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Use actual chunk bitrate instead of average in ABR decisions to improve performance for VBR streams.

See original GitHub issue

Hi,

In our experience ExoPlayer does not use lower bitrate even there is latency in downloading big chunks and this causes freezing and buffering. However the bandwith is 6 Mbit, because of VBR sometimes the size of one 2 second chunk differs from 1.5 MegeByte to 15 MegaByte. In our experience when there is increase in bitrate the player still tries to download next chunk using same bitrate instead of lowering bitrate. What is causing this problem. Is there a way or configuration to fix this?

Trace Screenshot

Our MPD

<?xml version="1.0" encoding="UTF-8"?> <MPD xmlns="urn:mpeg:dash:schema:mpd:2011" xmlns:cenc="urn:mpeg:cenc:2013" xmlns:mspr="urn:microsoft:playready" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="urn:mpeg:DASH:schema:MPD:2011 http://standards.iso.org/ittf/PubliclyAvailableStandards/MPEG-DASH_schema_files/DASH-MPD.xsd" profiles="urn:mpeg:dash:profile:isoff-live:2011" type="dynamic" minimumUpdatePeriod="PT500S" suggestedPresentationDelay="PT2S" availabilityStartTime="2020-09-09T00:10:16Z" publishTime="2021-01-23T17:28:55Z" minBufferTime="PT4.0S" timeShiftBufferDepth="PT86400.0S"> <ProgramInformation /> <Period id="0" start="PT0.0S"> <AdaptationSet id="0" contentType="video" segmentAlignment="true" bitstreamSwitching="true" maxFrameRate="50/1"> <Representation id="0" mimeType="video/mp4" codecs="avc1.4d4015" bandwidth="800000" width="480" height="270" frameRate="25/1"> <SegmentTemplate timescale="12800" duration="25600" initialization="ExtAst1599610204_init_$RepresentationID$.m4i?hw_dash=1&servicetype=1&rrsip=izmottrrs.tvplus.com.tr:443&zoneoffset=0&devkbps=190-7000&accounttype=1&limitflux=-1&limitdur=-1&tenantId=9001&validdev=5499,5270&vqe=3&mount=1000001&targetdev=5387&pbf=2_2_2_2331729884" media="ExtAst1599610204_chunk_20200909T001000_$RepresentationID$_$Number$.m4v?hw_dash=1&servicetype=1&rrsip=izmottrrs.tvplus.com.tr:443&zoneoffset=0&devkbps=190-7000&accounttype=1&limitflux=-1&limitdur=-1&tenantId=9001&validdev=5499,5270&vqe=3&mount=1000001&targetdev=5387&pbf=2_2_2_2331729884" startNumber="1" /> </Representation> <Representation id="1" mimeType="video/mp4" codecs="avc1.4d401e" bandwidth="1400000" width="704" height="396" frameRate="25/1"> <SegmentTemplate timescale="12800" duration="25600" initialization="ExtAst1599610204_init_$RepresentationID$.m4i?hw_dash=1&servicetype=1&rrsip=izmottrrs.tvplus.com.tr:443&zoneoffset=0&devkbps=190-7000&accounttype=1&limitflux=-1&limitdur=-1&tenantId=9001&validdev=5499,5270&vqe=3&mount=1000001&targetdev=5387&pbf=2_2_2_2331729884" media="ExtAst1599610204_chunk_20200909T001000_$RepresentationID$_$Number$.m4v?hw_dash=1&servicetype=1&rrsip=izmottrrs.tvplus.com.tr:443&zoneoffset=0&devkbps=190-7000&accounttype=1&limitflux=-1&limitdur=-1&tenantId=9001&validdev=5499,5270&vqe=3&mount=1000001&targetdev=5387&pbf=2_2_2_2331729884" startNumber="1" /> </Representation> <Representation id="2" mimeType="video/mp4" codecs="avc1.4d401f" bandwidth="2000000" width="960" height="540" frameRate="25/1"> <SegmentTemplate timescale="12800" duration="25600" initialization="ExtAst1599610204_init_$RepresentationID$.m4i?hw_dash=1&servicetype=1&rrsip=izmottrrs.tvplus.com.tr:443&zoneoffset=0&devkbps=190-7000&accounttype=1&limitflux=-1&limitdur=-1&tenantId=9001&validdev=5499,5270&vqe=3&mount=1000001&targetdev=5387&pbf=2_2_2_2331729884" media="ExtAst1599610204_chunk_20200909T001000_$RepresentationID$_$Number$.m4v?hw_dash=1&servicetype=1&rrsip=izmottrrs.tvplus.com.tr:443&zoneoffset=0&devkbps=190-7000&accounttype=1&limitflux=-1&limitdur=-1&tenantId=9001&validdev=5499,5270&vqe=3&mount=1000001&targetdev=5387&pbf=2_2_2_2331729884" startNumber="1" /> </Representation> <Representation id="3" mimeType="video/mp4" codecs="avc1.4d4020" bandwidth="3150000" width="1280" height="720" frameRate="50/1"> <SegmentTemplate timescale="12800" duration="25600" initialization="ExtAst1599610204_init_$RepresentationID$.m4i?hw_dash=1&servicetype=1&rrsip=izmottrrs.tvplus.com.tr:443&zoneoffset=0&devkbps=190-7000&accounttype=1&limitflux=-1&limitdur=-1&tenantId=9001&validdev=5499,5270&vqe=3&mount=1000001&targetdev=5387&pbf=2_2_2_2331729884" media="ExtAst1599610204_chunk_20200909T001000_$RepresentationID$_$Number$.m4v?hw_dash=1&servicetype=1&rrsip=izmottrrs.tvplus.com.tr:443&zoneoffset=0&devkbps=190-7000&accounttype=1&limitflux=-1&limitdur=-1&tenantId=9001&validdev=5499,5270&vqe=3&mount=1000001&targetdev=5387&pbf=2_2_2_2331729884" startNumber="1" /> </Representation> <Representation id="4" mimeType="video/mp4" codecs="avc1.4d402a" bandwidth="6000000" width="1920" height="1080" frameRate="50/1"> <SegmentTemplate timescale="12800" duration="25600" initialization="ExtAst1599610204_init_$RepresentationID$.m4i?hw_dash=1&servicetype=1&rrsip=izmottrrs.tvplus.com.tr:443&zoneoffset=0&devkbps=190-7000&accounttype=1&limitflux=-1&limitdur=-1&tenantId=9001&validdev=5499,5270&vqe=3&mount=1000001&targetdev=5387&pbf=2_2_2_2331729884" media="ExtAst1599610204_chunk_20200909T001000_$RepresentationID$_$Number$.m4v?hw_dash=1&servicetype=1&rrsip=izmottrrs.tvplus.com.tr:443&zoneoffset=0&devkbps=190-7000&accounttype=1&limitflux=-1&limitdur=-1&tenantId=9001&validdev=5499,5270&vqe=3&mount=1000001&targetdev=5387&pbf=2_2_2_2331729884" startNumber="1" /> </Representation> <Representation id="5" mimeType="video/mp4" codecs="avc1.4d400d" bandwidth="400000" width="416" height="234" frameRate="25/1"> <SegmentTemplate timescale="12800" duration="25600" initialization="ExtAst1599610204_init_$RepresentationID$.m4i?hw_dash=1&servicetype=1&rrsip=izmottrrs.tvplus.com.tr:443&zoneoffset=0&devkbps=190-7000&accounttype=1&limitflux=-1&limitdur=-1&tenantId=9001&validdev=5499,5270&vqe=3&mount=1000001&targetdev=5387&pbf=2_2_2_2331729884" media="ExtAst1599610204_chunk_20200909T001000_$RepresentationID$_$Number$.m4v?hw_dash=1&servicetype=1&rrsip=izmottrrs.tvplus.com.tr:443&zoneoffset=0&devkbps=190-7000&accounttype=1&limitflux=-1&limitdur=-1&tenantId=9001&validdev=5499,5270&vqe=3&mount=1000001&targetdev=5387&pbf=2_2_2_2331729884" startNumber="1" /> </Representation> <Representation id="6" mimeType="video/mp4" codecs="avc1.4d400d" bandwidth="200000" width="416" height="234" frameRate="25/1"> <SegmentTemplate timescale="12800" duration="25600" initialization="ExtAst1599610204_init_$RepresentationID$.m4i?hw_dash=1&servicetype=1&rrsip=izmottrrs.tvplus.com.tr:443&zoneoffset=0&devkbps=190-7000&accounttype=1&limitflux=-1&limitdur=-1&tenantId=9001&validdev=5499,5270&vqe=3&mount=1000001&targetdev=5387&pbf=2_2_2_2331729884" media="ExtAst1599610204_chunk_20200909T001000_$RepresentationID$_$Number$.m4v?hw_dash=1&servicetype=1&rrsip=izmottrrs.tvplus.com.tr:443&zoneoffset=0&devkbps=190-7000&accounttype=1&limitflux=-1&limitdur=-1&tenantId=9001&validdev=5499,5270&vqe=3&mount=1000001&targetdev=5387&pbf=2_2_2_2331729884" startNumber="1" /> </Representation> </AdaptationSet> <AdaptationSet id="1" contentType="audio" segmentAlignment="true" bitstreamSwitching="true" lang="tur"> <Representation id="8" mimeType="audio/mp4" codecs="mp4a.40.5" bandwidth="128000" audioSamplingRate="48000"> <AudioChannelConfiguration schemeIdUri="urn:mpeg:dash:23003:3:audio_channel_configuration:2011" value="2" /> <SegmentTemplate timescale="48000" duration="96000" initialization="ExtAst1599610204_init_$RepresentationID$.m4i?hw_dash=1&servicetype=1&rrsip=izmottrrs.tvplus.com.tr:443&zoneoffset=0&devkbps=190-7000&accounttype=1&limitflux=-1&limitdur=-1&tenantId=9001&validdev=5499,5270&vqe=3&mount=1000001&targetdev=5387&pbf=2_2_2_2331729884" media="ExtAst1599610204_chunk_20200909T001000_$RepresentationID$_$Number$.m4a?hw_dash=1&servicetype=1&rrsip=izmottrrs.tvplus.com.tr:443&zoneoffset=0&devkbps=190-7000&accounttype=1&limitflux=-1&limitdur=-1&tenantId=9001&validdev=5499,5270&vqe=3&mount=1000001&targetdev=5387&pbf=2_2_2_2331729884" startNumber="1" /> </Representation> </AdaptationSet> </Period> <UTCTiming schemeIdUri="urn:mpeg:dash:utc:http-iso:2014" value="https://time.akamai.com/?iso" /> </MPD>

Issue Analytics

State:
Created 3 years ago
Comments:10 (1 by maintainers)

Top GitHub Comments

1reaction

tanhancommented, Jan 26, 2021

I am not sure latency is the problem. Because making the connections is fast however downloading the big chunks takes some time. How is the download speed is calculated in this case?

I am trying to understand why is the player insisting on downloading big chunks on same high profile instead of lowering bitrate on this experience which causes an empty buffer as a result. Can high VBR cause this problem?

0reactions

toniheicommented, Jul 25, 2022

I think we should turn this into a low-priority enhancement. If I understand the issue correctly, our ABR algorithm works with the average bitrate when making decisions and may run into problems if the actual chunk bitrate is much higher.

Note that all the information about the actual bitrate of potential future and past chunks is already available in the queue and mediaChunkIterators parameters of updateSelectedTrack, so it’s possible to adjust the logic by overriding AdaptiveTrackSelection or providing a completely custom track selection class.

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