Issues with very, very, very low framerate input

[joshinils]

Problem Description

I generated a video from a png with ffmpeg:

ffmpeg -loop 1 -framerate 1/200 -i bg.png -c:v libx264 -t 9:57 -pix_fmt yuv420p out.mkv

My idea behind this was to replace a 25fps video of a still image with a low fps video of the same still image, thus massively reducing file size.
This worked, but vlc is kinda wonky at playing it, after I added an audio track, mpv is much better at playing this weird file.

For 1/10 fps vlc plays more nice, 1 fps is even better.

So, I tried to remux it with handbrake, but it just got stuck;

1/100 fps handbrake can handle, I only also tried 1/200 fps, which is when handbrake got stuck.
The encoding progress is a negative percentage, the preview image is black and white and 4 images appear, where my bg.png is only one of those, and in color.
The displayed framerate of the input is a negative number fps.

The frame count of my "video" according to mediainfo is 3.

I know what I'm doing is a weird niche thing, but hey, a bug is a bug.

Activity Log, Crash Log or any other details

-

What Operating System are you running?

ubuntu 22.04.2 LTS

What version of HandBrake are you running?

1.7.3 (x86_64)

Where did you download HandBrake from?

flathub

[galad87]

There is a minimum fps limit, because of the way HandBrake stores timescales, that would take a bit of refactoring to remove. However it looks like I broke something because such low fps are not sanitized anymore in some cases, whoops.