From 44035d414e773f48bd675142cc6074b341b933a8 Mon Sep 17 00:00:00 2001 From: thalka Date: Fri, 17 Jul 2020 15:02:00 +0200 Subject: [PATCH 1/6] Learn2Adapt Low Latency bitrate adaptation algo --- samples/low-latency/L2ALL_index.html | 286 +++++++++++++++++++ src/streaming/rules/abr/L2ARule.js | 409 +++++++++++++++++++++++++++ 2 files changed, 695 insertions(+) create mode 100644 samples/low-latency/L2ALL_index.html create mode 100644 src/streaming/rules/abr/L2ARule.js diff --git a/samples/low-latency/L2ALL_index.html b/samples/low-latency/L2ALL_index.html new file mode 100644 index 0000000000..2fc0fc64d2 --- /dev/null +++ b/samples/low-latency/L2ALL_index.html @@ -0,0 +1,286 @@ + + + + + Low latency live stream instantiation example + + + + + + + + + + + + + + +
+
+ +
+
+
+
+ Configurable parameters +

Target Latency (secs):

+

Min. drift (secs):

+

Catch-up playback rate (%):

+ +
+
+
+
+
+ Current values +
    +
  • Latency:
    • +
  • Min. drift:
    • +
  • Playback rate:
    • +
  • Buffer:
    • +
  • Quality:
    • +
+
+
+
+
+ +

Concepts definition

+
+
+

Latency

+

Lowering this value will lower latency but may decrease the player's ability to build a stable buffer.

+

setLiveDelay() doc

+
+ +
+

Min. drift

+

Minimum latency deviation allowed before activating catch-up mechanism.

+

setLowLatencyMinDrift() doc

+
+ +
+

Catch-up playback rate

+

Maximum catch-up rate, as a percentage, for low latency live streams.

+

setCatchUpPlaybackRate() doc

+
+
+
+ + + + + + diff --git a/src/streaming/rules/abr/L2ARule.js b/src/streaming/rules/abr/L2ARule.js new file mode 100644 index 0000000000..7376163e09 --- /dev/null +++ b/src/streaming/rules/abr/L2ARule.js @@ -0,0 +1,409 @@ + +/** + * The copyright in this software is being made available under the BSD License, + * included below. This software may be subject to other third party and contributor + * rights, including patent rights, and no such rights are granted under this license. + * + * Copyright (c) 2020, Unified Streaming. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without modification, + * are permitted provided that the following conditions are met: + * * Redistributions of source code must retain the above copyright notice, this + * list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation and/or + * other materials provided with the distribution. + * * Neither the name of Dash Industry Forum nor the names of its + * contributors may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS AS IS AND ANY + * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, + * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, + * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +// For a description of the Learn2Adapt-LowLatency (L2A-LL) bitrate adaptation algorithm, see https://github.com/unifiedstreaming/Learn2Adapt-LowLatency/blob/master/Online_learning_for_bitrate_adaptation_in_low_latency_live_streaming_CR.pdf + +import MetricsConstants from '../../constants/MetricsConstants'; +import SwitchRequest from '../SwitchRequest'; +import FactoryMaker from '../../../core/FactoryMaker'; +import { HTTPRequest } from '../../vo/metrics/HTTPRequest'; +import EventBus from '../../../core/EventBus'; +import Events from '../../../core/events/Events'; +import Debug from '../../../core/Debug'; + +// L2A_STATE_ONE_BITRATE : If there is only one bitrate (or initialization failed), always return NO_CHANGE. +// L2A_STATE_STARTUP : Set placeholder buffer such that we download fragments at most recently measured throughput. +// L2A_STATE_STEADY : Buffer primed, we switch to steady operation. +const L2A_STATE_ONE_BITRATE = 0; +const L2A_STATE_STARTUP = 1; +const L2A_STATE_STEADY = 2; + + +let w = [];//Vector of probabilities associated with bitrate decisions +let prev_w = [];//Vector of probabilities associated with bitrate decisions calculated in the previous step +let Q=0;//Initialization of Lagrangian multiplier (This keeps track of the buffer displacement) +let segment_request_start_s=0; +let segment_download_finish_s=0; +let B_target=1.5;//Target buffer level + + + +function L2ARule(config) { + + config = config || {}; + const context = this.context; + + const dashMetrics = config.dashMetrics; + const eventBus = EventBus(context).getInstance(); + + let instance, + logger, + L2AStateDict; + + function setup() { + logger = Debug(context).getInstance().getLogger(instance); + resetInitialSettings(); + + eventBus.on(Events.PLAYBACK_SEEKING, onPlaybackSeeking, instance); + eventBus.on(Events.MEDIA_FRAGMENT_LOADED, onMediaFragmentLoaded, instance); + eventBus.on(Events.METRIC_ADDED, onMetricAdded, instance); + eventBus.on(Events.QUALITY_CHANGE_REQUESTED, onQualityChangeRequested, instance); + } + + function getInitialL2AState(rulesContext) { + const initialState = {}; + const mediaInfo = rulesContext.getMediaInfo(); + const bitrates = mediaInfo.bitrateList.map(b => b.bandwidth)/1000; + initialState.state = L2A_STATE_STARTUP; + initialState.bitrates = bitrates; + initialState.lastQuality = 0; + clearL2AStateOnSeek(initialState); + return initialState; + } + + function clearL2AStateOnSeek(L2AState) { + L2AState.placeholderBuffer = 0; + L2AState.mostAdvancedSegmentStart = NaN; + L2AState.lastSegmentWasReplacement = false; + L2AState.lastSegmentStart = NaN; + L2AState.lastSegmentDurationS = NaN; + L2AState.lastSegmentRequestTimeMs = NaN; + L2AState.lastSegmentFinishTimeMs = NaN; + } + + function getL2AState(rulesContext) { + const mediaType = rulesContext.getMediaType(); + let L2AState = L2AStateDict[mediaType]; + if (!L2AState) { + L2AState = getInitialL2AState(rulesContext); + L2AStateDict[mediaType] = L2AState; + } + return L2AState; + } + + function onPlaybackSeeking() { + for (const mediaType in L2AStateDict) { + if (L2AStateDict.hasOwnProperty(mediaType)) { + const L2AState = L2AStateDict[mediaType]; + if (L2AState.state !== L2A_STATE_ONE_BITRATE) { + L2AState.state = L2A_STATE_STARTUP; + clearL2AStateOnSeek(L2AState); + } + } + } + } + + function onMediaFragmentLoaded(e) { + if (e && e.chunk && e.chunk.mediaInfo) { + const L2AState = L2AStateDict[e.chunk.mediaInfo.type]; + if (L2AState && L2AState.state !== L2A_STATE_ONE_BITRATE) { + const start = e.chunk.start; + if (isNaN(L2AState.mostAdvancedSegmentStart) || start > L2AState.mostAdvancedSegmentStart) { + L2AState.mostAdvancedSegmentStart = start; + L2AState.lastSegmentWasReplacement = false; + } else { + L2AState.lastSegmentWasReplacement = true; + } + + L2AState.lastSegmentStart = start; + L2AState.lastSegmentDurationS = e.chunk.duration; + L2AState.lastQuality = e.chunk.quality; + + checkNewSegment(L2AState, e.chunk.mediaInfo.type); + } + } + } + + function onMetricAdded(e) { + if (e && e.metric === MetricsConstants.HTTP_REQUEST && e.value && e.value.type === HTTPRequest.MEDIA_SEGMENT_TYPE && e.value.trace && e.value.trace.length) { + const L2AState = L2AStateDict[e.mediaType]; + if (L2AState && L2AState.state !== L2A_STATE_ONE_BITRATE) { + L2AState.lastSegmentRequestTimeMs = e.value.trequest.getTime(); + L2AState.lastSegmentFinishTimeMs = e.value._tfinish.getTime(); + + checkNewSegment(L2AState, e.mediaType); + } + } + } + + function checkNewSegment(L2AState, mediaType) { + if (!isNaN(L2AState.lastSegmentStart) && !isNaN(L2AState.lastSegmentRequestTimeMs)){ + + segment_request_start_s=0.001*L2AState.lastSegmentRequestTimeMs; + segment_download_finish_s=0.001*L2AState.lastSegmentFinishTimeMs; + L2AState.lastSegmentStart = NaN; + L2AState.lastSegmentRequestTimeMs = NaN; + } + } + + function onQualityChangeRequested(e) { + // Useful to store change requests when abandoning a download. + if (e) { + const L2AState = L2AStateDict[e.mediaType]; + if (L2AState && L2AState.state !== L2A_STATE_ONE_BITRATE) { + L2AState.abrQuality = e.newQuality; + } + } + } + + function indexOfMin(arr) { + // Calculates teh index of the minimum value of an array + if (arr.length === 0) { + return -1; + } + var min = arr[0]; + var minIndex = 0; + for (var i = 0; i < arr.length; i++) { + if (arr[i] <= min) { + minIndex = i; + min = arr[i]; + } + } + return minIndex; + } + + function dotmultiplication(arr1,arr2) { + // Dot multiplication of two arrays + if (arr1.length != arr2.length) { + return -1; + } + var sumdot =0; + for (var i = 0; i < arr1.length; i++) { + sumdot=sumdot+arr1[i]*arr2[i]; + } + return sumdot; + } + + function Euclidean_projection(arr) { + //project an n-dim vector y to the simplex Dn + // Dn = { x : x n-dim, 1 >= x >= 0, sum(x) = 1} + //Algorithm is explained at http://arxiv.org/abs/1101.6081 + const m = arr.length + var bget = false; + var arr2=[]; + for (let ii = 0; ii < m; ++ii) { + arr2[ii]=arr[ii]; + } + var s =arr.sort(function(a, b){return b-a}); + var tmpsum = 0; + var tmax = 0; + var x=[]; + for (let ii = 0; ii < m-1; ++ii) { + tmpsum = tmpsum + s[ii]; + tmax = (tmpsum - 1)/(ii+1); + if (tmax >= s[ii+1]){ + bget = true; + break; + } + } + if (!bget){ + tmax = (tmpsum + s[m-1] -1)/m; + } + for (let ii = 0; ii < m; ++ii) { + x[ii] = Math.max(arr2[ii]-tmax,0); + } + return x; + } + + function getMaxIndex(rulesContext) { + const switchRequest = SwitchRequest(context).create(); + const horizon=8//Optimization horizon + const VL = Math.pow(horizon,0.2);//Cautiousness parameter + const alpha =Math.max(Math.pow(horizon,0.7),VL*Math.sqrt(horizon));//Step size + let diff1=[]//Used to calculate the difference between consecutive decisions (w-w_prev) + const mediaInfo = rulesContext.getMediaInfo(); + const mediaType = rulesContext.getMediaType(); + const bitrates = mediaInfo.bitrateList.map(b => b.bandwidth); + const bitrateCount = bitrates.length; + const scheduleController = rulesContext.getScheduleController(); + const streamInfo = rulesContext.getStreamInfo(); + const abrController = rulesContext.getAbrController(); + const throughputHistory = abrController.getThroughputHistory(); + const isDynamic = streamInfo && streamInfo.manifestInfo && streamInfo.manifestInfo.isDynamic; + const useL2AABR = rulesContext.useL2AABR(); + const bufferLevel = dashMetrics.getCurrentBufferLevel(mediaType, true); + const safeThroughput = throughputHistory.getSafeAverageThroughput(mediaType, isDynamic); + const throughput = throughputHistory.getAverageThroughput(mediaType, isDynamic); + const c_throughput=throughput/1000;//Throughput in Mbps + const react=20;///Reactiveness to throughput drops + const latency = throughputHistory.getAverageLatency(mediaType); + let quality; + + if (!rulesContext || !rulesContext.hasOwnProperty('getMediaInfo') || !rulesContext.hasOwnProperty('getMediaType') || + !rulesContext.hasOwnProperty('getScheduleController') || !rulesContext.hasOwnProperty('getStreamInfo') || + !rulesContext.hasOwnProperty('getAbrController') || !rulesContext.hasOwnProperty('useL2AABR')) { + console.log(!rulesContext.hasOwnProperty('useL2AABR')) + return switchRequest; + } + + switchRequest.reason = switchRequest.reason || {}; + + if (!useL2AABR) { + return switchRequest; + } + + scheduleController.setTimeToLoadDelay(0); + + const L2AState = getL2AState(rulesContext); + + if (L2AState.state === L2A_STATE_ONE_BITRATE) { + // shouldn't even have been called + return switchRequest; + } + + switchRequest.reason.state = L2AState.state; + switchRequest.reason.throughput = throughput; + switchRequest.reason.latency = latency; + + if (isNaN(throughput)) { + // still starting up - not enough information + return switchRequest; + } + + switch (L2AState.state) { + case L2A_STATE_STARTUP: + quality = abrController.getQualityForBitrate(mediaInfo, safeThroughput, latency); + + switchRequest.quality = quality; + switchRequest.reason.throughput = safeThroughput; + + L2AState.lastQuality = quality; + + if (!isNaN(L2AState.lastSegmentDurationS) && bufferLevel >= L2AState.lastSegmentDurationS) { + L2AState.state = L2A_STATE_STEADY; + } + + break; // L2A_STATE_STARTUP + + case L2A_STATE_STEADY: + + + ///////////////////////////////////////////////////////// + + //Main adaptation logic of L2A-LL + let V=L2AState.lastSegmentDurationS; + //const cc_throughput=(bitrates[L2AState.lastQuality]*V/(segment_download_finish_s-segment_request_start_s))/(1000*1000); + //console.log('Computed throughput:',cc_throughput); + + if (w.length==0){//Initialization of w and w_prev + Q=0; + for (let i = 0; i < bitrateCount; ++i) { + if (i==0){ + w[i]=0.33; + prev_w[i]=1 + } + else{ + w[i]=0.33; + prev_w[i]=0; + } + } + } + + for (let i = 0; i < bitrateCount; ++i) { + bitrates[i]=bitrates[i]/(1000*1000); //Bitrates in Mbps + w[i]=prev_w[i]-(1/(2*alpha))*(V*bitrates[i])*((Q-VL)/Math.min(2*bitrates[bitrateCount-1],c_throughput)); //Lagrangian descent + diff1[i]=w[i]-prev_w[i]; + } + + w=Euclidean_projection(w); + + if (bitrates[L2AState.lastQuality]>((bitrates[L2AState.lastQuality]*V/(segment_download_finish_s-segment_request_start_s)))){if (Q=VL){Q=0;}}////********* changed + + Q=Math.max(0,Q+V*dotmultiplication(bitrates,prev_w)/Math.min(2*bitrates[bitrateCount-1],c_throughput)-(react/2)*V+V*(dotmultiplication(bitrates,diff1)/Math.min(2*bitrates[bitrateCount-1],c_throughput))); + + let temp=[]; + + for (let i = 0; i < bitrateCount; ++i) { + prev_w[i]=w[i]; + temp[i]=Math.abs(bitrates[i]-dotmultiplication(w,bitrates)); + } + + //// Quality is calculated as argmin of the aboslute differnce between available bitrates (bitrates[i]) and bitrate estimation (dotmultiplication(w,bitrates)). We employ a stepwise ascent/descent + + if (indexOfMin(temp)>L2AState.lastQuality){quality=L2AState.lastQuality+1;} + else if(indexOfMin(temp)=c_throughput)&&(bufferLevel Date: Fri, 17 Jul 2020 16:56:55 +0200 Subject: [PATCH 2/6] Definition of L2ARule in ABRRules --- src/streaming/controllers/AbrController.js | 44 ++++++++++++------- src/streaming/rules/RulesContext.js | 7 ++- src/streaming/rules/abr/ABRRulesCollection.js | 12 +++++ 3 files changed, 47 insertions(+), 16 deletions(-) diff --git a/src/streaming/controllers/AbrController.js b/src/streaming/controllers/AbrController.js index a2099d7cf7..6a9e84615c 100644 --- a/src/streaming/controllers/AbrController.js +++ b/src/streaming/controllers/AbrController.js @@ -77,6 +77,7 @@ function AbrController() { droppedFramesHistory, throughputHistory, isUsingBufferOccupancyABRDict, + isUsingL2AABRDict, dashMetrics, settings; @@ -91,6 +92,7 @@ function AbrController() { abandonmentStateDict[type] = abandonmentStateDict[type] || {}; abandonmentStateDict[type].state = MetricsConstants.ALLOW_LOAD; isUsingBufferOccupancyABRDict[type] = false; + isUsingL2AABRDict[type] = false; eventBus.on(Events.LOADING_PROGRESS, onFragmentLoadProgress, this); if (type == Constants.VIDEO) { eventBus.on(Events.QUALITY_CHANGE_RENDERED, onQualityChangeRendered, this); @@ -126,6 +128,7 @@ function AbrController() { streamProcessorDict = {}; switchHistoryDict = {}; isUsingBufferOccupancyABRDict = {}; + isUsingL2AABRDict = {}; if (windowResizeEventCalled === undefined) { windowResizeEventCalled = false; } @@ -308,7 +311,9 @@ function AbrController() { currentValue: oldQuality, switchHistory: switchHistoryDict[type], droppedFramesHistory: droppedFramesHistory, - useBufferOccupancyABR: useBufferOccupancyABR(type) + useBufferOccupancyABR: useBufferOccupancyABR(type), + useL2AABR: useL2AABR(type) + }); if (droppedFramesHistory) { @@ -336,7 +341,7 @@ function AbrController() { changeQuality(type, oldQuality, newQuality, topQualityIdx, switchRequest.reason); } } else if (settings.get().debug.logLevel === Debug.LOG_LEVEL_DEBUG) { - const bufferLevel = dashMetrics.getCurrentBufferLevel(type); + const bufferLevel = dashMetrics.getCurrentBufferLevel(type, true); logger.debug('[' + type + '] stay on ' + oldQuality + '/' + topQualityIdx + ' (buffer: ' + bufferLevel + ')'); } } @@ -360,7 +365,7 @@ function AbrController() { const streamInfo = streamProcessorDict[type].getStreamInfo(); const id = streamInfo ? streamInfo.id : null; if (settings.get().debug.logLevel === Debug.LOG_LEVEL_DEBUG) { - const bufferLevel = dashMetrics.getCurrentBufferLevel(type); + const bufferLevel = dashMetrics.getCurrentBufferLevel(type, true); logger.info('[' + type + '] switch from ' + oldQuality + ' to ' + newQuality + '/' + topQualityIdx + ' (buffer: ' + bufferLevel + ') ' + (reason ? JSON.stringify(reason) : '.')); } setQualityFor(type, id, newQuality); @@ -442,16 +447,23 @@ function AbrController() { function updateIsUsingBufferOccupancyABR(mediaType, bufferLevel) { const strategy = settings.get().streaming.abr.ABRStrategy; - - if (strategy === Constants.ABR_STRATEGY_BOLA) { + if (strategy === Constants.ABR_STRATEGY_L2A) { + isUsingBufferOccupancyABRDict[mediaType] = true; + isUsingL2AABRDict[mediaType] = true; + return; + } + else if (strategy === Constants.ABR_STRATEGY_BOLA) { isUsingBufferOccupancyABRDict[mediaType] = true; + isUsingL2AABRDict[mediaType] = false; + return; } else if (strategy === Constants.ABR_STRATEGY_THROUGHPUT) { isUsingBufferOccupancyABRDict[mediaType] = false; + isUsingL2AABRDict[mediaType] = false; return; } // else ABR_STRATEGY_DYNAMIC - + console.log(strategy); const stableBufferTime = mediaPlayerModel.getStableBufferTime(); const switchOnThreshold = stableBufferTime; const switchOffThreshold = 0.5 * stableBufferTime; @@ -472,21 +484,22 @@ function AbrController() { function useBufferOccupancyABR(mediaType) { return isUsingBufferOccupancyABRDict[mediaType]; } + function useL2AABR(mediaType) { + return isUsingL2AABRDict[mediaType]; + } function getThroughputHistory() { return throughputHistory; } function updateTopQualityIndex(mediaInfo) { - if (mediaInfo) { - const type = mediaInfo.type; - const streamId = mediaInfo.streamInfo.id; - const max = mediaInfo.representationCount - 1; + const type = mediaInfo.type; + const streamId = mediaInfo.streamInfo.id; + const max = mediaInfo.representationCount - 1; - setTopQualityIndex(type, streamId, max); + setTopQualityIndex(type, streamId, max); - return max; - } + return max; } function isPlayingAtTopQuality(streamInfo) { @@ -612,7 +625,8 @@ function AbrController() { abrController: instance, streamProcessor: streamProcessor, currentRequest: e.request, - useBufferOccupancyABR: useBufferOccupancyABR(type) + useBufferOccupancyABR: useBufferOccupancyABR(type), + useL2AABR: useL2AABR(type) }); const switchRequest = abrRulesCollection.shouldAbandonFragment(rulesContext); @@ -670,4 +684,4 @@ AbrController.__dashjs_factory_name = 'AbrController'; const factory = FactoryMaker.getSingletonFactory(AbrController); factory.QUALITY_DEFAULT = QUALITY_DEFAULT; FactoryMaker.updateSingletonFactory(AbrController.__dashjs_factory_name, factory); -export default factory; +export default factory; \ No newline at end of file diff --git a/src/streaming/rules/RulesContext.js b/src/streaming/rules/RulesContext.js index 7987a55bd9..5001081bdb 100644 --- a/src/streaming/rules/RulesContext.js +++ b/src/streaming/rules/RulesContext.js @@ -40,6 +40,7 @@ function RulesContext(config) { const droppedFramesHistory = config.droppedFramesHistory; const currentRequest = config.currentRequest; const bufferOccupancyABR = config.useBufferOccupancyABR; + const L2AABR = config.useL2AABR; const scheduleController = config.streamProcessor ? config.streamProcessor.getScheduleController() : null; const representationInfo = config.streamProcessor ? config.streamProcessor.getRepresentationInfo() : null; @@ -84,6 +85,9 @@ function RulesContext(config) { function useBufferOccupancyABR() { return bufferOccupancyABR; } + function useL2AABR() { + return L2AABR; + } instance = { getMediaType: getMediaType, @@ -95,7 +99,8 @@ function RulesContext(config) { getScheduleController: getScheduleController, getAbrController: getAbrController, getRepresentationInfo: getRepresentationInfo, - useBufferOccupancyABR: useBufferOccupancyABR + useBufferOccupancyABR: useBufferOccupancyABR, + useL2AABR: useL2AABR }; return instance; diff --git a/src/streaming/rules/abr/ABRRulesCollection.js b/src/streaming/rules/abr/ABRRulesCollection.js index 4196261405..808e962ce8 100644 --- a/src/streaming/rules/abr/ABRRulesCollection.js +++ b/src/streaming/rules/abr/ABRRulesCollection.js @@ -34,6 +34,7 @@ import AbandonRequestsRule from './AbandonRequestsRule'; import DroppedFramesRule from './DroppedFramesRule'; import SwitchHistoryRule from './SwitchHistoryRule'; import BolaRule from './BolaRule'; +import L2ARule from './L2ARule.js'; import FactoryMaker from '../../../core/FactoryMaker'; import SwitchRequest from '../SwitchRequest'; @@ -67,6 +68,7 @@ function ABRRulesCollection(config) { settings: settings }) ); + qualitySwitchRules.push( ThroughputRule(context).create({ dashMetrics: dashMetrics @@ -91,6 +93,16 @@ function ABRRulesCollection(config) { }) ); } + else if(settings.get().streaming.abr.ABRStrategy=='abrL2A'){ + qualitySwitchRules.push( + L2ARule(context).create({ + dashMetrics: dashMetrics, + mediaPlayerModel: mediaPlayerModel, + settings: settings + }) + ); + + } // add custom ABR rules if any const customRules = mediaPlayerModel.getABRCustomRules(); From dd5e97645a2eedcddd9979e65af9e0ca71ada02b Mon Sep 17 00:00:00 2001 From: thalka Date: Wed, 22 Jul 2020 16:39:15 +0200 Subject: [PATCH 3/6] Update with abrL2A strategy --- src/streaming/constants/Constants.js | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/src/streaming/constants/Constants.js b/src/streaming/constants/Constants.js index c69cd5a817..edafb70bed 100644 --- a/src/streaming/constants/Constants.js +++ b/src/streaming/constants/Constants.js @@ -136,6 +136,13 @@ class Constants { */ this.ABR_STRATEGY_BOLA = 'abrBola'; + /** + * @constant {string} ABR_STRATEGY_L2A Adaptive bitrate algorithm based on Bola (buffer level) + * @memberof Constants# + * @static + */ + this.ABR_STRATEGY_L2A= 'abrL2A'; + /** * @constant {string} ABR_STRATEGY_THROUGHPUT Adaptive bitrate algorithm based on throughput * @memberof Constants# @@ -170,6 +177,7 @@ class Constants { * @static */ this.MISSING_CONFIG_ERROR = 'Missing config parameter(s)'; + this.LOCATION = 'Location'; this.INITIALIZE = 'initialize'; this.TEXT_SHOWING = 'showing'; @@ -179,10 +187,9 @@ class Constants { this.UTF8 = 'utf-8'; this.SCHEME_ID_URI = 'schemeIdUri'; this.START_TIME = 'starttime'; + this.SERVICE_DESCRIPTION_LL_SCHEME = 'urn:dvb:dash:lowlatency:scope:2019'; this.SUPPLEMENTAL_PROPERTY_LL_SCHEME = 'urn:dvb:dash:lowlatency:critical:2019'; - this.XML = 'XML'; - this.ARRAY_BUFFER = 'ArrayBuffer'; } constructor () { From ee8cbfb1df10c404bc1f9dd5851e4f4a1047bf2e Mon Sep 17 00:00:00 2001 From: thalka Date: Wed, 22 Jul 2020 16:49:13 +0200 Subject: [PATCH 4/6] comments --- samples/low-latency/L2ALL_index.html | 21 +++------------------ 1 file changed, 3 insertions(+), 18 deletions(-) diff --git a/samples/low-latency/L2ALL_index.html b/samples/low-latency/L2ALL_index.html index 2fc0fc64d2..082e7305a7 100644 --- a/samples/low-latency/L2ALL_index.html +++ b/samples/low-latency/L2ALL_index.html @@ -2,15 +2,10 @@ - Low latency live stream instantiation example + Low latency live stream instantiation example with local execution - - - - + + + + + + + + + +
+
+ +
+
+
+
+ Configurable parameters +

Target Latency (secs):

+

Min. drift (secs):

+

Catch-up playback rate (%):

+ +
+
+
+
+
+ Current values +
    +
  • Latency:
    • +
  • Min. drift:
    • +
  • Playback rate:
    • +
  • Buffer:
    • +
  • Quality:
    • +
+
+
+
+
+ +

Concepts definition

+
+
+

Latency

+

Lowering this value will lower latency but may decrease the player's ability to build a stable buffer.

+

setLiveDelay() doc

+
+ +
+

Min. drift

+

Minimum latency deviation allowed before activating catch-up mechanism.

+

setLowLatencyMinDrift() doc

+
+ +
+

Catch-up playback rate

+

Maximum catch-up rate, as a percentage, for low latency live streams.

+

setCatchUpPlaybackRate() doc

+
+
+
+ + + + + + diff --git a/src/streaming/constants/Constants.js b/src/streaming/constants/Constants.js index c69cd5a817..489c842b27 100644 --- a/src/streaming/constants/Constants.js +++ b/src/streaming/constants/Constants.js @@ -136,6 +136,13 @@ class Constants { */ this.ABR_STRATEGY_BOLA = 'abrBola'; + /** + * @constant {string} ABR_STRATEGY_L2A Adaptive bitrate algorithm based on L2A (online learning) + * @memberof Constants# + * @static + */ + this.ABR_STRATEGY_L2A = 'abrL2A'; + /** * @constant {string} ABR_STRATEGY_THROUGHPUT Adaptive bitrate algorithm based on throughput * @memberof Constants# @@ -170,6 +177,7 @@ class Constants { * @static */ this.MISSING_CONFIG_ERROR = 'Missing config parameter(s)'; + this.LOCATION = 'Location'; this.INITIALIZE = 'initialize'; this.TEXT_SHOWING = 'showing'; @@ -179,10 +187,9 @@ class Constants { this.UTF8 = 'utf-8'; this.SCHEME_ID_URI = 'schemeIdUri'; this.START_TIME = 'starttime'; + this.SERVICE_DESCRIPTION_LL_SCHEME = 'urn:dvb:dash:lowlatency:scope:2019'; this.SUPPLEMENTAL_PROPERTY_LL_SCHEME = 'urn:dvb:dash:lowlatency:critical:2019'; - this.XML = 'XML'; - this.ARRAY_BUFFER = 'ArrayBuffer'; } constructor () { diff --git a/src/streaming/controllers/AbrController.js b/src/streaming/controllers/AbrController.js index a2099d7cf7..c138fb43be 100644 --- a/src/streaming/controllers/AbrController.js +++ b/src/streaming/controllers/AbrController.js @@ -77,6 +77,7 @@ function AbrController() { droppedFramesHistory, throughputHistory, isUsingBufferOccupancyABRDict, + isUsingL2AABRDict, dashMetrics, settings; @@ -91,6 +92,7 @@ function AbrController() { abandonmentStateDict[type] = abandonmentStateDict[type] || {}; abandonmentStateDict[type].state = MetricsConstants.ALLOW_LOAD; isUsingBufferOccupancyABRDict[type] = false; + isUsingL2AABRDict[type] = false; eventBus.on(Events.LOADING_PROGRESS, onFragmentLoadProgress, this); if (type == Constants.VIDEO) { eventBus.on(Events.QUALITY_CHANGE_RENDERED, onQualityChangeRendered, this); @@ -126,6 +128,7 @@ function AbrController() { streamProcessorDict = {}; switchHistoryDict = {}; isUsingBufferOccupancyABRDict = {}; + isUsingL2AABRDict = {}; if (windowResizeEventCalled === undefined) { windowResizeEventCalled = false; } @@ -308,7 +311,9 @@ function AbrController() { currentValue: oldQuality, switchHistory: switchHistoryDict[type], droppedFramesHistory: droppedFramesHistory, - useBufferOccupancyABR: useBufferOccupancyABR(type) + useBufferOccupancyABR: useBufferOccupancyABR(type), + useL2AABR: useL2AABR(type) + }); if (droppedFramesHistory) { @@ -336,7 +341,7 @@ function AbrController() { changeQuality(type, oldQuality, newQuality, topQualityIdx, switchRequest.reason); } } else if (settings.get().debug.logLevel === Debug.LOG_LEVEL_DEBUG) { - const bufferLevel = dashMetrics.getCurrentBufferLevel(type); + const bufferLevel = dashMetrics.getCurrentBufferLevel(type, true); logger.debug('[' + type + '] stay on ' + oldQuality + '/' + topQualityIdx + ' (buffer: ' + bufferLevel + ')'); } } @@ -360,7 +365,7 @@ function AbrController() { const streamInfo = streamProcessorDict[type].getStreamInfo(); const id = streamInfo ? streamInfo.id : null; if (settings.get().debug.logLevel === Debug.LOG_LEVEL_DEBUG) { - const bufferLevel = dashMetrics.getCurrentBufferLevel(type); + const bufferLevel = dashMetrics.getCurrentBufferLevel(type, true); logger.info('[' + type + '] switch from ' + oldQuality + ' to ' + newQuality + '/' + topQualityIdx + ' (buffer: ' + bufferLevel + ') ' + (reason ? JSON.stringify(reason) : '.')); } setQualityFor(type, id, newQuality); @@ -442,16 +447,21 @@ function AbrController() { function updateIsUsingBufferOccupancyABR(mediaType, bufferLevel) { const strategy = settings.get().streaming.abr.ABRStrategy; - - if (strategy === Constants.ABR_STRATEGY_BOLA) { + if (strategy === Constants.ABR_STRATEGY_L2A) { + isUsingBufferOccupancyABRDict[mediaType] = true; + isUsingL2AABRDict[mediaType] = true; + return; + }else if (strategy === Constants.ABR_STRATEGY_BOLA) { isUsingBufferOccupancyABRDict[mediaType] = true; + isUsingL2AABRDict[mediaType] = false; return; - } else if (strategy === Constants.ABR_STRATEGY_THROUGHPUT) { + }else if (strategy === Constants.ABR_STRATEGY_THROUGHPUT) { isUsingBufferOccupancyABRDict[mediaType] = false; + isUsingL2AABRDict[mediaType] = false; return; } // else ABR_STRATEGY_DYNAMIC - + console.log(strategy); const stableBufferTime = mediaPlayerModel.getStableBufferTime(); const switchOnThreshold = stableBufferTime; const switchOffThreshold = 0.5 * stableBufferTime; @@ -472,21 +482,22 @@ function AbrController() { function useBufferOccupancyABR(mediaType) { return isUsingBufferOccupancyABRDict[mediaType]; } + function useL2AABR(mediaType) { + return isUsingL2AABRDict[mediaType]; + } function getThroughputHistory() { return throughputHistory; } function updateTopQualityIndex(mediaInfo) { - if (mediaInfo) { - const type = mediaInfo.type; - const streamId = mediaInfo.streamInfo.id; - const max = mediaInfo.representationCount - 1; + const type = mediaInfo.type; + const streamId = mediaInfo.streamInfo.id; + const max = mediaInfo.representationCount - 1; - setTopQualityIndex(type, streamId, max); + setTopQualityIndex(type, streamId, max); - return max; - } + return max; } function isPlayingAtTopQuality(streamInfo) { @@ -612,7 +623,8 @@ function AbrController() { abrController: instance, streamProcessor: streamProcessor, currentRequest: e.request, - useBufferOccupancyABR: useBufferOccupancyABR(type) + useBufferOccupancyABR: useBufferOccupancyABR(type), + useL2AABR: useL2AABR(type) }); const switchRequest = abrRulesCollection.shouldAbandonFragment(rulesContext); @@ -670,4 +682,4 @@ AbrController.__dashjs_factory_name = 'AbrController'; const factory = FactoryMaker.getSingletonFactory(AbrController); factory.QUALITY_DEFAULT = QUALITY_DEFAULT; FactoryMaker.updateSingletonFactory(AbrController.__dashjs_factory_name, factory); -export default factory; +export default factory; \ No newline at end of file diff --git a/src/streaming/rules/RulesContext.js b/src/streaming/rules/RulesContext.js index 7987a55bd9..5001081bdb 100644 --- a/src/streaming/rules/RulesContext.js +++ b/src/streaming/rules/RulesContext.js @@ -40,6 +40,7 @@ function RulesContext(config) { const droppedFramesHistory = config.droppedFramesHistory; const currentRequest = config.currentRequest; const bufferOccupancyABR = config.useBufferOccupancyABR; + const L2AABR = config.useL2AABR; const scheduleController = config.streamProcessor ? config.streamProcessor.getScheduleController() : null; const representationInfo = config.streamProcessor ? config.streamProcessor.getRepresentationInfo() : null; @@ -84,6 +85,9 @@ function RulesContext(config) { function useBufferOccupancyABR() { return bufferOccupancyABR; } + function useL2AABR() { + return L2AABR; + } instance = { getMediaType: getMediaType, @@ -95,7 +99,8 @@ function RulesContext(config) { getScheduleController: getScheduleController, getAbrController: getAbrController, getRepresentationInfo: getRepresentationInfo, - useBufferOccupancyABR: useBufferOccupancyABR + useBufferOccupancyABR: useBufferOccupancyABR, + useL2AABR: useL2AABR }; return instance; diff --git a/src/streaming/rules/abr/ABRRulesCollection.js b/src/streaming/rules/abr/ABRRulesCollection.js index 4196261405..20135b889f 100644 --- a/src/streaming/rules/abr/ABRRulesCollection.js +++ b/src/streaming/rules/abr/ABRRulesCollection.js @@ -34,6 +34,7 @@ import AbandonRequestsRule from './AbandonRequestsRule'; import DroppedFramesRule from './DroppedFramesRule'; import SwitchHistoryRule from './SwitchHistoryRule'; import BolaRule from './BolaRule'; +import L2ARule from './L2ARule.js'; import FactoryMaker from '../../../core/FactoryMaker'; import SwitchRequest from '../SwitchRequest'; @@ -91,7 +92,15 @@ function ABRRulesCollection(config) { }) ); } - + else if (settings.get().streaming.abr.ABRStrategy == 'abrL2A') { + qualitySwitchRules.push( + L2ARule(context).create({ + dashMetrics: dashMetrics, + mediaPlayerModel: mediaPlayerModel, + settings: settings + }) + ); + } // add custom ABR rules if any const customRules = mediaPlayerModel.getABRCustomRules(); customRules.forEach(function (rule) { diff --git a/src/streaming/rules/abr/L2ARule.js b/src/streaming/rules/abr/L2ARule.js new file mode 100644 index 0000000000..baad275200 --- /dev/null +++ b/src/streaming/rules/abr/L2ARule.js @@ -0,0 +1,374 @@ + +/** + * The copyright in this software is being made available under the BSD License, + * included below. This software may be subject to other third party and contributor + * rights, including patent rights, and no such rights are granted under this license. + * + * Copyright (c) 2020, Unified Streaming. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without modification, + * are permitted provided that the following conditions are met: + * * Redistributions of source code must retain the above copyright notice, this + * list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation and/or + * other materials provided with the distribution. + * * Neither the name of Dash Industry Forum nor the names of its + * contributors may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS AS IS AND ANY + * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, + * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, + * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +// For a description of the Learn2Adapt-LowLatency (L2A-LL) bitrate adaptation algorithm, see https://github.com/unifiedstreaming/Learn2Adapt-LowLatency/blob/master/Online_learning_for_bitrate_adaptation_in_low_latency_live_streaming_CR.pdf + +import MetricsConstants from '../../constants/MetricsConstants'; +import SwitchRequest from '../SwitchRequest'; +import FactoryMaker from '../../../core/FactoryMaker'; +import { HTTPRequest } from '../../vo/metrics/HTTPRequest'; +import EventBus from '../../../core/EventBus'; +import Events from '../../../core/events/Events'; +import Debug from '../../../core/Debug'; + +// L2A_STATE_ONE_BITRATE : If there is only one bitrate (or initialization failed), always return NO_CHANGE. +// L2A_STATE_STARTUP : Set placeholder buffer such that we download fragments at most recently measured throughput. +// L2A_STATE_STEADY : Buffer primed, we switch to steady operation. +const L2A_STATE_ONE_BITRATE = 0; +const L2A_STATE_STARTUP = 1; +const L2A_STATE_STEADY = 2; + + +let w = [];//Vector of probabilities associated with bitrate decisions +let prev_w = [];//Vector of probabilities associated with bitrate decisions calculated in the previous step +let Q = 0;//Initialization of Lagrangian multiplier (This keeps track of the buffer displacement) +let segment_request_start_s = 0; +let segment_download_finish_s = 0; +let B_target = 1.5;//Target buffer level + + + +function L2ARule(config) { + console.log('Welcome to L2A'); + config = config || {}; + const context = this.context; + + const dashMetrics = config.dashMetrics; + const eventBus = EventBus(context).getInstance(); + + let instance, + logger, + L2AStateDict; + + function setup() { + logger = Debug(context).getInstance().getLogger(instance); + resetInitialSettings(); + + eventBus.on(Events.PLAYBACK_SEEKING, onPlaybackSeeking, instance); + eventBus.on(Events.MEDIA_FRAGMENT_LOADED, onMediaFragmentLoaded, instance); + eventBus.on(Events.METRIC_ADDED, onMetricAdded, instance); + eventBus.on(Events.QUALITY_CHANGE_REQUESTED, onQualityChangeRequested, instance); + } + + function getInitialL2AState(rulesContext) { + const initialState = {}; + const mediaInfo = rulesContext.getMediaInfo(); + const bitrates = mediaInfo.bitrateList.map(b => b.bandwidth) / 1000; + initialState.state = L2A_STATE_STARTUP; + initialState.bitrates = bitrates; + initialState.lastQuality = 0; + clearL2AStateOnSeek(initialState); + return initialState; + } + + function clearL2AStateOnSeek(L2AState) { + L2AState.placeholderBuffer = 0; + L2AState.mostAdvancedSegmentStart = NaN; + L2AState.lastSegmentWasReplacement = false; + L2AState.lastSegmentStart = NaN; + L2AState.lastSegmentDurationS = NaN; + L2AState.lastSegmentRequestTimeMs = NaN; + L2AState.lastSegmentFinishTimeMs = NaN; + } + + function getL2AState(rulesContext) { + const mediaType = rulesContext.getMediaType(); + let L2AState = L2AStateDict[mediaType]; + if (!L2AState) { + L2AState = getInitialL2AState(rulesContext); + L2AStateDict[mediaType] = L2AState; + } + return L2AState; + } + + function onPlaybackSeeking() { + for (const mediaType in L2AStateDict) { + if (L2AStateDict.hasOwnProperty(mediaType)) { + const L2AState = L2AStateDict[mediaType]; + if (L2AState.state !== L2A_STATE_ONE_BITRATE) { + L2AState.state = L2A_STATE_STARTUP; + clearL2AStateOnSeek(L2AState); + } + } + } + } + + function onMediaFragmentLoaded(e) { + if (e && e.chunk && e.chunk.mediaInfo) { + const L2AState = L2AStateDict[e.chunk.mediaInfo.type]; + if (L2AState && L2AState.state !== L2A_STATE_ONE_BITRATE) { + const start = e.chunk.start; + if (isNaN(L2AState.mostAdvancedSegmentStart) || start > L2AState.mostAdvancedSegmentStart) { + L2AState.mostAdvancedSegmentStart = start; + L2AState.lastSegmentWasReplacement = false; + } else { + L2AState.lastSegmentWasReplacement = true; + } + + L2AState.lastSegmentStart = start; + L2AState.lastSegmentDurationS = e.chunk.duration; + L2AState.lastQuality = e.chunk.quality; + + checkNewSegment(L2AState, e.chunk.mediaInfo.type); + } + } + } + + function onMetricAdded(e) { + if (e && e.metric === MetricsConstants.HTTP_REQUEST && e.value && e.value.type === HTTPRequest.MEDIA_SEGMENT_TYPE && e.value.trace && e.value.trace.length) { + const L2AState = L2AStateDict[e.mediaType]; + if (L2AState && L2AState.state !== L2A_STATE_ONE_BITRATE) { + L2AState.lastSegmentRequestTimeMs = e.value.trequest.getTime(); + L2AState.lastSegmentFinishTimeMs = e.value._tfinish.getTime(); + checkNewSegment(L2AState, e.mediaType); + } + } + } + + function checkNewSegment(L2AState, mediaType) { + if (!isNaN(L2AState.lastSegmentStart) && !isNaN(L2AState.lastSegmentRequestTimeMs)) { + const bufferLevel = dashMetrics.getCurrentBufferLevel(mediaType); + console.log(bufferLevel); + segment_request_start_s = 0.001 * L2AState.lastSegmentRequestTimeMs; + segment_download_finish_s = 0.001 * L2AState.lastSegmentFinishTimeMs; + L2AState.lastSegmentStart = NaN; + L2AState.lastSegmentRequestTimeMs = NaN; + } + } + + function onQualityChangeRequested(e) { + // Useful to store change requests when abandoning a download. + if (e) { + const L2AState = L2AStateDict[e.mediaType]; + if (L2AState && L2AState.state !== L2A_STATE_ONE_BITRATE) { + L2AState.abrQuality = e.newQuality; + } + } + } + + function indexOfMin(arr) {// Calculates the index of the minimum value of an array + if (arr.length === 0) { + return -1; + } + var min = arr[0]; + var minIndex = 0; + for (var i = 0; i < arr.length; i++) { + if (arr[i] <= min) { + minIndex = i; + min = arr[i]; + } + } + return minIndex; + } + + function dotmultiplication(arr1, arr2) {// Dot multiplication of two arrays + if (arr1.length != arr2.length) { + return -1; + } + var sumdot = 0; + for (var i = 0; i < arr1.length; i++) { + sumdot = sumdot + arr1[i] * arr2[i]; + } + return sumdot; + } + + function Euclidean_projection(arr) { + //project an n-dim vector y to the simplex Dn + // Dn = { x : x n-dim, 1 >= x >= 0, sum(x) = 1} + //Algorithm is explained at http://arxiv.org/abs/1101.6081 + const m = arr.length; + var bget = false; + var arr2 = []; + for (let ii = 0; ii < m; ++ii) { + arr2[ii] = arr[ii]; + } + var s = arr.sort(function (a, b) {return b - a;}); + var tmpsum = 0; + var tmax = 0; + var x = []; + for (let ii = 0; ii < m - 1; ++ii) { + tmpsum = tmpsum + s[ii]; + tmax = (tmpsum - 1) / (ii + 1); + if (tmax >= s[ii + 1]) { + bget = true; + break; + } + } + if (!bget) { + tmax = (tmpsum + s[m - 1] - 1) / m; + } + for (let ii = 0; ii < m; ++ii) { + x[ii] = Math.max(arr2[ii] - tmax,0); + } + return x; + } + + function getMaxIndex(rulesContext) { + const switchRequest = SwitchRequest(context).create(); + const horizon = 8;//Optimization horizon + const VL = Math.pow(horizon, 0.2);//Cautiousness parameter + const alpha = Math.max(Math.pow(horizon, 0.7), VL * Math.sqrt(horizon));//Step size + let diff1 = [];//Used to calculate the difference between consecutive decisions (w-w_prev) + const mediaInfo = rulesContext.getMediaInfo(); + const mediaType = rulesContext.getMediaType(); + const bitrates = mediaInfo.bitrateList.map(b => b.bandwidth); + const bitrateCount = bitrates.length; + const scheduleController = rulesContext.getScheduleController(); + const streamInfo = rulesContext.getStreamInfo(); + const abrController = rulesContext.getAbrController(); + const throughputHistory = abrController.getThroughputHistory(); + const isDynamic = streamInfo && streamInfo.manifestInfo && streamInfo.manifestInfo.isDynamic; + const useL2AABR = rulesContext.useL2AABR(); + const bufferLevel = dashMetrics.getCurrentBufferLevel(mediaType, true); + const safeThroughput = throughputHistory.getSafeAverageThroughput(mediaType, isDynamic); + const throughput = throughputHistory.getAverageThroughput(mediaType, isDynamic); + const c_throughput = throughput / 1000;//Throughput in Mbps + const react = 20;///Reactiveness to throughput drops + const latency = throughputHistory.getAverageLatency(mediaType); + let quality; + if (!rulesContext || !rulesContext.hasOwnProperty('getMediaInfo') || !rulesContext.hasOwnProperty('getMediaType') || + !rulesContext.hasOwnProperty('getScheduleController') || !rulesContext.hasOwnProperty('getStreamInfo') || + !rulesContext.hasOwnProperty('getAbrController') || !rulesContext.hasOwnProperty('useL2AABR')) { + console.log(!rulesContext.hasOwnProperty('useL2AABR')); + return switchRequest; + } + switchRequest.reason = switchRequest.reason || {}; + if (!useL2AABR) { + return switchRequest; + } + scheduleController.setTimeToLoadDelay(0); + const L2AState = getL2AState(rulesContext); + if (L2AState.state === L2A_STATE_ONE_BITRATE) { + // shouldn't even have been called + return switchRequest; + } + switchRequest.reason.state = L2AState.state; + switchRequest.reason.throughput = throughput; + switchRequest.reason.latency = latency; + if (isNaN(throughput)) { + // still starting up - not enough information + return switchRequest; + } + switch (L2AState.state) { + case L2A_STATE_STARTUP: + quality = abrController.getQualityForBitrate(mediaInfo, safeThroughput, latency); + switchRequest.quality = quality; + switchRequest.reason.throughput = safeThroughput; + L2AState.lastQuality = quality; + if (!isNaN(L2AState.lastSegmentDurationS) && bufferLevel >= L2AState.lastSegmentDurationS) { + L2AState.state = L2A_STATE_STEADY; + } + break; // L2A_STATE_STARTUP + case L2A_STATE_STEADY: + /////////////////////////////Main adaptation logic of L2A-LL + let V = L2AState.lastSegmentDurationS; + //const cc_throughput=(bitrates[L2AState.lastQuality]*V/(segment_download_finish_s-segment_request_start_s))/(1000*1000); + //console.log('Computed throughput:',c_throughput); + if (w.length === 0) {//Initialization of w and w_prev + Q = 0; + for (let i = 0; i < bitrateCount; ++i) { + if (i === 0) { + w[i] = 0.33; + prev_w[i] = 1; + } + else { + w[i] = 0.33; + prev_w[i] = 0; + } + } + } + for (let i = 0; i < bitrateCount; ++i) { + bitrates[i] = bitrates[i] / (1000 * 1000); //Bitrates in Mbps + w[i] = prev_w[i] - (1 / (2 * alpha)) * (V * bitrates[i]) * ((Q - VL) / Math.min(2 * bitrates[bitrateCount - 1], c_throughput));//Lagrangian descent + diff1[i] = w[i] - prev_w[i]; + } + w = Euclidean_projection(w); + if (bitrates[L2AState.lastQuality] > ((bitrates[L2AState.lastQuality] * V / (segment_download_finish_s - segment_request_start_s)))) { + if (Q < VL) { + Q = horizon * VL * react; + } + }//Reset Lagrangian multiplier (Q) to speed up potential bitrate switch based on previous throughput measurement + Q = Math.max(0, Q + V * dotmultiplication(bitrates, prev_w) / Math.min(2 * bitrates[bitrateCount - 1],c_throughput) - (react / 2) * V + V * (dotmultiplication(bitrates, diff1) / Math.min(2 * bitrates[bitrateCount - 1], c_throughput))); + let temp = []; + for (let i = 0; i < bitrateCount; ++i) { + prev_w[i] = w[i]; + temp[i] = Math.abs(bitrates[i] - dotmultiplication(w, bitrates)); + }//// Quality is calculated as argmin of the aboslute differnce between available bitrates (bitrates[i]) and bitrate estimation (dotmultiplication(w,bitrates)). We employ a stepwise ascent/descent + if (indexOfMin(temp) > L2AState.lastQuality) { + quality = L2AState.lastQuality + 1; + } + else if (indexOfMin(temp) < L2AState.lastQuality) { + quality = L2AState.lastQuality - 1; + } + else { + quality = indexOfMin(temp); + } + /// Provision againts over-estimation. + if ((bitrates[quality] >= c_throughput) && (bufferLevel < B_target)) { + quality = L2AState.lastQuality; + } + switchRequest.quality = quality; + switchRequest.reason.throughput = throughput; + switchRequest.reason.latency = latency; + switchRequest.reason.bufferLevel = bufferLevel; + L2AState.lastQuality = quality; + break; // L2A_STATE_STEADY + default: + logger.debug('L2A ABR rule invoked in bad state.');// should not arrive here, try to recover + switchRequest.quality = abrController.getQualityForBitrate(mediaInfo, safeThroughput, latency); + switchRequest.reason.state = L2AState.state; + switchRequest.reason.throughput = safeThroughput; + switchRequest.reason.latency = latency; + L2AState.state = L2A_STATE_STARTUP; + clearL2AStateOnSeek(L2AState); + } + return switchRequest; + } + function resetInitialSettings() { + L2AStateDict = {}; + } + function reset() { + resetInitialSettings(); + eventBus.off(Events.PLAYBACK_SEEKING, onPlaybackSeeking, instance); + eventBus.off(Events.MEDIA_FRAGMENT_LOADED, onMediaFragmentLoaded, instance); + eventBus.off(Events.METRIC_ADDED, onMetricAdded, instance); + eventBus.off(Events.QUALITY_CHANGE_REQUESTED, onQualityChangeRequested, instance); + } + instance = { + getMaxIndex: getMaxIndex, + reset: reset + }; + setup(); + return instance; +} +L2ARule.__dashjs_factory_name = 'L2ARule'; +export default FactoryMaker.getClassFactory(L2ARule); \ No newline at end of file