Tracking de l'application VApp (IHM du jeu)

VApp/node_modules/mux.js/lib/mp4/samples.js

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+const { parseTrun } = require("../tools/mp4-inspector");
+const { findBox } = require("./probe");
+var window = require('global/window');
+
+/**
+ * Utility function for parsing data from mdat boxes.
+ * @param {Array<Uint8Array>} segment the segment data to create mdat/traf pairs from.
+ * @returns mdat and traf boxes paired up for easier parsing.
+ */
+var getMdatTrafPairs = function(segment) {
+  var trafs = findBox(segment, ['moof', 'traf']);
+  var mdats = findBox(segment, ['mdat']);
+
+  var mdatTrafPairs = [];
+
+  // Pair up each traf with a mdat as moofs and mdats are in pairs
+  mdats.forEach(function(mdat, index) {
+    var matchingTraf = trafs[index];
+    mdatTrafPairs.push({
+      mdat: mdat,
+      traf: matchingTraf
+    });
+  });
+
+  return mdatTrafPairs;
+};
+
+/**
+  * Parses sample information out of Track Run Boxes and calculates
+  * the absolute presentation and decode timestamps of each sample.
+  *
+  * @param {Array<Uint8Array>} truns - The Trun Run boxes to be parsed
+  * @param {Number|BigInt} baseMediaDecodeTime - base media decode time from tfdt
+      @see ISO-BMFF-12/2015, Section 8.8.12
+  * @param {Object} tfhd - The parsed Track Fragment Header
+  *   @see inspect.parseTfhd
+  * @return {Object[]} the parsed samples
+  *
+  * @see ISO-BMFF-12/2015, Section 8.8.8
+ **/
+var parseSamples = function(truns, baseMediaDecodeTime, tfhd) {
+  var currentDts = baseMediaDecodeTime;
+  var defaultSampleDuration = tfhd.defaultSampleDuration || 0;
+  var defaultSampleSize = tfhd.defaultSampleSize || 0;
+  var trackId = tfhd.trackId;
+  var allSamples = [];
+
+  truns.forEach(function(trun) {
+    // Note: We currently do not parse the sample table as well
+    // as the trun. It's possible some sources will require this.
+    // moov > trak > mdia > minf > stbl
+    var trackRun = parseTrun(trun);
+    var samples = trackRun.samples;
+
+    samples.forEach(function(sample) {
+      if (sample.duration === undefined) {
+        sample.duration = defaultSampleDuration;
+      }
+      if (sample.size === undefined) {
+        sample.size = defaultSampleSize;
+      }
+      sample.trackId = trackId;
+      sample.dts = currentDts;
+      if (sample.compositionTimeOffset === undefined) {
+        sample.compositionTimeOffset = 0;
+      }
+
+      if (typeof currentDts === 'bigint') {
+        sample.pts = currentDts + window.BigInt(sample.compositionTimeOffset);
+        currentDts += window.BigInt(sample.duration);
+
+      } else {
+        sample.pts = currentDts + sample.compositionTimeOffset;
+        currentDts += sample.duration;
+      }
+    });
+
+    allSamples = allSamples.concat(samples);
+  });
+
+  return allSamples;
+};
+
+module.exports = { 
+  getMdatTrafPairs,
+  parseSamples
+};