I've searched, but can't find an answer.
Is it possible to create/extract a photo from a video stream with exiftool automated from all mp4's in a directory?
It's from a GoPro Hero 7 and what I know of, there is no preview embedded. I would like to extract a video frame from the video stream and use that photo as a preview for the video and aslo to hold all relevant metadata.
No, exiftool only deals with metadata, not the actual image/video stream data. You might want to look to FFMpeg as a way to extract an image. For example see this stackoverflow (https://stackoverflow.com/questions/27568254/how-to-extract-1-screenshot-for-a-video-with-ffmpeg-at-a-given-time).
To extract an image from all mp4s in a directory would take some scripting, but there are lots of examples on the StackExchange sites (https://stackexchange.com/search?q=%5Bffmpeg%5D).
Exiftool would be able to copy metadata from the original MP4 to the extracted image, but there might have to be some redirection from one tag to another (see the -TagsFromFile option (https://exiftool.org/exiftool_pod.html#tagsFromFile-SRCFILE-or-FMT)) as there is often not a direct correlation between the types of video metadata and image metadata.
Ok, thanks.
I'll look into ffmpeg.