Hi there, welcome to the Concentus package. You're about to ask me for sample code, so I'll get straight to it:
If you're already using something like P/Opus then your code probably looks like this:
[DllImport(OPUS_TARGET_DLL, CallingConvention = CallingConvention.Cdecl)]
private static extern IntPtr opus_encoder_create(int Fs, int channels, int application, out IntPtr error);
[DllImport(OPUS_TARGET_DLL, CallingConvention = CallingConvention.Cdecl)]
private static extern int opus_encode(IntPtr st, byte[] pcm, int frame_size, IntPtr data, int max_data_bytes);
// Initialize
IntPtr error;
IntPtr _encoder = opus_encoder_create(48000, 1, OPUS_APPLICATION_AUDIO, out error);
opus_encoder_ctl(_encoder, OPUS_SET_BITRATE_REQUEST, 12000);
// Encoding loop
byte[] inputAudioSamplesInterleaved; // 16-bit pcm data interleaved into a byte array
byte[] outputBuffer[1000];
int frameSize = 960;
unsafe
{
fixed (byte* benc = outputBuffer)
{
IntPtr encodedPtr = new IntPtr(benc);
int thisPacketSizeOrSometimesAnErrorCode = opus_encode(_encoder, inputAudioSamplesInterleaved, frameSize, encodedPtr, outputBuffer.Length);
}
}
Here is what you can replace it with:
// Initialize
OpusEncoder encoder = OpusEncoder.Create(48000, 1, OpusApplication.OPUS_APPLICATION_AUDIO);
encoder.Bitrate = 12000;
// Encoding loop
short[] inputAudioSamples
byte[] outputBuffer[1000];
int frameSize = 960;
int thisPacketSize = encoder.Encode(inputAudioSamples, 0, frameSize, outputBuffer, 0, outputBuffer.Length); // this throws OpusException on a failure, rather than returning a negative number
And here is the decoder path:
OpusDecoder decoder = OpusDecoder.Create(48000, 1);
// Decoding loop
byte[] compressedPacket;
int frameSize = 960; // must be same as framesize used in input, you can use OpusPacketInfo.GetNumSamples() to determine this dynamically
short[] outputBuffer = new short[frameSize];
int thisFrameSize = _decoder.Decode(compressedPacket, 0, compressedPacket.Length, outputBuffer, 0, frameSize, false);
