Transcription with diarization

Identify the different speakers in the audio sample.

Code sample

Java

To learn how to install and use the client library for Cloud STT, see Cloud STT client libraries. For more information, see the Cloud STT Java API reference documentation.

To authenticate to Cloud STT, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

import com.google.cloud.speech.v1.RecognitionAudio;
import com.google.cloud.speech.v1.RecognitionConfig;
import com.google.cloud.speech.v1.RecognizeResponse;
import com.google.cloud.speech.v1.SpeakerDiarizationConfig;
import com.google.cloud.speech.v1.SpeechClient;
import com.google.cloud.speech.v1.SpeechRecognitionAlternative;
import com.google.cloud.speech.v1.WordInfo;
import com.google.protobuf.ByteString;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

class TranscribeDiarization {

  static void transcribeDiarization() throws IOException {
    // TODO(developer): Replace these variables before running the sample.
    String fileName = "resources/commercial_mono.wav";
    transcribeDiarization(fileName);
  }

  // Transcribe the given audio file using speaker diarization.
  static void transcribeDiarization(String fileName) throws IOException {
    Path path = Paths.get(fileName);
    byte[] content = Files.readAllBytes(path);

    // Initialize client that will be used to send requests. This client only needs to be created
    // once, and can be reused for multiple requests. After completing all of your requests, call
    // the "close" method on the client to safely clean up any remaining background resources.
    try (SpeechClient client = SpeechClient.create()) {
      // Get the contents of the local audio file
      RecognitionAudio recognitionAudio =
          RecognitionAudio.newBuilder().setContent(ByteString.copyFrom(content)).build();
      SpeakerDiarizationConfig speakerDiarizationConfig =
          SpeakerDiarizationConfig.newBuilder()
              .setEnableSpeakerDiarization(true)
              .setMinSpeakerCount(2)
              .setMaxSpeakerCount(2)
              .build();
      // Configure request to enable Speaker diarization
      RecognitionConfig config =
          RecognitionConfig.newBuilder()
              .setEncoding(RecognitionConfig.AudioEncoding.LINEAR16)
              .setLanguageCode("en-US")
              .setSampleRateHertz(8000)
              .setDiarizationConfig(speakerDiarizationConfig)
              .build();

      // Perform the transcription request
      RecognizeResponse recognizeResponse = client.recognize(config, recognitionAudio);

      // Speaker Tags are only included in the last result object, which has only one alternative.
      SpeechRecognitionAlternative alternative =
          recognizeResponse.getResults(recognizeResponse.getResultsCount() - 1).getAlternatives(0);
      // The alternative is made up of WordInfo objects that contain the speaker_tag.
      WordInfo wordInfo = alternative.getWords(0);
      int currentSpeakerTag = wordInfo.getSpeakerTag();
      // For each word, get all the words associated with one speaker, once the speaker changes,
      // add a new line with the new speaker and their spoken words.
      StringBuilder speakerWords =
          new StringBuilder(
              String.format("Speaker %d: %s", wordInfo.getSpeakerTag(), wordInfo.getWord()));
      for (int i = 1; i < alternative.getWordsCount(); i++) {
        wordInfo = alternative.getWords(i);
        if (currentSpeakerTag == wordInfo.getSpeakerTag()) {
          speakerWords.append(" ");
          speakerWords.append(wordInfo.getWord());
        } else {
          speakerWords.append(
              String.format("\nSpeaker %d: %s", wordInfo.getSpeakerTag(), wordInfo.getWord()));
          currentSpeakerTag = wordInfo.getSpeakerTag();
        }
      }
      System.out.println(speakerWords.toString());
    }
  }
}

Node.js

To learn how to install and use the client library for Cloud STT, see Cloud STT client libraries. For more information, see the Cloud STT Node.js API reference documentation.

To authenticate to Cloud STT, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

const fs = require('fs');

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

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

// Set config for Diarization
const diarizationConfig = {
  enableSpeakerDiarization: true,
  maxSpeakerCount: 2,
};

const config = {
  encoding: 'LINEAR16',
  sampleRateHertz: 8000,
  languageCode: 'en-US',
  diarizationConfig: diarizationConfig,
  model: 'phone_call',
};

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

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}`);
console.log('Speaker Diarization:');
const result = response.results[response.results.length - 1];
const wordsInfo = result.alternatives[0].words;
// Note: The transcript within each result is separate and sequential per result.
// However, the words list within an alternative includes all the words
// from all the results thus far. Thus, to get all the words with speaker
// tags, you only have to take the words list from the last result:
wordsInfo.forEach(a =>
  console.log(` word: ${a.word}, speakerTag: ${a.speakerTag}`)
);

What's next

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