Since recently I’m proudly using the new 16” M1Pro MBP. While I’m enjoying its performance and quiteness in comparison to the MBP 2019, one thing is annoying: In video calls the integrated FaceTime HD camera provides a flickering picture. So this is bothering me each single day, and I looked how to fix this.

TLDR;

This is a known issue with the new Macs, and unfortunately there is no solution with current macOS for it. I found this workaround, and it fixes the issue also for me:

1. Install OBS Studio
2. Add Video Capture Device => Create New
3. Choose Device: Facetime HD Camera
4. Unselect “Use Preset”
5. Set Frame Rate: 25 FPS

The flickering stops! However, it requires that you open OBS Studio once you start a video call. For me the frame rate is also OK when I close OBS then once a call has started.

The Frame Rate Problem

The default frame rate of the build in camera seems to be 30 fps, and in PAL countries 25 fps is used. The 30fps seems to cause the flickering. So the build in camera needs to change its frame rate. However, there is no way to configure this setting in macOS by default.

Why OBS?

Unfortunately it means I need to have a 300MB application just to change a device setting.

OBS Studio is a widely used software and available for free. With it, you can create a virtual device and adjust the frame rate. There are other applications in the app store that allow you to adjust the frame rate of input devices, but I prefer to use a free one here to apply the workaround.

What does OBS do to change the framerate?

I was interested if there is a hidden configuration switch in macOS to influence the default settings for the camera. So I wanted to know what OBS is doing under the hood.

Just for those who are interested, the main source here seems to be av-capure.mm. It uses the the AVCaptureDevice API, which allows to query and modify the settings of capture devices. I did not find traces to a preference that I could set via CLI.

I’m not skilled in programming native tools for macOS, but with this it should not be a big issue for someone skilled to provide a small utility that just takes the default camera and sets its frame rate to 25fps. When you know of such a (free/cheap) utility, give me a link here.

Since this is a common problem I hope that Apple will just provide a fix in a future macOS version.

I just wanted to clean up my Maven repository a bit and remove some old artifacts. This is unproblematic since all missing artifacts would be fetched again. But then the question arised: How can I find files that are older then a specific date? Unfortunately the Finder does not have an appropriate search function, nor Spotlight helps. Yes, there is the find command, but it only has a -newer option, no -older.

In my search I found this forum post, which gave me the solution. The solution is to create a temporary file with the touch command and give it the timestamp you want to compare with. Then use the find command and invert the query with “!”.

Let’s say we want to find all files older then 2008-01-01 from the current directoy “./” and below. The result will be stored in a temp file that is used as input for the tar command to archive the old files. The result can be queried like this:

touch -t 200801010000 /tmp/touchfile
find ./ ! -newer /tmp/touchfile > /tmp/filelist
tar --create --gzip --files-from /tmp/filelist --file repository-before-2008.tar.gz
rm /tmp/touchfile
rm /tmp/filelist

Maybe you want to use a date relative to the current date instead of a fixed date. This can be achieved by evaluating the date command in combination with touch. For an example, to modify the timestamp file’s modification date 6 months back, use

touch -t $(date -v -6m "+%Y%m%d%H%M") /tmp/filelist

With the zip command the older files can be archived in one command:

zip -rttq 2008-01-01 repository-before-2008 ./

In my case the tar (and also tar.gz) archive was by far larger then the zip archive. I did not investigate the reason further yet.

After creating the backup zip I used the find command again to delete the old files from the repository.

find ./ ! -newer /tmp/touchfile -delete