NTSC_HBLK_DURATION_TYP_NS
#define NTSC_HBLK_DURATION_MIN_NS (NTSC_HBLK_DURATION_TYP_NS - 200)
#define NTSC_HBLK_DURATION_MAX_NS (NTSC_HBLK_DURATION_TYP_NS + 200)
#define NTSC_HACT_DURATION_TYP_NS (NTSC_LINE_DURATION_NS - NTSC_HBLK_DURATION_TYP_NS)
NTSC_HBLK_DURATION_TYP_NS,