Pre-generating derivatives on the client side

[danielnc]

Hi

I am currently generating Video attachment thumbnails from the client side. Whenever a file is added to the file field, I get the screenshot from the video using custom javascript code, and show the preview as a blob on the form, users can pick a specific time-frame from the video to preview this image too

Since all this process is handled by the client side, I don't want to re-generate the specific derivative on the backend(re-download a huge file from s3, transcode, etc) just to store a derivative image that I already have access on the form as an attachment file.

Is it possible to submit thru shrine alongside the metadata hidden input, derivative data?

I couldn't find anything on the discussion or issues related to generate derivatives on the client side

I am also planning on allowing doing the same thing for an image uploader with custom image editor and compressor to save on server resources, this is a secure environment with heavy load due to high amount of videos and images processed by users

Thanks