/// <summary> Creates a new Opus encoder. </summary>
/// <param name="samplingRate">Sampling rate of the input signal (Hz). Supported Values: 8000, 12000, 16000, 24000, or 48000.</param>
/// <param name="channels">Number of channels (1 or 2) in input signal.</param>
/// <param name="frameLength">Length, in milliseconds, that each frame takes. Supported Values: 2.5, 5, 10, 20, 40, 60</param>
/// <param name="application">Coding mode.</param>
/// <returns>A new <c>OpusEncoder</c></returns>
public OpusEncoder(int samplingRate, int channels, int frameLength, Opus.Application application)
{
if (samplingRate != 8000 && samplingRate != 12000 &&
samplingRate != 16000 && samplingRate != 24000 &&
samplingRate != 48000)
{
throw new ArgumentOutOfRangeException(nameof(samplingRate));
}
if (channels != 1 && channels != 2)
{
throw new ArgumentOutOfRangeException(nameof(channels));
}
InputSamplingRate = samplingRate;
InputChannels = channels;
Application = application;
FrameLength = frameLength;
SampleSize = (BitRate / 8) * channels;
SamplesPerFrame = samplingRate / 1000 * FrameLength;
FrameSize = SamplesPerFrame * SampleSize;
Opus.Error error;
_ptr = Opus.CreateEncoder(samplingRate, channels, (int)application, out error);
if (error != Opus.Error.OK)
{
throw new InvalidOperationException($"Error occured while creating encoder: {error}");
}
SetForwardErrorCorrection(true);
}
/// <summary> Gets or sets whether Forward Error Correction is enabled. </summary>
public void SetForwardErrorCorrection(bool value)
{
if (disposed)
{
throw new ObjectDisposedException(nameof(OpusEncoder));
}
var result = Opus.EncoderCtl(_ptr, Opus.Ctl.SetInbandFECRequest, value ? 1 : 0);
if (result < 0)
{
throw new Exception("Encoder error: " + ((Opus.Error)result).ToString());
}
}
public void Dispose()
{
if (disposed)
{
return;
}
GC.SuppressFinalize(this);
if (_ptr != IntPtr.Zero)
{
Opus.DestroyEncoder(_ptr);
}
disposed = true;
}
/// <summary> Produces Opus encoded audio from PCM samples. </summary>
/// <param name="input">PCM samples to encode.</param>
/// <param name="inputOffset">Offset of the frame in pcmSamples.</param>
/// <param name="output">Buffer to store the encoded frame.</param>
/// <returns>Length of the frame contained in outputBuffer.</returns>
public unsafe int EncodeFrame(byte[] input, int inputOffset, byte[] output)
{
if (disposed)
{
throw new ObjectDisposedException(nameof(OpusEncoder));
}
int result = 0;
fixed(byte *inPtr = input)
result = Opus.Encode(_ptr, inPtr + inputOffset, SamplesPerFrame, output, output.Length);
if (result < 0)
{
throw new Exception("Encoding failed: " + ((Opus.Error)result).ToString());
}
return(result);
}
/// <summary> Creates a new Opus encoder. </summary>
/// <param name="samplingRate">Sampling rate of the input signal (Hz). Supported Values: 8000, 12000, 16000, 24000, or 48000.</param>
/// <param name="channels">Number of channels (1 or 2) in input signal.</param>
/// <param name="frameLength">Length, in milliseconds, that each frame takes. Supported Values: 2.5, 5, 10, 20, 40, 60</param>
/// <param name="application">Coding mode.</param>
/// <returns>A new <c>OpusEncoder</c></returns>
public OpusEncoder(int samplingRate, int channels, int frameLength, Opus.Application application)
{
if (samplingRate != 8000 && samplingRate != 12000 &&
samplingRate != 16000 && samplingRate != 24000 &&
samplingRate != 48000)
throw new ArgumentOutOfRangeException(nameof(samplingRate));
if (channels != 1 && channels != 2)
throw new ArgumentOutOfRangeException(nameof(channels));
InputSamplingRate = samplingRate;
InputChannels = channels;
Application = application;
FrameLength = frameLength;
SampleSize = (BitRate / 8) * channels;
SamplesPerFrame = samplingRate / 1000 * FrameLength;
FrameSize = SamplesPerFrame * SampleSize;
Opus.Error error;
_ptr = Opus.CreateEncoder(samplingRate, channels, (int)application, out error);
if (error != Opus.Error.OK)
throw new InvalidOperationException($"Error occured while creating encoder: {error}");
SetForwardErrorCorrection(true);
}