在 Cloud Speech-to-Text 中启用语言识别

预览版

此功能 受服务专用条款的约束。 非正式版功能“按原样”提供，且可能仅提供有限支持。 如需了解详情，请参阅发布阶段说明。

本页面介绍了如何为发送到 Cloud Speech-to-Text 的音频转写请求启用语言识别。

有些时候，您并不确定音频录音中会包含哪些语言。例如，如果您在具有多种官方语言的国家/地区发布服务、应用或产品，则可能会接收用户以多种语言提供的音频输入。这种情况下，为转录请求指定单独一种语言代码的难度很大。

多语言识别

Cloud Speech-to-Text 为您提供了一种方法，让您可以指定音频数据可能包含的一组备用语言。当您向 Cloud Speech-to-Text 发送音频转写请求时，您可以提供一份列表，在其中列明音频数据可能包含的其他语言。如果您在请求中包含语言列表，则 Cloud Speech-to-Text 会尝试根据您提供的备用项中最适合样本的语言转录音频。随后，Cloud Speech-to-Text 会使用预测的语言代码标记转录结果。

此功能非常适合需要转录语音指令或搜索等简短语句的应用。除了主要语言之外，您还可以从 Cloud Speech-to-Text 支持的语言中任选三种，作为备用语言列出（总共四种语言）。

尽管您可以为语音转录请求指定备用语言，但仍然必须在 languageCode 字段中提供主要语言代码。此外，您应该将请求使用的语言数量限制在最低限度。请求使用的备用语言代码越少，就越有助于 Cloud Speech-to-Text 成功选择正确的语言代码。仅指定一种语言的效果最为理想。

在音频转录请求中启用语言识别

如需在音频转录中指定备用语言，必须将请求的 RecognitionConfig 参数的 alternativeLanguageCodes 字段设置为语言代码的列表。Cloud STT 的备用语言代码支持以下所有语音识别方法：speech:recognize、speech:longrunningrecognize 和流式。

注意：备用语言功能仅在模型可用于所有请求的语言时才有效。如需详细了解如何指定不同的模型，请参阅 RecognitionConfig 参考文档。

使用本地文件

协议

如需了解完整的详细信息，请参阅 speech:recognize API 端点。

如需执行同步语音识别，请发出 POST 请求并提供相应的请求正文。以下示例展示了一个使用 curl 发出的 POST 请求。该示例使用 Google Cloud CLI 生成访问令牌。如需了解如何安装 gcloud CLI，请参阅快速入门。

以下示例展示了如何请求可能包含英语、法语或德语语音的音频文件的转录。

curl -s -H "Content-Type: application/json" \
    -H "Authorization: Bearer $(gcloud auth application-default print-access-token)" \
    https://speech.googleapis.com/v1p1beta1/speech:recognize \
    --data '{
    "config": {
        "encoding": "LINEAR16",
        "languageCode": "en-US",
        "alternativeLanguageCodes": ["fr-FR", "de-DE"],
        "model": "command_and_search"
    },
    "audio": {
        "uri": "gs://cloud-samples-tests/speech/commercial_mono.wav"
    }
}' > multi-language.txt

如果请求成功，服务器将返回一个 200 OK HTTP 状态代码以及 JSON 格式的响应（该响应会保存到名为 multi-language.txt 的文件中）。

{
  "results": [
    {
      "alternatives": [
        {
          "transcript": "hi I'd like to buy a Chromecast I'm ..."
          "confidence": 0.9466864
        }
      ],
      "languageCode": "en-us"
    },
    {
      "alternatives": [
        {
          "transcript": " let's go with the black one",
          "confidence": 0.9829583
        }
      ],
      "languageCode": "en-us"
    },
  ]
}

Java

如需了解如何安装和使用 Cloud STT 客户端库，请参阅 Cloud STT 客户端库。如需了解详情，请参阅 Cloud STT Java API 参考文档。

如需向 Cloud STT 进行身份验证，请设置应用默认凭证。如需了解详情，请参阅为本地开发环境设置身份验证。

/**
 * Transcribe a local audio file with multi-language recognition
 *
 * @param fileName the path to the audio file
 */
public static void transcribeMultiLanguage(String fileName) throws Exception {
  Path path = Paths.get(fileName);
  // Get the contents of the local audio file
  byte[] content = Files.readAllBytes(path);

  try (SpeechClient speechClient = SpeechClient.create()) {

    RecognitionAudio recognitionAudio =
        RecognitionAudio.newBuilder().setContent(ByteString.copyFrom(content)).build();
    ArrayList<String> languageList = new ArrayList<>();
    languageList.add("es-ES");
    languageList.add("en-US");

    // Configure request to enable multiple languages
    RecognitionConfig config =
        RecognitionConfig.newBuilder()
            .setEncoding(AudioEncoding.LINEAR16)
            .setSampleRateHertz(16000)
            .setLanguageCode("ja-JP")
            .addAllAlternativeLanguageCodes(languageList)
            .build();
    // Perform the transcription request
    RecognizeResponse recognizeResponse = speechClient.recognize(config, recognitionAudio);

    // Print out the results
    for (SpeechRecognitionResult result : recognizeResponse.getResultsList()) {
      // There can be several alternative transcripts for a given chunk of speech. Just use the
      // first (most likely) one here.
      SpeechRecognitionAlternative alternative = result.getAlternatives(0);
      System.out.format("Transcript : %s\n\n", alternative.getTranscript());
    }
  }
}

Node.js

如需了解如何安装和使用 Cloud STT 客户端库，请参阅 Cloud STT 客户端库。如需了解详情，请参阅 Cloud STT Node.js API 参考文档。

如需向 Cloud STT 进行身份验证，请设置应用默认凭证。如需了解详情，请参阅为本地开发环境设置身份验证。

const fs = require('fs');

// Imports the Google Cloud client library
const speech = require('@google-cloud/speech').v1p1beta1;

// Creates a client
const client = new speech.SpeechClient();

/**
 * TODO(developer): Uncomment the following lines before running the sample.
 */
// const fileName = 'Local path to audio file, e.g. /path/to/audio.raw';

const config = {
  encoding: 'LINEAR16',
  sampleRateHertz: 44100,
  languageCode: 'en-US',
  alternativeLanguageCodes: ['es-ES', 'en-US'],
};

const audio = {
  content: fs.readFileSync(fileName).toString('base64'),
};

const request = {
  config: config,
  audio: audio,
};

const [response] = await client.recognize(request);
const transcription = response.results
  .map(result => result.alternatives[0].transcript)
  .join('\n');
console.log(`Transcription: ${transcription}`);

Python

如需了解如何安装和使用 Cloud STT 客户端库，请参阅 Cloud STT 客户端库。如需了解详情，请参阅 Cloud STT Python API 参考文档。

如需向 Cloud STT 进行身份验证，请设置应用默认凭证。如需了解详情，请参阅为本地开发环境设置身份验证。

from google.cloud import speech_v1p1beta1 as speech

client = speech.SpeechClient()

speech_file = "resources/multi.wav"
first_lang = "en-US"
second_lang = "es"

with open(speech_file, "rb") as audio_file:
    content = audio_file.read()

audio = speech.RecognitionAudio(content=content)

config = speech.RecognitionConfig(
    encoding=speech.RecognitionConfig.AudioEncoding.LINEAR16,
    sample_rate_hertz=44100,
    audio_channel_count=2,
    language_code=first_lang,
    alternative_language_codes=[second_lang],
)

print("Waiting for operation to complete...")
response = client.recognize(config=config, audio=audio)

for i, result in enumerate(response.results):
    alternative = result.alternatives[0]
    print("-" * 20)
    print(f"First alternative of result {i}: {alternative}")
    print(f"Transcript: {alternative.transcript}")

return response.results

使用远程文件

Java

如需了解如何安装和使用 Cloud STT 客户端库，请参阅 Cloud STT 客户端库。如需了解详情，请参阅 Cloud STT Java API 参考文档。

如需向 Cloud STT 进行身份验证，请设置应用默认凭证。如需了解详情，请参阅为本地开发环境设置身份验证。

/**
 * Transcribe a remote audio file with multi-language recognition
 *
 * @param gcsUri the path to the remote audio file
 */
public static void transcribeMultiLanguageGcs(String gcsUri) throws Exception {
  try (SpeechClient speechClient = SpeechClient.create()) {

    ArrayList<String> languageList = new ArrayList<>();
    languageList.add("es-ES");
    languageList.add("en-US");

    // Configure request to enable multiple languages
    RecognitionConfig config =
        RecognitionConfig.newBuilder()
            .setEncoding(AudioEncoding.LINEAR16)
            .setSampleRateHertz(16000)
            .setLanguageCode("ja-JP")
            .addAllAlternativeLanguageCodes(languageList)
            .build();

    // Set the remote path for the audio file
    RecognitionAudio audio = RecognitionAudio.newBuilder().setUri(gcsUri).build();

    // Use non-blocking call for getting file transcription
    OperationFuture<LongRunningRecognizeResponse, LongRunningRecognizeMetadata> response =
        speechClient.longRunningRecognizeAsync(config, audio);

    while (!response.isDone()) {
      System.out.println("Waiting for response...");
      Thread.sleep(10000);
    }

    for (SpeechRecognitionResult result : response.get().getResultsList()) {

      // There can be several alternative transcripts for a given chunk of speech. Just use the
      // first (most likely) one here.
      SpeechRecognitionAlternative alternative = result.getAlternativesList().get(0);

      // Print out the result
      System.out.printf("Transcript : %s\n\n", alternative.getTranscript());
    }
  }
}

Node.js

如需了解如何安装和使用 Cloud STT 客户端库，请参阅 Cloud STT 客户端库。如需了解详情，请参阅 Cloud STT Node.js API 参考文档。

如需向 Cloud STT 进行身份验证，请设置应用默认凭证。如需了解详情，请参阅为本地开发环境设置身份验证。

// Imports the Google Cloud client library
const speech = require('@google-cloud/speech').v1p1beta1;

// Creates a client
const client = new speech.SpeechClient();

/**
 * TODO(developer): Uncomment the following line before running the sample.
 */
// const uri = path to GCS audio file e.g. `gs:/bucket/audio.wav`;

const config = {
  encoding: 'LINEAR16',
  sampleRateHertz: 44100,
  languageCode: 'en-US',
  alternativeLanguageCodes: ['es-ES', 'en-US'],
};

const audio = {
  uri: gcsUri,
};

const request = {
  config: config,
  audio: audio,
};

const [operation] = await client.longRunningRecognize(request);
const [response] = await operation.promise();
const transcription = response.results
  .map(result => result.alternatives[0].transcript)
  .join('\n');
console.log(`Transcription: ${transcription}`);

Python

如需了解如何安装和使用 Cloud STT 客户端库，请参阅 Cloud STT 客户端库。如需了解详情，请参阅 Cloud STT Python API 参考文档。

如需向 Cloud STT 进行身份验证，请设置应用默认凭证。如需了解详情，请参阅为本地开发环境设置身份验证。

from google.cloud import speech_v1p1beta1 as speech


def transcribe_file_with_multilanguage_gcs(audio_uri: str) -> str:
    """Transcribe a remote audio file with multi-language recognition
    Args:
        audio_uri (str): The Google Cloud Storage path to an audio file.
            E.g., gs://[BUCKET]/[FILE]
    Returns:
        str: The generated transcript from the audio file provided.
    """

    client = speech.SpeechClient()

    first_language = "es-ES"
    alternate_languages = ["en-US", "fr-FR"]

    # Configure request to enable multiple languages
    recognition_config = speech.RecognitionConfig(
        encoding=speech.RecognitionConfig.AudioEncoding.FLAC,
        sample_rate_hertz=44100,
        language_code=first_language,
        alternative_language_codes=alternate_languages,
    )

    # Set the remote path for the audio file
    audio = speech.RecognitionAudio(uri=audio_uri)

    # Use non-blocking call for getting file transcription
    response = client.long_running_recognize(
        config=recognition_config, audio=audio
    ).result(timeout=300)

    transcript_builder = []
    for i, result in enumerate(response.results):
        alternative = result.alternatives[0]
        transcript_builder.append("-" * 20 + "\n")
        transcript_builder.append(f"First alternative of result {i}: {alternative}")
        transcript_builder.append(f"Transcript: {alternative.transcript} \n")

    transcript = "".join(transcript_builder)
    print(transcript)

    return transcript