I have imported a large number of .mp4 format videos (converted from .mts format) into the Photos app on my MacBook. They will play in Photos, but they appear as a black thumbnail instead of a thumbnail showing a preview image of what the video is. How do I get them to update with a preview of the video? When viewed in Finder (prior to importing into Photos app), I can see previews/thumbnails of the videos fine.
Do the videos start with a fade-in from Black? Then Photos will use the first, black frame as the keyframe.
You may want to set a different frame as the keyframe of the video. It will depend on the version of Photos you are using how to change the keyframe.
On masOS 14 Sonoma I open the video in Edit mode, then use the video controls to select the frame I want, then go to the "image" menu and click "Set keyframe".
Do the videos start with a fade-in from Black? Then Photos will use the first, black frame as the keyframe.
You may want to set a different frame as the keyframe of the video. It will depend on the version of Photos you are using how to change the keyframe.
On masOS 14 Sonoma I open the video in Edit mode, then use the video controls to select the frame I want, then go to the "image" menu and click "Set keyframe".
> Is there a way to change the frame on multiple videos at one time
I searched if it is possible to set a custom Poster Frame (losslessly to a certain time or % in the movie) outside Photos.app with ffmpeg. But it seems that is not possible. Very little info about this, only some commands how to add an image to the 1st frame in a movie as a "Poster Frame" (with a lossy re-encode). Please chime in if I am missing something.
https://stackoverflow.com/questions/61979660/how-to-add-a-poster-frame-to-an-mp4-video-by-timecode
Compressor.app can add a "Poster Frame" but it is displayed only in the Finder > Get Info (and the same can be done losslessly in QuickTime Player by copying a frame from the movie and then pasting it to Finder > Get Info). Photos.app does not display that.
I guess it is up to the viewer app whether it displays the 1st frame or a frame at 50% of the movie.
Maybe AppleScript could be used to set the Poster Frame at some % inside Photos.app to a batch of movies?
Thank you. Is there a way to change the frame on multiple videos at one time, or does this need to be done manually one at a time (there are over 1700 video files!).
mp4 videos not showing a preview in Photos app on MacBook
