Commit updated Javascript packages

build/javascript/node_modules/mpd-parser/src/segment/segmentTemplate.js

@@ -0,0 +1,170 @@
+import resolveUrl from '@videojs/vhs-utils/dist/resolve-url';
+import urlTypeToSegment from './urlType';
+import { parseByTimeline } from './timelineTimeParser';
+import { parseByDuration } from './durationTimeParser';
+
+const identifierPattern = /\$([A-z]*)(?:(%0)([0-9]+)d)?\$/g;
+
+/**
+ * Replaces template identifiers with corresponding values. To be used as the callback
+ * for String.prototype.replace
+ *
+ * @name replaceCallback
+ * @function
+ * @param {string} match
+ *        Entire match of identifier
+ * @param {string} identifier
+ *        Name of matched identifier
+ * @param {string} format
+ *        Format tag string. Its presence indicates that padding is expected
+ * @param {string} width
+ *        Desired length of the replaced value. Values less than this width shall be left
+ *        zero padded
+ * @return {string}
+ *         Replacement for the matched identifier
+ */
+
+/**
+ * Returns a function to be used as a callback for String.prototype.replace to replace
+ * template identifiers
+ *
+ * @param {Obect} values
+ *        Object containing values that shall be used to replace known identifiers
+ * @param {number} values.RepresentationID
+ *        Value of the Representation@id attribute
+ * @param {number} values.Number
+ *        Number of the corresponding segment
+ * @param {number} values.Bandwidth
+ *        Value of the Representation@bandwidth attribute.
+ * @param {number} values.Time
+ *        Timestamp value of the corresponding segment
+ * @return {replaceCallback}
+ *         Callback to be used with String.prototype.replace to replace identifiers
+ */
+export const identifierReplacement = (values) => (match, identifier, format, width) => {
+  if (match === '$$') {
+    // escape sequence
+    return '$';
+  }
+
+  if (typeof values[identifier] === 'undefined') {
+    return match;
+  }
+
+  const value = '' + values[identifier];
+
+  if (identifier === 'RepresentationID') {
+    // Format tag shall not be present with RepresentationID
+    return value;
+  }
+
+  if (!format) {
+    width = 1;
+  } else {
+    width = parseInt(width, 10);
+  }
+
+  if (value.length >= width) {
+    return value;
+  }
+
+  return `${(new Array(width - value.length + 1)).join('0')}${value}`;
+};
+
+/**
+ * Constructs a segment url from a template string
+ *
+ * @param {string} url
+ *        Template string to construct url from
+ * @param {Obect} values
+ *        Object containing values that shall be used to replace known identifiers
+ * @param {number} values.RepresentationID
+ *        Value of the Representation@id attribute
+ * @param {number} values.Number
+ *        Number of the corresponding segment
+ * @param {number} values.Bandwidth
+ *        Value of the Representation@bandwidth attribute.
+ * @param {number} values.Time
+ *        Timestamp value of the corresponding segment
+ * @return {string}
+ *         Segment url with identifiers replaced
+ */
+export const constructTemplateUrl = (url, values) =>
+  url.replace(identifierPattern, identifierReplacement(values));
+
+/**
+ * Generates a list of objects containing timing and duration information about each
+ * segment needed to generate segment uris and the complete segment object
+ *
+ * @param {Object} attributes
+ *        Object containing all inherited attributes from parent elements with attribute
+ *        names as keys
+ * @param {Object[]|undefined} segmentTimeline
+ *        List of objects representing the attributes of each S element contained within
+ *        the SegmentTimeline element
+ * @return {{number: number, duration: number, time: number, timeline: number}[]}
+ *         List of Objects with segment timing and duration info
+ */
+export const parseTemplateInfo = (attributes, segmentTimeline) => {
+  if (!attributes.duration && !segmentTimeline) {
+    // if neither @duration or SegmentTimeline are present, then there shall be exactly
+    // one media segment
+    return [{
+      number: attributes.startNumber || 1,
+      duration: attributes.sourceDuration,
+      time: 0,
+      timeline: attributes.periodIndex
+    }];
+  }
+
+  if (attributes.duration) {
+    return parseByDuration(attributes);
+  }
+
+  return parseByTimeline(attributes, segmentTimeline);
+};
+
+/**
+ * Generates a list of segments using information provided by the SegmentTemplate element
+ *
+ * @param {Object} attributes
+ *        Object containing all inherited attributes from parent elements with attribute
+ *        names as keys
+ * @param {Object[]|undefined} segmentTimeline
+ *        List of objects representing the attributes of each S element contained within
+ *        the SegmentTimeline element
+ * @return {Object[]}
+ *         List of segment objects
+ */
+export const segmentsFromTemplate = (attributes, segmentTimeline) => {
+  const templateValues = {
+    RepresentationID: attributes.id,
+    Bandwidth: attributes.bandwidth || 0
+  };
+
+  const { initialization = { sourceURL: '', range: '' } } = attributes;
+
+  const mapSegment = urlTypeToSegment({
+    baseUrl: attributes.baseUrl,
+    source: constructTemplateUrl(initialization.sourceURL, templateValues),
+    range: initialization.range
+  });
+
+  const segments = parseTemplateInfo(attributes, segmentTimeline);
+
+  return segments.map(segment => {
+    templateValues.Number = segment.number;
+    templateValues.Time = segment.time;
+
+    const uri = constructTemplateUrl(attributes.media || '', templateValues);
+
+    return {
+      uri,
+      timeline: segment.timeline,
+      duration: segment.duration,
+      resolvedUri: resolveUrl(attributes.baseUrl || '', uri),
+      map: mapSegment,
+      number: segment.number
+    };
+  });
+};