Data production method and apparatus
View Patent ↗A watermark information detection process prevents prolonging of time required for setup process when no watermark information can be detected from an optical disc where watermark information has been recorded. During a setup, the number of retrials is limited. Weighting of the retrial is changed so that detection of watermark information is performed when it is confirmed that watermark information is recorded. This enables detection of information for copyright protection in an appropriate processing time.
1. A data reproduction method for reading out information from a recording medium and reproducing the information, the method comprising steps of:
identifying a type of a recording medium inserted;
reading out watermark information from the recording medium; and
outputting the information associated with the watermark information read out from the recording medium;
wherein if no watermark information is detected from the recording medium, the watermark information read-out processing method is switched depending on whether the detection of watermark information is performed during a setup process or after the setup process;
wherein if the detection is performed during the setup process, the number of retrials of read-out of watermark information is limited to n times, and if the detection is performed after the setup process, control is switched to limit the number of retrials to m times (n<m).
2. The data reproduction method as claimed in claim 1 , wherein if the detection is performed during the setup process, control is performed not to perform a retrial of read-out of watermark information, and
if the detection is performed after the setup process, control is switched to perform the retrial.
3. The data reproduction method as claimed in claim 1 , wherein the retrial is performed by modifying a parameter used for detection of a data reproduction signal in the retrial after the setup process.
4. A data reproduction apparatus for reading out information from a recording medium and reproducing the information, the apparatus comprising:
a rotation control circuit for controlling rotation of a recording medium;
an optical pickup for reading out data from the recording medium;
a servo control circuit for performing focusing, tracking, and access control of the optical pickup;
a reproduction signal processing circuit for reproducing the signal read out by the optical pickup; and
a detection circuit for detecting watermark information from the signal read out from the optical pickup;
wherein watermark information is recorded in the recording medium,
the watermark information recorded is detected by the detection circuit, and
if the watermark information recorded in the recording medium cannot be detected, the watermark information read-out method is switched depending on whether the detection of the watermark information is performed during a setup process or after the setup process;
wherein if the detection is performed during the setup process, the number of retrials of read-out of watermark information is limited to n times, and if the detection is performed after the setup process, control is switched to limit the number of retrials to m times (n<m).
5. The data reproduction apparatus as claimed in claim 4 , wherein if the detection is performed during the setup process, control is performed not to perform a retrial of read-out of watermark information, and
if the detection is performed after the setup process, control is switched to perform the retrial.
6. The data reproduction apparatus as claimed in claim 4 , wherein the retrial is performed by modifying a parameter used for detection of a data reproduction signal in the retrial after the setup process.