Add HLS objects and basic routines to parse manifests into them.

Issue shaka-project#279.

Change-Id: I5b6f90b682d77849ce075a2a76a4202c56e5d882

build/types/hls

@@ -0,0 +1,4 @@
+# The HLS manifest parser plugin.
+
++../../lib/hls/hls_classes.js
++../../lib/hls/hls_parser.js

build/types/manifests

@@ -1,4 +1,5 @@
 # All standard manifest parser plugins.
 
 +@dash
++@hls
 +@offline

lib/hls/hls_classes.js

@@ -0,0 +1,105 @@
+/**
+ * @license
+ * Copyright 2016 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+goog.provide('shaka.hls.Attribute');
+goog.provide('shaka.hls.Playlist');
+goog.provide('shaka.hls.PlaylistType');
+goog.provide('shaka.hls.Tag');
+
+
+
+/**
+ * Creates an HLS playlist object.
+ *
+ * @param {!shaka.hls.PlaylistType} type
+ * @param {Array.<shaka.hls.Tag>} tags
+ * @param {Array.<string>=} opt_segmentsData
+ *
+ * @constructor
+ * @struct
+ */
+shaka.hls.Playlist = function(type, tags, opt_segmentsData) {
+  /** @const {shaka.hls.PlaylistType} */
+  this.type = type;
+
+  /** @const {Array.<shaka.hls.Tag>} */
+  this.tags = tags;
+
+  /** @const {Array.<string>} */
+  this.segmentsData = opt_segmentsData || null;
+};
+
+
+/**
+ * @enum {number}
+ */
+shaka.hls.PlaylistType = {
+  MASTER: 0,
+  MEDIA: 1
+};
+
+
+
+/**
+ * Creates an HLS tag object.
+ *
+ * @param {!string} name
+ * @param {!Array.<shaka.hls.Attribute>} attributes
+ * @param {?string=} opt_value
+ *
+ * @constructor
+ * @struct
+ */
+shaka.hls.Tag = function(name, attributes, opt_value) {
+  /** @const {!string} */
+  this.name = name;
+
+  /** @const {!Array.<shaka.hls.Attribute>} */
+  this.attributes = attributes;
+
+  /** @const {?string} */
+  this.value = opt_value || null;
+};
+
+
+
+/**
+ * Creates an HLS attribute object.
+ *
+ * @param {!string} name
+ * @param {!string} value
+ *
+ * @constructor
+ * @struct
+ */
+shaka.hls.Attribute = function(name, value) {
+  /** @const {!string} */
+  this.name = name;
+
+  /** @const {!string} */
+  this.value = value;
+};
+
+
+/**
+ * Adds an attribute to an HLS Tag.
+ *
+ * @param {!shaka.hls.Attribute} attribute
+ */
+shaka.hls.Tag.prototype.addAttribute = function(attribute) {
+  this.attributes.push(attribute);
+};

lib/hls/hls_parser.js

@@ -0,0 +1,194 @@
+/**
+ * @license
+ * Copyright 2016 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+goog.provide('shaka.hls.HlsParser');
+
+goog.require('shaka.hls.Attribute');
+goog.require('shaka.hls.Playlist');
+goog.require('shaka.hls.PlaylistType');
+goog.require('shaka.hls.Tag');
+goog.require('shaka.util.Error');
+goog.require('shaka.util.StringUtils');
+goog.require('shaka.util.TextParser');
+
+
+
+/**
+ * Creates a new HLS parser.
+ *
+ * @struct
+ * @constructor
+ */
+// TODO: make it implement {shakaExtern.ManifestParser}
+shaka.hls.HlsParser = function() {};
+
+
+/**
+ * @param {ArrayBuffer} data
+ * @return {!shaka.hls.Playlist}
+ * @throws {shaka.util.Error}
+ */
+// TODO: make private
+shaka.hls.HlsParser.prototype.parsePlaylist = function(data) {
+  // Get the input as a string.  Normalize newlines to \n.
+  var str = shaka.util.StringUtils.fromUTF8(data);
+  str = str.replace(/\r\n|\r(?=[^\n]|$)/gm, '\n');
+
+  var lines = str.split(/\n+/m);
+
+  if (!/^#EXTM3U($|[ \t\n])/m.test(lines[0])) {
+    throw new shaka.util.Error(
+        shaka.util.Error.Category.MANIFEST,
+        shaka.util.Error.Code.HLS_PLAYLIST_HEADER_MISSING);
+  }
+
+  var HlsParser = shaka.hls.HlsParser;
+
+  /** shaka.hls.PlaylistType */
+  var playlistType = shaka.hls.PlaylistType.MASTER;
+
+  /** {Array.<shaka.hls.Tag>} */
+  var tags = [];
+
+  var i = 1;
+  while (i < lines.length) {
+    // Skip comments
+    if (/^#(?!EXT)/m.test(lines[i])) {
+      i += 1;
+      continue;
+    }
+
+    var tag = this.parseTag_(lines[i]);
+
+
+    if (HlsParser.MEDIA_PLAYLIST_TAGS.indexOf(tag.name) >= 0) {
+      playlistType = shaka.hls.PlaylistType.MEDIA;
+    } else if (HlsParser.SEGMENT_TAGS.indexOf(tag.name) >= 0) {
+      if (playlistType != shaka.hls.PlaylistType.MEDIA) {
+        // Only media playlist should contain segment tags
+        throw new shaka.util.Error(
+            shaka.util.Error.Category.MANIFEST,
+            shaka.util.Error.Code.HLS_INVALID_PLAYLIST_HIERARCHY);
+      }
+
+      var segmentsData = lines.splice(i, lines.length - i);
+      return new shaka.hls.Playlist(playlistType, tags, segmentsData);
+    }
+
+    tags.push(tag);
+    i += 1;
+
+    // EXT-X-STREAM-INF tag is followed by a uri of a media playlist.
+    // Add uri to the tag object.
+    if (tag.name == 'EXT-X-STREAM-INF') {
+      var uri = new shaka.hls.Attribute('URI', lines[i]);
+      tag.addAttribute(uri);
+      i += 1;
+    }
+  }
+
+  return new shaka.hls.Playlist(playlistType, tags);
+};
+
+
+/**
+ * Parses a string into an HLS Tag object.
+ *
+ * @param {!string} word
+ * @return {!shaka.hls.Tag}
+ * @throws {shaka.util.Error}
+ * @private
+ */
+shaka.hls.HlsParser.prototype.parseTag_ = function(word) {
+  /* HLS tags start with '#EXT'. A tag can have a set of attributes
+    (#EXT-<tagname>:<attribute list>) or a value (#EXT-<tagname>:<value>).
+    Attributes' format is 'AttributeName=AttributeValue'.
+    The parsing logic goes like this:
+     1) Everything before ':' is a name (we ignore '#').
+     2) Everything after should be parsed as attributes if it contains '='.
+     3) Otherwise, this is a value.
+     4) If there is no ":", it's a simple tag with no attributes and no value */
+
+  var blocks = word.match(/^#(EXT[^:]*)(?::(.*))?$/);
+  if (!blocks) {
+    throw new shaka.util.Error(
+        shaka.util.Error.Category.MANIFEST,
+        shaka.util.Error.Code.INVALID_HLS_TAG);
+  }
+  var name = blocks[1];
+  var data = blocks[2];
+  var attributes = [];
+
+  if (data && data.indexOf('=') >= 0) {
+    var parser = new shaka.util.TextParser(data);
+    var blockAttrs;
+
+    // Regex:
+    // 1. Key name ([1])
+    // 2. Equals sign
+    // 3. Either:
+    //   a. A quoted string (everything up to the next quote, [2])
+    //   b. An unquoted string (everything up to the next comma or end of line,
+    //                                                                    [3])
+    // 4. Either:
+    //   a. A comma
+    //   b. End of line
+    var regex = /([^=]+)=(?:"([^"]*)"|([^",]*))(?:,|$)/g;
+    while (blockAttrs = parser.readRegex(regex)) {
+      var attrName = blockAttrs[1];
+      var attrValue = blockAttrs[2] || blockAttrs[3];
+      var attribute = new shaka.hls.Attribute(attrName, attrValue);
+      attributes.push(attribute);
+    }
+  } else if (data) {
+    return new shaka.hls.Tag(name, attributes, data);
+  }
+
+  return new shaka.hls.Tag(name, attributes);
+};
+
+
+/**
+ * HLS tags that only appear on Media Playlists.
+ * Used to determine a playlist type.
+ *
+ * @const {!Array<!string>}
+ */
+shaka.hls.HlsParser.MEDIA_PLAYLIST_TAGS = [
+  'EXT-X-TARGETDURATION',
+  'EXT-X-MEDIA-SEQUENCE',
+  'EXT-X-DISCONTINUITY-SEQUENCE',
+  'EXT-X-PLAYLIST-TYPE',
+  'EXT-X-I-FRAMES-ONLY'
+];
+
+
+/**
+ * HLS tags that only appear on Segments in a Media Playlists.
+ * Used to determine the start of the segments info.
+ *
+ * @const {!Array<!string>}
+ */
+shaka.hls.HlsParser.SEGMENT_TAGS = [
+  'EXTINF',
+  'EXT-X-BYTERANGE',
+  'EXT-X-DISCONTINUITY',
+  'EXT-X-KEY',
+  'EXT-X-MAP',
+  'EXT-X-PROGRAM-DATE-TIME',
+  'EXT-X-DATERANGE'
+];

lib/util/error.js

@@ -417,6 +417,20 @@ shaka.util.Error.Code = {
    */
   'NO_PERIODS': 4014,
 
+  /**
+   * HLS playlist doesn't start with a mandory #EXTM3U tag.
+   */
+  'HLS_PLAYLIST_HEADER_MISSING': 4015,
+
+  /**
+   * HLS tag has an invalid name that doesn't start with '#EXT'
+   */
+  'INVALID_HLS_TAG': 4016,
+
+  /**
+   * HLS playlist has both Master and Media/Segment tags.
+   */
+  'HLS_INVALID_PLAYLIST_HIERARCHY': 4017,
 
   // RETIRED: 'INCONSISTENT_BUFFER_STATE': 5000,
   // RETIRED: 'INVALID_SEGMENT_INDEX': 5001,

shaka-player.uncompiled.js

@@ -25,6 +25,7 @@ goog.require('shaka.abr.SimpleAbrManager');
 goog.require('shaka.cast.CastProxy');
 goog.require('shaka.cast.CastReceiver');
 goog.require('shaka.dash.DashParser');
+goog.require('shaka.hls.HlsParser');
 goog.require('shaka.log');
 goog.require('shaka.media.InitSegmentReference');
 goog.require('shaka.media.ManifestParser');