+$thumbnail_support = current_theme_supports( 'post-thumbnails', $post_type ) && post_type_supports( $post_type, 'thumbnail' );
+if ( ! $thumbnail_support && 'attachment' === $post_type && $post->post_mime_type ) {
+ if ( 0 === strpos( $post->post_mime_type, 'audio/' ) ) {
+ $thumbnail_support = post_type_supports( 'attachment:audio', 'thumbnail' ) || current_theme_supports( 'post-thumbnails', 'attachment:audio' );
+ } elseif ( 0 === strpos( $post->post_mime_type, 'video/' ) ) {
+ $thumbnail_support = post_type_supports( 'attachment:video', 'thumbnail' ) || current_theme_supports( 'post-thumbnails', 'attachment:video' );
+ }
+}
+
+if ( $thumbnail_support ) {