Source: lib/media/segment_reference.js

  1. /*! @license
  2.  * Shaka Player
  3.  * Copyright 2016 Google LLC
  4.  * SPDX-License-Identifier: Apache-2.0
  5.  */
  7. goog.provide('shaka.media.InitSegmentReference');
  8. goog.provide('shaka.media.SegmentReference');
  10. goog.require('goog.asserts');
  11. goog.require('shaka.log');
  12. goog.require('shaka.util.ArrayUtils');
  13. goog.require('shaka.util.BufferUtils');
  16. /**
  17.  * Creates an InitSegmentReference, which provides the location to an
  18.  * initialization segment.
  19.  *
  20.  * @export
  21.  */
  22. shaka.media.InitSegmentReference = class {
  23.   /**
  24.    * @param {function(): !Array<string>} uris A function that creates the URIs
  25.    *   of the resource containing the segment.
  26.    * @param {number} startByte The offset from the start of the resource to the
  27.    *   start of the segment.
  28.    * @param {?number} endByte The offset from the start of the resource
  29.    *   to the end of the segment, inclusive.  A value of null indicates that the
  30.    *   segment extends to the end of the resource.
  31.    * @param {null|shaka.extern.MediaQualityInfo=} mediaQuality Information about
  32.    *   the quality of the media associated with this init segment.
  33.    * @param {(null|number)=} timescale
  34.    * @param {(null|BufferSource)=} segmentData
  35.    * @param {?shaka.extern.aesKey=} aesKey
  36.    *  The segment's AES-128-CBC full segment encryption key and iv.
  37.    * @param {boolean=} encrypted
  38.    */
  39.   constructor(uris, startByte, endByte, mediaQuality = null, timescale = null,
  40.       segmentData = null, aesKey = null, encrypted = false) {
  41.     /** @type {function(): !Array<string>} */
  42.     this.getUris = uris;
  44.     /** @const {number} */
  45.     this.startByte = startByte;
  47.     /** @const {?number} */
  48.     this.endByte = endByte;
  50.     /** @type {shaka.extern.MediaQualityInfo|null} */
  51.     this.mediaQuality = mediaQuality;
  53.     /** @type {number|null} */
  54.     this.timescale = timescale;
  56.     /** @type {BufferSource|null} */
  57.     this.segmentData = segmentData;
  59.     /** @type {?shaka.extern.aesKey} */
  60.     this.aesKey = aesKey;
  62.     /** @type {?string} */
  63.     this.codecs = null;
  65.     /** @type {?string} */
  66.     this.mimeType = null;
  68.     /** @const {boolean} */
  69.     this.encrypted = encrypted;
  70.   }
  72.   /**
  73.    * Returns the offset from the start of the resource to the
  74.    * start of the segment.
  75.    *
  76.    * @return {number}
  77.    * @export
  78.    */
  79.   getStartByte() {
  80.     return this.startByte;
  81.   }
  83.   /**
  84.    * Returns the offset from the start of the resource to the end of the
  85.    * segment, inclusive.  A value of null indicates that the segment extends
  86.    * to the end of the resource.
  87.    *
  88.    * @return {?number}
  89.    * @export
  90.    */
  91.   getEndByte() {
  92.     return this.endByte;
  93.   }
  95.   /**
  96.    * Returns the size of the init segment.
  97.    * @return {?number}
  98.    */
  99.   getSize() {
  100.     if (this.endByte) {
  101.       return this.endByte - this.startByte;
  102.     } else {
  103.       return null;
  104.     }
  105.   }
  107.   /**
  108.    * Returns media quality information for the segments associated with
  109.    * this init segment.
  110.    *
  111.    * @return {?shaka.extern.MediaQualityInfo}
  112.    */
  113.   getMediaQuality() {
  114.     return this.mediaQuality;
  115.   }
  117.   /**
  118.    * Return the segment data.
  119.    *
  120.    * @return {?BufferSource}
  121.    */
  122.   getSegmentData() {
  123.     return this.segmentData;
  124.   }
  127.   /**
  128.    * Check if two initSegmentReference have all the same values.
  129.    * @param {?shaka.media.InitSegmentReference} reference1
  130.    * @param {?shaka.media.InitSegmentReference} reference2
  131.    * @return {boolean}
  132.    */
  133.   static equal(reference1, reference2) {
  134.     const ArrayUtils = shaka.util.ArrayUtils;
  135.     const BufferUtils = shaka.util.BufferUtils;
  137.     if (reference1 === reference2) {
  138.       return true;
  139.     } else if (!reference1 || !reference2) {
  140.       return reference1 == reference2;
  141.     } else {
  142.       return reference1.getStartByte() == reference2.getStartByte() &&
  143.           reference1.getEndByte() == reference2.getEndByte() &&
  144.           ArrayUtils.equal(
  145.               reference1.getUris().sort(), reference2.getUris().sort()) &&
  146.           BufferUtils.equal(reference1.getSegmentData(),
  147.               reference2.getSegmentData());
  148.     }
  149.   }
  150. };
  153. /**
  154.  * SegmentReference provides the start time, end time, and location to a media
  155.  * segment.
  156.  *
  157.  * @export
  158.  */
  159. shaka.media.SegmentReference = class {
  160.   /**
  161.    * @param {number} startTime The segment's start time in seconds.
  162.    * @param {number} endTime The segment's end time in seconds.  The segment
  163.    *   ends the instant before this time, so |endTime| must be strictly greater
  164.    *   than |startTime|.
  165.    * @param {function(): !Array<string>} uris
  166.    *   A function that creates the URIs of the resource containing the segment.
  167.    * @param {number} startByte The offset from the start of the resource to the
  168.    *   start of the segment.
  169.    * @param {?number} endByte The offset from the start of the resource to the
  170.    *   end of the segment, inclusive.  A value of null indicates that the
  171.    *   segment extends to the end of the resource.
  172.    * @param {shaka.media.InitSegmentReference} initSegmentReference
  173.    *   The segment's initialization segment metadata, or null if the segments
  174.    *   are self-initializing.
  175.    * @param {number} timestampOffset
  176.    *   The amount of time, in seconds, that must be added to the segment's
  177.    *   internal timestamps to align it to the presentation timeline.
  178.    *   <br>
  179.    *   For DASH, this value should equal the Period start time minus the first
  180.    *   presentation timestamp of the first frame/sample in the Period.  For
  181.    *   example, for MP4 based streams, this value should equal Period start
  182.    *   minus the first segment's tfdt box's 'baseMediaDecodeTime' field (after
  183.    *   it has been converted to seconds).
  184.    *   <br>
  185.    *   For HLS, this value should be the start time of the most recent
  186.    *   discontinuity, or 0 if there is no preceding discontinuity. Only used
  187.    *   in segments mode.
  188.    * @param {number} appendWindowStart
  189.    *   The start of the append window for this reference, relative to the
  190.    *   presentation.  Any content from before this time will be removed by
  191.    *   MediaSource.
  192.    * @param {number} appendWindowEnd
  193.    *   The end of the append window for this reference, relative to the
  194.    *   presentation.  Any content from after this time will be removed by
  195.    *   MediaSource.
  196.    * @param {!Array<!shaka.media.SegmentReference>=} partialReferences
  197.    *   A list of SegmentReferences for the partial segments.
  198.    * @param {?string=} tilesLayout
  199.    *   The value is a grid-item-dimension consisting of two positive decimal
  200.    *   integers in the format: column-x-row ('4x3'). It describes the
  201.    *   arrangement of Images in a Grid. The minimum valid LAYOUT is '1x1'.
  202.    * @param {?number=} tileDuration
  203.    *  The explicit duration of an individual tile within the tiles grid.
  204.    *  If not provided, the duration should be automatically calculated based on
  205.    *  the duration of the reference.
  206.    * @param {?number=} syncTime
  207.    *  A time value, expressed in seconds since 1970, which is used to
  208.    *  synchronize between streams.  Both produced and consumed by the HLS
  209.    *  parser.  Other components should not need this value.
  210.    * @param {shaka.media.SegmentReference.Status=} status
  211.    *  The segment status is used to indicate that a segment does not exist or is
  212.    *  not available.
  213.    * @param {?shaka.extern.aesKey=} aesKey
  214.    *  The segment's AES-128-CBC full segment encryption key and iv.
  215.    * @param {boolean=} allPartialSegments
  216.    *  Indicate if the segment has all partial segments
  217.    */
  218.   constructor(
  219.       startTime, endTime, uris, startByte, endByte, initSegmentReference,
  220.       timestampOffset, appendWindowStart, appendWindowEnd,
  221.       partialReferences = [], tilesLayout = '', tileDuration = null,
  222.       syncTime = null, status = shaka.media.SegmentReference.Status.AVAILABLE,
  223.       aesKey = null, allPartialSegments = false) {
  224.     // A preload hinted Partial Segment has the same startTime and endTime.
  225.     goog.asserts.assert(startTime <= endTime,
  226.         'startTime must be less than or equal to endTime');
  227.     goog.asserts.assert((endByte == null) || (startByte < endByte),
  228.         'startByte must be < endByte');
  230.     /** @type {number} */
  231.     this.startTime = startTime;
  233.     /** @type {number} */
  234.     this.endTime = endTime;
  236.     /**
  237.      * The "true" end time of the segment, without considering the period end
  238.      * time.  This is necessary for thumbnail segments, where timing requires us
  239.      * to know the original segment duration as described in the manifest.
  240.      * @type {number}
  241.      */
  242.     this.trueEndTime = endTime;
  244.     /** @type {function(): !Array<string>} */
  245.     this.getUrisInner = uris;
  247.     /** @const {number} */
  248.     this.startByte = startByte;
  250.     /** @const {?number} */
  251.     this.endByte = endByte;
  253.     /** @type {shaka.media.InitSegmentReference} */
  254.     this.initSegmentReference = initSegmentReference;
  256.     /** @type {number} */
  257.     this.timestampOffset = timestampOffset;
  259.     /** @type {number} */
  260.     this.appendWindowStart = appendWindowStart;
  262.     /** @type {number} */
  263.     this.appendWindowEnd = appendWindowEnd;
  265.     /** @type {!Array<!shaka.media.SegmentReference>} */
  266.     this.partialReferences = partialReferences;
  268.     /** @type {?string} */
  269.     this.tilesLayout = tilesLayout;
  271.     /** @type {?number} */
  272.     this.tileDuration = tileDuration;
  274.     /**
  275.      * A time value, expressed in seconds since 1970, which is used to
  276.      * synchronize between streams.  Both produced and consumed by the HLS
  277.      * parser.  Other components should not need this value.
  278.      *
  279.      * @type {?number}
  280.      */
  281.     this.syncTime = syncTime;
  283.     /** @type {shaka.media.SegmentReference.Status} */
  284.     this.status = status;
  286.     /** @type {boolean} */
  287.     this.preload = false;
  289.     /** @type {boolean} */
  290.     this.independent = true;
  292.     /** @type {boolean} */
  293.     this.byterangeOptimization = false;
  295.     /** @type {?shaka.extern.aesKey} */
  296.     this.aesKey = aesKey;
  298.     /** @type {?shaka.extern.ThumbnailSprite} */
  299.     this.thumbnailSprite = null;
  301.     /** @type {number} */
  302.     this.discontinuitySequence = -1;
  304.     /** @type {boolean} */
  305.     this.allPartialSegments = allPartialSegments;
  307.     /** @type {boolean} */
  308.     this.partial = false;
  310.     /** @type {boolean} */
  311.     this.lastPartial = false;
  313.     for (const partial of this.partialReferences) {
  314.       partial.markAsPartial();
  315.     }
  316.     if (this.allPartialSegments && this.partialReferences.length) {
  317.       const lastPartial =
  318.           this.partialReferences[this.partialReferences.length - 1];
  319.       lastPartial.markAsLastPartial();
  320.     }
  322.     /** @type {?string} */
  323.     this.codecs = null;
  325.     /** @type {?string} */
  326.     this.mimeType = null;
  328.     /** @type {?number} */
  329.     this.bandwidth = null;
  331.     /** @type {BufferSource|null} */
  332.     this.segmentData = null;
  333.   }
  335.   /**
  336.    * Creates and returns the URIs of the resource containing the segment.
  337.    *
  338.    * @return {!Array<string>}
  339.    * @export
  340.    */
  341.   getUris() {
  342.     return this.getUrisInner();
  343.   }
  345.   /**
  346.    * Returns the segment's start time in seconds.
  347.    *
  348.    * @return {number}
  349.    * @export
  350.    */
  351.   getStartTime() {
  352.     return this.startTime;
  353.   }
  355.   /**
  356.    * Returns the segment's end time in seconds.
  357.    *
  358.    * @return {number}
  359.    * @export
  360.    */
  361.   getEndTime() {
  362.     return this.endTime;
  363.   }
  365.   /**
  366.    * Returns the offset from the start of the resource to the
  367.    * start of the segment.
  368.    *
  369.    * @return {number}
  370.    * @export
  371.    */
  372.   getStartByte() {
  373.     return this.startByte;
  374.   }
  376.   /**
  377.    * Returns the offset from the start of the resource to the end of the
  378.    * segment, inclusive.  A value of null indicates that the segment extends to
  379.    * the end of the resource.
  380.    *
  381.    * @return {?number}
  382.    * @export
  383.    */
  384.   getEndByte() {
  385.     return this.endByte;
  386.   }
  388.   /**
  389.    * Returns the size of the segment.
  390.    * @return {?number}
  391.    */
  392.   getSize() {
  393.     if (this.endByte) {
  394.       return this.endByte - this.startByte;
  395.     } else {
  396.       return null;
  397.     }
  398.   }
  400.   /**
  401.    * Returns true if it contains partial SegmentReferences.
  402.    * @return {boolean}
  403.    */
  404.   hasPartialSegments() {
  405.     return this.partialReferences.length > 0;
  406.   }
  408.   /**
  409.    * Returns true if it contains all partial SegmentReferences.
  410.    * @return {boolean}
  411.    */
  412.   hasAllPartialSegments() {
  413.     return this.allPartialSegments;
  414.   }
  416.   /**
  417.    * Returns the segment's tiles layout. Only defined in image segments.
  418.    *
  419.    * @return {?string}
  420.    * @export
  421.    */
  422.   getTilesLayout() {
  423.     return this.tilesLayout;
  424.   }
  426.   /**
  427.    * Returns the segment's explicit tile duration.
  428.    * Only defined in image segments.
  429.    *
  430.    * @return {?number}
  431.    * @export
  432.    */
  433.   getTileDuration() {
  434.     return this.tileDuration;
  435.   }
  437.   /**
  438.    * Returns the segment's status.
  439.    *
  440.    * @return {shaka.media.SegmentReference.Status}
  441.    * @export
  442.    */
  443.   getStatus() {
  444.     return this.status;
  445.   }
  447.   /**
  448.    * Mark the reference as unavailable.
  449.    *
  450.    * @export
  451.    */
  452.   markAsUnavailable() {
  453.     this.status = shaka.media.SegmentReference.Status.UNAVAILABLE;
  454.   }
  456.   /**
  457.    * Mark the reference as preload.
  458.    *
  459.    * @export
  460.    */
  461.   markAsPreload() {
  462.     this.preload = true;
  463.   }
  465.   /**
  466.    * Returns true if the segment is preloaded.
  467.    *
  468.    * @return {boolean}
  469.    * @export
  470.    */
  471.   isPreload() {
  472.     return this.preload;
  473.   }
  475.   /**
  476.    * Mark the reference as non-independent.
  477.    *
  478.    * @export
  479.    */
  480.   markAsNonIndependent() {
  481.     this.independent = false;
  482.   }
  484.   /**
  485.    * Returns true if the segment is independent.
  486.    *
  487.    * @return {boolean}
  488.    * @export
  489.    */
  490.   isIndependent() {
  491.     return this.independent;
  492.   }
  494.   /**
  495.    * Mark the reference as partial.
  496.    *
  497.    * @export
  498.    */
  499.   markAsPartial() {
  500.     this.partial = true;
  501.   }
  503.   /**
  504.    * Returns true if the segment is partial.
  505.    *
  506.    * @return {boolean}
  507.    * @export
  508.    */
  509.   isPartial() {
  510.     return this.partial;
  511.   }
  513.   /**
  514.    * Mark the reference as being the last part of the full segment
  515.    *
  516.    * @export
  517.    */
  518.   markAsLastPartial() {
  519.     this.lastPartial = true;
  520.   }
  522.   /**
  523.    * Returns true if reference as being the last part of the full segment.
  524.    *
  525.    * @return {boolean}
  526.    * @export
  527.    */
  528.   isLastPartial() {
  529.     return this.lastPartial;
  530.   }
  532.   /**
  533.    * Mark the reference as byterange optimization.
  534.    *
  535.    * The "byterange optimization" means that it is playable using MP4 low
  536.    * latency streaming with chunked data.
  537.    *
  538.    * @export
  539.    */
  540.   markAsByterangeOptimization() {
  541.     this.byterangeOptimization = true;
  542.   }
  544.   /**
  545.    * Returns true if the segment has a byterange optimization.
  546.    *
  547.    * @return {boolean}
  548.    * @export
  549.    */
  550.   hasByterangeOptimization() {
  551.     return this.byterangeOptimization;
  552.   }
  554.   /**
  555.    * Set the segment's thumbnail sprite.
  556.    *
  557.    * @param {shaka.extern.ThumbnailSprite} thumbnailSprite
  558.    * @export
  559.    */
  560.   setThumbnailSprite(thumbnailSprite) {
  561.     this.thumbnailSprite = thumbnailSprite;
  562.   }
  564.   /**
  565.    * Returns the segment's thumbnail sprite.
  566.    *
  567.    * @return {?shaka.extern.ThumbnailSprite}
  568.    * @export
  569.    */
  570.   getThumbnailSprite() {
  571.     return this.thumbnailSprite;
  572.   }
  574.   /**
  575.    * Offset the segment reference by a fixed amount.
  576.    *
  577.    * @param {number} offset The amount to add to the segment's start and end
  578.    *   times.
  579.    * @export
  580.    */
  581.   offset(offset) {
  582.     this.startTime += offset;
  583.     this.endTime += offset;
  584.     this.trueEndTime += offset;
  586.     for (const partial of this.partialReferences) {
  587.       partial.startTime += offset;
  588.       partial.endTime += offset;
  589.       partial.trueEndTime += offset;
  590.     }
  591.   }
  593.   /**
  594.    * Sync this segment against a particular sync time that will serve as "0" in
  595.    * the presentation timeline.
  596.    *
  597.    * @param {number} lowestSyncTime
  598.    * @export
  599.    */
  600.   syncAgainst(lowestSyncTime) {
  601.     if (this.syncTime == null) {
  602.       shaka.log.alwaysError('Sync attempted without sync time!');
  603.       return;
  604.     }
  605.     const desiredStart = this.syncTime - lowestSyncTime;
  606.     const offset = desiredStart - this.startTime;
  607.     if (Math.abs(offset) >= 0.001) {
  608.       this.offset(offset);
  609.     }
  610.   }
  612.   /**
  613.    * Set the segment data.
  614.    *
  615.    * @param {!BufferSource} segmentData
  616.    * @export
  617.    */
  618.   setSegmentData(segmentData) {
  619.     this.segmentData = segmentData;
  620.   }
  622.   /**
  623.    * Return the segment data.
  624.    *
  625.    * @return {?BufferSource}
  626.    * @export
  627.    */
  628.   getSegmentData() {
  629.     return this.segmentData;
  630.   }
  632.   /**
  633.    * Updates the init segment reference and propagates the update to all partial
  634.    * references.
  635.    * @param {shaka.media.InitSegmentReference} initSegmentReference
  636.    */
  637.   updateInitSegmentReference(initSegmentReference) {
  638.     this.initSegmentReference = initSegmentReference;
  639.     for (const partialReference of this.partialReferences) {
  640.       partialReference.updateInitSegmentReference(initSegmentReference);
  641.     }
  642.   }
  643. };
  646. /**
  647.  * Rather than using booleans to communicate what the state of the reference,
  648.  * we have this enum.
  649.  *
  650.  * @enum {number}
  651.  * @export
  652.  */
  653. shaka.media.SegmentReference.Status = {
  654.   AVAILABLE: 0,
  655.   UNAVAILABLE: 1,
  656.   MISSING: 2,
  657. };
  660. /**
  661.  * A convenient typedef for when either type of reference is acceptable.
  662.  *
  663.  * @typedef {shaka.media.InitSegmentReference|shaka.media.SegmentReference}
  664.  */
  665. shaka.media.AnySegmentReference;
  668. /**
  669.  * @typedef {{
  670.  *   height: number,
  671.  *   positionX: number,
  672.  *   positionY: number,
  673.  *   width: number
  674.  * }}
  675.  *
  676.  * @property {number} height
  677.  *    The thumbnail height in px.
  678.  * @property {number} positionX
  679.  *    The thumbnail left position in px.
  680.  * @property {number} positionY
  681.  *    The thumbnail top position in px.
  682.  * @property {number} width
  683.  *    The thumbnail width in px.
  684.  * @export
  685.  */
  686. shaka.media.SegmentReference.ThumbnailSprite;