Source

File: wp-includes/media.php

function get_attached_media( $type, $post = 0 ) {
	$post = get_post( $post );

	if ( ! $post ) {
		return array();
	}

	$args = array(
		'post_parent'    => $post->ID,
		'post_type'      => 'attachment',
		'post_mime_type' => $type,
		'posts_per_page' => -1,
		'orderby'        => 'menu_order',
		'order'          => 'ASC',
	);

	/**
	 * Filters arguments used to retrieve media attached to the given post.
	 *
	 * @since 3.6.0
	 *
	 * @param array   $args Post query arguments.
	 * @param string  $type Mime type of the desired media.
	 * @param WP_Post $post Post object.
	 */
	$args = apply_filters( 'get_attached_media_args', $args, $type, $post );

	$children = get_children( $args );

	/**
	 * Filters the list of media attached to the given post.
	 *
	 * @since 3.6.0
	 *
	 * @param WP_Post[] $children Array of media attached to the given post.
	 * @param string    $type     Mime type of the media desired.
	 * @param WP_Post   $post     Post object.
	 */
	return (array) apply_filters( 'get_attached_media', $children, $type, $post );
}