/// <summary>
/// Initializes a new <see cref="OpusEncoder"/> instance, with the specified intended application, sample rate and channels.
/// </summary>
/// <param name="application">The intended application.</param>
/// <param name="sampleRate">The sample rate in the input audio, 48000, 24000, 16000, 12000 or 8000 Hz.</param>
/// <param name="channels">The channels in the input audio, mono or stereo.</param>
public OpusEncoder(Application application, int sampleRate, int channels)
{
if (!Enum.IsDefined(typeof(Application), application))
{
throw new ArgumentException("Value is not defined in the enumeration.", nameof(application));
}
switch (sampleRate)
{
case 8000:
case 12000:
case 16000:
case 24000:
case 48000:
break;
default:
throw new ArgumentException("Value must be one of the following: 8000, 12000, 16000, 24000 or 48000.", nameof(sampleRate));
}
if (channels < 1 || channels > 2)
{
throw new ArgumentOutOfRangeException(nameof(channels), "Value must be between 1 and 2.");
}
Application = application;
SampleRate = sampleRate;
Channels = channels;
Bitrate = 128000;
_handle = API.opus_encoder_create(sampleRate, channels, (int)application, out int error);
API.ThrowIfError(error);
// Setting to -1 (OPUS_BITRATE_MAX) enables bitrate to be regulated by the output buffer length.
int result = API.opus_encoder_ctl(_handle, (int)Control.SetBitrate, -1);
API.ThrowIfError(result);
}
public static extern int opus_encoder_ctl(SafeEncoderHandle st, int request, int value);
public static extern int opus_encode(SafeEncoderHandle st, IntPtr pcm, int frame_size, IntPtr data, int max_data_bytes);