fix: Disable seek retry cooldown on most platforms (#7010)

Previously, we added a 1 second "cooldown" period between attempts to perform a corrective seek. This was for the benefit of old v1 Chromecasts, which found the process of seeking so slow that they would sometimes get stuck in an infinite loop trying to start a presentation. However, that cooldown period was causing issues in some situations during seeking, so this PR removes the restriction on everything but pre-Android Chromecast devices. Fixes #4393 Fixes #5202 --------- Co-authored-by: Álvaro Velad Galván <[email protected]>
shaka-project · Jul 9, 2024 · dcc60f9 · dcc60f9
1 parent dc34ec4
commit dcc60f9
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diff --git a/lib/media/playhead.js b/lib/media/playhead.js
@@ -18,6 +18,7 @@ goog.require('shaka.media.VideoWrapper');
 goog.require('shaka.util.EventManager');
 goog.require('shaka.util.IReleasable');
 goog.require('shaka.util.MediaReadyState');
+goog.require('shaka.util.Platform');
 goog.require('shaka.util.Timer');
 goog.requireType('shaka.media.PresentationTimeline');
 
@@ -420,12 +421,20 @@ shaka.media.MediaSourcePlayhead = class {
 
     const gapLimit = shaka.media.GapJumpingController.BROWSER_GAP_TOLERANCE;
     if (Math.abs(targetTime - currentTime) > gapLimit) {
-      // You can only seek like this every so often. This is to prevent an
-      // infinite loop on systems where changing currentTime takes a significant
-      // amount of time (e.g. Chromecast).
-      const time = Date.now() / 1000;
-      if (!this.lastCorrectiveSeek_ || this.lastCorrectiveSeek_ < time - 1) {
-        this.lastCorrectiveSeek_ = time;
+      let canCorrectiveSeek = false;
+      if (shaka.util.Platform.isSeekingSlow()) {
+        // You can only seek like this every so often. This is to prevent an
+        // infinite loop on systems where changing currentTime takes a
+        // significant amount of time (e.g. Chromecast).
+        const time = Date.now() / 1000;
+        if (!this.lastCorrectiveSeek_ || this.lastCorrectiveSeek_ < time - 1) {
+          this.lastCorrectiveSeek_ = time;
+          canCorrectiveSeek = true;
+        }
+      } else {
+        canCorrectiveSeek = true;
+      }
+      if (canCorrectiveSeek) {
         this.videoWrapper_.setTime(targetTime);
         return;
       }

diff --git a/lib/util/platform.js b/lib/util/platform.js
@@ -645,6 +645,25 @@ shaka.util.Platform = class {
     return true;
   }
 
+  /**
+   * On some platforms, such as v1 Chromecasts, the act of seeking can take a
+   * significant amount of time.
+   *
+   * @return {boolean}
+   */
+  static isSeekingSlow() {
+    const Platform = shaka.util.Platform;
+    if (Platform.isChromecast()) {
+      if (Platform.isAndroidCastDevice()) {
+        // Android-based Chromecasts are new enough to not be a problem.
+        return false;
+      } else {
+        return true;
+      }
+    }
+    return false;
+  }
+
   /**
    * Returns true if MediaKeys is polyfilled
    *

diff --git a/test/media/playhead_unit.js b/test/media/playhead_unit.js
@@ -593,7 +593,10 @@ describe('Playhead', () => {
     expect(onSeek).toHaveBeenCalled();
   });  // clamps playhead after seeking for VOD
 
-  it('doesn\'t repeatedly re-seek', () => {
+  it('doesn\'t repeatedly re-seek in seeking slow platforms', () => {
+    if (!shaka.util.Platform.isSeekingSlow()) {
+      pending('No seeking slow platform');
+    }
     video.readyState = HTMLMediaElement.HAVE_METADATA;
 
     video.buffered = createFakeBuffered([{start: 25, end: 55}]);