Using a tool you already have, get clean screenshots of (most) browser video for training.

Many animated works have been released on free ad supported streaming, and have characters that should have a LoRA of them made. Some works have also had extensive enough previews released that you could make a LoRA from just them or them and various other images (e.g., early merch reveals). I have discovered there's actually an easy way to get clean screenshots of these that likely won't require any additional programs or plugins!

Chrome and derived browsers (at least on PC) have a feature called GlobalMediaControls, identified in tooltip as “Control your music, videos, and more” . When media is active and unmuted (even when paused) a musical note icon will appear on your browser toolbar (generally top right of window, below the minimize and close buttons). Click this and it will identify all tabs with active media that have sound. Easily missed in this control is the small “Save Video Frame” icon made of a play button surrounded by three right angles and an underlined down arrow. Just click it and you can save a clean picture of the current frame to your machine.

For YouTube, you can also double right click and to get an option to save a frame, and frame crawl with the < and > keys. Don’t know if there’s any way to framecrawl with GlobalMediaControls. (edit: While I'm thinking of it, I'll mention that spacebar generally pauses videos without being interpreted as a double click)

Since you will likely encounter the issue with these captures, I have a guide to cleaning up pillarboxed or stretched 4:3 automatically without any extra tools.

Edit Oct 30th: Rearranged title so lack of new tools is not behind truncation. Also I'll note the worst part of discovering this is having to go back and make V2s of several LoRAs (because their original data was very suboptimal) right after Kohya training died. After an exhausting re-rewatch for data I've got two of four sent for training run and should have the rest within the weekend, assuming no moderator misclicks.