@bbc/react-transcript-editor/dist/Util/timecode-converter/secondsToTimecode.js

A React component to make transcribing audio and video easier and faster.

/**
* Raised in this comment https://github.com/bbc/react-transcript-editor/pull/9
* abstracted from https://github.com/bbc/newslabs-cdn/blob/master/js/20-bbcnpf.utils.js
* In broadcast VIDEO, timecode is NOT hh:mm:ss:ms, it's hh:mm:ss:ff where ff is frames, 
* dependent on the framerate of the media concerned.
* `hh:mm:ss:ff` 
*/

/**
 * Helper function 
 * Rounds to the 14milliseconds boundaries 
 * Time in video can only "exist in" 14milliseconds boundaries.
 * This makes it possible for the HTML5 player to be frame accurate.
 * @param {*} seconds 
 * @param {*} fps 
 */
const normalisePlayerTime = function (seconds, fps) {
  return Number((1.0 / fps * Math.floor(Number((fps * seconds).toPrecision(12)))).toFixed(2));
};
/*
* @param {*} seconds 
* @param {*} fps 
*/


const secondsToTimecode = function (seconds, framePerSeconds) {
  // written for PAL non-drop timecode
  let fps = 25;

  if (framePerSeconds !== undefined) {
    fps = framePerSeconds;
  }

  const normalisedSeconds = normalisePlayerTime(seconds, fps);
  const wholeSeconds = Math.floor(normalisedSeconds);
  const frames = ((normalisedSeconds - wholeSeconds) * fps).toFixed(2); // prepends zero - example pads 3 to 03

  function _padZero(n) {
    if (n < 10) return '0' + parseInt(n);else return parseInt(n);
  }

  return _padZero(wholeSeconds / 60 / 60 % 60) + ':' + _padZero(wholeSeconds / 60 % 60) + ':' + _padZero(wholeSeconds % 60) + ':' + _padZero(frames);
};

export default secondsToTimecode;