First release

node_modules/mux.js/es/m2ts/timestamp-rollover-stream.js

@@ -0,0 +1,92 @@
+/**
+ * mux.js
+ *
+ * Copyright (c) Brightcove
+ * Licensed Apache-2.0 https://github.com/videojs/mux.js/blob/master/LICENSE
+ *
+ * Accepts program elementary stream (PES) data events and corrects
+ * decode and presentation time stamps to account for a rollover
+ * of the 33 bit value.
+ */
+'use strict';
+
+var Stream = require('../utils/stream');
+
+var MAX_TS = 8589934592;
+var RO_THRESH = 4294967296;
+var TYPE_SHARED = 'shared';
+
+var handleRollover = function handleRollover(value, reference) {
+  var direction = 1;
+
+  if (value > reference) {
+    // If the current timestamp value is greater than our reference timestamp and we detect a
+    // timestamp rollover, this means the roll over is happening in the opposite direction.
+    // Example scenario: Enter a long stream/video just after a rollover occurred. The reference
+    // point will be set to a small number, e.g. 1. The user then seeks backwards over the
+    // rollover point. In loading this segment, the timestamp values will be very large,
+    // e.g. 2^33 - 1. Since this comes before the data we loaded previously, we want to adjust
+    // the time stamp to be `value - 2^33`.
+    direction = -1;
+  } // Note: A seek forwards or back that is greater than the RO_THRESH (2^32, ~13 hours) will
+  // cause an incorrect adjustment.
+
+
+  while (Math.abs(reference - value) > RO_THRESH) {
+    value += direction * MAX_TS;
+  }
+
+  return value;
+};
+
+var TimestampRolloverStream = function TimestampRolloverStream(type) {
+  var lastDTS, referenceDTS;
+  TimestampRolloverStream.prototype.init.call(this); // The "shared" type is used in cases where a stream will contain muxed
+  // video and audio. We could use `undefined` here, but having a string
+  // makes debugging a little clearer.
+
+  this.type_ = type || TYPE_SHARED;
+
+  this.push = function (data) {
+    // Any "shared" rollover streams will accept _all_ data. Otherwise,
+    // streams will only accept data that matches their type.
+    if (this.type_ !== TYPE_SHARED && data.type !== this.type_) {
+      return;
+    }
+
+    if (referenceDTS === undefined) {
+      referenceDTS = data.dts;
+    }
+
+    data.dts = handleRollover(data.dts, referenceDTS);
+    data.pts = handleRollover(data.pts, referenceDTS);
+    lastDTS = data.dts;
+    this.trigger('data', data);
+  };
+
+  this.flush = function () {
+    referenceDTS = lastDTS;
+    this.trigger('done');
+  };
+
+  this.endTimeline = function () {
+    this.flush();
+    this.trigger('endedtimeline');
+  };
+
+  this.discontinuity = function () {
+    referenceDTS = void 0;
+    lastDTS = void 0;
+  };
+
+  this.reset = function () {
+    this.discontinuity();
+    this.trigger('reset');
+  };
+};
+
+TimestampRolloverStream.prototype = new Stream();
+module.exports = {
+  TimestampRolloverStream: TimestampRolloverStream,
+  handleRollover: handleRollover
+};