Properties for Video Capture Device dialog does not properly match to output frame rate, or allow choosing input frame rate or custom integer frame rate

Operating System Info

Windows 10

Other OS

No response

OBS Studio Version

Other

OBS Studio Version (Other)

28.0.3 (64bit)

OBS Studio Log URL

N/A

OBS Studio Crash Log URL

No response

Expected Behavior

When user chooses a custom Integer FPS Value in the File->Settings->Video tab, e.g. in my case, I have set it to 70Hz:

and then goes to the Properties tab for a Video Capture Device Source, e.g. at

there is no possibility to select the same 70Hz as the capture frame rate as the project, or the source video. I use a FPGA based device to generate a 70hz input video capture signal for DOS gaming captures (DOS VGA 320x200 resolutions typically followed a 70hz video frame rate).

There is a setting Match Output FPS (autoselect: 60) which also looks a bit odd. I am having a hard time interpreting what "Output" here should refer to: should it be the project output? In my case that was set to 70 (as seen above), so if that is the case, the "autoselect: 60" seems to have gotten detected wrong.

Or I wonder if "Output" here intends to be referring to the Input video frame rate of the capture device? In my case, that should also be 70Hz since I am generating a VESA CVT standard 70hz HDMI signal using an FPGA.

I wonder if the "Match Output FPS" is being incorrectly calculated here? I would have expected to see this read 70Hz. There is no support for specifying a custom integer value here either, like there was in the File->Settings->Video tab.

Current Behavior

(please see above)

Steps to Reproduce

(please see above)

Anything else we should know?

No response

Start with the File→Settings→Video entry point and the Video Capture Device source's Properties dialog described in the report. Reproduce the 70 Hz project and input scenario on Windows 10, then trace how “Match Output FPS” and custom integer frame rates are presented; done means the dialog correctly exposes and matches the relevant 70 Hz rate.