Cloud Speech-to-Text API C++ Client Library (original) (raw)

Cloud Speech-to-Text API C++ Client Library

An idiomatic C++ client library for the Cloud Speech-to-Text API, a service which converts audio to text by applying powerful neural network models.

While this library is GA, please note Google Cloud C++ client libraries do not follow Semantic Versioning.

Quickstart

The following shows the code that you'll run in the google/cloud/speech/quickstart/ directory, which should give you a taste of the Cloud Speech-to-Text API C++ client library API.

#include "google/cloud/speech/v2/speech_client.h"
#include "google/cloud/project.h"
#include <iostream>

// Configure a simple recognizer for en-US.
void ConfigureRecognizer(google:☁️:speech::v2::RecognizeRequest& request) {
  *request.mutable_config()->add_language_codes() = "en-US";
  request.mutable_config()->set_model("short");
  *request.mutable_config()->mutable_auto_decoding_config() = {};
}

int main(int argc, char* argv[]) try {
  auto constexpr kDefaultUri = "gs://cloud-samples-data/speech/hello.wav";
  if (argc != 3 && argc != 4) {
    std::cerr << "Usage: " << argv[0] << " project <region>|global [gcs-uri]\n"
              << "  Specify the region desired or \"global\"\n"
              << "  The gcs-uri must be in gs://... format. It defaults to "
              << kDefaultUri << "\n";
    return 1;
  }
  std::string const project = argv[1];
  std::string location = argv[2];
  auto const uri = std::string{argc == 4 ? argv[3] : kDefaultUri};
  namespace speech = ::google:☁️:speech_v2;

  std::shared_ptr<speech::SpeechConnection> connection;
  google:☁️:speech::v2::RecognizeRequest request;
  ConfigureRecognizer(request);
  request.set_uri(uri);
  request.set_recognizer("projects/" + project + "/locations/" + location +
                         "/recognizers/_");

  if (location == "global") {
    // An empty location string indicates that the global endpoint of the
    // service should be used.
    location = "";
  }

  auto client = speech::SpeechClient(speech::MakeSpeechConnection(location));
  auto response = client.Recognize(request);
  if (!response) throw std::move(response).status();
  std::cout << response->DebugString() << "\n";

  return 0;
} catch (google:☁️:Status const& status) {
  std::cerr << "google:☁️:Status thrown: " << status << "\n";
  return 1;
}

Main classes

This library offers multiple *Client classes, which are listed below. Each one of these classes exposes all the RPCs for a service as member functions of the class. This library groups multiple services because they are part of the same product or are often used together. A typical example may be the administrative and data plane operations for a single product.

The library also has other classes that provide helpers, configuration parameters, and infrastructure to mock the *Client classes when testing your application.

• speech_v1::AdaptationClient
• speech_v1::SpeechClient
• speech_v2::SpeechClient

More Information

• Error Handling - describes how the library reports errors.
• How to Override the Default Endpoint - describes how to override the default endpoint.
• How to Override the Authentication Credentials - describes how to change the authentication credentials used by the library.
• Override Retry, Backoff, and Idempotency Policies - describes how to change the default retry policies.
• Environment Variables - describes environment variables that can configure the behavior of the library.
• How to Override the Default Universe Domain - describes how to override the default universe domain.

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Last updated 2026-03-31 UTC.