During manufacturing of optical disks, mastering equipment inserts marks (“high frequency wobble marks” or “HFWMs”) into the wobble of the groove on optical disks to store data. The presence of a HFWM at a zero crossing of the wobble indicates an active bit and the absence of the HFWM indicates an inactive bit. The zero crossing is, for example, a negative zero crossing. A matched filter is used to detect the shape of the HFWMs. If a HFWM is detected during a wobble cycle, an active bit is saved in a register or a memory. If a HFWM is not detected during a wobble cycle, an inactive bit is saved in a register or a memory. The active and inactive bits may be coded bits that must be decoded to data bits. The data bits include information such as a synchronization mark, a sector identification data, and an error detection code.