Asynchronicity 24Hz/23.98Hz for 24Hz content

Hi everyone,

I stumbled upon an issue that is bothering me for quite some time. It is the often discussed 24Hz/23.98Hz topic that is driving me crazy. I run MPV under Debian and although having set the NVidia config to 4K@24Hz (GeForce 1050Ti connected via HDMI to a JVC X7900 projector), the actual display refresh rate seems to be 23.98Hz which is perfectly fine for most of the content that is 23.98Hz but with content that is 24Hz, I get the dropped frames regularly.

My config:

audio-device=alsa/hdmi:CARD=NVidia,DEV=1
audio-spdif=ac3,eac3,dts-hd,truehd
audio-channels=7.1,5.1,stereo

profile=gpu-hq
fs=yes
video-output-levels=full
fbo-format=auto

glsl-shaders-clr
glsl-shaders="/home/player/.config/mpv/shaders/FSRCNNX_x2_8-0-4-1.glsl"
glsl-shaders-append="/home/player/.config/mpv/shaders/adaptive-sharpen.glsl"

scale=ewa_lanczossharp
dscale=ewa_lanczossharp

I read about --video-sync=display-resample but I would miss audio passthrough and I want to keep HD-Audio and 3D-Audio so that does not seem like an option for me. The dynamic tone mapping and HD-Audio is the main reason why I switched from an Apple TV to MPV on a HTPC and I am sure there is a solution somewhere out there. 😄

What options do I have? Is there a way to set the display to real 24Hz instead of 23.98Hz (or any other refresh rate to always match content)?

Appreciating any help! Thanks a lot in advance.

Important Information

Provide following Information:

• mpv version: 0.34.1
• Linux Debian version: Bookworm (Linux 5.15.0-2-amd64)
• GPU driver: NVidia 470.86 CUDA Version: 11.4

Expected behavior

No dropped frames and actually setting the display to 24p instead of 23.98p

Actual behavior

Dropped frames due to framerate mismatch between 24Hz and 23.98Hz.

Log file

Will be supplied as soon as I am at home!

Sample files

Basically every material in 24p (not 23.98p)

No source files or tests are named. Start by reproducing the 24 Hz versus 23.98 Hz mismatch with the stated mpv, Debian, NVIDIA, and projector setup, then identify the relevant display-mode and video-sync entry points. Done means a confirmed configuration or a scoped change that prevents dropped frames for 24 Hz content.