Source: lib/cea/i_caption_decoder.js

  1. /*! @license
  2.  * Shaka Player
  3.  * Copyright 2016 Google LLC
  4.  * SPDX-License-Identifier: Apache-2.0
  5.  */
  7. goog.provide('shaka.cea.ICaptionDecoder');
  9. goog.require('shaka.text.Cue');
  12. /**
  13.  * Interface for decoding inband closed captions from packets.
  14.  * @interface
  15.  */
  16. shaka.cea.ICaptionDecoder = class {
  17.   /**
  18.    * Extracts packets and prepares them for decoding. In a given media fragment,
  19.    * all the caption packets found in its SEI messages should be extracted by
  20.    * successive calls to extract(), followed by a single call to decode().
  21.    *
  22.    * @param {!Uint8Array} userDataSeiMessage
  23.    * This is a User Data registered by Rec.ITU-T T.35 SEI message.
  24.    * It is described in sections D.1.6 and D.2.6 of Rec. ITU-T H.264 (06/2019).
  25.    * @param {number} pts PTS when this packet was received, in seconds.
  26.    */
  27.   extract(userDataSeiMessage, pts) {}
  29.   /**
  30.    * Decodes all currently extracted packets and then clears them.
  31.    * This should be called once for a set of extracts (see comment on extract).
  32.    * @return {!Array.<!shaka.cea.ICaptionDecoder.ClosedCaption>}
  33.    */
  34.   decode() {}
  36.   /**
  37.    * Clears the decoder state completely.
  38.    * Should be used when an action renders the decoder state invalid,
  39.    * e.g. unbuffered seeks.
  40.    */
  41.   clear() {}
  42. };
  44. /**
  45.  * Parsed Cue.
  46.  * @typedef {{
  47.  *   cue: !shaka.text.Cue,
  48.  *   stream: string
  49.  * }}
  50.  */
  51. shaka.cea.ICaptionDecoder.ClosedCaption;