Player: Jerky 23.976 playback with auto refresh rate switching on Windows

[chriscurtis]

Test environment

PMS Version: N/A
PMP Version: 2.11.0 and later
Platform (Windows/OSX/Embedded): Windows

Steps to reproduce

Forum topic: https://forums.plex.tv/t/newest-version-of-plex-media-player-broke-something-on-23-976fps-playback/237046

Sorry, I don't have specific steps to reproduce. User's report that playback suddenly becomes "jerky" for content when the app switches output to 23.976fps via refresh rate switching. Some notes from users:

• Affects Windows (10) installs
• Occurs when refresh rate switching is enabled
• May only occur with Sync Mode: Display enabled (user reports it's the same under both "resample" and "drop/duplicate")
• May only occur with hardware decoding set to Enabled (copy-back)
• Possibly related to using NVIDIA graphics cards

Current behavior

Auto refresh rate switching and playing the 23.976 content results in "jerky" playback.

Expected behavior

Playback should be smooth at the correct framerate.

[dan-the-man-nz]

not just nvidia, i tested it on a intel onboard gfx, was same issue

also, did NOT have Enabled (copy-back) enabled when testing that

suspect it was from the bump in QT

doesnt effect me however since i use the default Sync Mode: Audio, no issues at all

[mseeley]

Hey @dan-the-man-nz just double checking the possibly obvious... do I understand the forum thread activity correctly that 2.10.849 was the last working version?

[dan-the-man-nz]

thats how i understand the forum thread yes

2.10.849 and versions below this, was no issue

then from 2.11.0 onwards it became a issue for them

in 2.11.0 Qt was updated to 5.9.5 - which was my guess as the cause, maybe it was something else tho.

not sure why they are not using the default Sync Mode: Audio which has no issues

[ghost]

Hi. I am the person who reported the issue. Good to see that something is being done to fix it. Thank you. I am not using Sync Mode: Audio as that causes audio and video to drift out of sync over a period of time.

[ghost]

Here is some more info about what that setting should do, and why it is important for smooth video playback and audio sync:

https://github.com/mpv-player/mpv/wiki/Display-synchronization

[dan-the-man-nz]

this maybe caused by this (found by archilles)
http://github.com/plexinc/plex-media-player/commit/94ff609846fe9f82b0b9b959483a398c9fbd108c

replacing libEGL.dll libGLESv2.dll d3dcompiler_47.dll from those that come with 2.10 release seem to fix the problem with sync mode = display

i tried this on a Win10 Machine running 2.21 with those 3 dlls from 2.10

[ghost]

I am getting mixed results with that workaround. On machines where it works, the d3dcompiler_47.dll file is not needed, just the libEGL.dll libGLESv2.dll files.

However, it brings back an old bug on other machines, seemingly those with an AMD or Intel graphics chip, running Windows 10, whereby it prevents refresh rate switching happening at all. The flashing screen and mouse cursor appears, which I remember as being an old bug.

[ghost]

Hi, is it acceptable for me to bump this issue?