Opus Codec for Windows Runtime

opus-winrt is a simple Windows Runtime component for decoding (so far) Opus files. It is being written completely in C++/CX, and is based on original opus v1.1 and opusfile v0.6 C libraries source code. It is available for C# and C++/CX developers writing Windows Store apps for Windows (Phone) 8.1 and higher.

Opus Codec for Windows Runtime currently only exposes a part of decoding functionality found in original opusfile library. If you think encoder and low-level Opus API access are necessary, feel free to contribute ;)

Sample usage

opus-winrt's API is similar to original Opusfile API, except that it's object-oriented. The main class that you will use to decode an Opus file stream is Opusfile.WindowsRuntime.OggOpusFile class. Instantiate the class and then call OggOpusFile.Open to initialize the stream decoder. To get samples from the decoder, simply use OggOpusFile.Read method.

Here's the sample usage. Assume you have a managed helper class with OggOpusFile _opusFile field that is supposed to help you wrap all the decoder logic. Here's how you initialize the decoder:

public void Initialize(IRandomAccessStream fileStream)
{
    this._opusFile.Open(fileStream);
    
    if (!this._opusFile.IsValid)
        throw new InvalidOperationException();
}

Note that if something goes wrong, the OggOpusFile.Open() method will throw an exception with HResult equal to one of opusfile's error codes, but still it's a good practice to check for OggOpusFile.IsValid each time you call any OggOpusFile API.

Now, to get a sample from the decoder, you can write a simple method like this:

public IBuffer GetSample(int length)
{
    if (!this._opusFile.IsValid)
        throw new InvalidOperationException();
    
    return this._opusFile.Read(length);
}

How to build

opus-winrt includes all the necessary source code to build the libraries. Opus Codec for Windows Runtime solution includes original Opus libraries and their dependencies, including libogg, and contains opusfile_winrt project that is the main output of the solution.

You will need Visual Studio 2015 or higher to build the library for Windows 10 or higher. Also, if you want to build the solution for Windows (Phone) 8.1, you will need to make some changes to the project files. The easiest way to go with Windows (Phone) 8.1 is to take the source code from this tag.