Generate highlight movie with Transcoder API

highlight.js

const projectId = "your-project-id";
const location = "asia-east1";

const {TranscoderServiceClient} = require("@google-cloud/video-transcoder").v1;
const client = new TranscoderServiceClient();

/**
 * calcOffsetNanoSec
 * @param {number} offsetValueFractionalSecs input
 * @return {number}
 */
function calcOffsetNanoSec(offsetValueFractionalSecs) {
  if (offsetValueFractionalSecs.toString().indexOf(".") !== -1) {
    return (
      1000000000 *
      Number("." + offsetValueFractionalSecs.toString().split(".")[1])
    );
  }
  return 0;
}

/** @typedef {{start: number, end: number}} startAndEndResult */

/**
 * get start and end from duration and minimum length.
 * @param {number} duration
 * @param {number} minimumLength
 * @return {startAndEndResult}
 */
function startAndEnd(duration, minimumLength) {
  if (duration > minimumLength) {
    const halfDuration = duration / 2;
    const halfMinimumLength = minimumLength / 2;
    return {
      "start": halfDuration - halfMinimumLength,
      "end": halfDuration + halfMinimumLength - 0.01,
    };
  } else {
    return {
      "start": 0, "end": duration - 0.01,
    };
  }
}

/**
 * @typedef {{input: string, start: number, end: number}} resource
 */
/**
 * create job
 * @param {resource[]} resources inputs
 * @param {string} output url
 */
async function createJob(resources, output) {
  const inputs = resources.map((resource, index) => {
    return {
      key: `input${index + 1}`,
      uri: resource.input,
    };
  });
  const editList = resources.map((resource, index) => {
    const startTimeOffsetSec = Math.trunc(resource.start);
    const startTimeOffsetNanoSec = calcOffsetNanoSec(resource.start);
    const endTimeOffsetSec = Math.trunc(resource.end);
    const endTimeOffsetNanoSec = calcOffsetNanoSec(resource.end);
    return {
      key: `atom${index + 1}`,
      inputs: [`input${index + 1}`],
      startTimeOffset: {
        seconds: startTimeOffsetSec,
        nanos: startTimeOffsetNanoSec,
      },
      endTimeOffset: {
        seconds: endTimeOffsetSec,
        nanos: endTimeOffsetNanoSec,
      },
    };
  });
  const request = {
    parent: client.locationPath(projectId, location),
    job: {
      outputUri: output,
      config: {
        inputs: inputs,
        editList: editList,
        elementaryStreams: [
          {
            key: "video-stream0",
            videoStream: {
              h264: {
                heightPixels: 1024,
                widthPixels: 1024,
                bitrateBps: 1100000,
                frameRate: 30,
              },
            },
          },
          {
            key: "audio-stream0",
            audioStream: {
              codec: "aac",
              bitrateBps: 64000,
            },
          },
        ],
        muxStreams: [
          {
            key: "hd",
            container: "mp4",
            elementaryStreams: ["video-stream0", "audio-stream0"],
          },
        ],
      },
    },
  };

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

function main() async {
  const contents = await getYourContents();
  /** @type {resource[]} */
  const resources = contents.map((content) => {
    /** @type {number} */
    const duration = startAndEnd(content.duration, 1);
    return {
      "input": `gs://your-project.appspot.com/${content.path}`,
      "start": duration.start,
      "end": duration.end,
    };
  });
  const outputUrl = `gs://your-project.appspot.com/highlight/`;
  await createJob(resources, outputUrl);
}