Source: lib/cea/i_cea_parser.js

  1. /*! @license
  2.  * Shaka Player
  3.  * Copyright 2016 Google LLC
  4.  * SPDX-License-Identifier: Apache-2.0
  5.  */
  7. goog.provide('shaka.cea.ICeaParser');
  9. /**
  10.  * Interface for parsing inband closed caption data from MP4 streams.
  11.  * @interface
  12.  */
  13. shaka.cea.ICeaParser = class {
  14.   /**
  15.    * Initializes the parser with init segment data.
  16.    * @param {!BufferSource} initSegment init segment to parse.
  17.    */
  18.   init(initSegment) {}
  20.   /**
  21.    * Parses the stream and extracts closed captions packets.
  22.    * @param {!BufferSource} mediaSegment media segment to parse.
  23.    * @return {!Array<!shaka.cea.ICeaParser.CaptionPacket>}
  24.    */
  25.   parse(mediaSegment) {}
  26. };
  28. /**
  29.  * NALU type for Supplemental Enhancement Information (SEI).
  30.  * @const {number}
  31.  */
  32. shaka.cea.ICeaParser.NALU_TYPE_SEI = 0x06;
  34. /**
  35.  * Default timescale value for a track.
  36.  */
  37. shaka.cea.ICeaParser.DEFAULT_TIMESCALE_VALUE = 90000;
  39. /**
  40.  * @typedef {{
  41.  *   packet: !Uint8Array,
  42.  *   pts: number
  43.  * }}
  44.  *
  45.  * @description Parsed Caption Packet.
  46.  * @property {!Uint8Array} packet
  47.  * Caption packet. More specifically, it contains a "User data
  48.  * registered by Recommendation ITU-T T.35 SEI message", from section D.1.6
  49.  * and section D.2.6 of Rec. ITU-T H.264 (06/2019).
  50.  * @property {number} pts
  51.  * The presentation timestamp (pts) at which the ITU-T T.35 data shows up.
  52.  * in seconds.
  53.  * @exportDoc
  54.  */
  55. shaka.cea.ICeaParser.CaptionPacket;