Reimplement WebWorkers on top of the v4.0.0

.gitignore

@@ -24,6 +24,8 @@
 
 /dist/_esm5.processed
 /dist/_esm5.raw
+/dist/multithread
+!/dist/multithread/index.html
 
 /doc/generated
 

package.json

@@ -24,6 +24,9 @@
   "sideEffects": false,
   "scripts": {
     "build": "webpack --progress --config webpack.config.js --env production",
+    "build:multi": "npm run build:multi:main && npm run build:multi:worker",
+    "build:multi:main": "esbuild ./src/main/index.ts --bundle --outfile=dist/multithread/main.js --define:__ENVIRONMENT__=\"{ \\\"PRODUCTION\\\": 0, \\\"DEV\\\": 1, \\\"CURRENT_ENV\\\": 1 }\"",
+    "build:multi:worker": "esbuild ./src/worker/index.ts --bundle --outfile=dist/multithread/worker.js --define:__ENVIRONMENT__=\"{ \\\"PRODUCTION\\\": 0, \\\"DEV\\\": 1, \\\"CURRENT_ENV\\\": 1 }\"",
     "build:all": "npm run build && npm run build:min && npm run build:wasm:release && npm run build:modular",
     "build:min": "webpack --progress --config webpack.config.js --env minify --env production",
     "build:min:report": "webpack --progress --config webpack.config.js --env minify --env production --env reportSize",

src/compat/eme/custom_media_keys/old_webkit_media_keys.ts

@@ -43,10 +43,11 @@ export interface IOldWebkitHTMLMediaElement extends HTMLVideoElement {
  * @returns {Boolean}
  */
 export function isOldWebkitMediaElement(
-  element : HTMLMediaElement|IOldWebkitHTMLMediaElement
+  element : unknown
 ) : element is IOldWebkitHTMLMediaElement {
-  return typeof (element as IOldWebkitHTMLMediaElement)
-    .webkitGenerateKeyRequest === "function";
+  return typeof (
+    element as IOldWebkitHTMLMediaElement
+  )?.webkitGenerateKeyRequest === "function";
 }
 
 /**

src/compat/eme/eme-api-implementation.ts

@@ -158,7 +158,7 @@ function getEmeApiImplementation(
       implementation = "webkit";
     } else {
       // This is for Chrome with unprefixed EME api
-      if (isOldWebkitMediaElement(HTMLVideoElement.prototype)) {
+      if (isOldWebkitMediaElement(globalScope.HTMLVideoElement?.prototype)) {
         onEncrypted = createCompatibleEventListener(["needkey"]);
         const callbacks = getOldKitWebKitMediaKeyCallbacks();
         isTypeSupported = callbacks.isTypeSupported;

src/compat/is_codec_supported.ts

@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+import isWorker from "../compat/is_worker";
 import { MediaSource_ } from "./browser_compatibility_types";
 
 /**
@@ -26,6 +27,10 @@ import { MediaSource_ } from "./browser_compatibility_types";
  * @returns {Boolean}
  */
 export default function isCodecSupported(mimeType : string) : boolean {
+  if (isWorker) {
+    // XXX TODO
+    return mimeType.indexOf("ec-3") < 0;
+  }
   if (MediaSource_ == null) {
     return false;
   }

src/compat/is_worker.ts

@@ -1,5 +1,5 @@
 /* eslint-disable-next-line @typescript-eslint/no-explicit-any */
-declare const WorkerGlobalScope : any | undefined;
+declare const WorkerGlobalScope : any;
 
 /**
  * `true` if the current code is running in a WebWorker.

src/core/adaptive/adaptive_representation_selector.ts

@@ -14,7 +14,6 @@
  * limitations under the License.
  */
 
-import config from "../../config";
 import log from "../../log";
 import Manifest, {
   Adaptation,
@@ -253,7 +252,7 @@ function getEstimateReference(
     }, { includeLastObservation: false, clearSignal: innerCancellationSignal });
 
     onAddedSegment = function (val : IAddedSegmentCallbackPayload) {
-      if (lastPlaybackObservation === null) {
+      if (lastPlaybackObservation === null || val.buffered === null) {
         return;
       }
       const { position, speed } = lastPlaybackObservation;
@@ -283,7 +282,7 @@ function getEstimateReference(
 
     /** Returns the actual estimate based on all methods and algorithm available. */
     function getCurrentEstimate(): IABREstimate {
-      const { bufferGap, position, maximumPosition } = lastPlaybackObservation;
+      const { position, maximumPosition } = lastPlaybackObservation;
       const resolutionLimit = filters.limitResolution.getValue();
       const bitrateThrottle = filters.throttleBitrate.getValue();
       const currentRepresentationVal = currentRepresentation.getValue();
@@ -306,17 +305,7 @@ function getEstimateReference(
                                           lastPlaybackObservation.speed :
                                           1);
 
-      const { ABR_ENTER_BUFFER_BASED_ALGO,
-              ABR_EXIT_BUFFER_BASED_ALGO } = config.getCurrent();
-
-      if (allowBufferBasedEstimates && bufferGap <= ABR_EXIT_BUFFER_BASED_ALGO) {
-        allowBufferBasedEstimates = false;
-      } else if (!allowBufferBasedEstimates &&
-                 isFinite(bufferGap) &&
-                  bufferGap >= ABR_ENTER_BUFFER_BASED_ALGO)
-      {
-        allowBufferBasedEstimates = true;
-      }
+      allowBufferBasedEstimates = false;
 
       /**
        * Representation chosen when considering only [pessimist] bandwidth
@@ -576,7 +565,7 @@ export interface IRepresentationEstimatorPlaybackObservation {
    * For the concerned media buffer, difference in seconds between the next
    * position where no segment data is available and the current position.
    */
-  bufferGap : number;
+  // bufferGap : number;
   /**
    * Information on the current media position in seconds at the time of a
    * Playback Observation.
@@ -686,7 +675,7 @@ export interface IAddedSegmentCallbackPayload {
    * The buffered ranges of the related media buffer after that segment has
    * been pushed.
    */
-  buffered : TimeRanges;
+  buffered : TimeRanges | null;
   /** The context for the segment that has been pushed. */
   content : { representation : Representation };
 }

src/core/adaptive/guess_based_chooser.ts

@@ -84,11 +84,6 @@ export default class GuessBasedChooser {
   public getGuess(
     representations : Representation[],
     observation : {
-      /**
-       * For the concerned media buffer, difference in seconds between the next
-       * position where no segment data is available and the current position.
-       */
-      bufferGap: number;
       /**
        * Last "playback rate" set by the user. This is the ideal "playback rate" at
        * which the media should play.
@@ -99,7 +94,7 @@ export default class GuessBasedChooser {
     incomingBestBitrate : number,
     requests : IRequestInfo[]
   ) : Representation | null {
-    const { bufferGap, speed } = observation;
+    const { speed } = observation;
     const lastChosenRep = this._lastAbrEstimate.representation;
     if (lastChosenRep === null) {
       return null; // There's nothing to base our guess on
@@ -122,7 +117,7 @@ export default class GuessBasedChooser {
       if (scoreData === undefined) {
         return null; // not enough information to start guessing
       }
-      if (this._canGuessHigher(bufferGap, speed, scoreData)) {
+      if (this._canGuessHigher(5, speed, scoreData)) {
         const nextRepresentation = getNextRepresentation(representations,
                                                          currentRepresentation);
         if (nextRepresentation !== null) {
@@ -146,7 +141,7 @@ export default class GuessBasedChooser {
 
     const shouldStopGuess = this._shouldStopGuess(currentRepresentation,
                                                   scoreData,
-                                                  bufferGap,
+                                                  5,
                                                   requests);
     if (shouldStopGuess) {
       // Block guesses for a time
@@ -158,7 +153,7 @@ export default class GuessBasedChooser {
       return currentRepresentation;
     }
 
-    if (this._canGuessHigher(bufferGap, speed, scoreData)) {
+    if (this._canGuessHigher(5, speed, scoreData)) {
       const nextRepresentation = getNextRepresentation(representations,
                                                        currentRepresentation);
       if (nextRepresentation !== null) {

src/core/adaptive/network_analyzer.ts

@@ -31,7 +31,7 @@ import {
  /** Object describing the current playback conditions. */
 type IPlaybackConditionsInfo = Pick<
   IRepresentationEstimatorPlaybackObservation,
-  "bufferGap" | "position" | "speed" | "duration">;
+  "position" | "speed" | "duration">;
 
 /**
  * Get pending segment request(s) starting with the asked segment position.
@@ -149,9 +149,8 @@ function estimateStarvationModeBitrate(
     // TODO Skip only for newer segments?
     return undefined;
   }
-  const { bufferGap, speed, position } = playbackInfo;
-  const realBufferGap = isFinite(bufferGap) ? bufferGap :
-                                              0;
+  const { speed, position } = playbackInfo;
+  const realBufferGap = 5;
   const nextNeededPosition = position.last + realBufferGap;
   const concernedRequests = getConcernedRequests(pendingRequests, nextNeededPosition);
 
@@ -234,8 +233,7 @@ function shouldDirectlySwitchToLowBitrate(
     // TODO only when playing close to the live edge?
     return true;
   }
-  const realBufferGap = isFinite(playbackInfo.bufferGap) ? playbackInfo.bufferGap :
-                                                           0;
+  const realBufferGap = 5;
   const nextNeededPosition = playbackInfo.position.last + realBufferGap;
   const nextRequest = arrayFind(requests, ({ content }) =>
     content.segment.duration > 0 &&
@@ -326,9 +324,8 @@ export default class NetworkAnalyzer {
     let newBitrateCeil : number | undefined; // bitrate ceil for the chosen Representation
     let bandwidthEstimate;
     const localConf = this._config;
-    const { bufferGap, position, duration } = playbackInfo;
-    const realBufferGap = isFinite(bufferGap) ? bufferGap :
-                                                0;
+    const { position, duration } = playbackInfo;
+    const realBufferGap = 5;
     const { ABR_STARVATION_DURATION_DELTA } = config.getCurrent();
     // check if should get in/out of starvation mode
     if (isNaN(duration) ||

src/core/api/debug/modules/segment_buffer_content.ts

@@ -1,7 +1,8 @@
 import {
-  Adaptation,
-  Period,
-  Representation,
+  getPeriodForTime,
+  IAdaptationMetadata,
+  IPeriodMetadata,
+  IRepresentationMetadata,
 } from "../../../../manifest";
 import isNullOrUndefined from "../../../../utils/is_null_or_undefined";
 import { CancellationSignal } from "../../../../utils/task_canceller";
@@ -94,7 +95,7 @@ export default function createSegmentBufferGraph(
       const adap = instance.__priv_getCurrentAdaptation()?.[bufferType];
       const manifest = instance.__priv_getManifest();
       if (manifest !== null && !isNullOrUndefined(rep) && !isNullOrUndefined(adap)) {
-        const period = manifest.getPeriodForTime(currentTime);
+        const period = getPeriodForTime(manifest, currentTime);
         if (period !== undefined) {
           loadingRangeRepInfoElt.appendChild(createMetricTitle("load"));
           loadingRangeRepInfoElt.appendChild(createElement("span", {
@@ -112,9 +113,9 @@ export default function createSegmentBufferGraph(
 
 function constructRepresentationInfo(
   content : {
-    period : Period;
-    adaptation : Adaptation;
-    representation : Representation;
+    period : IPeriodMetadata;
+    adaptation : IAdaptationMetadata;
+    representation : IRepresentationMetadata;
   }
 ) : string {
   const period = content.period;

src/core/api/option_utils.ts

@@ -57,6 +57,10 @@ export interface IParsedConstructorOptions {
 
   videoElement : HTMLMediaElement;
   baseBandwidth : number;
+  workerOptions : {
+    workerUrl: string;
+    dashWasmUrl: string;
+  } | undefined;
 }
 
 /**
@@ -215,6 +219,7 @@ function parseConstructorOptions(
            videoElement,
            wantedBufferAhead,
            maxVideoBufferSize,
+           workerOptions: options.workerOptions,
            throttleVideoBitrateWhenHidden,
            baseBandwidth };
 }

src/core/api/playback_observer.ts

@@ -511,23 +511,38 @@ export interface IPlaybackObservation extends IMediaInfos {
  * `IReadOnlyPlaybackObserver` to "remove" its right to update playback.
  */
 export interface IReadOnlyPlaybackObserver<TObservationType> {
-  /** Get the current playing position, in seconds. */
-  getCurrentTime() : number;
+  /**
+   * Get the current playing position, in seconds.
+   * Returns `undefined` when this cannot be known, such as when the playback
+   * observer is running in a WebWorker.
+   * @returns {number|undefined}
+   */
+  getCurrentTime() : number | undefined;
   /**
    * Returns the current playback rate advertised by the `HTMLMediaElement`.
-   * @returns {number}
+   * Returns `undefined` when this cannot be known, such as when the playback
+   * observer is running in a WebWorker.
+   * @returns {number|undefined}
    */
-  getPlaybackRate() : number;
-  /** Get the HTMLMediaElement's current `readyState`. */
-  getReadyState() : number;
+  getPlaybackRate() : number | undefined;
+  /**
+   * Get the HTMLMediaElement's current `readyState`.
+   * Returns `undefined` when this cannot be known, such as when the playback
+   * observer is running in a WebWorker.
+   * @returns {number|undefined}
+   */
+  getReadyState() : number | undefined;
   /**
    * Returns the current `paused` status advertised by the `HTMLMediaElement`.
    *
    * Use this instead of the same status emitted on an observation when you want
    * to be sure you're using the current value.
-   * @returns {boolean}
+   *
+   * Returns `undefined` when this cannot be known, such as when the playback
+   * observer is running in a WebWorker.
+   * @returns {boolean|undefined}
    */
-  getIsPaused() : boolean;
+  getIsPaused() : boolean | undefined;
   /**
    * Returns an `IReadOnlySharedReference` storing the last playback observation
    * produced by the `IReadOnlyPlaybackObserver` and updated each time a new one
@@ -939,7 +954,7 @@ function prettyPrintBuffered(
  * @param {Function} transform
  * @returns {Object}
  */
-function generateReadOnlyObserver<TSource, TDest>(
+export function generateReadOnlyObserver<TSource, TDest>(
   src : IReadOnlyPlaybackObserver<TSource>,
   transform : (
     observationRef : IReadOnlySharedReference<TSource>,
@@ -955,7 +970,7 @@ function generateReadOnlyObserver<TSource, TDest>(
     getReadyState() {
       return src.getReadyState();
     },
-    getPlaybackRate() : number {
+    getPlaybackRate() {
       return src.getPlaybackRate();
     },
     getIsPaused() {