I would like to be able to generate a 400px x ??? size landscape image from the media library.
Currently the options close to the size that I want are 495 x 400 and 300 x 226.
How can I add this size as an additional option please?
Thank you for the inquiry.
You can use the avf_modify_thumb_size filter to adjust the dimension of the existing thumbnails. Usage examples can be found in the following threads.