, samplesPerFrame, false);

Static Usage Example

This example shows a forced usage of OpusSharp to use the statically linked opus binary.

// On iOS OpusSharp switches to StaticNativeOpus automatically.
// You can still force the same behavior manually with use_static: true.
var encoder = new OpusEncoder(sampleRate, channels, OpusPredefinedValues.OPUS_APPLICATION_VOIP, use_static: true);
var encoder = new OpusDecoder(sampleRate, channels, use_static: true);

Unity Example

For unity integration, you may want to use Static.OpusDecoder, Dynamic.OpusDecoder, Static.OpusEncoder or Dynamic.OpusEncoder to prevent IL2CPP errors for example...

using OpusSharp.Core;
    
IOpusEncoder encoder;
IOpusDecoder decoder;
//Decoder
#if UNITY_IOS && !UNITY_EDITOR
encoder = new Static.OpusEncoder(...);
decoder = new Static.OpusDecoder(...);
#else
encoder = new Dynamic.OpusEncoder(...);
decoder = new Dynamic.OpusDecoder(...);

Basic NAudio Example

using NAudio.Wave;
using OpusSharp.Core;

var format = new WaveFormat(48000, 2);
var buffer = new BufferedWaveProvider(format) { ReadFully = true };
var encoder = new OpusEncoder(format.SampleRate, format.Channels, OpusPredefinedValues.OPUS_APPLICATION_VOIP);
var decoder = new OpusDecoder(format.SampleRate, format.Channels);
var recorder = new WaveInEvent() { BufferMilliseconds = 20, WaveFormat = format };
var player = new WaveOutEvent();
recorder.DataAvailable += Recorder_DataAvailable;

recorder.StartRecording();
player.Init(buffer);
player.Play();

void Recorder_DataAvailable(object? sender, WaveInEventArgs e)
{
    var encoded = new byte[1000];
    var encodedBytes = encoder.Encode(e.Buffer, 960, encoded, encoded.Length);
    Console.WriteLine(encodedBytes);
    var decoded = new byte[3840];
    var decodedSamples = decoder.Decode(encoded, encodedBytes, decoded, 960, false);
    Console.WriteLine(decodedSamples);
    buffer.AddSamples(decoded, 0, decoded.Length);
}

Console.ReadLine();

CTL Example using OpusSharp.Core.Extensions

This CTL example shows the usage of extensions to make setting CTL's easier.

using OpusSharp.Core;
using OpusSharp.Core.Extensions;

OpusEncoder encoder = new OpusEncoder(48000, 2, OpusPredefinedValues.OPUS_APPLICATION_AUDIO);

encoder.SetComplexity(2);
Console.WriteLine(encoder.GetComplexity());

CTL Example

This example shows the raw usage of calling a CTL with no extensions, OpusSharp will directly pass the call to the opus binary.

using OpusSharp.Core;

OpusEncoder encoder = new OpusEncoder(48000, 2, OpusPredefinedValues.OPUS_APPLICATION_VOIP);

//1 == true, 0 == false
encoder.Ctl<int>(EncoderCTL.OPUS_SET_VBR, 1); //OpusSharp already checks if an error occurred with the CTL request and will throw an OpusException if there is an error, otherwise OpusErrorCodes.OPUS_OK.

//Most setter CTL's do not require a pointer reference. All Getter CTL's require a pointer reference (for now).

Supported Devices

• ✅ Fully and natively supported.
• ❎ Can be supported but no reason to.
• ❗ Not yet available.
• ❌ Not planned, Not supported.

Installation

Please check QuickStart OR Nuget. For the default cross-platform experience, install OpusSharp. It brings in both OpusSharp.Core and the prebuilt native assets, including automatic iOS linking through OpusSharp.Natives.

If you want to manage native binaries yourself, only install the OpusSharp.Core package.

API Documentation

https://avionblock.github.io/OpusSharp/api/OpusSharp.Core.html

Opus License

https://opus-codec.org/license/