Add additional logic to InsufficientBufferRule.js

Dash-Industry-Forum · Jul 10, 2021 · f3aa47a · f3aa47a
1 parent 86d151f
commit f3aa47a
Showing 1 changed file with 42 additions and 22 deletions.
diff --git a/src/streaming/rules/abr/InsufficientBufferRule.js b/src/streaming/rules/abr/InsufficientBufferRule.js
@@ -40,6 +40,7 @@ import MediaPlayerEvents from '../../MediaPlayerEvents';
 function InsufficientBufferRule(config) {
 
     config = config || {};
+    const INSUFFICIENT_BUFFER_SAFETY_FACTOR = 0.5;
     const SEGMENT_IGNORE_COUNT = 2;
 
     const context = this.context;
@@ -77,29 +78,48 @@ function InsufficientBufferRule(config) {
     function getMaxIndex(rulesContext) {
         const switchRequest = SwitchRequest(context).create();
 
-        if (!rulesContext || !rulesContext.hasOwnProperty('getMediaType')) {
-            return switchRequest;
-        }
+        try {
 
-        checkConfig();
+            if (!rulesContext || !rulesContext.hasOwnProperty('getMediaType')) {
+                return switchRequest;
+            }
 
-        const mediaType = rulesContext.getMediaType();
-        const currentBufferState = dashMetrics.getCurrentBufferState(mediaType);
-        const representationInfo = rulesContext.getRepresentationInfo();
-        const fragmentDuration = representationInfo.fragmentDuration;
+            checkConfig();
 
-        // Don't ask for a bitrate change if there is not info about buffer state or if fragmentDuration is not defined
-        if (shouldIgnore(mediaType) || !fragmentDuration) {
-            return switchRequest;
-        }
+            const mediaType = rulesContext.getMediaType();
+            const currentBufferState = dashMetrics.getCurrentBufferState(mediaType);
+            const representationInfo = rulesContext.getRepresentationInfo();
+            const fragmentDuration = representationInfo.fragmentDuration;
+            const streamInfo = rulesContext.getStreamInfo();
+            const streamId = streamInfo ? streamInfo.id : null;
 
-        if (currentBufferState && currentBufferState.state === MetricsConstants.BUFFER_EMPTY) {
-            logger.debug('[' + mediaType + '] Switch to index 0; buffer is empty.');
-            switchRequest.quality = 0;
-            switchRequest.reason = 'InsufficientBufferRule: Buffer is empty';
-        }
+            // Don't ask for a bitrate change if there is not info about buffer state or if fragmentDuration is not defined
+            if (shouldIgnore(mediaType) || !fragmentDuration) {
+                return switchRequest;
+            }
+
+            if (currentBufferState && currentBufferState.state === MetricsConstants.BUFFER_EMPTY) {
+                logger.debug('[' + mediaType + '] Switch to index 0; buffer is empty.');
+                switchRequest.quality = 0;
+                switchRequest.reason = 'InsufficientBufferRule: Buffer is empty';
+            } else {
+                const mediaInfo = rulesContext.getMediaInfo();
+                const abrController = rulesContext.getAbrController();
+                const throughputHistory = abrController.getThroughputHistory();
+
+                const bufferLevel = dashMetrics.getCurrentBufferLevel(mediaType);
+                const throughput = throughputHistory.getAverageThroughput(mediaType);
+                const latency = throughputHistory.getAverageLatency(mediaType);
+                const bitrate = throughput * (bufferLevel / fragmentDuration) * INSUFFICIENT_BUFFER_SAFETY_FACTOR;
+
+                switchRequest.quality = abrController.getQualityForBitrate(mediaInfo, bitrate, streamId, latency);
+                switchRequest.reason = 'InsufficientBufferRule: being conservative to avoid immediate rebuffering';
+            }
 
-        return switchRequest;
+            return switchRequest;
+        } catch (e) {
+            return switchRequest;
+        }
     }
 
     function shouldIgnore(mediaType) {
@@ -108,8 +128,8 @@ function InsufficientBufferRule(config) {
 
     function resetInitialSettings() {
         bufferStateDict = {};
-        bufferStateDict[Constants.VIDEO] = {ignoreCount: SEGMENT_IGNORE_COUNT};
-        bufferStateDict[Constants.AUDIO] = {ignoreCount: SEGMENT_IGNORE_COUNT};
+        bufferStateDict[Constants.VIDEO] = { ignoreCount: SEGMENT_IGNORE_COUNT };
+        bufferStateDict[Constants.AUDIO] = { ignoreCount: SEGMENT_IGNORE_COUNT };
     }
 
     function _onPlaybackSeeking() {
@@ -131,8 +151,8 @@ function InsufficientBufferRule(config) {
     }
 
     instance = {
-        getMaxIndex: getMaxIndex,
-        reset: reset
+        getMaxIndex,
+        reset
     };
 
     setup();