Long time Plex user. Using a 7700k for 10-bit HEVC HW Transcoding on an Ubuntu 16.04 headless server. 9 times out of 10, there are zero issues, and it works fantastic. Every once in a while, i get a text from a family member saying “it’s buffering”. I take a look, at the Plex web interface and it shows both decoding and encoding in HW. I check Plexpy and it indicates it’s transcoding at less than 1.0 (around .7 to .9), as if it wasn’t using hardware encode/decoding. When i see this is happening, i try and pull up a stream on a random fire stick and my phone app and see if it works–which it does perfectly fine. I have tried capturing logs to see if i can see where the issue is, but i cannot.
The devices it has happened on so far are a Fire stick and an Xbox One. Has anyone else experienced this?
It sounds like the cpu is getting involved and the most likely suspect is subtitles. Subtitle rendering must be done in software. The ASIC which provides hw transcoding doesn’t include support for subtitles. That means the last phase of the encoding is cpu. Hw hevc decode, hw h.264 encode, software subtitle burning.
You can verify this by playing files without subtitles in them or creating s temporary version and stripping out subtitles to have them try
If the problem still exists, we will need to capture debug-only logs up to the point of the first stuttering. (Stop playback at that point and capture logs at that point and attach the zip file for me to check)
Thanks so much for a quick reply. I thought this as well, but verified that subtitles were not being used. I also ran the same movie on multiple platforms of my own in order to try and recreate the issue. I will continue to try and recreate the problem, and go from there. I’m just hoping someone else has had the issue. Thanks again!
