Imagemagick

In a folder, convert all png files to jpg.

magick mogrify -format jpg *.png

Resizing

magick mogrify -resize 960x528 *.png

This command resizes all of the .png files in your directory to a size of 960 pixels by 528 pixels. Perhaps the height isn’t as important as the width. You can simply enter:

magick mogrify -resize 960 *.png

This will scale all of your images to a width of 960 pixels, the height will be scaled accordingly, preserving the aspect ratio. Perhaps you have a height and width you are aiming for, but want to preserve the aspect ratio. You can enter:

magick mogrify -resize 960x528! *.png