upload_per_page filter-hook . WP 2.9.0

Filters the number of items to list per page when listing media items.

Usage

add_filter( 'upload_per_page', 'filter_function_name_983' );
function filter_function_name_983( $media_per_page ){
	// filter...

	return $media_per_page;
}

$media_per_page(int)

Number of media to list.
Default: 20

Where the hook is called

$q['posts_per_page'] = apply_filters( 'upload_per_page', $media_per_page );

Where in WP core the hook is used WordPress