/// <summary>
///
/// </summary>
/// <param name="settings"></param>
/// <param name="cancellationToken"></param>
/// <returns></returns>
public override async Task <IStreamingRecognition> StartStreamingRecognitionAsync(
AudioSettings?settings = null,
CancellationToken cancellationToken = default)
{
settings ??= SupportedStreamingSettings.First();
IamToken ??= await RequestIamTokenByOAuthTokenAsync(OAuthToken, cancellationToken).ConfigureAwait(false);
var channel = new Channel("stt.api.cloud.yandex.net", 443, new SslCredentials());
var client = new SttService.SttServiceClient(channel);
var call = client.StreamingRecognize(new Metadata
{
{ "authorization", $"Bearer {IamToken}" }
}, cancellationToken: cancellationToken);
await call.RequestStream.WriteAsync(new StreamingRecognitionRequest
{
Config = new RecognitionConfig
{
Specification = new RecognitionSpec
{
LanguageCode = Lang,
ProfanityFilter = ProfanityFilter,
Model = Topic,
AudioEncoding = settings.Format switch
{
AudioFormat.Ogg => RecognitionSpec.Types.AudioEncoding.OggOpus,
AudioFormat.Raw => RecognitionSpec.Types.AudioEncoding.Linear16Pcm,
_ => RecognitionSpec.Types.AudioEncoding.Unspecified,
},
private const int MAX_BYTES_SENT = 10 * 1024 * 1024; // check https://cloud.yandex.com/docs/speechkit/stt/streaming#session-restrictions for limitation details
private AsyncDuplexStreamingCall <StreamingRecognitionRequest, StreamingRecognitionResponse> ActiveCall()
{
if (this._call != null)
{
try
{
Status status = this._call.GetStatus();
log.Information($"Call status: ${status.StatusCode} ${status.Detail}");
this._call.Dispose();
this._call = null;
if (this._readTask != null)
{
log.Information($"Call status: ${status.StatusCode} ${status.Detail}. Disposing.");
this._readTask.Dispose(); // Close read task
}
this._readTask = null;
// call is finished
}
catch (Exception ex)
{
log.Information($"Call is in process - reuse. ${ex.Message}");
return(this._call);
}
}
try
{
Log.Information($"Initialize gRPC call is finished");
this._call = speechKitRpctClient.StreamingRecognize(
headers: this.MakeMetadata(),
deadline: DateTime.UtcNow.AddMinutes(5)); // check https://cloud.yandex.com/docs/speechkit/stt/streaming#session-restrictions for limitation details
this.bytesSent = 0; // reset bytes counter
StreamingRecognitionRequest rR = new StreamingRecognitionRequest();
rR.Config = this.rConf;
this._call.RequestStream.WriteAsync(rR).Wait();
// Start reading task for call
if (this._readTask == null)
{
this._readTask = SpeechToTextResponseReader.ReadResponseStream(this._call);
}
return(this._call);
}
catch (RpcException ex) //when (ex.StatusCode == StatusCode.DeadlineExceeded)
{
Log.Warning($"gRPC request on create exception {ex.Message} with status {ex.Status} code {ex.StatusCode}");
// Maximum duration exeeded reestablish connection
if (ex.StatusCode == StatusCode.DeadlineExceeded) //|| StatusCode=\"InvalidArgument\", Detail=\"audio should be less than 10MB\")"
{
return(ActiveCall());
}
else
{
throw ex;
}
}
catch (Exception ex) //when (ex.StatusCode == StatusCode.DeadlineExceeded)
{
Log.Error($"during data sent exception {ex.Message} ");
throw ex;
}
}