All videos recorded in MKV have black thumbnails on Discord, Twitter, and Bluesky. #12949

Operating System Info

Windows 11

Other OS

No response

OBS Studio Version

32.0.2

OBS Studio Version (Other)

No response

OBS Studio Log URL

https://obsproject.com/logs/NbBfeaWzKkY0wDGJ

OBS Studio Crash Log URL

No response

Expected Behavior

Videos should start with the first frame of the video.

Current Behavior

Videos start with a black frame, causing most thumbnail generators to display a black thumbnail.

Steps to Reproduce

1. Record a video with the container as MKV.
2. Uses HandBrake with default settings to compress video.
3. Upload to Discord.

Anything else we should know?

When recording with MKV, the first frame is black, which causes most thumbnail generators to display the video as black. This occurs on Discord, GitHub, Twitter, Bluesky, LinkedIn, Patreon, and probably more platforms.

Looking in VLC, this black frame is present in the original MKV file. If I use mkvtoolnix to clip out the first frame at 00:00:00:01, the black frame disappears. This behavior does not occur when recording in MP4.

I record in MKV because I like keeping lossless versions of development footage, but I also run it through HandBrake to share with team members. This black-first-frame issue has caused me a few problems.

I can’t update MKV files on GitHub, but I have linked a MP4 video that showcase the problem in Discord, and also the problem itself is present in the video.

Also, I’m not exactly sure when this started. It was not present on October 11th, but was present on November 19th. I believe OBS was up to date, though I can’t recall the details 100%.