owncast/build/javascript/node_modules/mux.js/lib/utils/clock.js

/**
 * mux.js
 *
 * Copyright (c) Brightcove
 * Licensed Apache-2.0 https://github.com/videojs/mux.js/blob/master/LICENSE
 */
var
  ONE_SECOND_IN_TS = 90000, // 90kHz clock
  secondsToVideoTs,
  secondsToAudioTs,
  videoTsToSeconds,
  audioTsToSeconds,
  audioTsToVideoTs,
  videoTsToAudioTs,
  metadataTsToSeconds;

secondsToVideoTs = function(seconds) {
  return seconds * ONE_SECOND_IN_TS;
};

secondsToAudioTs = function(seconds, sampleRate) {
  return seconds * sampleRate;
};

videoTsToSeconds = function(timestamp) {
  return timestamp / ONE_SECOND_IN_TS;
};

audioTsToSeconds = function(timestamp, sampleRate) {
  return timestamp / sampleRate;
};

audioTsToVideoTs = function(timestamp, sampleRate) {
  return secondsToVideoTs(audioTsToSeconds(timestamp, sampleRate));
};

videoTsToAudioTs = function(timestamp, sampleRate) {
  return secondsToAudioTs(videoTsToSeconds(timestamp), sampleRate);
};

/**
 * Adjust ID3 tag or caption timing information by the timeline pts values
 * (if keepOriginalTimestamps is false) and convert to seconds
 */
metadataTsToSeconds = function(timestamp, timelineStartPts, keepOriginalTimestamps) {
  return videoTsToSeconds(keepOriginalTimestamps ? timestamp : timestamp - timelineStartPts);
};

module.exports = {
  ONE_SECOND_IN_TS: ONE_SECOND_IN_TS,
  secondsToVideoTs: secondsToVideoTs,
  secondsToAudioTs: secondsToAudioTs,
  videoTsToSeconds: videoTsToSeconds,
  audioTsToSeconds: audioTsToSeconds,
  audioTsToVideoTs: audioTsToVideoTs,
  videoTsToAudioTs: videoTsToAudioTs,
  metadataTsToSeconds: metadataTsToSeconds
};