shaka-player/lib/cea/i_cea_parser.js

DASH/EME video player library

/*! @license
 * Shaka Player
 * Copyright 2016 Google LLC
 * SPDX-License-Identifier: Apache-2.0
 */

goog.provide('shaka.cea.ICeaParser');

/**
 * Interface for parsing inband closed caption data from MP4 streams.
 * @interface
 */
shaka.cea.ICeaParser = class {
  /**
   * Initializes the parser with init segment data.
   * @param {!BufferSource} initSegment init segment to parse.
   */
  init(initSegment) {}

  /**
   * Parses the stream and extracts closed captions packets.
   * @param {!BufferSource} mediaSegment media segment to parse.
   * @return {!Array<!shaka.cea.ICeaParser.CaptionPacket>}
   */
  parse(mediaSegment) {}
};

/**
 * NALU type for Supplemental Enhancement Information (SEI).
 * @const {number}
 */
shaka.cea.ICeaParser.NALU_TYPE_SEI = 0x06;

/**
 * Default timescale value for a track.
 */
shaka.cea.ICeaParser.DEFAULT_TIMESCALE_VALUE = 90000;

/**
 * @typedef {{
 *   packet: !Uint8Array,
 *   pts: number
 * }}
 *
 * @description Parsed Caption Packet.
 * @property {!Uint8Array} packet
 * Caption packet. More specifically, it contains a "User data
 * registered by Recommendation ITU-T T.35 SEI message", from section D.1.6
 * and section D.2.6 of Rec. ITU-T H.264 (06/2019).
 * @property {number} pts
 * The presentation timestamp (pts) at which the ITU-T T.35 data shows up.
 * in seconds.
 * @exportDoc
 */
shaka.cea.ICeaParser.CaptionPacket;