Some files cause PMS to go crazy and send insane stream data - 250mbps+

[OnTheMF]

Server Version#: 1.20.1.3252
Player Version#: DesktopAF 1.18.0.1392-cf94f6a1

I’ve had this issue for about six months. Some video files cause PMS to go crazy, transferring 250+mbps data to the player despite the source being a 5mbps 720p video. The player stutters every second. The vast majority of videos are totally fine, 99%+. Even 4k, high bitrate, transcode, you name it.

The issue is reproducible 100% of the time. The stream is set to directly play / original. The player is connected via gigabit ethernet, the server is a quad-core i5 3.1GHz, 16GB ram, 25TB raid5 running Debian Linux. I can play the file no problem on the same PC using VLC and network shares. The file does not play at all on the Android viewer, and it plays fine on chromecast.

I have verified CPU, GPU, and I/O usage is low. This stuttering appears to be a network bottleneck hit by plex turning a 5mbps video into a 250mbps stream, somehow.

Attached is the codec info for all of the streams.
CodecInfo.txt (15.3 KB)

Also attached is the Tautulli log, showing the continuous buffering and a screenshot of the network usage of Plex. The PMS log and transcoder log show nothing of interest.
TautulliLog.txt (972 Bytes)

It’s worth mentioning that transcoding to anything below 480p somehow fixes the issue, but 480p and above have the issue still.

[OttoKerner]

see High Bandwidth via Direct Play on Windows 10

[OnTheMF]

Thanks! That explains it. On one hand, I would appreciate if Plex handled/worked-around badly encoded files like this, as VLC obviously does, but on the other hand I understand this is a problem related to the source file and is not a Plex problem per se. Maybe a good feature request for the future.

[OttoKerner]

VLC doesn’t stream. It is a lot easier to seek in a file when accessing it over a local lan, with appropriate network protocols. But streaming is a different animal.
And since Direct Playing is a very desirable playback mode, Plex will not lightly revert to Direct Streaming instead (which would indeed prevent the issue).