It's reserved by gettext. gettext("") will output the headers.
#define ENC_MCBLK_WIDTH "mc-blk-width"
#define ENC_MCBLK_WIDTH_TEXT N_("Width of motion compensation blocks")
-#define ENC_MCBLK_WIDTH_LONGTEXT N_("")
+#define ENC_MCBLK_WIDTH_LONGTEXT ""
#define ENC_MCBLK_HEIGHT "mc-blk-height"
#define ENC_MCBLK_HEIGHT_TEXT N_("Height of motion compensation blocks")
-#define ENC_MCBLK_HEIGHT_LONGTEXT N_("")
+#define ENC_MCBLK_HEIGHT_LONGTEXT ""
/* also known as XBSEP and YBSEP */
#define ENC_MCBLK_OVERLAP "mc-blk-overlap"