Fix a bug that lead to playback stalling when bufferToKeep is larger …

…than bufferTimeAtTopQuality (#4488)

src/streaming/controllers/BufferController.js

@@ -587,7 +587,7 @@ function BufferController(config) {
             return clearRanges;
         }
 
-        // if no target time is provided we clear everyhing
+        // if no target time is provided we clear everything
         if ((!seekTime && seekTime !== 0) || isNaN(seekTime)) {
             clearRanges.push({
                 start: ranges.start(0),
@@ -597,7 +597,6 @@ function BufferController(config) {
 
         // otherwise we need to calculate the correct pruning range
         else {
-
             const behindPruningRange = _getRangeBehindForPruning(seekTime, ranges);
             const aheadPruningRange = _getRangeAheadForPruning(seekTime, ranges);
 
@@ -926,6 +925,7 @@ function BufferController(config) {
     function clearBuffers(ranges) {
         return new Promise((resolve, reject) => {
             if (!ranges || !sourceBufferSink || ranges.length === 0) {
+                _updateBufferLevel();
                 resolve();
                 return;
             }

test/functional/adapter/DashJsAdapter.js

@@ -595,6 +595,33 @@ class DashJsAdapter {
             delayPollInterval = setInterval(_checkDelay, 100);
         })
     }
+
+    async reachedTargetForwardBuffer(timeoutValue, targetBuffer, tolerance) {
+        return new Promise((resolve) => {
+            let timeout = null;
+            let delayPollInterval = null;
+
+            const _onComplete = (res) => {
+                clearTimeout(timeout);
+                clearInterval(delayPollInterval);
+                delayPollInterval = null;
+                timeout = null;
+                resolve(res);
+            }
+            const _onTimeout = () => {
+                _onComplete(false);
+            }
+
+            const _checkBuffer = () => {
+                const buffer = this.getBufferLengthByType();
+                if (buffer >= targetBuffer) {
+                    _onComplete(true);
+                }
+            };
+            timeout = setTimeout(_onTimeout, timeoutValue);
+            delayPollInterval = setInterval(_checkBuffer, 100);
+        })
+    }
 }
 
 export default DashJsAdapter;

test/functional/src/Constants.js

@@ -32,6 +32,7 @@ const TEST_TIMEOUT_THRESHOLDS = {
     EVENT_WAITING_TIME: 10000,
     BUFFER_CLEANUP: 45000,
     TARGET_DELAY_REACHED: 20000,
+    TARGET_BUFFER_REACHED: 20000,
     ENDED_EVENT_OFFSET: 2000,
     IS_FINISHED_OFFSET_TO_DURATION: 5000
 };
@@ -91,6 +92,10 @@ const TEST_INPUTS = {
     ATTACH_WITH_POSIX: {
         DELAY: 30,
         TOLERANCE: 5
+    },
+    BUFFER_TO_KEEP_SEEK: {
+        TOLERANCE: 1,
+        SEEK_OFFSET: 40
     }
 };
 
@@ -134,6 +139,7 @@ TESTCASES.AUDIO.SWITCH = TESTCASES.CATEGORIES.AUDIO + 'switch-audio';
 TESTCASES.BUFFER.CLEANUP = TESTCASES.CATEGORIES.BUFFER + 'buffer-cleanup';
 TESTCASES.BUFFER.INITIAL_TARGET = TESTCASES.CATEGORIES.BUFFER + 'initial-buffer-target';
 TESTCASES.BUFFER.TARGET = TESTCASES.CATEGORIES.BUFFER + 'buffer-target';
+TESTCASES.BUFFER.TO_KEEP_SEEK = TESTCASES.CATEGORIES.BUFFER + 'buffer-to-keep-seek';
 
 TESTCASES.FEATURE_SUPPORT.EMSG_TRIGGERED = TESTCASES.CATEGORIES.FEATURE_SUPPORT + 'emsg-triggered';
 TESTCASES.FEATURE_SUPPORT.MPD_PATCHING = TESTCASES.CATEGORIES.FEATURE_SUPPORT + 'mpd-patching';

test/functional/test/buffer/buffer-to-keep-seek.js

@@ -0,0 +1,88 @@
+/**
+ * This test checks if playback resumes after a seek in case bufferToKeep is larger than bufferTimeAtTopQuality
+ */
+import Constants from '../../src/Constants.js';
+import {
+    checkIsNotProgressing,
+    checkIsPlaying,
+    checkIsProgressing,
+    checkNoCriticalErrors, checkTimeWithinThresholdForDvrWindow,
+    initializeDashJsAdapter,
+    reachedTargetForwardBuffer
+} from '../common/common.js';
+
+const TESTCASE = Constants.TESTCASES.BUFFER.TO_KEEP_SEEK;
+
+const item = {
+    url: 'https://dash.akamaized.net/akamai/bbb_30fps/bbb_30fps.mpd',
+    type: 'vod',
+    name: 'Segment Template BBB'
+}
+
+const mpd = item.url;
+describe(`${TESTCASE} - ${item.name} - ${mpd}`, () => {
+
+    let playerAdapter;
+    const TARGET_BUFFER = 10;
+    const BUFFER_TO_KEEP = TARGET_BUFFER + 100
+
+    before(() => {
+        const settings = {
+            streaming: {
+                buffer: {
+                    bufferTimeDefault: TARGET_BUFFER,
+                    bufferTimeAtTopQuality: TARGET_BUFFER,
+                    bufferTimeAtTopQualityLongForm: TARGET_BUFFER,
+                    longFormContentDurationThreshold: 6000,
+                    bufferToKeep: BUFFER_TO_KEEP,
+                    bufferPruningInterval: 10,
+                },
+            }
+        }
+        playerAdapter = initializeDashJsAdapter(item, mpd, settings);
+    })
+
+    after(() => {
+        playerAdapter.destroy();
+    })
+
+    it(`Checking playing state`, async () => {
+        await checkIsPlaying(playerAdapter, true);
+    })
+
+    it(`Checking progressing state`, async () => {
+        await checkIsProgressing(playerAdapter);
+    });
+
+    it(`Pause the playback`, async () => {
+        playerAdapter.pause();
+        await checkIsPlaying(playerAdapter, false);
+        await checkIsNotProgressing(playerAdapter);
+    });
+
+    it(`Wait for forward buffer to be filled`, async () => {
+        await reachedTargetForwardBuffer(playerAdapter, TARGET_BUFFER, Constants.TEST_INPUTS.BUFFER_TO_KEEP_SEEK.TOLERANCE);
+    });
+
+    it(`Seek to an unbuffered range`, () => {
+        const bufferEnd = playerAdapter.getBufferLengthByType() + playerAdapter.getCurrentTime();
+        const targetTime = Math.min(bufferEnd + Constants.TEST_INPUTS.BUFFER_TO_KEEP_SEEK.SEEK_OFFSET, playerAdapter.getDuration() - 10);
+        playerAdapter.seek(targetTime);
+
+        checkTimeWithinThresholdForDvrWindow(playerAdapter, targetTime, Constants.TEST_INPUTS.GENERAL.MAXIMUM_ALLOWED_SEEK_DIFFERENCE);
+    });
+
+    it(`Resume playback`, async () => {
+        playerAdapter.play()
+        await checkIsPlaying(playerAdapter, true);
+    })
+
+    it(`Checking progressing state`, async () => {
+        await checkIsProgressing(playerAdapter);
+    });
+
+    it(`Expect no critical errors to be thrown`, () => {
+        checkNoCriticalErrors(playerAdapter);
+    })
+})
+

test/functional/test/buffer/initial-buffer-target.js

@@ -1,4 +1,3 @@
-import DashJsAdapter from '../../adapter/DashJsAdapter.js';
 import Constants from '../../src/Constants.js';
 import Utils from '../../src/Utils.js';
 import {expect} from 'chai'

test/functional/test/common/common.js

@@ -27,6 +27,11 @@ export async function checkForEndedEvent(playerAdapter) {
     expect(ended).to.be.true;
 }
 
+export async function reachedTargetForwardBuffer(playerAdapter, targetBuffer, tolerance) {
+    const reachedBuffer = await playerAdapter.reachedTargetForwardBuffer(Constants.TEST_TIMEOUT_THRESHOLDS.TARGET_BUFFER_REACHED, targetBuffer, tolerance);
+    expect(reachedBuffer).to.be.true;
+}
+
 export function checkLiveDelay(playerAdapter, lowerThreshold, upperThreshold) {
     const liveDelay = playerAdapter.getCurrentLiveLatency();
     expect(liveDelay).to.be.at.least(lowerThreshold);