{% setvar launch_type %}api{% endsetvar %} {% setvar launch_name %}Cloud Speech-to-Text API{% endsetvar %} {% setvar info_params %}realtime_warning{% endsetvar %}

Transcribing Video Files

This tutorial shows how to transcribe the audio track from a video file using Cloud Speech-to-Text.

Audio files can come from many different sources. Audio data can come from a phone (like voicemail) or the soundtrack included in a video file.

Speech-to-Text can use one of several machine learning models to transcribe your audio file, to best match the original source of the audio. You can get better results from your speech transcription by specifying the source of the original audio. This allows Speech-to-Text to process your audio files using a machine learning model trained for data similar to your audio file.

Objectives

  • Send a audio transcription request for a video file to Speech-to-Text .

Costs

This tutorial uses billable components of Cloud Platform, including:

  • Cloud Speech-to-Text

Use the Pricing Calculator to generate a cost estimate based on your projected usage. New Cloud Platform users might be eligible for a free trial.

Before you begin

This tutorial has several prerequisites:

Sending a request

The following code samples demonstrate how to select a specific transcription model when calling Speech-to-Text .

Protocol

Refer to the speech:recognize API endpoint for complete details.

To perform synchronous speech recognition, make a POST request and provide the appropriate request body. The following shows an example of a POST request using curl. The example uses the access token for a service account set up for the project using the Google Cloud Platform Cloud SDK. For instructions on installing the Cloud SDK, setting up a project with a service account, and obtaining an access token, see the Quickstart.

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',
    'sampleRateHertz': 16000,
    'languageCode': 'en-US',
    'enableWordTimeOffsets': false,
    'enableAutomaticPunctuation': true,
    'model': 'video'
  },
  'audio': {
    'uri':'gs://cloud-samples-tests/speech/Google_Gnome.wav'
  }
}"

See the RecognitionConfig reference documentation for more information on configuring the request body.

If the request is successful, the server returns a 200 OK HTTP status code and the response in JSON format:

{
  "results": [
    {
      "alternatives": [
        {
          "transcript": "OK Google stream stranger things from
            Netflix to my TV okay stranger things from
            Netflix playing on TV from the people that brought you
            Google home comes the next evolution of the smart home
            and it's just outside your window me Google know hi
            how can I help okay no what's the weather like outside
            the weather outside is sunny and 76 degrees he's right
            okay no turn on the hose I'm holding sure okay no I'm can
            I eat this lemon tree leaf yes what about this Daisy yes
            but I wouldn't recommend it but I could eat it okay
            Nomad milk to my shopping list I'm sorry that sounds like
            an indoor request I keep doing that sorry you do keep
            doing that okay no is this compost really we're all
            compost if you think about it pretty much everything is
            made up of organic matter and will return",
          "confidence": 0.9251011
        }
      ]
    }
  ]
}

Node.js

For more on installing and creating a Speech-to-Text client, refer to Speech-to-Text Client Libraries.

// Imports the Google Cloud client library for Beta API
/**
 * TODO(developer): Update client library import to use new
 * version of API when desired features become available
 */
const speech = require('@google-cloud/speech').v1p1beta1;
const fs = require('fs');

// 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 model = 'Model to use, e.g. phone_call, video, default';
// const encoding = 'Encoding of the audio file, e.g. LINEAR16';
// const sampleRateHertz = 16000;
// const languageCode = 'BCP-47 language code, e.g. en-US';

const config = {
  encoding: encoding,
  sampleRateHertz: sampleRateHertz,
  languageCode: languageCode,
  model: model,
};
const audio = {
  content: fs.readFileSync(filename).toString('base64'),
};

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

// Detects speech in the audio file
client
  .recognize(request)
  .then(data => {
    const response = data[0];
    const transcription = response.results
      .map(result => result.alternatives[0].transcript)
      .join('\n');
    console.log(`Transcription: `, transcription);
  })
  .catch(err => {
    console.error('ERROR:', err);
  });

Python

For more on installing and creating a Speech-to-Text client, refer to Speech-to-Text Client Libraries.

def transcribe_model_selection(speech_file, model):
    """Transcribe the given audio file synchronously with
    the selected model."""
    from google.cloud import speech_v1p1beta1 as speech
    client = speech.SpeechClient()

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

    audio = speech.types.RecognitionAudio(content=content)

    config = speech.types.RecognitionConfig(
        encoding=speech.enums.RecognitionConfig.AudioEncoding.LINEAR16,
        sample_rate_hertz=16000,
        language_code='en-US',
        model=model)

    response = client.recognize(config, audio)

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

Java

For more on installing and creating a Speech-to-Text client, refer to Speech-to-Text Client Libraries.

/**
 * Performs transcription of the given audio file synchronously with
 * the selected model.
 * @param fileName the path to a audio file to transcribe
 */
public static void transcribeModelSelection(String fileName) throws Exception {
  Path path = Paths.get(fileName);
  byte[] content = Files.readAllBytes(path);

  try (SpeechClient speech = SpeechClient.create()) {
    // Configure request with video media type
    RecognitionConfig recConfig = RecognitionConfig.newBuilder()
        // encoding may either be omitted or must match the value in the file header
        .setEncoding(AudioEncoding.LINEAR16)
        .setLanguageCode("en-US")
        // sample rate hertz may be either be omitted or must match the value in the file header
        .setSampleRateHertz(16000)
        .setModel("video")
        .build();

    RecognitionAudio recognitionAudio = RecognitionAudio.newBuilder()
        .setContent(ByteString.copyFrom(content))
        .build();


    RecognizeResponse recognizeResponse = speech.recognize(recConfig, recognitionAudio);
    // Just print the first result here.
    SpeechRecognitionResult result = recognizeResponse.getResultsList().get(0);
    // 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);
    System.out.printf("Transcript : %s\n", alternative.getTranscript());
  }

Cleaning up

To avoid incurring charges to your Google Cloud Platform account for the resources used in this tutorial:

Deleting the project

The easiest way to eliminate billing is to delete the project you created for the tutorial.

To delete the project:

  1. In the GCP Console, go to the Projects page.

    Go to the Projects page

  2. In the project list, select the project you want to delete and click Delete project. After selecting the checkbox next to the project name, click
      Delete project
  3. In the dialog, type the project ID, and then click Shut down to delete the project.

Deleting instances

To delete a Compute Engine instance:

  1. In the GCP Console, go to the VM Instances page.

    Go to the VM Instances page

  2. Click the checkbox next to the instance you want to delete.
  3. Click the Delete button at the top of the page to delete the instance.

Deleting firewall rules for the default network

To delete a firewall rule:

  1. In the GCP Console, go to the Firewall Rules page.

    Go to the Firewall Rules page

  2. Click the checkbox next to the firewall rule you want to delete.
  3. Click the Delete button at the top of the page to delete the firewall rule.

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Cloud Speech API Documentation