Source: lib/text/mp4_ttml_parser.js

  1. /**
  2.  * @license
  3.  * Copyright 2016 Google Inc.
  4.  *
  5.  * Licensed under the Apache License, Version 2.0 (the "License");
  6.  * you may not use this file except in compliance with the License.
  7.  * You may obtain a copy of the License at
  8.  *
  9.  *     http://www.apache.org/licenses/LICENSE-2.0
  10.  *
  11.  * Unless required by applicable law or agreed to in writing, software
  12.  * distributed under the License is distributed on an "AS IS" BASIS,
  13.  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14.  * See the License for the specific language governing permissions and
  15.  * limitations under the License.
  16.  */
  18. goog.provide('shaka.text.Mp4TtmlParser');
  20. goog.require('shaka.text.TextEngine');
  21. goog.require('shaka.text.TtmlTextParser');
  22. goog.require('shaka.util.Error');
  23. goog.require('shaka.util.Mp4Parser');
  26. /**
  27.  * @struct
  28.  * @constructor
  29.  * @implements {shaka.extern.TextParser}
  30.  */
  31. shaka.text.Mp4TtmlParser = function() {
  32.   /**
  33.    * @type {!shaka.extern.TextParser}
  34.    * @private
  35.    */
  36.   this.parser_ = new shaka.text.TtmlTextParser();
  37. };
  40. /** @override **/
  41. shaka.text.Mp4TtmlParser.prototype.parseInit = function(data) {
  42.   const Mp4Parser = shaka.util.Mp4Parser;
  44.   let sawSTPP = false;
  46.   new Mp4Parser()
  47.       .box('moov', Mp4Parser.children)
  48.       .box('trak', Mp4Parser.children)
  49.       .box('mdia', Mp4Parser.children)
  50.       .box('minf', Mp4Parser.children)
  51.       .box('stbl', Mp4Parser.children)
  52.       .fullBox('stsd', Mp4Parser.sampleDescription)
  53.       .box('stpp', function(box) {
  54.         sawSTPP = true;
  55.         box.parser.stop();
  56.       }).parse(data);
  58.   if (!sawSTPP) {
  59.     throw new shaka.util.Error(
  60.         shaka.util.Error.Severity.CRITICAL,
  61.         shaka.util.Error.Category.TEXT,
  62.         shaka.util.Error.Code.INVALID_MP4_TTML);
  63.   }
  64. };
  67. /** @override **/
  68. shaka.text.Mp4TtmlParser.prototype.parseMedia = function(data, time) {
  69.   const Mp4Parser = shaka.util.Mp4Parser;
  71.   let sawMDAT = false;
  72.   let payload = [];
  74.   new Mp4Parser()
  75.       .box('mdat', Mp4Parser.allData(function(data) {
  76.         sawMDAT = true;
  77.         // Join this to any previous payload, in case the mp4 has multiple
  78.         // mdats.
  79.         payload = payload.concat(this.parser_.parseMedia(data, time));
  80.       }.bind(this))).parse(data);
  82.   if (!sawMDAT) {
  83.     throw new shaka.util.Error(
  84.         shaka.util.Error.Severity.CRITICAL,
  85.         shaka.util.Error.Category.TEXT,
  86.         shaka.util.Error.Code.INVALID_MP4_TTML);
  87.   }
  89.   return payload;
  90. };
  93. shaka.text.TextEngine.registerParser(
  94.     'application/mp4; codecs="stpp"',
  95.     shaka.text.Mp4TtmlParser);
  96. shaka.text.TextEngine.registerParser(
  97.     'application/mp4; codecs="stpp.TTML.im1t"',
  98.     shaka.text.Mp4TtmlParser);