Emby Windows 2.317.2 – severe judder with 1080p50 H.264 Direct Play / gpu-next – render queue underruns

[schnigges 0]

Hi,

I'm experiencing severe and consistently reproducible judder with 1080p50 H.264 content in Emby Windows 2.317.2.

System

• Emby Windows 2.317.2.0 (Microsoft Store)
• Windows 11
• AMD Ryzen 3 3200G
• Radeon Vega 8 iGPU
• AMD driver 31.0.21925.1001
• LG 4K OLED connected to the PC
• Display manually set to 50 Hz during testing
• Emby Server on TrueNAS

Test file

• MKV
• H.264 High@L4.2
• 1920x1080
• 50.000 fps progressive
• 8-bit YUV420P
• BT.709 SDR
• ~3-3.7 Mbps
• AAC 2.0
• Direct Play

The same exact file on the same PC and network connection plays smoothly in:

• MPC-HC
• Emby Web in the browser
• Moonfin

In Emby Windows, however, playback has continuous visible judder.

I have reproduced the problem with both software decoding and D3D11VA. Updating the AMD graphics driver did not change the behavior. I also tested with Windows itself set to 1920x1080 @ 50 Hz, with the same result.

The most interesting comparison is:

GPU-Next + D3D11VA + All Hardware processing:
→ visible continuous judder

legacy GPU + D3D11VA + All Hardware processing:
→ smooth 50 fps playback (but darker image)

So the system is capable of decoding and presenting the stream smoothly; the problem appears to be specific to the GPU-Next playback/rendering path.

During the GPU-Next reproduction, the mpv debug log repeatedly reports:

Invalid video timestamp

Non monotonically increasing PTS

Render queue underrun

At one point it also reports:

Estimated source FPS: 50.000, display FPS: 25.000

while the D3D11 output itself detects the physical display at 50 Hz.

I have attached the complete debug log from this reproduction using the current AMD driver.

Since the same file plays smoothly in MPC-HC, Emby Web, Moonfin, and even Emby's legacy GPU output on the same machine, this looks like a GPU-Next/frame-presentation issue rather than a decoding, network or source-performance limitation.

Please let me know if you need a short sample of the source file or a reproduction with a specific configuration.

Thanks.

Emby_Windows_2.317.2_1080p50_judder_debug_log.txt

[Luke 43051]

Hi there, please attach the Emby server log from when the problem occurred:

How to Report a Problem

Thanks!

 

[schnigges 0]

What other logs than the one I attached are needed?