Request the next event with some extra time

Author: dmitrylyzo

src/subtitles-octopus.js

@@ -56,6 +56,7 @@ var SubtitlesOctopus = function (options) {
         iteration: 0,
         renderRequested: false,
         requestNextTimestamp: -1,
+        requestOffset: 0,
         prevWidth: null,
         prevHeight: null
     }
@@ -207,6 +208,7 @@ var SubtitlesOctopus = function (options) {
                 self.video.addEventListener("timeupdate", timeupdate, false);
                 self.setCurrentTime(video.currentTime + self.timeOffset);
                 if (self.renderAhead > 0) {
+                    self.oneshotState.requestOffset = 0;
                     _cleanPastRendered(video.currentTime + self.timeOffset, true);
                 }
             }, false);
@@ -380,13 +382,23 @@ var SubtitlesOctopus = function (options) {
         if (!self.video) return;
 
         var currentTime = self.video.currentTime + self.timeOffset;
+        var nextTime = currentTime + self.oneshotState.requestOffset;
+
+        // request the next event with some extra time, because we won't get it instantly
+        self.oneshotState.requestOffset = self.video.playbackRate / self.targetFps;
+
         var eventToShow = null;
         var finishTime = -1, animated = false;
         for (var i = 0, len = self.renderedItems.length; i < len; i++) {
             var item = self.renderedItems[i];
+
             // we need the last started event
             if (item.eventStart <= currentTime) {
                 eventToShow = item;
+            }
+
+            // we need to find a series of events from the request time
+            if (item.eventStart <= nextTime) {
                 finishTime = item.emptyFinish;
             } else if (finishTime >= 0) {
                 // we've already found a known event, now find
@@ -405,11 +417,13 @@ var SubtitlesOctopus = function (options) {
             _renderSubtitleEvent(eventToShow, currentTime);
 
             if (_cleanPastRendered(currentTime) && finishTime >= 0) {
-                tryRequestOneshot(finishTime, animated);
+                // request the next event from the most distant time (the next frame or the end of events in the series)
+                nextTime = Math.max(finishTime, nextTime);
+                tryRequestOneshot(nextTime, nextTime === finishTime ? animated : true);
             }
-        } else if (Math.abs(self.oneshotState.requestNextTimestamp - currentTime) > EVENTTIME_ULP) {
+        } else if (Math.abs(self.oneshotState.requestNextTimestamp - nextTime) > EVENTTIME_ULP) {
             _cleanPastRendered(currentTime);
-            tryRequestOneshot(currentTime, true);
+            tryRequestOneshot(nextTime, true);
         }
     }
 
@@ -831,6 +845,8 @@ var SubtitlesOctopus = function (options) {
     self.render = self.setCurrentTime;
 
     self.setIsPaused = function (isPaused, currentTime) {
+        self.oneshotState.requestOffset = 0;
+
         self.worker.postMessage({
             target: 'video',
             isPaused: isPaused,