Google speech to text API in C#

Question

My program get a correct respon from google when the flac file recorded manual by using windows\'s sound recorder and convert it using a software converter.
But when I

Answer 1

It's clearly mentioned in the Google cloud api url i.e

https://cloud.google.com/speech-to-text/docs/async-recognize#speech-async-recognize-gcs-protocol

If the operation has not completed, you can poll the endpoint by repeatedly making the GET request until the done property of the response is true.

        {
      "name": "operationname here",
      "metadata": {
        "@type": "type.googleapis.com/google.cloud.speech.v1.LongRunningRecognizeMetadata",
        "progressPercent": 0,
        "startTime": "2018-12-18T10:56:09.425584Z",
        "lastUpdateTime": "2018-12-18T11:10:27.147310Z"
      },
      "done": true,
    }

poll the endpoint by repeatedly making the GET request until the done property of the response is true or you can check for the "progressPercent": 0 until it's value become 100. Once its 100 percent then done property becomes true.

I did the same in my code using operation name, for reference here is the code

public async Task TranscribeLongMediaFile(string operationName)
    {
        string bearerToken = GetOAuthToken();
        var baseUrl = new Uri(googleSpeechBaseUrl + operationName);
        string resultContent = string.Empty;
        using (var client = new HttpClient())
        {
            client.DefaultRequestHeaders.Add(HttpRequestHeader.Authorization.ToString(), "Bearer " + bearerToken);
            client.DefaultRequestHeaders.Add(HttpRequestHeader.ContentType.ToString(), "application/json; charset=utf-8");

            client.Timeout = TimeSpan.FromMilliseconds(Timeout.Infinite);

            int currentPercentage = 0;
            bool responseStatus = false;
            while (!responseStatus)
            {
                responseStatus = false;
                // Send request
                using (var result = await client.GetAsync(baseUrl))
                {
                    resultContent = await result.Content.ReadAsStringAsync();

                    ResponseObject responseObject = JsonConvert.DeserializeObject(resultContent);
                    currentPercentage = responseObject.metadata.progressPercent;
                    responseStatus = (responseObject.done && currentPercentage == 100);

                    // Delay the request based on percentage value to repeatedly making the GET request until the done property of the response is true.
                    await Task.Delay(CalculateDealy(currentPercentage));
                }
            }
        };
        return resultContent;
    }

In order to delay the get request:

/// 

    /// Delay the request to number of milliseconds
    /// 
    /// 
    /// 
    private int CalculateDealy(int currentPercentage)
    {
        int x = currentPercentage / 10;
        return (10 - x) * 1500;
    }

Get auth token:

/// 

    /// Get OAuth token
    /// 
    /// 
    public string GetOAuthToken()
    {
        return googleCredential.UnderlyingCredential.GetAccessTokenForRequestAsync("https://accounts.google.com/o/oauth2/v2/auth", CancellationToken.None).Result;
    }

At last, you will get the result like:

    {
  "name": "operationname here",
  "metadata": {
    "@type": "type.googleapis.com/google.cloud.speech.v1.LongRunningRecognizeMetadata",
    "progressPercent": 100,
    "startTime": "2018-12-18T10:56:09.425584Z",
    "lastUpdateTime": "2018-12-18T11:10:27.147310Z"
  },
  "done": true,
  "response": {
    "@type": "type.googleapis.com/google.cloud.speech.v1.LongRunningRecognizeResponse",
    "results": [
      {
        "alternatives": [
          {
            "transcript": "okay let's get started",
            "confidence": 0.97442055
          }
        ]
      }, and so on .....

Things required:

1. api-key.json file
2. Install package Google.Apis.Auth.OAuth2 in order to authorize the HTTP web request

Thanks