Create a job that embeds captions in the output video

Create a transcoding job that embeds captions in the output video. Captions can include both closed captions and subtitles.

Explore further

For detailed documentation that includes this code sample, see the following:

• Adding closed captions and subtitles

Code sample

Go

Before trying this sample, follow the Go setup instructions in the Transcoder API quickstart using client libraries. For more information, see the Transcoder API Go API reference documentation.

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

import (
	"context"
	"fmt"
	"io"

	transcoder "cloud.google.com/go/video/transcoder/apiv1"
	"cloud.google.com/go/video/transcoder/apiv1/transcoderpb"
)

// createJobWithEmbeddedCaptions creates a job that embeds closed captions in the
// output video. See https://cloud.google.com/transcoder/docs/how-to/captions-and-subtitles
// for more information.
func createJobWithEmbeddedCaptions(w io.Writer, projectID string, location string, inputVideoURI string, inputCaptionsURI string, outputURI string) error {
	// projectID := "my-project-id"
	// location := "us-central1"
	// inputVideoURI := "gs://my-bucket/my-video-file"
	// inputCaptionsURI := "gs://my-bucket/my-captions-file"
	// outputURI := "gs://my-bucket/my-output-folder/"

	ctx := context.Background()
	client, err := transcoder.NewClient(ctx)
	if err != nil {
		return fmt.Errorf("NewClient: %w", err)
	}
	defer client.Close()

	// Set up elementary streams. The InputKey field refers to inputs in
	// the Inputs array defined the job config.
	elementaryStreams := []*transcoderpb.ElementaryStream{
		{
			Key: "video_stream0",
			ElementaryStream: &transcoderpb.ElementaryStream_VideoStream{
				VideoStream: &transcoderpb.VideoStream{
					CodecSettings: &transcoderpb.VideoStream_H264{
						H264: &transcoderpb.VideoStream_H264CodecSettings{
							BitrateBps:   550000,
							FrameRate:    60,
							HeightPixels: 360,
							WidthPixels:  640,
						},
					},
				},
			},
		},
		{
			Key: "audio_stream0",
			ElementaryStream: &transcoderpb.ElementaryStream_AudioStream{
				AudioStream: &transcoderpb.AudioStream{
					Codec:      "aac",
					BitrateBps: 64000,
				},
			},
		},
		{
			Key: "cea_stream0",
			ElementaryStream: &transcoderpb.ElementaryStream_TextStream{
				TextStream: &transcoderpb.TextStream{
					Codec: "cea608",
					Mapping: []*transcoderpb.TextStream_TextMapping{
						{
							AtomKey:    "atom0",
							InputKey:   "caption_input0",
							InputTrack: 0,
						},
					},
					LanguageCode: "en-US",
					DisplayName:  "English",
				},
			},
		},
	}

	req := &transcoderpb.CreateJobRequest{
		Parent: fmt.Sprintf("projects/%s/locations/%s", projectID, location),
		Job: &transcoderpb.Job{
			OutputUri: outputURI,
			JobConfig: &transcoderpb.Job_Config{
				Config: &transcoderpb.JobConfig{
					Inputs: []*transcoderpb.Input{
						{
							Key: "input0",
							Uri: inputVideoURI,
						},
						{
							Key: "caption_input0",
							Uri: inputCaptionsURI,
						},
					},
					EditList: []*transcoderpb.EditAtom{
						{
							Key:    "atom0",
							Inputs: []string{"input0", "caption_input0"},
						},
					},
					ElementaryStreams: elementaryStreams,
					MuxStreams: []*transcoderpb.MuxStream{
						{
							Key:               "sd-hls",
							Container:         "ts",
							ElementaryStreams: []string{"video_stream0", "audio_stream0"},
						},
						{
							Key:               "sd-dash",
							Container:         "fmp4",
							ElementaryStreams: []string{"video_stream0"},
						},
						{
							Key:               "audio-dash",
							Container:         "fmp4",
							ElementaryStreams: []string{"audio_stream0"},
						},
					},
					Manifests: []*transcoderpb.Manifest{
						{
							FileName:   "manifest.m3u8",
							Type:       transcoderpb.Manifest_HLS,
							MuxStreams: []string{"sd-hls"},
						},
						{
							FileName:   "manifest.mpd",
							Type:       transcoderpb.Manifest_DASH,
							MuxStreams: []string{"sd-dash", "audio-dash"},
						},
					},
				},
			},
		},
	}
	// Creates the job. Jobs take a variable amount of time to run.
	// You can query for the job state; see getJob() in get_job.go.
	response, err := client.CreateJob(ctx, req)
	if err != nil {
		return fmt.Errorf("CreateJob: %w", err)
	}

	fmt.Fprintf(w, "Job: %v", response.GetName())
	return nil
}

Java

Before trying this sample, follow the Java setup instructions in the Transcoder API quickstart using client libraries. For more information, see the Transcoder API Java API reference documentation.

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

import com.google.cloud.video.transcoder.v1.AudioStream;
import com.google.cloud.video.transcoder.v1.CreateJobRequest;
import com.google.cloud.video.transcoder.v1.EditAtom;
import com.google.cloud.video.transcoder.v1.ElementaryStream;
import com.google.cloud.video.transcoder.v1.Input;
import com.google.cloud.video.transcoder.v1.Job;
import com.google.cloud.video.transcoder.v1.JobConfig;
import com.google.cloud.video.transcoder.v1.LocationName;
import com.google.cloud.video.transcoder.v1.Manifest;
import com.google.cloud.video.transcoder.v1.Manifest.ManifestType;
import com.google.cloud.video.transcoder.v1.MuxStream;
import com.google.cloud.video.transcoder.v1.Output;
import com.google.cloud.video.transcoder.v1.TextStream;
import com.google.cloud.video.transcoder.v1.TextStream.TextMapping;
import com.google.cloud.video.transcoder.v1.TranscoderServiceClient;
import com.google.cloud.video.transcoder.v1.VideoStream;
import java.io.IOException;

public class CreateJobWithEmbeddedCaptions {

  public static void main(String[] args) throws IOException {
    // TODO(developer): Replace these variables before running the sample.
    String projectId = "my-project-id";
    String location = "us-central1";
    String inputVideoUri = "gs://my-bucket/my-video-file";
    String inputCaptionsUri = "gs://my-bucket/my-captions-file";
    String outputUri = "gs://my-bucket/my-output-folder/";

    createJobWithEmbeddedCaptions(projectId, location, inputVideoUri, inputCaptionsUri, outputUri);
  }

  // Creates a job from an ad-hoc configuration that embeds captions in the output video.
  public static void createJobWithEmbeddedCaptions(
      String projectId,
      String location,
      String inputVideoUri,
      String inputCaptionsUri,
      String outputUri)
      throws IOException {
    // Initialize client that will be used to send requests. This client only needs to be created
    // once, and can be reused for multiple requests.
    try (TranscoderServiceClient transcoderServiceClient = TranscoderServiceClient.create()) {

      VideoStream videoStream0 =
          VideoStream.newBuilder()
              .setH264(
                  VideoStream.H264CodecSettings.newBuilder()
                      .setBitrateBps(550000)
                      .setFrameRate(60)
                      .setHeightPixels(360)
                      .setWidthPixels(640))
              .build();

      AudioStream audioStream0 =
          AudioStream.newBuilder().setCodec("aac").setBitrateBps(64000).build();

      TextStream textStream0 =
          TextStream.newBuilder()
              .setCodec("cea608")
              .addMapping(
                  0,
                  TextMapping.newBuilder()
                      .setAtomKey("atom0")
                      .setInputKey("caption_input0")
                      .setInputTrack(0)
                      .build())
              .build();

      JobConfig config =
          JobConfig.newBuilder()
              .addInputs(Input.newBuilder().setKey("input0").setUri(inputVideoUri))
              .addInputs(Input.newBuilder().setKey("caption_input0").setUri(inputCaptionsUri))
              .addEditList(
                  0, // Index in the edit list
                  EditAtom.newBuilder()
                      .setKey("atom0")
                      .addInputs("input0")
                      .addInputs("caption_input0")
                      .build())
              .setOutput(Output.newBuilder().setUri(outputUri))
              .addElementaryStreams(
                  ElementaryStream.newBuilder()
                      .setKey("video_stream0")
                      .setVideoStream(videoStream0))
              .addElementaryStreams(
                  ElementaryStream.newBuilder()
                      .setKey("audio_stream0")
                      .setAudioStream(audioStream0))
              .addElementaryStreams(
                  ElementaryStream.newBuilder().setKey("cea_stream0").setTextStream(textStream0))
              .addMuxStreams(
                  0,
                  MuxStream.newBuilder()
                      .setKey("sd")
                      .setContainer("mp4")
                      .addElementaryStreams("video_stream0")
                      .addElementaryStreams("audio_stream0")
                      .build())
              .addMuxStreams(
                  1,
                  MuxStream.newBuilder()
                      .setKey("sd_hls")
                      .setContainer("ts")
                      .addElementaryStreams("video_stream0")
                      .addElementaryStreams("audio_stream0")
                      .build())
              .addMuxStreams(
                  2,
                  MuxStream.newBuilder()
                      .setKey("sd_dash")
                      .setContainer("fmp4")
                      .addElementaryStreams("video_stream0")
                      .build())
              .addMuxStreams(
                  3,
                  MuxStream.newBuilder()
                      .setKey("audio_dash")
                      .setContainer("fmp4")
                      .addElementaryStreams("audio_stream0")
                      .build())
              .addManifests(
                  0,
                  Manifest.newBuilder()
                      .setFileName("manifest.m3u8")
                      .setType(ManifestType.HLS)
                      .addMuxStreams("sd_hls")
                      .build())
              .addManifests(
                  1,
                  Manifest.newBuilder()
                      .setFileName("manifest.mpd")
                      .setType(ManifestType.DASH)
                      .addMuxStreams("sd_dash")
                      .addMuxStreams("audio_dash")
                      .build())
              .build();

      CreateJobRequest createJobRequest =
          CreateJobRequest.newBuilder()
              .setJob(Job.newBuilder().setOutputUri(outputUri).setConfig(config).build())
              .setParent(LocationName.of(projectId, location).toString())
              .build();

      // Send the job creation request and process the response.
      Job job = transcoderServiceClient.createJob(createJobRequest);
      System.out.println("Job: " + job.getName());
    }
  }
}

Node.js

Before trying this sample, follow the Node.js setup instructions in the Transcoder API quickstart using client libraries. For more information, see the Transcoder API Node.js API reference documentation.

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

/**
 * TODO(developer): Uncomment these variables before running the sample.
 */
// projectId = 'my-project-id';
// location = 'us-central1';
// inputVideoUri = 'gs://my-bucket/my-video-file';
// inputCaptionsUri = 'gs://my-bucket/my-captions-file';
// outputUri = 'gs://my-bucket/my-output-folder/';

// Imports the Transcoder library
const {TranscoderServiceClient} =
  require('@google-cloud/video-transcoder').v1;

// Instantiates a client
const transcoderServiceClient = new TranscoderServiceClient();

async function createJobWithEmbeddedCaptions() {
  // Construct request
  const request = {
    parent: transcoderServiceClient.locationPath(projectId, location),
    job: {
      outputUri: outputUri,
      config: {
        inputs: [
          {
            key: 'input0',
            uri: inputVideoUri,
          },
          {
            key: 'caption_input0',
            uri: inputCaptionsUri,
          },
        ],
        editList: [
          {
            key: 'atom0',
            inputs: ['input0', 'caption_input0'],
          },
        ],
        elementaryStreams: [
          {
            key: 'video-stream0',
            videoStream: {
              h264: {
                heightPixels: 360,
                widthPixels: 640,
                bitrateBps: 550000,
                frameRate: 60,
              },
            },
          },
          {
            key: 'audio-stream0',
            audioStream: {
              codec: 'aac',
              bitrateBps: 64000,
            },
          },
          {
            key: 'cea-stream0',
            textStream: {
              codec: 'cea608',
              mapping: [
                {
                  atomKey: 'atom0',
                  inputKey: 'caption_input0',
                  inputTrack: 0,
                },
              ],
              languageCode: 'en-US',
              displayName: 'English',
            },
          },
        ],
        muxStreams: [
          {
            key: 'sd-hls',
            container: 'ts',
            elementaryStreams: ['video-stream0', 'audio-stream0'],
          },
          {
            key: 'sd-dash',
            container: 'fmp4',
            elementaryStreams: ['video-stream0'],
          },
          {
            key: 'audio-dash',
            container: 'fmp4',
            elementaryStreams: ['audio-stream0'],
          },
        ],
        manifests: [
          {
            fileName: 'manifest.m3u8',
            type: 'HLS',
            muxStreams: ['sd-hls'],
          },
          {
            fileName: 'manifest.mpd',
            type: 'DASH',
            muxStreams: ['sd-dash', 'audio-dash'],
          },
        ],
      },
    },
  };

  // Run request
  const [response] = await transcoderServiceClient.createJob(request);
  console.log(`Job: ${response.name}`);
}

createJobWithEmbeddedCaptions();

Python

Before trying this sample, follow the Python setup instructions in the Transcoder API quickstart using client libraries. For more information, see the Transcoder API Python API reference documentation.

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

import argparse

from google.cloud.video import transcoder_v1
from google.cloud.video.transcoder_v1.services.transcoder_service import (
    TranscoderServiceClient,
)


def create_job_with_embedded_captions(
    project_id: str,
    location: str,
    input_video_uri: str,
    input_captions_uri: str,
    output_uri: str,
) -> transcoder_v1.types.resources.Job:
    """Creates a job based on an ad-hoc job configuration that embeds closed captions in the output video.

    Args:
        project_id (str): The GCP project ID.
        location (str): The location to start the job in.
        input_video_uri (str): Uri of the input video in the Cloud Storage
          bucket.
        input_captions_uri (str): Uri of the input captions file in the Cloud
          Storage bucket.
        output_uri (str): Uri of the video output folder in the Cloud Storage
          bucket.

    Returns:
        The job resource.
    """

    client = TranscoderServiceClient()

    parent = f"projects/{project_id}/locations/{location}"
    job = transcoder_v1.types.Job()
    job.output_uri = output_uri
    job.config = transcoder_v1.types.JobConfig(
        inputs=[
            transcoder_v1.types.Input(
                key="input0",
                uri=input_video_uri,
            ),
            transcoder_v1.types.Input(
                key="caption-input0",
                uri=input_captions_uri,
            ),
        ],
        edit_list=[
            transcoder_v1.types.EditAtom(
                key="atom0",
                inputs=["input0", "caption-input0"],
            ),
        ],
        elementary_streams=[
            transcoder_v1.types.ElementaryStream(
                key="video-stream0",
                video_stream=transcoder_v1.types.VideoStream(
                    h264=transcoder_v1.types.VideoStream.H264CodecSettings(
                        height_pixels=360,
                        width_pixels=640,
                        bitrate_bps=550000,
                        frame_rate=60,
                    ),
                ),
            ),
            transcoder_v1.types.ElementaryStream(
                key="audio-stream0",
                audio_stream=transcoder_v1.types.AudioStream(
                    codec="aac",
                    bitrate_bps=64000,
                ),
            ),
            transcoder_v1.types.ElementaryStream(
                key="cea-stream0",
                text_stream=transcoder_v1.types.TextStream(
                    codec="cea608",
                    mapping_=[
                        transcoder_v1.types.TextStream.TextMapping(
                            atom_key="atom0",
                            input_key="caption-input0",
                            input_track=0,
                        ),
                    ],
                    language_code="en-US",
                    display_name="English",
                ),
            ),
        ],
        mux_streams=[
            transcoder_v1.types.MuxStream(
                key="sd-hls",
                container="ts",
                elementary_streams=["video-stream0", "audio-stream0"],
            ),
            transcoder_v1.types.MuxStream(
                key="sd-dash",
                container="fmp4",
                elementary_streams=["video-stream0"],
            ),
            transcoder_v1.types.MuxStream(
                key="audio-dash",
                container="fmp4",
                elementary_streams=["audio-stream0"],
            ),
        ],
        manifests=[
            transcoder_v1.types.Manifest(
                file_name="manifest.m3u8",
                type_="HLS",
                mux_streams=["sd-hls"],
            ),
            transcoder_v1.types.Manifest(
                file_name="manifest.mpd",
                type_="DASH",
                mux_streams=["sd-dash", "audio-dash"],
            ),
        ],
    )
    response = client.create_job(parent=parent, job=job)
    print(f"Job: {response.name}")
    return response

What's next

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