XDG Portal & Kwin Capture framerate is incorrect

[Slashic]

Is there an existing issue for this?

• I have searched the existing issues

Is your issue described in the documentation?

• I have read the documentation

Is your issue present in the latest beta/pre-release?

This issue is present in the latest pre-release

Describe the Bug

XDG Portal Capture seems to produce a video stream with few more frames than expected.
This happens when the game is capped at 60 or 90 fps for instance, the resulting output on moonlight side will be 63fps and 95 or so fps, producing judder/stutter in game.
It also happens no matter framerate the client ask, be it 60 or 120.

This isn't the case with KMS capture nor Windows.
All games tested produce the same behavior.

Expected Behavior

Matching framerate from host to moonlight client.

Additional Context

No response

Host Operating System

Linux

Operating System Version

Fedora 44, KDE Plasma 6.6.5

Architecture

amd64/x86_64

Package

Linux - Fedora Copr

GPU Type

AMD

GPU Model

7900 XTX

GPU Driver/Mesa Version

Mesa 26.0.6

Capture Method

XDG Portal Grab (FreeBSD/Linux)

Apps

Log output

[2026-05-25 19:01:09.929]: Info: Trying encoder [vaapi]
[2026-05-25 19:01:09.929]: Info: Screencasting with XDG portal
[2026-05-25 19:01:09.929]: Info: [pipewire] Requested frame rate [60/1, approx. 60 fps]
[2026-05-25 19:01:09.929]: Info: [wayland] Found display [wayland-0]
[2026-05-25 19:01:09.939]: Info: [portalgrab] Loaded portal restore token from disk
[2026-05-25 19:01:09.948]: Info: [wayland] Found display [wayland-0]
[2026-05-25 19:01:09.950]: Info: [wayland] Found interface: zxdg_output_manager_v1(31) version 3
[2026-05-25 19:01:09.950]: Info: [wayland] Found interface: zwp_linux_dmabuf_v1(57) version 5
[2026-05-25 19:01:09.950]: Info: [wayland] Found interface: wl_output(129) version 4
[2026-05-25 19:01:09.950]: Info: [wayland] Found interface: wl_output(133) version 4
[2026-05-25 19:01:09.950]: Info: [wayland] Resolution: 1920x1080
[2026-05-25 19:01:09.950]: Info: [wayland] Resolution: 3440x1440
[2026-05-25 19:01:09.950]: Info: [wayland] Offset: 3440x180
[2026-05-25 19:01:09.950]: Info: [wayland] Logical size: 1920x1080
[2026-05-25 19:01:09.950]: Info: [wayland] Name: DP-2
[2026-05-25 19:01:09.950]: Info: [wayland] Found monitor: Lenovo Group Limited LEN T22i-10
[2026-05-25 19:01:09.950]: Info: [wayland] Offset: 0x0
[2026-05-25 19:01:09.950]: Info: [wayland] Logical size: 3440x1440
[2026-05-25 19:01:09.950]: Info: [wayland] Name: DP-1
[2026-05-25 19:01:09.950]: Info: [wayland] Found monitor: LG Electronics LG ULTRAGEAR
[2026-05-25 19:01:09.951]: Info: [portalgrab] Using first available stream as no matching stream was found for: '0'
[2026-05-25 19:01:09.951]: Info: [pipewire] Streaming display '0' offset: 0x0 resolution: 3440x1440
[2026-05-25 19:01:09.951]: Info: [wayland] Found display [wayland-0]
[2026-05-25 19:01:09.952]: Info: [wayland] Found interface: zxdg_output_manager_v1(31) version 3
[2026-05-25 19:01:09.952]: Info: [wayland] Found interface: zwp_linux_dmabuf_v1(57) version 5
[2026-05-25 19:01:09.952]: Info: [wayland] Found interface: wl_output(129) version 4
[2026-05-25 19:01:09.952]: Info: [wayland] Found interface: wl_output(133) version 4
[2026-05-25 19:01:09.952]: Info: [wayland] Resolution: 1920x1080
[2026-05-25 19:01:09.952]: Info: [wayland] Resolution: 3440x1440
[2026-05-25 19:01:09.952]: Info: [wayland] Offset: 3440x180
[2026-05-25 19:01:09.952]: Info: [wayland] Logical size: 1920x1080
[2026-05-25 19:01:09.952]: Info: [wayland] Name: DP-2
[2026-05-25 19:01:09.952]: Info: [wayland] Found monitor: Lenovo Group Limited LEN T22i-10
[2026-05-25 19:01:09.952]: Info: [wayland] Offset: 0x0
[2026-05-25 19:01:09.952]: Info: [wayland] Logical size: 3440x1440
[2026-05-25 19:01:09.952]: Info: [wayland] Name: DP-1
[2026-05-25 19:01:09.952]: Info: [wayland] Found monitor: LG Electronics LG ULTRAGEAR
[2026-05-25 19:01:09.954]: Info: [pipewire] Connected to pipewire version 1.6.5
[2026-05-25 19:01:09.956]: Info: [pipewire] Video format: 12
[2026-05-25 19:01:09.956]: Info: [pipewire] Size: 3440x1440
[2026-05-25 19:01:09.956]: Info: [pipewire] Color primaries: 0
[2026-05-25 19:01:09.956]: Info: [pipewire] Transfer function: 0
[2026-05-25 19:01:09.956]: Info: [pipewire] Framerate (from compositor): 0/1 (variable rate capture)
[2026-05-25 19:01:09.956]: Info: [pipewire] using DMA-BUF buffers
[2026-05-25 19:01:09.956]: Info: [pipewire] Video format: 12
[2026-05-25 19:01:09.956]: Info: [pipewire] Size: 3440x1440
[2026-05-25 19:01:09.956]: Info: [pipewire] Color primaries: 0
[2026-05-25 19:01:09.956]: Info: [pipewire] Transfer function: 0
[2026-05-25 19:01:09.956]: Info: [pipewire] Framerate (from compositor): 0/1 (variable rate capture)
[2026-05-25 19:01:09.956]: Info: [pipewire] using DMA-BUF buffers
[2026-05-25 19:01:09.964]: Info: Creating encoder [h264_vaapi]
[2026-05-25 19:01:09.964]: Info: Color coding: SDR (Rec. 601)
[2026-05-25 19:01:09.964]: Info: Color depth: 8-bit
[2026-05-25 19:01:09.964]: Info: Color range: JPEG
[2026-05-25 19:01:09.970]: Warning: EGL: context priority set to HIGH but CAP_SYS_NICE capability is missing
[2026-05-25 19:01:09.974]: Info: vaapi vendor: Mesa Gallium driver 26.0.6 for AMD Radeon RX 7900 XTX (radeonsi, navi31, ACO, DRM 3.64, 7.0.9-205.fc44.x86_64)
[2026-05-25 19:01:09.974]: Info: Streaming bitrate is 1000000
[2026-05-25 19:01:09.974]: Info: Using normal encoding mode
[2026-05-25 19:01:09.974]: Info: Using default rate control
[2026-05-25 19:01:09.994]: Info: Creating encoder [hevc_vaapi]
[2026-05-25 19:01:09.994]: Info: Color coding: SDR (Rec. 601)
[2026-05-25 19:01:09.994]: Info: Color depth: 8-bit
[2026-05-25 19:01:09.994]: Info: Color range: JPEG
[2026-05-25 19:01:09.998]: Warning: EGL: context priority set to HIGH but CAP_SYS_NICE capability is missing
[2026-05-25 19:01:10.002]: Info: vaapi vendor: Mesa Gallium driver 26.0.6 for AMD Radeon RX 7900 XTX (radeonsi, navi31, ACO, DRM 3.64, 7.0.9-205.fc44.x86_64)
[2026-05-25 19:01:10.002]: Info: Streaming bitrate is 1000000
[2026-05-25 19:01:10.002]: Info: Using normal encoding mode
[2026-05-25 19:01:10.002]: Info: Using default rate control
[2026-05-25 19:01:10.020]: Info: Creating encoder [av1_vaapi]
[2026-05-25 19:01:10.020]: Info: Color coding: SDR (Rec. 601)
[2026-05-25 19:01:10.020]: Info: Color depth: 8-bit
[2026-05-25 19:01:10.020]: Info: Color range: JPEG
[2026-05-25 19:01:10.024]: Warning: EGL: context priority set to HIGH but CAP_SYS_NICE capability is missing
[2026-05-25 19:01:10.026]: Info: vaapi vendor: Mesa Gallium driver 26.0.6 for AMD Radeon RX 7900 XTX (radeonsi, navi31, ACO, DRM 3.64, 7.0.9-205.fc44.x86_64)
[2026-05-25 19:01:10.026]: Info: Streaming bitrate is 1000000
[2026-05-25 19:01:10.026]: Info: Using normal encoding mode
[2026-05-25 19:01:10.026]: Info: Using VBR with single frame VBV size
[2026-05-25 19:01:10.026]: Warning: [av1_vaapi @ 0x7f61fc774340] Multiple slices were requested but this codec does not support controlling slices.
[2026-05-25 19:01:10.040]: Info: Screencasting with XDG portal
[2026-05-25 19:01:10.040]: Info: [pipewire] Requested frame rate [60/1, approx. 60 fps]
[2026-05-25 19:01:10.040]: Info: [wayland] Found display [wayland-0]
[2026-05-25 19:01:10.045]: Info: [portalgrab] Loaded portal restore token from disk
[2026-05-25 19:01:10.054]: Info: [wayland] Found display [wayland-0]
[2026-05-25 19:01:10.056]: Info: [wayland] Found interface: zxdg_output_manager_v1(31) version 3
[2026-05-25 19:01:10.056]: Info: [wayland] Found interface: zwp_linux_dmabuf_v1(57) version 5
[2026-05-25 19:01:10.056]: Info: [wayland] Found interface: wl_output(129) version 4
[2026-05-25 19:01:10.056]: Info: [wayland] Found interface: wl_output(133) version 4
[2026-05-25 19:01:10.056]: Info: [wayland] Resolution: 1920x1080
[2026-05-25 19:01:10.056]: Info: [wayland] Resolution: 3440x1440
[2026-05-25 19:01:10.056]: Info: [wayland] Offset: 3440x180
[2026-05-25 19:01:10.056]: Info: [wayland] Logical size: 1920x1080
[2026-05-25 19:01:10.056]: Info: [wayland] Name: DP-2
[2026-05-25 19:01:10.056]: Info: [wayland] Found monitor: Lenovo Group Limited LEN T22i-10
[2026-05-25 19:01:10.056]: Info: [wayland] Offset: 0x0
[2026-05-25 19:01:10.056]: Info: [wayland] Logical size: 3440x1440
[2026-05-25 19:01:10.056]: Info: [wayland] Name: DP-1
[2026-05-25 19:01:10.056]: Info: [wayland] Found monitor: LG Electronics LG ULTRAGEAR
[2026-05-25 19:01:10.057]: Info: [portalgrab] Using first available stream as no matching stream was found for: '0'
[2026-05-25 19:01:10.057]: Info: [pipewire] Streaming display '0' offset: 0x0 resolution: 3440x1440
[2026-05-25 19:01:10.057]: Info: [wayland] Found display [wayland-0]
[2026-05-25 19:01:10.059]: Info: [wayland] Found interface: zxdg_output_manager_v1(31) version 3
[2026-05-25 19:01:10.059]: Info: [wayland] Found interface: zwp_linux_dmabuf_v1(57) version 5
[2026-05-25 19:01:10.059]: Info: [wayland] Found interface: wl_output(129) version 4
[2026-05-25 19:01:10.059]: Info: [wayland] Found interface: wl_output(133) version 4
[2026-05-25 19:01:10.059]: Info: [wayland] Resolution: 1920x1080
[2026-05-25 19:01:10.059]: Info: [wayland] Resolution: 3440x1440
[2026-05-25 19:01:10.059]: Info: [wayland] Offset: 3440x180
[2026-05-25 19:01:10.059]: Info: [wayland] Logical size: 1920x1080
[2026-05-25 19:01:10.059]: Info: [wayland] Name: DP-2
[2026-05-25 19:01:10.059]: Info: [wayland] Found monitor: Lenovo Group Limited LEN T22i-10
[2026-05-25 19:01:10.059]: Info: [wayland] Offset: 0x0
[2026-05-25 19:01:10.059]: Info: [wayland] Logical size: 3440x1440
[2026-05-25 19:01:10.059]: Info: [wayland] Name: DP-1
[2026-05-25 19:01:10.059]: Info: [wayland] Found monitor: LG Electronics LG ULTRAGEAR
[2026-05-25 19:01:10.060]: Info: [pipewire] Connected to pipewire version 1.6.5
[2026-05-25 19:01:10.062]: Info: [pipewire] Video format: 12
[2026-05-25 19:01:10.062]: Info: [pipewire] Size: 3440x1440
[2026-05-25 19:01:10.062]: Info: [pipewire] Color primaries: 0
[2026-05-25 19:01:10.062]: Info: [pipewire] Transfer function: 0
[2026-05-25 19:01:10.062]: Info: [pipewire] Framerate (from compositor): 0/1 (variable rate capture)
[2026-05-25 19:01:10.062]: Info: [pipewire] using DMA-BUF buffers
[2026-05-25 19:01:10.062]: Info: [pipewire] Video format: 12
[2026-05-25 19:01:10.062]: Info: [pipewire] Size: 3440x1440
[2026-05-25 19:01:10.062]: Info: [pipewire] Color primaries: 0
[2026-05-25 19:01:10.062]: Info: [pipewire] Transfer function: 0
[2026-05-25 19:01:10.062]: Info: [pipewire] Framerate (from compositor): 0/1 (variable rate capture)
[2026-05-25 19:01:10.062]: Info: [pipewire] using DMA-BUF buffers
[2026-05-25 19:01:10.070]: Info: Creating encoder [hevc_vaapi]
[2026-05-25 19:01:10.070]: Info: Color coding: SDR (Rec. 709)
[2026-05-25 19:01:10.070]: Info: Color depth: 10-bit
[2026-05-25 19:01:10.070]: Info: Color range: JPEG
[2026-05-25 19:01:10.076]: Warning: EGL: context priority set to HIGH but CAP_SYS_NICE capability is missing
[2026-05-25 19:01:10.080]: Info: vaapi vendor: Mesa Gallium driver 26.0.6 for AMD Radeon RX 7900 XTX (radeonsi, navi31, ACO, DRM 3.64, 7.0.9-205.fc44.x86_64)
[2026-05-25 19:01:10.080]: Info: Streaming bitrate is 1000000
[2026-05-25 19:01:10.080]: Info: Using normal encoding mode
[2026-05-25 19:01:10.080]: Info: Using default rate control
[2026-05-25 19:01:10.098]: Info: Creating encoder [av1_vaapi]
[2026-05-25 19:01:10.098]: Info: Color coding: SDR (Rec. 709)
[2026-05-25 19:01:10.098]: Info: Color depth: 10-bit
[2026-05-25 19:01:10.098]: Info: Color range: JPEG
[2026-05-25 19:01:10.101]: Warning: EGL: context priority set to HIGH but CAP_SYS_NICE capability is missing
[2026-05-25 19:01:10.103]: Info: vaapi vendor: Mesa Gallium driver 26.0.6 for AMD Radeon RX 7900 XTX (radeonsi, navi31, ACO, DRM 3.64, 7.0.9-205.fc44.x86_64)
[2026-05-25 19:01:10.104]: Info: Streaming bitrate is 1000000
[2026-05-25 19:01:10.104]: Info: Using normal encoding mode
[2026-05-25 19:01:10.104]: Info: Using VBR with single frame VBV size
[2026-05-25 19:01:10.104]: Warning: [av1_vaapi @ 0x7f61fc4e56c0] Multiple slices were requested but this codec does not support controlling slices.
[2026-05-25 19:01:10.117]: Info: // Testing for available encoders, this may generate errors. You can safely ignore those errors. //
[2026-05-25 19:01:10.117]: Info: 
[2026-05-25 19:01:10.117]: Info: // Ignore any errors mentioned above, they are not relevant. //
[2026-05-25 19:01:10.117]: Info: 
[2026-05-25 19:01:10.117]: Info: Found H.264 encoder: h264_vaapi [vaapi]
[2026-05-25 19:01:10.117]: Info: Found HEVC encoder: hevc_vaapi [vaapi]
[2026-05-25 19:01:10.117]: Info: Found AV1 encoder: av1_vaapi [vaapi]
[2026-05-25 19:01:10.117]: Info: Executing Do Cmd: [sh -c "/home/slash/Applications/scripts/sunshine-do.sh ${SUNSHINE_CLIENT_WIDTH} ${SUNSHINE_CLIENT_HEIGHT} ${SUNSHINE_CLIENT_FPS} ${SUNSHINE_CLIENT_HDR}"]
[2026-05-25 19:01:10.157]: Info: Qt: There are no outputs - creating placeholder screen
[2026-05-25 19:01:10.164]: Info: Spawning [setsid steam steam://open/bigpicture] in ["/usr/bin"]
[2026-05-25 19:01:10.178]: Info: Executing [Desktop]
[2026-05-25 19:01:10.269]: Info: New streaming session started [active sessions: 1]
[2026-05-25 19:01:10.464]: Info: CLIENT CONNECTED
[2026-05-25 19:01:10.465]: Info: [portalgrab] Loaded portal restore token from disk
[2026-05-25 19:01:10.471]: Info: [wayland] Found display [wayland-0]
[2026-05-25 19:01:10.474]: Info: [wayland] Found interface: zxdg_output_manager_v1(31) version 3
[2026-05-25 19:01:10.474]: Info: [wayland] Found interface: zwp_linux_dmabuf_v1(57) version 5
[2026-05-25 19:01:10.474]: Info: [wayland] Found interface: wl_output(134) version 4
[2026-05-25 19:01:10.474]: Info: [wayland] Resolution: 3840x2160
[2026-05-25 19:01:10.474]: Info: [wayland] Offset: 0x0
[2026-05-25 19:01:10.474]: Info: [wayland] Logical size: 1920x1080
[2026-05-25 19:01:10.474]: Info: [wayland] Name: DP-3
[2026-05-25 19:01:10.474]: Info: [wayland] Found monitor: LG Electronics LG TV
[2026-05-25 19:01:10.476]: Info: [portalgrab] Found stream for display id/name: 'DP-3' position: 0x0 resolution: 1920x1080
[2026-05-25 19:01:10.477]: Info: Screencasting with XDG portal
[2026-05-25 19:01:10.477]: Info: [pipewire] Requested frame rate [120fps]
[2026-05-25 19:01:10.477]: Info: [wayland] Found display [wayland-0]
[2026-05-25 19:01:10.482]: Info: [portalgrab] Loaded portal restore token from disk
[2026-05-25 19:01:10.489]: Info: [wayland] Found display [wayland-0]
[2026-05-25 19:01:10.492]: Info: [wayland] Found interface: zxdg_output_manager_v1(31) version 3
[2026-05-25 19:01:10.492]: Info: [wayland] Found interface: zwp_linux_dmabuf_v1(57) version 5
[2026-05-25 19:01:10.492]: Info: [wayland] Found interface: wl_output(134) version 4
[2026-05-25 19:01:10.492]: Info: [wayland] Resolution: 3840x2160
[2026-05-25 19:01:10.492]: Info: [wayland] Offset: 0x0
[2026-05-25 19:01:10.492]: Info: [wayland] Logical size: 1920x1080
[2026-05-25 19:01:10.492]: Info: [wayland] Name: DP-3
[2026-05-25 19:01:10.492]: Info: [wayland] Found monitor: LG Electronics LG TV
[2026-05-25 19:01:10.493]: Info: [pipewire] Streaming display 'DP-3' offset: 0x0 resolution: 1920x1080
[2026-05-25 19:01:10.493]: Info: [wayland] Found display [wayland-0]
[2026-05-25 19:01:10.494]: Info: [wayland] Found interface: zxdg_output_manager_v1(31) version 3
[2026-05-25 19:01:10.495]: Info: [wayland] Found interface: zwp_linux_dmabuf_v1(57) version 5
[2026-05-25 19:01:10.495]: Info: [wayland] Found interface: wl_output(134) version 4
[2026-05-25 19:01:10.495]: Info: [wayland] Resolution: 3840x2160
[2026-05-25 19:01:10.495]: Info: [wayland] Offset: 0x0
[2026-05-25 19:01:10.495]: Info: [wayland] Logical size: 1920x1080
[2026-05-25 19:01:10.495]: Info: [wayland] Name: DP-3
[2026-05-25 19:01:10.495]: Info: [wayland] Found monitor: LG Electronics LG TV
[2026-05-25 19:01:10.496]: Info: [pipewire] Connected to pipewire version 1.6.5
[2026-05-25 19:01:10.498]: Info: [pipewire] Video format: 12
[2026-05-25 19:01:10.498]: Info: [pipewire] Size: 3840x2160
[2026-05-25 19:01:10.498]: Info: [pipewire] Color primaries: 0
[2026-05-25 19:01:10.498]: Info: [pipewire] Transfer function: 0
[2026-05-25 19:01:10.498]: Info: [pipewire] Framerate (from compositor): 0/1 (variable rate capture)
[2026-05-25 19:01:10.498]: Info: [pipewire] using DMA-BUF buffers
[2026-05-25 19:01:10.499]: Info: [pipewire] Video format: 12
[2026-05-25 19:01:10.499]: Info: [pipewire] Size: 3840x2160
[2026-05-25 19:01:10.499]: Info: [pipewire] Color primaries: 0
[2026-05-25 19:01:10.499]: Info: [pipewire] Transfer function: 0
[2026-05-25 19:01:10.499]: Info: [pipewire] Framerate (from compositor): 0/1 (variable rate capture)
[2026-05-25 19:01:10.499]: Info: [pipewire] using DMA-BUF buffers
[2026-05-25 19:01:10.506]: Info: [pipewire] Using negotiated Resolution: 3840x2160
[2026-05-25 19:01:10.506]: Info: [wayland] Found display [wayland-0]
[2026-05-25 19:01:10.508]: Info: [wayland] Found interface: zxdg_output_manager_v1(31) version 3
[2026-05-25 19:01:10.508]: Info: [wayland] Found interface: zwp_linux_dmabuf_v1(57) version 5
[2026-05-25 19:01:10.508]: Info: [wayland] Found interface: wl_output(134) version 4
[2026-05-25 19:01:10.508]: Info: [wayland] Resolution: 3840x2160
[2026-05-25 19:01:10.508]: Info: [wayland] Offset: 0x0
[2026-05-25 19:01:10.508]: Info: [wayland] Logical size: 1920x1080
[2026-05-25 19:01:10.508]: Info: [wayland] Name: DP-3
[2026-05-25 19:01:10.508]: Info: [wayland] Found monitor: LG Electronics LG TV
[2026-05-25 19:01:10.508]: Info: Creating encoder [hevc_vaapi]
[2026-05-25 19:01:10.508]: Info: Color coding: SDR (Rec. 601)
[2026-05-25 19:01:10.508]: Info: Color depth: 8-bit
[2026-05-25 19:01:10.508]: Info: Color range: MPEG
[2026-05-25 19:01:10.512]: Warning: EGL: context priority set to HIGH but CAP_SYS_NICE capability is missing
[2026-05-25 19:01:10.516]: Info: vaapi vendor: Mesa Gallium driver 26.0.6 for AMD Radeon RX 7900 XTX (radeonsi, navi31, ACO, DRM 3.64, 7.0.9-205.fc44.x86_64)
[2026-05-25 19:01:10.516]: Info: Streaming bitrate is 117964000
[2026-05-25 19:01:10.516]: Info: Using normal encoding mode
[2026-05-25 19:01:10.516]: Info: Using default rate control
[2026-05-25 19:01:10.520]: Info: Minimum FPS target set to ~60fps (16.6667ms)
[2026-05-25 19:01:10.549]: Warning: Skipping FEC for abnormally large encoded frame (needed 7 FEC blocks)
[2026-05-25 19:01:10.719]: Warning: Skipping FEC for abnormally large encoded frame (needed 13 FEC blocks)
[2026-05-25 19:01:10.748]: Info: Setting default sink to: [sink-sunshine-surround51]
[2026-05-25 19:01:10.748]: Info: Found default monitor by name: sink-sunshine-surround51.monitor
[2026-05-25 19:01:10.752]: Info: Gamepad 0 will be Xbox One controller (default)
[2026-05-25 19:01:10.779]: Info: Opus initialized: 48 kHz, 6 channels, 1536 kbps (total), LOWDELAY
[2026-05-25 19:01:10.858]: Warning: Skipping FEC for abnormally large encoded frame (needed 8 FEC blocks)
[2026-05-25 19:01:10.879]: Warning: Skipping FEC for abnormally large encoded frame (needed 7 FEC blocks)
[2026-05-25 19:01:30.933]: Warning: Skipping FEC for abnormally large encoded frame (needed 5 FEC blocks)
[2026-05-25 19:02:25.486]: Warning: Skipping FEC for abnormally large encoded frame (needed 5 FEC blocks)
[2026-05-25 19:02:34.251]: Warning: Skipping FEC for abnormally large encoded frame (needed 8 FEC blocks)
[2026-05-25 19:03:48.463]: Warning: Skipping FEC for abnormally large encoded frame (needed 5 FEC blocks)
[2026-05-25 19:04:03.535]: Warning: Skipping FEC for abnormally large encoded frame (needed 5 FEC blocks)
[2026-05-25 19:04:36.296]: Warning: Skipping FEC for abnormally large encoded frame (needed 8 FEC blocks)
[2026-05-25 19:05:52.325]: Warning: Skipping FEC for abnormally large encoded frame (needed 5 FEC blocks)
[2026-05-25 19:06:26.689]: Warning: Skipping FEC for abnormally large encoded frame (needed 5 FEC blocks)
[2026-05-25 19:06:50.887]: Warning: Skipping FEC for abnormally large encoded frame (needed 8 FEC blocks)
[2026-05-25 19:06:55.463]: Warning: Skipping FEC for abnormally large encoded frame (needed 9 FEC blocks)
[2026-05-25 19:08:57.032]: Warning: Skipping FEC for abnormally large encoded frame (needed 5 FEC blocks)
[2026-05-25 19:09:00.231]: Warning: Skipping FEC for abnormally large encoded frame (needed 5 FEC blocks)
[2026-05-25 19:09:05.564]: Warning: Skipping FEC for abnormally large encoded frame (needed 8 FEC blocks)
[2026-05-25 19:09:20.442]: Warning: Skipping FEC for abnormally large encoded frame (needed 13 FEC blocks)
[2026-05-25 19:09:20.463]: Info: CLIENT DISCONNECTED
[2026-05-25 19:09:20.467]: Info: Setting default sink to: [alsa_output.pci-0000_00_1f.3.analog-stereo]
[2026-05-25 19:09:27.830]: Info: Executing Undo Cmd: [sh -c "/home/slash/Applications/scripts/sunshine-undo.sh"]
[2026-05-25 19:09:27.876]: Info: Qt: There are no outputs - creating placeholder screen

Online logs

No response

[Kishi85]

Out of curiosity since you're using KDE, does this also happen with kwingrab?

EDIT: Another thing you could test is using the Vulkan encoder and see if there's anything different using that.

[psyke83]

This is your problem:

[2026-05-25 19:01:09.929]: Info: [pipewire] Requested frame rate [60/1, approx. 60 fps]
[2026-05-25 19:01:10.520]: Info: Minimum FPS target set to ~60fps (16.6667ms) <-- here

The minimum_fps_target value should never be set so close to the actual stream framerate. Pipewire capture is particularly sensitive to this setting due to multiple frames arriving in close/ irregular intervals which triggers erroneous duplicate frame insertion. You'll see an even worse effect (a consistent 90fps) if you try to display content running at 45fps on your 60fps stream with the exact settings shown in your logs. Change or reset the value of the Minimum FPS target so that it's no more than half the stream framerate.

[Slashic]

Out of curiosity since you're using KDE, does this also happen with kwingrab?

EDIT: Another thing you could test is using the Vulkan encoder and see if there's anything different using that.

Kwin capture and the Vulkan encoder behaves the exact same way as XDG and Vaapi.

The minimum_fps_target value should never be set so close to the actual stream framerate. Pipewire capture is particularly sensitive to this setting due to multiple frames arriving in close/ irregular intervals which triggers erroneous duplicate frame insertion. You'll see an even worse effect (a consistent 90fps) if you try to display content running at 45fps on your 60fps stream with the exact settings shown in your logs. Change or reset the value of the Minimum FPS target so that it's no more than half the stream framerate.

Thanks for the suggestion, unfortunately setting this value to 20 doesn't solve the issue (i also tried, 1,30,40):

[2026-05-26 19:08:34.196]: Info: Trying encoder [vaapi]
[2026-05-26 19:08:34.196]: Info: Screencasting with XDG portal
[2026-05-26 19:08:34.197]: Info: [pipewire] Requested frame rate [60/1, approx. 60 fps]
[2026-05-26 19:08:34.197]: Info: [wayland] Found display [wayland-0]
[2026-05-26 19:08:34.203]: Info: [portalgrab] Loaded portal restore token from disk
[2026-05-26 19:08:34.215]: Info: [wayland] Found display [wayland-0]
[2026-05-26 19:08:34.217]: Info: [wayland] Found interface: zxdg_output_manager_v1(31) version 3
[2026-05-26 19:08:34.217]: Info: [wayland] Found interface: zwp_linux_dmabuf_v1(57) version 5
[2026-05-26 19:08:34.217]: Info: [wayland] Found interface: wl_output(98) version 4
[2026-05-26 19:08:34.217]: Info: [wayland] Found interface: wl_output(102) version 4
[2026-05-26 19:08:34.217]: Info: [wayland] Resolution: 1920x1080
[2026-05-26 19:08:34.217]: Info: [wayland] Resolution: 3440x1440
[2026-05-26 19:08:34.217]: Info: [wayland] Offset: 3440x180
[2026-05-26 19:08:34.217]: Info: [wayland] Logical size: 1920x1080
[2026-05-26 19:08:34.217]: Info: [wayland] Name: DP-2
[2026-05-26 19:08:34.217]: Info: [wayland] Found monitor: Lenovo Group Limited LEN T22i-10
[2026-05-26 19:08:34.217]: Info: [wayland] Offset: 0x0
[2026-05-26 19:08:34.217]: Info: [wayland] Logical size: 3440x1440
[2026-05-26 19:08:34.217]: Info: [wayland] Name: DP-1
[2026-05-26 19:08:34.217]: Info: [wayland] Found monitor: LG Electronics LG ULTRAGEAR
[2026-05-26 19:08:34.218]: Info: [portalgrab] Using first available stream as no matching stream was found for: '0'
[2026-05-26 19:08:34.218]: Info: [pipewire] Streaming display '0' offset: 0x0 resolution: 3440x1440
[2026-05-26 19:08:34.218]: Info: [wayland] Found display [wayland-0]
[2026-05-26 19:08:34.219]: Info: [wayland] Found interface: zxdg_output_manager_v1(31) version 3
[2026-05-26 19:08:34.219]: Info: [wayland] Found interface: zwp_linux_dmabuf_v1(57) version 5
[2026-05-26 19:08:34.219]: Info: [wayland] Found interface: wl_output(98) version 4
[2026-05-26 19:08:34.219]: Info: [wayland] Found interface: wl_output(102) version 4
[2026-05-26 19:08:34.219]: Info: [wayland] Resolution: 1920x1080
[2026-05-26 19:08:34.219]: Info: [wayland] Resolution: 3440x1440
[2026-05-26 19:08:34.219]: Info: [wayland] Offset: 3440x180
[2026-05-26 19:08:34.219]: Info: [wayland] Logical size: 1920x1080
[2026-05-26 19:08:34.219]: Info: [wayland] Name: DP-2
[2026-05-26 19:08:34.219]: Info: [wayland] Found monitor: Lenovo Group Limited LEN T22i-10
[2026-05-26 19:08:34.219]: Info: [wayland] Offset: 0x0
[2026-05-26 19:08:34.219]: Info: [wayland] Logical size: 3440x1440
[2026-05-26 19:08:34.219]: Info: [wayland] Name: DP-1
[2026-05-26 19:08:34.219]: Info: [wayland] Found monitor: LG Electronics LG ULTRAGEAR
[2026-05-26 19:08:34.221]: Info: [pipewire] Connected to pipewire version 1.6.5
[2026-05-26 19:08:34.223]: Info: [pipewire] Video format: 12
[2026-05-26 19:08:34.223]: Info: [pipewire] Size: 3440x1440
[2026-05-26 19:08:34.223]: Info: [pipewire] Color primaries: 0
[2026-05-26 19:08:34.223]: Info: [pipewire] Transfer function: 0
[2026-05-26 19:08:34.223]: Info: [pipewire] Framerate (from compositor): 0/1 (variable rate capture)
[2026-05-26 19:08:34.223]: Info: [pipewire] using DMA-BUF buffers
[2026-05-26 19:08:34.223]: Info: [pipewire] Video format: 12
[2026-05-26 19:08:34.223]: Info: [pipewire] Size: 3440x1440
[2026-05-26 19:08:34.223]: Info: [pipewire] Color primaries: 0
[2026-05-26 19:08:34.223]: Info: [pipewire] Transfer function: 0
[2026-05-26 19:08:34.223]: Info: [pipewire] Framerate (from compositor): 0/1 (variable rate capture)
[2026-05-26 19:08:34.223]: Info: [pipewire] using DMA-BUF buffers
[2026-05-26 19:08:34.230]: Info: Creating encoder [h264_vaapi]
[2026-05-26 19:08:34.230]: Info: Color coding: SDR (Rec. 601)
[2026-05-26 19:08:34.230]: Info: Color depth: 8-bit
[2026-05-26 19:08:34.230]: Info: Color range: JPEG
[2026-05-26 19:08:34.234]: Warning: EGL: context priority set to HIGH but CAP_SYS_NICE capability is missing
[2026-05-26 19:08:34.236]: Info: vaapi vendor: Mesa Gallium driver 26.0.6 for AMD Radeon RX 7900 XTX (radeonsi, navi31, ACO, DRM 3.64, 7.0.9-205.fc44.x86_64)
[2026-05-26 19:08:34.237]: Info: Streaming bitrate is 1000000
[2026-05-26 19:08:34.237]: Info: Using normal encoding mode
[2026-05-26 19:08:34.237]: Info: Using default rate control
[2026-05-26 19:08:34.253]: Info: Creating encoder [hevc_vaapi]
[2026-05-26 19:08:34.254]: Info: Color coding: SDR (Rec. 601)
[2026-05-26 19:08:34.254]: Info: Color depth: 8-bit
[2026-05-26 19:08:34.254]: Info: Color range: JPEG
[2026-05-26 19:08:34.257]: Warning: EGL: context priority set to HIGH but CAP_SYS_NICE capability is missing
[2026-05-26 19:08:34.261]: Info: vaapi vendor: Mesa Gallium driver 26.0.6 for AMD Radeon RX 7900 XTX (radeonsi, navi31, ACO, DRM 3.64, 7.0.9-205.fc44.x86_64)
[2026-05-26 19:08:34.261]: Info: Streaming bitrate is 1000000
[2026-05-26 19:08:34.261]: Info: Using normal encoding mode
[2026-05-26 19:08:34.261]: Info: Using default rate control
[2026-05-26 19:08:34.276]: Info: Creating encoder [av1_vaapi]
[2026-05-26 19:08:34.276]: Info: Color coding: SDR (Rec. 601)
[2026-05-26 19:08:34.276]: Info: Color depth: 8-bit
[2026-05-26 19:08:34.276]: Info: Color range: JPEG
[2026-05-26 19:08:34.279]: Warning: EGL: context priority set to HIGH but CAP_SYS_NICE capability is missing
[2026-05-26 19:08:34.281]: Info: vaapi vendor: Mesa Gallium driver 26.0.6 for AMD Radeon RX 7900 XTX (radeonsi, navi31, ACO, DRM 3.64, 7.0.9-205.fc44.x86_64)
[2026-05-26 19:08:34.281]: Info: Streaming bitrate is 1000000
[2026-05-26 19:08:34.281]: Info: Using normal encoding mode
[2026-05-26 19:08:34.281]: Info: Using VBR with single frame VBV size
[2026-05-26 19:08:34.281]: Warning: [av1_vaapi @ 0x7f51e839e580] Multiple slices were requested but this codec does not support controlling slices.
[2026-05-26 19:08:34.295]: Info: Screencasting with XDG portal
[2026-05-26 19:08:34.295]: Info: [pipewire] Requested frame rate [60/1, approx. 60 fps]
[2026-05-26 19:08:34.296]: Info: [wayland] Found display [wayland-0]
[2026-05-26 19:08:34.301]: Info: [portalgrab] Loaded portal restore token from disk
[2026-05-26 19:08:34.308]: Info: [wayland] Found display [wayland-0]
[2026-05-26 19:08:34.309]: Info: [wayland] Found interface: zxdg_output_manager_v1(31) version 3
[2026-05-26 19:08:34.309]: Info: [wayland] Found interface: zwp_linux_dmabuf_v1(57) version 5
[2026-05-26 19:08:34.309]: Info: [wayland] Found interface: wl_output(98) version 4
[2026-05-26 19:08:34.309]: Info: [wayland] Found interface: wl_output(102) version 4
[2026-05-26 19:08:34.309]: Info: [wayland] Resolution: 1920x1080
[2026-05-26 19:08:34.309]: Info: [wayland] Resolution: 3440x1440
[2026-05-26 19:08:34.309]: Info: [wayland] Offset: 3440x180
[2026-05-26 19:08:34.309]: Info: [wayland] Logical size: 1920x1080
[2026-05-26 19:08:34.309]: Info: [wayland] Name: DP-2
[2026-05-26 19:08:34.309]: Info: [wayland] Found monitor: Lenovo Group Limited LEN T22i-10
[2026-05-26 19:08:34.309]: Info: [wayland] Offset: 0x0
[2026-05-26 19:08:34.309]: Info: [wayland] Logical size: 3440x1440
[2026-05-26 19:08:34.309]: Info: [wayland] Name: DP-1
[2026-05-26 19:08:34.309]: Info: [wayland] Found monitor: LG Electronics LG ULTRAGEAR
[2026-05-26 19:08:34.310]: Info: [portalgrab] Using first available stream as no matching stream was found for: '0'
[2026-05-26 19:08:34.310]: Info: [pipewire] Streaming display '0' offset: 0x0 resolution: 3440x1440
[2026-05-26 19:08:34.310]: Info: [wayland] Found display [wayland-0]
[2026-05-26 19:08:34.312]: Info: [wayland] Found interface: zxdg_output_manager_v1(31) version 3
[2026-05-26 19:08:34.312]: Info: [wayland] Found interface: zwp_linux_dmabuf_v1(57) version 5
[2026-05-26 19:08:34.312]: Info: [wayland] Found interface: wl_output(98) version 4
[2026-05-26 19:08:34.312]: Info: [wayland] Found interface: wl_output(102) version 4
[2026-05-26 19:08:34.312]: Info: [wayland] Resolution: 1920x1080
[2026-05-26 19:08:34.312]: Info: [wayland] Resolution: 3440x1440
[2026-05-26 19:08:34.312]: Info: [wayland] Offset: 3440x180
[2026-05-26 19:08:34.312]: Info: [wayland] Logical size: 1920x1080
[2026-05-26 19:08:34.312]: Info: [wayland] Name: DP-2
[2026-05-26 19:08:34.312]: Info: [wayland] Found monitor: Lenovo Group Limited LEN T22i-10
[2026-05-26 19:08:34.312]: Info: [wayland] Offset: 0x0
[2026-05-26 19:08:34.312]: Info: [wayland] Logical size: 3440x1440
[2026-05-26 19:08:34.312]: Info: [wayland] Name: DP-1
[2026-05-26 19:08:34.312]: Info: [wayland] Found monitor: LG Electronics LG ULTRAGEAR
[2026-05-26 19:08:34.313]: Info: [pipewire] Connected to pipewire version 1.6.5
[2026-05-26 19:08:34.315]: Info: [pipewire] Video format: 12
[2026-05-26 19:08:34.315]: Info: [pipewire] Size: 3440x1440
[2026-05-26 19:08:34.315]: Info: [pipewire] Color primaries: 0
[2026-05-26 19:08:34.315]: Info: [pipewire] Transfer function: 0
[2026-05-26 19:08:34.315]: Info: [pipewire] Framerate (from compositor): 0/1 (variable rate capture)
[2026-05-26 19:08:34.315]: Info: [pipewire] using DMA-BUF buffers
[2026-05-26 19:08:34.315]: Info: [pipewire] Video format: 12
[2026-05-26 19:08:34.315]: Info: [pipewire] Size: 3440x1440
[2026-05-26 19:08:34.315]: Info: [pipewire] Color primaries: 0
[2026-05-26 19:08:34.315]: Info: [pipewire] Transfer function: 0
[2026-05-26 19:08:34.315]: Info: [pipewire] Framerate (from compositor): 0/1 (variable rate capture)
[2026-05-26 19:08:34.315]: Info: [pipewire] using DMA-BUF buffers
[2026-05-26 19:08:34.323]: Info: Creating encoder [hevc_vaapi]
[2026-05-26 19:08:34.323]: Info: Color coding: SDR (Rec. 709)
[2026-05-26 19:08:34.323]: Info: Color depth: 10-bit
[2026-05-26 19:08:34.323]: Info: Color range: JPEG
[2026-05-26 19:08:34.327]: Warning: EGL: context priority set to HIGH but CAP_SYS_NICE capability is missing
[2026-05-26 19:08:34.331]: Info: vaapi vendor: Mesa Gallium driver 26.0.6 for AMD Radeon RX 7900 XTX (radeonsi, navi31, ACO, DRM 3.64, 7.0.9-205.fc44.x86_64)
[2026-05-26 19:08:34.331]: Info: Streaming bitrate is 1000000
[2026-05-26 19:08:34.331]: Info: Using normal encoding mode
[2026-05-26 19:08:34.331]: Info: Using default rate control
[2026-05-26 19:08:34.348]: Info: Creating encoder [av1_vaapi]
[2026-05-26 19:08:34.348]: Info: Color coding: SDR (Rec. 709)
[2026-05-26 19:08:34.348]: Info: Color depth: 10-bit
[2026-05-26 19:08:34.348]: Info: Color range: JPEG
[2026-05-26 19:08:34.352]: Warning: EGL: context priority set to HIGH but CAP_SYS_NICE capability is missing
[2026-05-26 19:08:34.354]: Info: vaapi vendor: Mesa Gallium driver 26.0.6 for AMD Radeon RX 7900 XTX (radeonsi, navi31, ACO, DRM 3.64, 7.0.9-205.fc44.x86_64)
[2026-05-26 19:08:34.354]: Info: Streaming bitrate is 1000000
[2026-05-26 19:08:34.354]: Info: Using normal encoding mode
[2026-05-26 19:08:34.354]: Info: Using VBR with single frame VBV size
[2026-05-26 19:08:34.354]: Warning: [av1_vaapi @ 0x7f51e81a9c00] Multiple slices were requested but this codec does not support controlling slices.
[2026-05-26 19:08:34.366]: Info: // Testing for available encoders, this may generate errors. You can safely ignore those errors. //
[2026-05-26 19:08:34.366]: Info: 
[2026-05-26 19:08:34.366]: Info: // Ignore any errors mentioned above, they are not relevant. //
[2026-05-26 19:08:34.366]: Info: 
[2026-05-26 19:08:34.366]: Info: Found H.264 encoder: h264_vaapi [vaapi]
[2026-05-26 19:08:34.366]: Info: Found HEVC encoder: hevc_vaapi [vaapi]
[2026-05-26 19:08:34.366]: Info: Found AV1 encoder: av1_vaapi [vaapi]
[2026-05-26 19:08:34.367]: Info: Executing Do Cmd: [sh -c "/home/slash/Applications/scripts/sunshine-do.sh ${SUNSHINE_CLIENT_WIDTH} ${SUNSHINE_CLIENT_HEIGHT} ${SUNSHINE_CLIENT_FPS} ${SUNSHINE_CLIENT_HDR}"]
[2026-05-26 19:08:34.404]: Info: Qt: There are no outputs - creating placeholder screen
[2026-05-26 19:08:34.409]: Info: Spawning [setsid steam steam://open/bigpicture] in ["/usr/bin"]
[2026-05-26 19:08:34.415]: Info: Executing [Desktop]
[2026-05-26 19:08:34.493]: Info: New streaming session started [active sessions: 1]
[2026-05-26 19:08:34.704]: Info: CLIENT CONNECTED
[2026-05-26 19:08:34.705]: Info: [portalgrab] Loaded portal restore token from disk
[2026-05-26 19:08:34.712]: Info: [wayland] Found display [wayland-0]
[2026-05-26 19:08:34.714]: Info: [wayland] Found interface: zxdg_output_manager_v1(31) version 3
[2026-05-26 19:08:34.714]: Info: [wayland] Found interface: zwp_linux_dmabuf_v1(57) version 5
[2026-05-26 19:08:34.714]: Info: [wayland] Found interface: wl_output(103) version 4
[2026-05-26 19:08:34.715]: Info: [wayland] Resolution: 3840x2160
[2026-05-26 19:08:34.715]: Info: [wayland] Offset: 0x0
[2026-05-26 19:08:34.715]: Info: [wayland] Logical size: 1920x1080
[2026-05-26 19:08:34.715]: Info: [wayland] Name: DP-3
[2026-05-26 19:08:34.715]: Info: [wayland] Found monitor: LG Electronics LG TV
[2026-05-26 19:08:34.716]: Info: [portalgrab] Found stream for display id/name: 'DP-3' position: 0x0 resolution: 1920x1080
[2026-05-26 19:08:34.716]: Info: Screencasting with XDG portal
[2026-05-26 19:08:34.717]: Info: [pipewire] Requested frame rate [120fps]
[2026-05-26 19:08:34.717]: Info: [wayland] Found display [wayland-0]
[2026-05-26 19:08:34.722]: Info: [portalgrab] Loaded portal restore token from disk
[2026-05-26 19:08:34.728]: Info: [wayland] Found display [wayland-0]
[2026-05-26 19:08:34.730]: Info: [wayland] Found interface: zxdg_output_manager_v1(31) version 3
[2026-05-26 19:08:34.730]: Info: [wayland] Found interface: zwp_linux_dmabuf_v1(57) version 5
[2026-05-26 19:08:34.730]: Info: [wayland] Found interface: wl_output(103) version 4
[2026-05-26 19:08:34.730]: Info: [wayland] Resolution: 3840x2160
[2026-05-26 19:08:34.730]: Info: [wayland] Offset: 0x0
[2026-05-26 19:08:34.730]: Info: [wayland] Logical size: 1920x1080
[2026-05-26 19:08:34.730]: Info: [wayland] Name: DP-3
[2026-05-26 19:08:34.730]: Info: [wayland] Found monitor: LG Electronics LG TV
[2026-05-26 19:08:34.731]: Info: [pipewire] Streaming display 'DP-3' offset: 0x0 resolution: 1920x1080
[2026-05-26 19:08:34.731]: Info: [wayland] Found display [wayland-0]
[2026-05-26 19:08:34.733]: Info: [wayland] Found interface: zxdg_output_manager_v1(31) version 3
[2026-05-26 19:08:34.733]: Info: [wayland] Found interface: zwp_linux_dmabuf_v1(57) version 5
[2026-05-26 19:08:34.733]: Info: [wayland] Found interface: wl_output(103) version 4
[2026-05-26 19:08:34.733]: Info: [wayland] Resolution: 3840x2160
[2026-05-26 19:08:34.733]: Info: [wayland] Offset: 0x0
[2026-05-26 19:08:34.733]: Info: [wayland] Logical size: 1920x1080
[2026-05-26 19:08:34.733]: Info: [wayland] Name: DP-3
[2026-05-26 19:08:34.733]: Info: [wayland] Found monitor: LG Electronics LG TV
[2026-05-26 19:08:34.734]: Info: [pipewire] Connected to pipewire version 1.6.5
[2026-05-26 19:08:34.736]: Info: [pipewire] Video format: 12
[2026-05-26 19:08:34.737]: Info: [pipewire] Size: 3840x2160
[2026-05-26 19:08:34.737]: Info: [pipewire] Color primaries: 0
[2026-05-26 19:08:34.737]: Info: [pipewire] Transfer function: 0
[2026-05-26 19:08:34.737]: Info: [pipewire] Framerate (from compositor): 0/1 (variable rate capture)
[2026-05-26 19:08:34.737]: Info: [pipewire] using DMA-BUF buffers
[2026-05-26 19:08:34.737]: Info: [pipewire] Video format: 12
[2026-05-26 19:08:34.737]: Info: [pipewire] Size: 3840x2160
[2026-05-26 19:08:34.737]: Info: [pipewire] Color primaries: 0
[2026-05-26 19:08:34.737]: Info: [pipewire] Transfer function: 0
[2026-05-26 19:08:34.737]: Info: [pipewire] Framerate (from compositor): 0/1 (variable rate capture)
[2026-05-26 19:08:34.737]: Info: [pipewire] using DMA-BUF buffers
[2026-05-26 19:08:34.744]: Info: [pipewire] Using negotiated Resolution: 3840x2160
[2026-05-26 19:08:34.744]: Info: [wayland] Found display [wayland-0]
[2026-05-26 19:08:34.746]: Info: [wayland] Found interface: zxdg_output_manager_v1(31) version 3
[2026-05-26 19:08:34.746]: Info: [wayland] Found interface: zwp_linux_dmabuf_v1(57) version 5
[2026-05-26 19:08:34.746]: Info: [wayland] Found interface: wl_output(103) version 4
[2026-05-26 19:08:34.746]: Info: [wayland] Resolution: 3840x2160
[2026-05-26 19:08:34.746]: Info: [wayland] Offset: 0x0
[2026-05-26 19:08:34.746]: Info: [wayland] Logical size: 1920x1080
[2026-05-26 19:08:34.746]: Info: [wayland] Name: DP-3
[2026-05-26 19:08:34.746]: Info: [wayland] Found monitor: LG Electronics LG TV
[2026-05-26 19:08:34.746]: Info: Creating encoder [hevc_vaapi]
[2026-05-26 19:08:34.746]: Info: Color coding: SDR (Rec. 601)
[2026-05-26 19:08:34.746]: Info: Color depth: 8-bit
[2026-05-26 19:08:34.746]: Info: Color range: MPEG
[2026-05-26 19:08:34.751]: Warning: EGL: context priority set to HIGH but CAP_SYS_NICE capability is missing
[2026-05-26 19:08:34.754]: Info: vaapi vendor: Mesa Gallium driver 26.0.6 for AMD Radeon RX 7900 XTX (radeonsi, navi31, ACO, DRM 3.64, 7.0.9-205.fc44.x86_64)
[2026-05-26 19:08:34.755]: Info: Streaming bitrate is 117964000
[2026-05-26 19:08:34.755]: Info: Using normal encoding mode
[2026-05-26 19:08:34.755]: Info: Using default rate control
[2026-05-26 19:08:34.759]: Info: Minimum FPS target set to ~20fps (50ms)
[2026-05-26 19:08:34.809]: Warning: Skipping FEC for abnormally large encoded frame (needed 8 FEC blocks)
[2026-05-26 19:08:34.981]: Warning: Skipping FEC for abnormally large encoded frame (needed 14 FEC blocks)
[2026-05-26 19:08:34.982]: Info: Setting default sink to: [sink-sunshine-surround51]
[2026-05-26 19:08:34.982]: Info: Found default monitor by name: sink-sunshine-surround51.monitor
[2026-05-26 19:08:34.989]: Info: Gamepad 0 will be Xbox One controller (default)
[2026-05-26 19:08:35.013]: Info: Opus initialized: 48 kHz, 6 channels, 1536 kbps (total), LOWDELAY
[2026-05-26 19:08:35.115]: Warning: Skipping FEC for abnormally large encoded frame (needed 7 FEC blocks)
[2026-05-26 19:11:37.768]: Info: CLIENT DISCONNECTED
[2026-05-26 19:11:37.768]: Info: Setting default sink to: [alsa_output.usb-SteelSeries_Arctis_Nova_7-00.analog-stereo]
[2026-05-26 19:11:46.369]: Info: Executing Undo Cmd: [sh -c "/home/slash/Applications/scripts/sunshine-undo.sh"]
[2026-05-26 19:11:46.412]: Info: Qt: There are no outputs - creating placeholder screen
[2026-05-26 19:11:54.232]: Info: Web UI: [192.168.1.12] -- not authorized

One more thing i noticed but that may be another issue, i have to launch the game twice before Sunshine catches the game windows and adapts its framerate stream else it's stuck on the asked framerate by the client.

[Kishi85]

[2026-05-26 19:08:34.717]: Info: [pipewire] Requested frame rate [120fps]

Could it be that your moonlight client is configured to stream at 120fps by any chance?

[Slashic]

That's the case in that test, and seems to be irrelevant like i mentioned in the OP: setting it to 60fps is hard capping the stream at 60fps but doesn't solve the issue: there is still stutter on a perfectly smooth 60fps game and in a VRR scenario there is still +3 frames added: 55 -> 58fps and so on...

This looks like the capture is adding +3fps to the current stream no matter what the input framerate is.

[Kishi85]

I've been trying to reproduce this but I'm not able to find a combination of settings that make this occur in my setup. kwingrab capturing at 60fps leads to smooth and almost perfect 60 fps on the client (+-0.04fps) with 2 different systems (AMD9070XT and RTX4070). Same for portalgrab (it's basically the same pipewire stream source just a different request path for the pipewire node) with vulkan/vaapi or nvenc encoder.

The problem from what @psyke83 noted is that pipewire-based capture methods are event-driven and do not necessarily provide constant fps hence triggering frame insertion erroneously. I'm not expert on the topic so I'm hoping that @psyke83 might have an idea what's going here and might be able to suggest a fix.

[psyke83]

Can you share your full config to make sure there's nothing unusual? Some suggestions:

1. Never increase min_fps_target above half the stream FPS, even if doesn't appear to be the direct solution yet. As a troubleshooting measure, set min_fps_target = 1 to fully rule out duplicate frame insertion.
2. There's an unusual amount of Skipping FEC messages. Do these messages trigger at the exact time that the excess FPS is observed? As a troubleshooting measure, try to drastically reduce the bandwidth (e.g., ~5Mbps) to see if it resolves the issue.
3. Are other settings on the client impacting this behaviour? Make sure to enable vsync and frame pacing in Moonlight to eliminate variables on the client side.
4. Perhaps try to set the host resolution to 1080p@60 to rule out 4K capture (and/or the overhead of scaling down to 1080P) as the culprit.

[psyke83]

This may not be related, but another line of your log is suspicious:

[2026-05-25 19:01:09.970]: Warning: EGL: context priority set to HIGH but CAP_SYS_NICE capability is missing

I just verified on my Fedora 44 install that the Sunshine package installed from the Fedora stable copr has the CAP_SYS_NICE capability set correctly, so your log output doesn't make sense.

[Slashic]

Can you share your full config to make sure there's nothing unusual? Some suggestions:

Operating System: Fedora Linux 44
KDE Plasma Version: 6.6.5
KDE Frameworks Version: 6.26.0
Qt Version: 6.11.1
Kernel Version: 7.0.9-205.fc44.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 24 × 13th Gen Intel® Core™ i7-13700K
Memory: 64 Gio of RAM (62.6 Gio usable)
Graphics Processor: AMD Radeon RX 7900 XTX
Manufacturer: Gigabyte Technology Co., Ltd.
Product Name: Z790 AORUS MASTER
System Version: -CF

sunshine.conf:

av1_mode = 3
capture = kwin
csrf_allowed_origins = https://slashsrv:47990
encoder = vulkan
hevc_mode = 3
locale = fr
minimum_fps_target = 1
output_name = 2
sunshine_name = Slashsrv (Linux)

1. Never increase `min_fps_target` above half the stream FPS, even if doesn't appear to be the direct solution yet. As a troubleshooting measure, set `min_fps_target = 1` to fully rule out duplicate frame insertion.

Already tried with 1 as a value, i'll keep it for troubleshooting.

2. There's an unusual amount of `Skipping FEC` messages. Do these messages trigger at the exact time that the excess FPS is observed? As a troubleshooting measure, try to drastically reduce the bandwidth (e.g., ~5Mbps) to see if it resolves the issue.

A very low bitrate solves the Skipping FEC warnings but not the incorrect fps issue.

3. Are other settings on the client impacting this behaviour? Make sure to enable vsync and frame pacing in Moonlight to eliminate variables on the client side.

I tried in moonlight with no change on the issue:

• A low bitrate (5Mbps)
• 1080p, 1440p, 4k resolutions
• 60fps & 120fps stream
• HDR on & off
• H265, AV1 codecs
• Vsync, frame pacing
• Full screen, full screen windowed
• Game optimisation on & off

On Sunshine side:

• Vaapi, Vulkan encoder
• Vaapi with framerate enforcement for AMD cards
• Kwin capture, XDG capture (KMS works but fixed rate and washed out colors)
• No audio
• Changing the display (i use a script with Kscreen to disable and run an headless EDID, also not the issue, same behavior on actual monitor)
• Setting minimum_fps_target to: 0, 1, 20, 30, 40

4. Perhaps try to set the host resolution to 1080p@60 to rule out 4K capture (and/or the overhead of scaling down to 1080P) as the culprit.

Same behavior at 1080p60

This may not be related, but another line of your log is suspicious

I realize i didn't mention that i was testing with the latest beta using copr beta repo.
The same issue exists with the stable release and i can confirm the CAP_SYS_NICE message is gone using the stable release.

Edit: Also tried on moonlight android using my phone, same behavior.

[psyke83]

Is the framerate violation a transient issue or happening at all times when the framerate is high? For example, if you stream a browser tab running https://testufo.com/ at 60fps, will it exhibit the issue 100% of the time, or is there occasional bursting to 63fps?

[Slashic]

It is happening at all time on the whole framerate range and not transient but constant.
To completely eliminate any game quirk I also used VRRTest with a large FPS range (from 40 to 110) and always see an added ~3 fps on moonlight and a choppy motion (behaves the same as testufo).