I’m sorry but your logic and desire to bypass problems with bandaids is not the solution and does not work in the vast majority of cases
Audio + Video + Subtitles must all stay in sync with each other else there’s no point so any one thread can be a pinch point.
regarding subtitles:
On every Synology, with exception of the Xeon CPUs, subtitles are the downfall. No ifs, ands, or buts.
Trying to paint subtitles, in software, into a 30 Mbps video frame, and keep real-time speed – is not possible for J-series CPUs. I’ve benchmarked this on both Synology and QNAP systems in our lab countless times.
There is one characteristic of the J-series CPU , J4xxx CPUs in particular, with the default Intel IHD video driver which is a degenerate case.
- Low bit rate video
- exacerbated by tone mapping in a docker container.
- Subtitle conversion
- Subtitle burning.
I do have something you can try.
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Install the Synology Text Editor application
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Stop Plex
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Navigate into the Plex shared folder and down in until you see “Preferences.xml”
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Edit it (right-click, open in Text Editor)
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Cursor down to the closing
/>on the very bottom line. -
Carefully add
VaapiDriver="i965"in front of it. -
It will look like this when done:
SomePref="Value" VaapiDriver="i965" /> -
Save the file
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Start Plex
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retest
This tells Plex to use the older driver which known better tuned for low bit rate video (under 30 Mbps). It’s extremely effective for those videos < 20 Mbps which would be FASTER when done in software transcoding.
