串流輸入音訊來偵測意圖

本頁面說明如何使用 API,將音訊輸入串流至偵測意圖要求。Dialogflow 會先處理音訊並轉換成文字,再嘗試比對意圖。這個程序稱為「音訊輸入」、「語音辨識」、「語音轉文字」或「STT」。

事前準備

這項功能僅適用於使用 API 進行使用者互動的情況。如果您使用整合,可以略過本指南。

閱讀本指南前,請先完成下列工作:

建立虛擬服務專員

  1. 前往 Dialogflow ES 控制台。
  2. 如果出現提示,請登入控制台。詳情請參閱「Dialogflow 控制台總覽」。
  3. 在側欄選單中,展開「Loading agents」(載入代理程式)。
  4. 按一下「Create new agent」。
  5. 輸入代理名稱、預設語言和預設時區。
  6. 輸入現有專案。如要讓 Dialogflow 控制台建立專案,請選取「Create a new Google project」(建立新的 Google 專案)。
  7. 按一下「Create」(建立)。

串流基本概念

Session 類型的 streamingDetectIntent 方法會傳回雙向 gRPC 串流物件。這個物件可用的方法因語言而異,詳情請參閱用戶端程式庫的參考文件。

串流物件用於同時傳送及接收資料。用戶端會使用這個物件,將音訊內容串流至 Dialogflow,同時監聽 StreamingDetectIntentResponse。

streamingDetectIntent 方法有 query_input.audio_config.single_utterance 參數,會影響語音辨識:

  • 如果設為 false (預設),語音辨識功能會持續運作,直到用戶端關閉串流為止。
  • 如果設為 true,Dialogflow 會偵測輸入音訊中的單一語音語句。當 Dialogflow 偵測到音訊的語音已停止或暫停時,就會停止語音辨識,並將 StreamingDetectIntentResponse 傳送至用戶端,其中包含 END_OF_SINGLE_UTTERANCE 的辨識結果。收到 END_OF_SINGLE_UTTERANCE 後,Dialogflow 會忽略串流中傳送至 Dialogflow 的任何音訊。

在雙向串流中,用戶端可以「半關閉」串流物件,向伺服器表示不會再傳送資料。例如,在 Java 和 Go 中,這個方法稱為 closeSend。

在下列情況下,請務必半關閉 (而非取消) 串流:

  • 您的用戶端已完成資料傳送作業。
  • 用戶端的 single_utterance 設為 true,並收到辨識結果為 END_OF_SINGLE_UTTERANCE 的 StreamingDetectIntentResponse。

關閉串流後,用戶端應視需要使用新串流啟動新要求。

串流偵測意圖

以下範例使用 Session 類型的 streamingDetectIntent 方法來串流音訊內容。

Go

如要向 Dialogflow CX 進行驗證,請設定應用程式預設憑證。詳情請參閱「為本機開發環境設定驗證機制」。

func DetectIntentStream(projectID, sessionID, audioFile, languageCode string) (string, error) {
	ctx := context.Background()

	sessionClient, err := dialogflow.NewSessionsClient(ctx)
	if err != nil {
		return "", err
	}
	defer sessionClient.Close()

	if projectID == "" || sessionID == "" {
		return "", fmt.Errorf("detect.DetectIntentStream empty project (%s) or session (%s)", projectID, sessionID)
	}

	sessionPath := fmt.Sprintf("projects/%s/agent/sessions/%s", projectID, sessionID)

	// In this example, we hard code the encoding and sample rate for simplicity.
	audioConfig := dialogflowpb.InputAudioConfig{AudioEncoding: dialogflowpb.AudioEncoding_AUDIO_ENCODING_LINEAR_16, SampleRateHertz: 16000, LanguageCode: languageCode}

	queryAudioInput := dialogflowpb.QueryInput_AudioConfig{AudioConfig: &audioConfig}

	queryInput := dialogflowpb.QueryInput{Input: &queryAudioInput}

	streamer, err := sessionClient.StreamingDetectIntent(ctx)
	if err != nil {
		return "", err
	}

	f, err := os.Open(audioFile)
	if err != nil {
		return "", err
	}

	defer f.Close()

	go func() {
		audioBytes := make([]byte, 1024)

		request := dialogflowpb.StreamingDetectIntentRequest{Session: sessionPath, QueryInput: &queryInput}
		err = streamer.Send(&request)
		if err != nil {
			log.Fatal(err)
		}

		for {
			_, err := f.Read(audioBytes)
			if err == io.EOF {
				streamer.CloseSend()
				break
			}
			if err != nil {
				log.Fatal(err)
			}

			request = dialogflowpb.StreamingDetectIntentRequest{InputAudio: audioBytes}
			err = streamer.Send(&request)
			if err != nil {
				log.Fatal(err)
			}
		}
	}()

	var queryResult *dialogflowpb.QueryResult

	for {
		response, err := streamer.Recv()
		if err == io.EOF {
			break
		}
		if err != nil {
			log.Fatal(err)
		}

		recognitionResult := response.GetRecognitionResult()
		transcript := recognitionResult.GetTranscript()
		log.Printf("Recognition transcript: %s\n", transcript)

		queryResult = response.GetQueryResult()
	}

	fulfillmentText := queryResult.GetFulfillmentText()
	return fulfillmentText, nil
}

Java

如要向 Dialogflow CX 進行驗證,請設定應用程式預設憑證。詳情請參閱「為本機開發環境設定驗證機制」。


import com.google.api.gax.rpc.ApiException;
import com.google.api.gax.rpc.BidiStream;
import com.google.cloud.dialogflow.v2.AudioEncoding;
import com.google.cloud.dialogflow.v2.InputAudioConfig;
import com.google.cloud.dialogflow.v2.QueryInput;
import com.google.cloud.dialogflow.v2.QueryResult;
import com.google.cloud.dialogflow.v2.SessionName;
import com.google.cloud.dialogflow.v2.SessionsClient;
import com.google.cloud.dialogflow.v2.StreamingDetectIntentRequest;
import com.google.cloud.dialogflow.v2.StreamingDetectIntentResponse;
import com.google.protobuf.ByteString;
import java.io.FileInputStream;
import java.io.IOException;

class DetectIntentStream {

  // DialogFlow API Detect Intent sample with audio files processes as an audio stream.
  static void detectIntentStream(String projectId, String audioFilePath, String sessionId)
      throws IOException, ApiException {
    // String projectId = "YOUR_PROJECT_ID";
    // String audioFilePath = "path_to_your_audio_file";
    // Using the same `sessionId` between requests allows continuation of the conversation.
    // String sessionId = "Identifier of the DetectIntent session";

    // Instantiates a client
    try (SessionsClient sessionsClient = SessionsClient.create()) {
      // Set the session name using the sessionId (UUID) and projectID (my-project-id)
      SessionName session = SessionName.of(projectId, sessionId);

      // Instructs the speech recognizer how to process the audio content.
      // Note: hard coding audioEncoding and sampleRateHertz for simplicity.
      // Audio encoding of the audio content sent in the query request.
      InputAudioConfig inputAudioConfig =
          InputAudioConfig.newBuilder()
              .setAudioEncoding(AudioEncoding.AUDIO_ENCODING_LINEAR_16)
              .setLanguageCode("en-US") // languageCode = "en-US"
              .setSampleRateHertz(16000) // sampleRateHertz = 16000
              .build();

      // Build the query with the InputAudioConfig
      QueryInput queryInput = QueryInput.newBuilder().setAudioConfig(inputAudioConfig).build();

      // Create the Bidirectional stream
      BidiStream<StreamingDetectIntentRequest, StreamingDetectIntentResponse> bidiStream =
          sessionsClient.streamingDetectIntentCallable().call();

      // The first request must **only** contain the audio configuration:
      bidiStream.send(
          StreamingDetectIntentRequest.newBuilder()
              .setSession(session.toString())
              .setQueryInput(queryInput)
              .build());

      try (FileInputStream audioStream = new FileInputStream(audioFilePath)) {
        // Subsequent requests must **only** contain the audio data.
        // Following messages: audio chunks. We just read the file in fixed-size chunks. In reality
        // you would split the user input by time.
        byte[] buffer = new byte[4096];
        int bytes;
        while ((bytes = audioStream.read(buffer)) != -1) {
          bidiStream.send(
              StreamingDetectIntentRequest.newBuilder()
                  .setInputAudio(ByteString.copyFrom(buffer, 0, bytes))
                  .build());
        }
      }

      // Tell the service you are done sending data
      bidiStream.closeSend();

      for (StreamingDetectIntentResponse response : bidiStream) {
        QueryResult queryResult = response.getQueryResult();
        System.out.println("====================");
        System.out.format("Intent Display Name: %s\n", queryResult.getIntent().getDisplayName());
        System.out.format("Query Text: '%s'\n", queryResult.getQueryText());
        System.out.format(
            "Detected Intent: %s (confidence: %f)\n",
            queryResult.getIntent().getDisplayName(), queryResult.getIntentDetectionConfidence());
        System.out.format(
            "Fulfillment Text: '%s'\n",
            queryResult.getFulfillmentMessagesCount() > 0
                ? queryResult.getFulfillmentMessages(0).getText()
                : "Triggered Default Fallback Intent");
      }
    }
  }
}

Node.js

如要向 Dialogflow CX 進行驗證,請設定應用程式預設憑證。詳情請參閱「為本機開發環境設定驗證機制」。

const fs = require('fs');
const util = require('util');
const {Transform, pipeline} = require('stream');
const {struct} = require('pb-util');

const pump = util.promisify(pipeline);
// Imports the Dialogflow library
const dialogflow = require('@google-cloud/dialogflow');

// Instantiates a session client
const sessionClient = new dialogflow.SessionsClient();

// The path to the local file on which to perform speech recognition, e.g.
// /path/to/audio.raw const filename = '/path/to/audio.raw';

// The encoding of the audio file, e.g. 'AUDIO_ENCODING_LINEAR_16'
// const encoding = 'AUDIO_ENCODING_LINEAR_16';

// The sample rate of the audio file in hertz, e.g. 16000
// const sampleRateHertz = 16000;

// The BCP-47 language code to use, e.g. 'en-US'
// const languageCode = 'en-US';
const sessionPath = sessionClient.projectAgentSessionPath(
  projectId,
  sessionId
);

const initialStreamRequest = {
  session: sessionPath,
  queryInput: {
    audioConfig: {
      audioEncoding: encoding,
      sampleRateHertz: sampleRateHertz,
      languageCode: languageCode,
    },
  },
};

// Create a stream for the streaming request.
const detectStream = sessionClient
  .streamingDetectIntent()
  .on('error', console.error)
  .on('data', data => {
    if (data.recognitionResult) {
      console.log(
        `Intermediate transcript: ${data.recognitionResult.transcript}`
      );
    } else {
      console.log('Detected intent:');

      const result = data.queryResult;
      // Instantiates a context client
      const contextClient = new dialogflow.ContextsClient();

      console.log(`  Query: ${result.queryText}`);
      console.log(`  Response: ${result.fulfillmentText}`);
      if (result.intent) {
        console.log(`  Intent: ${result.intent.displayName}`);
      } else {
        console.log('  No intent matched.');
      }
      const parameters = JSON.stringify(struct.decode(result.parameters));
      console.log(`  Parameters: ${parameters}`);
      if (result.outputContexts && result.outputContexts.length) {
        console.log('  Output contexts:');
        result.outputContexts.forEach(context => {
          const contextId =
            contextClient.matchContextFromProjectAgentSessionContextName(
              context.name
            );
          const contextParameters = JSON.stringify(
            struct.decode(context.parameters)
          );
          console.log(`    ${contextId}`);
          console.log(`      lifespan: ${context.lifespanCount}`);
          console.log(`      parameters: ${contextParameters}`);
        });
      }
    }
  });

// Write the initial stream request to config for audio input.
detectStream.write(initialStreamRequest);

// Stream an audio file from disk to the Conversation API, e.g.
// "./resources/audio.raw"
await pump(
  fs.createReadStream(filename),
  // Format the audio stream into the request format.
  new Transform({
    objectMode: true,
    transform: (obj, _, next) => {
      next(null, {inputAudio: obj});
    },
  }),
  detectStream
);

Python

如要向 Dialogflow CX 進行驗證,請設定應用程式預設憑證。詳情請參閱「為本機開發環境設定驗證機制」。

def detect_intent_stream(project_id, session_id, audio_file_path, language_code):
    """Returns the result of detect intent with streaming audio as input.

    Using the same `session_id` between requests allows continuation
    of the conversation."""
    from google.cloud import dialogflow

    session_client = dialogflow.SessionsClient()

    # Note: hard coding audio_encoding and sample_rate_hertz for simplicity.
    audio_encoding = dialogflow.AudioEncoding.AUDIO_ENCODING_LINEAR_16
    sample_rate_hertz = 16000

    session_path = session_client.session_path(project_id, session_id)
    print("Session path: {}\n".format(session_path))

    def request_generator(audio_config, audio_file_path):
        query_input = dialogflow.QueryInput(audio_config=audio_config)

        # The first request contains the configuration.
        yield dialogflow.StreamingDetectIntentRequest(
            session=session_path, query_input=query_input
        )

        # Here we are reading small chunks of audio data from a local
        # audio file.  In practice these chunks should come from
        # an audio input device.
        with open(audio_file_path, "rb") as audio_file:
            while True:
                chunk = audio_file.read(4096)
                if not chunk:
                    break
                # The later requests contains audio data.
                yield dialogflow.StreamingDetectIntentRequest(input_audio=chunk)

    audio_config = dialogflow.InputAudioConfig(
        audio_encoding=audio_encoding,
        language_code=language_code,
        sample_rate_hertz=sample_rate_hertz,
    )

    requests = request_generator(audio_config, audio_file_path)
    responses = session_client.streaming_detect_intent(requests=requests)

    print("=" * 20)
    for response in responses:
        print(
            'Intermediate transcript: "{}".'.format(
                response.recognition_result.transcript
            )
        )
        # Note: Since Python gRPC doesn't have closeSend method, to stop processing the audio after result is recognized,
        # you may close the channel manually to prevent further iteration.
        # Keep in mind that if there is a silence chunk in the audio, part after it might be missed because of early teardown.
        # https://cloud.google.com/dialogflow/es/docs/how/detect-intent-stream#streaming_basics
        if response.recognition_result.is_final:
            session_client.transport.close()
            break

    # Note: The result from the last response is the final transcript along
    # with the detected content.
    query_result = response.query_result

    print("=" * 20)
    print("Query text: {}".format(query_result.query_text))
    print(
        "Detected intent: {} (confidence: {})\n".format(
            query_result.intent.display_name, query_result.intent_detection_confidence
        )
    )
    print("Fulfillment text: {}\n".format(query_result.fulfillment_text))

其他語言

C#:請按照用戶端程式庫頁面上的 C# 設定操作說明完成相關步驟,然後參閱 .NET 適用的 Dialogflow CX 參考文件。

PHP:請按照用戶端程式庫頁面上的 PHP 設定操作說明完成相關步驟,然後參閱 PHP 適用的 Dialogflow CX 參考文件。

Ruby:請按照用戶端程式庫頁面上的 Ruby 設定操作說明完成相關步驟,然後參閱 Ruby 適用的 Dialogflow CX 參考文件。

範例

如要進一步瞭解從瀏覽器麥克風串流至 Dialogflow 的最佳做法,請參閱範例頁面。