Server Version#: 4.79.4 (I’ve also seen this in a linux docker)
Player Version#: Multiple players, including Android TV beta and Roku current.
I’m confused with Plex’s behavior and need help.
I have a video file with a bit rate just under 2mbps. That includes a vbv-bufsize and vbv-maxrate to keep it under 2mbps in total, including random spikes. It’s a 1080p HEVC 10-bit file with AC3 encoding. It’s just a representative sample; I’ve also seen this problem with 1080p and AAC stereo. No subtitles are being used.
Plex has done deep analysis on the file, and shows: RequiredBandwidths="2132,2132,2132,2132,2132,2132,2132,2132"
I presume Plex is requesting bandwidth of over 100% of the bit rate to prevent any playback issues, based on past experiences and reading. However, it gets weird from here.
If I set my playback device to a 2mbps limit, the file transcodes. No surprise.
If I set my playback device to a 3mbps limit, the file still transcodes. That’s weird.
If I set my playback device to a 4mbps limit, the file again transcodes. C’mon.
If I set my playback device to a 8mbps limit (the next option after 4mbps), the file finally direct-plays.
So even though my file is under 2mbps in bit rate, I currently need to set the device’s minimum playback bandwidth to 8mbps per second.
In short: WTF? Does anyone understand why this is happening?
Here is the media portion of the XML for the file:
<Media id="173524" duration="677594" bitrate="1930" width="1920" height="1080" aspectRatio="1.78" audioChannels="6" audioCodec="ac3" videoCodec="hevc" videoResolution="1080" container="mp4" videoFrameRate="24p" optimizedForStreaming="1" has64bitOffsets="0" videoProfile="main 10">
<Part accessible="1" exists="1" id="181513" key="/library/parts/181513/1648013326/file.m4v" duration="677594" file="[filename removed]" size="163476199" container="mp4" deepAnalysisVersion="6" has64bitOffsets="0" optimizedForStreaming="1" requiredBandwidths="2132,2132,2132,2132,2132,2132,2132,2132" videoProfile="main 10">
<Stream id="484026" streamType="1" default="1" codec="hevc" index="0" bitrate="1540" bitDepth="10" chromaLocation="left" chromaSubsampling="4:2:0" codecID="hvc1" codedHeight="1080" codedWidth="1920" colorPrimaries="bt709" colorRange="tv" colorSpace="bt709" colorTrc="bt709" frameRate="23.976" height="1080" level="120" profile="main 10" refFrames="1" requiredBandwidths="1781,1781,1781,1781,1781,1781,1781,1781" streamIdentifier="1" width="1920" displayTitle="1080p (HEVC Main 10)" extendedDisplayTitle="1080p (HEVC Main 10)"> </Stream>
<Stream id="484027" streamType="2" selected="1" default="1" codec="ac3" index="1" channels="6" bitrate="384" language="English" languageTag="en" languageCode="eng" audioChannelLayout="5.1(side)" requiredBandwidths="382,382,382,382,382,382,382,382" samplingRate="48000" streamIdentifier="2" displayTitle="English (AC3 5.1)" extendedDisplayTitle="English (AC3 5.1)"> </Stream>
<Stream id="484028" streamType="3" default="1" codec="mov_text" index="2" bitrate="0" language="English" languageTag="en" languageCode="eng" requiredBandwidths="1,1,1,1,1,1,1,1" streamIdentifier="3" displayTitle="English (MOV_TEXT)" extendedDisplayTitle="English (MOV_TEXT)"> </Stream>
</Part>
</Media>
