feat: add EventStream support

videojs · Mar 7, 2023 · f1a09ca · f1a09ca
1 parent 3fc0486
commit f1a09ca
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Showing 3 changed files with 182 additions and 2 deletions.
diff --git a/src/inheritAttributes.js b/src/inheritAttributes.js
@@ -287,6 +287,45 @@ export const parseCaptionServiceMetadata = (service) => {
   }
 };
 
+/**
+ * A map callback that will parse all event stream data for a collection of periods
+ * DASH ISO_IEC_23009 5.10.2.2
+ * https://dashif-documents.azurewebsites.net/Events/master/event.html#mpd-event-timing
+ *
+ * @param {PeriodInformation} period object containing necessary period information
+ * @return a collection of parsed eventstream event objects with
+ */
+export const toEventStream = (period) => {
+  // get all EventStreams tags and parse attributes and children
+  return findChildren(period.node, 'EventStream').flatMap((eventStream) => {
+    const eventStreamAttributes = parseAttributes(eventStream);
+    const schemeIdUri = eventStreamAttributes.schemeIdUri;
+    // schemeIdUri is mandatory for EventStream tags
+
+    if (!schemeIdUri) {
+      return;
+    }
+
+    // find all Events per EventStream tag and map to return objects
+    return findChildren(eventStream, 'Event').map((event) => {
+      const eventAttributes = parseAttributes(event);
+      const presentationTime = eventAttributes.presentationTime || 0;
+      const timescale = eventStreamAttributes.timescale || 1;
+      const duration = eventAttributes.duration || 0;
+      const start = (presentationTime / timescale) + period.attributes.start;
+
+      return {
+        schemeIdUri,
+        value: eventStreamAttributes.value,
+        id: eventAttributes.id,
+        start,
+        end: start + (duration / timescale),
+        messageData: eventAttributes.messageData
+      };
+    });
+  });
+};
+
 /**
  * Maps an AdaptationSet node to a list of Representation information objects
  *
@@ -531,6 +570,7 @@ export const inheritAttributes = (mpd, options = {}) => {
 
   return {
     locations: mpdAttributes.locations,
-    representationInfo: flatten(periods.map(toAdaptationSets(mpdAttributes, mpdBaseUrls)))
+    representationInfo: flatten(periods.map(toAdaptationSets(mpdAttributes, mpdBaseUrls))),
+    eventStreamInfo: flatten(periods.map(toEventStream))
   };
 };
diff --git a/src/parseAttributes.js b/src/parseAttributes.js
@@ -241,6 +241,19 @@ export const parsers = {
     return parseInt(value, 10);
   },
 
+  /**
+   * Specifies the presentationTime.
+   *
+   * @param {string} value
+   *        value of the attribute as a string
+   *
+   * @return {number}
+   *         The parsed presentationTime
+   */
+  presentationTime(value) {
+    return parseInt(value, 10);
+  },
+
   /**
    * Default parser for all other attributes. Acts as a no-op and just returns the value
    * as a string

diff --git a/test/inheritAttributes.test.js b/test/inheritAttributes.test.js
@@ -3,13 +3,15 @@ import {
   buildBaseUrls,
   parseCaptionServiceMetadata,
   getSegmentInformation,
-  getPeriodStart
+  getPeriodStart,
+  toEventStream
 } from '../src/inheritAttributes';
 import { stringToMpdXml } from '../src/stringToMpdXml';
 import errors from '../src/errors';
 import QUnit from 'qunit';
 import { toPlaylists } from '../src/toPlaylists';
 import decodeB64ToUint8Array from '@videojs/vhs-utils/es/decode-b64-to-uint8-array';
+import { findChildren } from '../src/utils/xml';
 
 QUnit.module('buildBaseUrls');
 
@@ -544,6 +546,7 @@ QUnit.test('end to end - basic', function(assert) {
   `), { NOW });
 
   const expected = {
+    eventStreamInfo: [],
     locations: undefined,
     representationInfo: [{
       attributes: {
@@ -618,6 +621,7 @@ QUnit.test('end to end - basic dynamic', function(assert) {
   `), { NOW });
 
   const expected = {
+    eventStreamInfo: [],
     locations: undefined,
     representationInfo: [{
       attributes: {
@@ -699,6 +703,7 @@ QUnit.test('end to end - basic multiperiod', function(assert) {
   `), { NOW });
 
   const expected = {
+    eventStreamInfo: [],
     locations: undefined,
     representationInfo: [{
       attributes: {
@@ -785,6 +790,7 @@ QUnit.test('end to end - inherits BaseURL from all levels', function(assert) {
   `), { NOW });
 
   const expected = {
+    eventStreamInfo: [],
     locations: undefined,
     representationInfo: [{
       attributes: {
@@ -861,6 +867,7 @@ QUnit.test('end to end - alternate BaseURLs', function(assert) {
   `), { NOW });
 
   const expected = {
+    eventStreamInfo: [],
     locations: undefined,
     representationInfo: [{
       attributes: {
@@ -1028,6 +1035,7 @@ QUnit.test(
   `), { NOW });
 
     const expected = {
+      eventStreamInfo: [],
       locations: undefined,
       representationInfo: [{
         attributes: {
@@ -1140,6 +1148,7 @@ QUnit.test(
   `), { NOW });
 
     const expected = {
+      eventStreamInfo: [],
       locations: undefined,
       representationInfo: [{
         attributes: {
@@ -1263,6 +1272,7 @@ QUnit.test(
   `), { NOW });
 
     const expected = {
+      eventStreamInfo: [],
       locations: undefined,
       representationInfo: [{
         attributes: {
@@ -2106,6 +2116,7 @@ QUnit.test('keySystem info for representation - lowercase UUIDs', function(asser
 
   // inconsistent quoting because of quote-props
   const expected = {
+    eventStreamInfo: [],
     locations: undefined,
     representationInfo: [{
       attributes: {
@@ -2192,6 +2203,7 @@ QUnit.test('keySystem info for representation - uppercase UUIDs', function(asser
 
   // inconsistent quoting because of quote-props
   const expected = {
+    eventStreamInfo: [],
     locations: undefined,
     representationInfo: [{
       attributes: {
@@ -2238,3 +2250,118 @@ QUnit.test('keySystem info for representation - uppercase UUIDs', function(asser
   assert.equal(actual.representationInfo.length, 1);
   assert.deepEqual(actual, expected);
 });
+
+QUnit.test('gets EventStream data from toEventStream', function(assert) {
+  const mpd = stringToMpdXml(`
+    <MPD mediaPresentationDuration="PT30S" xmlns:cenc="urn:mpeg:cenc:2013">
+      <Period id="dai_pod-0001065804-ad-1" start="PT17738H17M14.156S" duration="PT9.977S">
+        <BaseURL>https://www.example.com/base/</BaseURL>
+        <SegmentTemplate media="$RepresentationID$/$Number$.mp4" initialization="$RepresentationID$/init.mp4"/>
+        <EventStream schemeIdUri="urn:google:dai:2018" timescale="1000">
+          <Event presentationTime="100" duration="0" id="0" messageData="foo"/>
+          <Event presentationTime="900" duration="0" id="5" messageData="bar"/>
+          <Event presentationTime="1900" duration="0" id="6" messageData="foo_bar"/>
+        </EventStream>
+      </Period>
+    </MPD>`);
+  const expected = [
+    {
+      end: 2.1,
+      id: '0',
+      messageData: 'foo',
+      schemeIdUri: 'urn:google:dai:2018',
+      start: 2.1,
+      value: undefined
+    },
+    {
+      end: 2.9,
+      id: '5',
+      messageData: 'bar',
+      schemeIdUri: 'urn:google:dai:2018',
+      start: 2.9,
+      value: undefined
+    },
+    {
+      end: 3.9,
+      id: '6',
+      messageData: 'foo_bar',
+      schemeIdUri: 'urn:google:dai:2018',
+      start: 3.9,
+      value: undefined
+    }
+  ];
+
+  const firstPeriod = { node: findChildren(mpd, 'Period')[0], attributes: { start: 2 } };
+  const eventStreams = toEventStream(firstPeriod);
+
+  assert.deepEqual(eventStreams, expected, 'getEventStreams returns the expected object');
+});
+
+QUnit.test('cannot get EventStream data from toEventStream with no schemeIdUri', function(assert) {
+  const mpd = stringToMpdXml(`
+    <MPD mediaPresentationDuration="PT30S" xmlns:cenc="urn:mpeg:cenc:2013">
+      <Period id="dai_pod-0001065804-ad-1" start="PT17738H17M14.156S" duration="PT9.977S">
+        <BaseURL>https://www.example.com/base/</BaseURL>
+        <SegmentTemplate media="$RepresentationID$/$Number$.mp4" initialization="$RepresentationID$/init.mp4"/>
+        <EventStream timescale="1000">
+          <Event presentationTime="100" duration="0" id="0" messageData="foo"/>
+          <Event presentationTime="900" duration="0" id="5" messageData="bar"/>
+          <Event presentationTime="1900" duration="0" id="6" messageData="foo_bar"/>
+        </EventStream>
+      </Period>
+    </MPD>`);
+
+  const firstPeriod = { node: findChildren(mpd, 'Period')[0], attributes: { start: 2} };
+  const eventStreams = toEventStream(firstPeriod);
+
+  assert.deepEqual(eventStreams, [undefined], 'getEventStreams returns the expected object');
+});
+
+QUnit.test('gets EventStreamInfo from inheritAttributes', function(assert) {
+  const mpd = stringToMpdXml(`
+    <MPD mediaPresentationDuration="PT30S" xmlns:cenc="urn:mpeg:cenc:2013">
+      <Period id="dai_pod-0001065804-ad-1" start="PT0H0M14.9S" duration="PT9.977S">
+        <BaseURL>https://www.example.com/base/</BaseURL>
+        <SegmentTemplate media="$RepresentationID$/$Number$.mp4" initialization="$RepresentationID$/init.mp4"/>
+        <EventStream schemeIdUri="urn:google:dai:2018" timescale="1000">
+          <Event presentationTime="100" duration="0" id="0" messageData="foo"/>
+          <Event presentationTime="1100" duration="0" id="5" messageData="bar"/>
+          <Event presentationTime="2100" duration="0" id="6" messageData="foo_bar"/>
+        </EventStream>
+      </Period>
+    </MPD>`);
+  const expected = {
+    eventStreamInfo: [
+      {
+        end: 15,
+        id: '0',
+        messageData: 'foo',
+        schemeIdUri: 'urn:google:dai:2018',
+        start: 15,
+        value: undefined
+      },
+      {
+        end: 16,
+        id: '5',
+        messageData: 'bar',
+        schemeIdUri: 'urn:google:dai:2018',
+        start: 16,
+        value: undefined
+      },
+      {
+        end: 17,
+        id: '6',
+        messageData: 'foo_bar',
+        schemeIdUri: 'urn:google:dai:2018',
+        start: 17,
+        value: undefined
+      }
+    ],
+    locations: undefined,
+    representationInfo: []
+  };
+
+  const eventStreams = inheritAttributes(mpd);
+
+  assert.deepEqual(eventStreams, expected, 'getEventStreams returns the expected object');
+});