Improve video detection speed

radian-software · Nov 11, 2022 · f3b1230 · f3b1230
1 parent eba8608
commit f3b1230
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diff --git a/extension/CHANGELOG.md b/extension/CHANGELOG.md
@@ -12,6 +12,11 @@ multiple positions when seeking, especially with a large number of
 clients connected. This has been made much less likely by implementing
 a slightly modified synchronization algorithm.
 
+Detection of the active video element is faster now in most cases. If
+there is only one choice, then it is selected immediately. Only if
+there is more than one candidate and Hypercast cannot disambiguate do
+you have to hit play on the main content to show it which is which.
+
 ## 0.0.7
 
 End-to-end encryption is now used, so the server has no knowledge of

diff --git a/extension/content-script.js b/extension/content-script.js
@@ -18,43 +18,58 @@ const getCandidateVideos = () => {
 };
 
 const detectPrimaryVideo = () => {
-  let looping = true;
   let guessedPrimaryVideo = null;
-  // Create a promise that will resolve when we have found at least
-  // one candidate video. However, we keep updating our best guess
-  // even after this promise resolves, until the caller of
-  // detectPrimaryVideo invokes the returned function, at which point
-  // we return the current best guess and abort further calculations
-  // (and, we block until at least one guess is found, if none has
-  // been found yet).
-  const foundOne = new Promise(async (resolve) => {
-    log(`Video detection: searching for active videos`);
-    const lastTimes = new Map();
-    while (looping) {
-      const activeVideos = new Set();
-      for (const video of getCandidateVideos()) {
-        if (
-          lastTimes.has(video) &&
-          lastTimes.get(video) !== video.currentTime
-        ) {
-          activeVideos.add(video);
-        }
-        lastTimes.set(video, video.currentTime);
-      }
+  let foundOne = null;
+  let looping = true;
+  const candidateVideos = getCandidateVideos();
+  log(`Video detection: found ${candidateVideos.length} candidate video(s)`);
+  if (candidateVideos.length === 1) {
+    log(
+      `Video detection: since exactly 1 candidate video, assuming it is correct`
+    );
+    guessedPrimaryVideo = candidateVideos[0];
+    foundOne = Promise.resolve();
+  } else {
+    // Create a promise that will resolve when we have found at least
+    // one candidate video. However, we keep updating our best guess
+    // even after this promise resolves, until the caller of
+    // detectPrimaryVideo invokes the returned function, at which point
+    // we return the current best guess and abort further calculations
+    // (and, we block until at least one guess is found, if none has
+    // been found yet).
+    foundOne = new Promise(async (resolve) => {
       log(
-        `Video detection: found ${
-          activeVideos.size
-        } active videos ${JSON.stringify(
-          [...activeVideos].map((video) => video.id || "(anonymous <video>)")
-        )}`
+        `Video detection: unable to disambiguate, checking for currently playing videos every 200ms`
       );
-      if (activeVideos.size > 0) {
-        guessedPrimaryVideo = [...activeVideos.values()][0];
-        resolve();
+      const lastTimes = new Map();
+      while (looping) {
+        const activeVideos = new Set();
+        for (const video of getCandidateVideos()) {
+          if (
+            lastTimes.has(video) &&
+            lastTimes.get(video) !== video.currentTime
+          ) {
+            activeVideos.add(video);
+          }
+          lastTimes.set(video, video.currentTime);
+        }
+        if (activeVideos.size > 0) {
+          log(
+            `Video detection: found ${
+              activeVideos.size
+            } active videos ${JSON.stringify(
+              [...activeVideos].map(
+                (video) => video.id || "(anonymous <video>)"
+              )
+            )}`
+          );
+          guessedPrimaryVideo = [...activeVideos.values()][0];
+          resolve();
+        }
+        await new Promise((resolve) => setTimeout(resolve, 200));
       }
-      await new Promise((resolve) => setTimeout(resolve, 1000));
-    }
-  });
+    });
+  }
   return {
     get: () =>
       foundOne.then(() => {