Video thubnail generation parameters

The generation of thumbnails from videos apparently uses either the first frame, or selects an early frame. This is OK if there is no black “leader” in the begining. When the first second of so of the video is black I get a black thumbnail. Can someone tell me where and how to change the frame number selected so there are no black thumbnails? I’m a newbie, so I hope this change is not to complicated.

There’s an option called page that you can set for the thumbnailer; for a video, this will control what frame is used to generate the thumbnail.

You set that option in the config/local.config.php file, as described in the manual. The page option would go in the thumbnailer_options array:

        'thumbnailer_options' => [
            'imagemagick_dir' => null,
            'page' => 42

There’s a wrinkle here though: setting this option uses that “page” for all files, so you might have a problem once you set it with non-video thumbnails (as non-videos have many fewer “pages” typically).

Thanks! Point of clairification: would a still image be considered one “page”? Or to put it another way, if I change “page” to some number > 1, will it fail to make a thumbnail of a still image?

There shouldn’t be an issue with still images: they always use their single “page” regardless of what page we ask for.

Got it! Thanks muchly!