Change file format?

[panthro100]

I need to create webp images, I have tried the following without any success:

 $model->addMediaFromUrl($url)->format(Manipulations::FORMAT_WEBP)->toMediaCollection();

Am I correct thinking that it needs to be added as a conversion?

$this->addMediaConversion('thumb')->format(Manipulations::FORMAT_WEBP)->withResponsiveImages();

When I do this, I store the original uploaded file (jpeg) and an extra converted file under conversions, which is the original jpeg converted to webp, and then the various responsive image versions of the webp in webp format in the responsive image folder.

Is there a way to just store the responsive webp images? Without storing the original converted webp file in the conversions folder?

[hesammoosapour]

I do this :
$this ->addMediaConversion('poster') ->performOnCollections('thumb') ->withResponsiveImages() ->nonQueued() ->format('WEBP');

Can you delete media afterwards?