NCO based timebase recovery system and method for A/V decoder
View Patent ↗Systems and methods are disclosed for recovering a clock or time reference for A/V systems. One method comprises receiving at least one input time reference generated using a first clock and generating, using a second clock asynchronous to the first clock, at least one time reference value representative of the at least one input time reference. The method further comprises outputting the generated time reference value used by the A/V system.
1. A method for recovering a time reference in an A/V system comprising:
(a) receiving at least one input time reference from an input data stream, said at least one input time reference generated using a first clock;
(b) generating, using a second clock that is asynchronous to said first clock, at least one time reference value representative of said at least one input time reference; and
(c) outputting said at least one generated time reference value.
2. The method of claim 1 , comprising repeating steps (a) through (c).
3. The method of claim 1 , wherein said time reference value is generated using an NCO and a digital PLL.
4. The method of claim 1 , further comprising generating one or more stepsize offset signals.
5. The method of claim 4 , wherein an NCO uses said stepsize offset signals to generate said time reference values.
6. The method of claim 5 , wherein said offset values are NCO stepsize offset signals.
7. The method of claim 1 , wherein said time reference value is a system time reference value.
8. The method of claim 1 , comprising controlling a rate of outputting said at least one generated time reference value using at least one generated time reference value.
9. A method of processing data in a data stream using an A/V decoder comprising:
(a) receiving at least one input time reference value from the data in the data stream;
(b) generating at least one system time reference value;
(c) comparing said system time reference value to said input time reference value;
(d) locking said system time reference value to said input time reference value, forming at least one recovered system time reference value;
(e) outputting said recovered system time reference value; and
(f) processing the data using at least one clock asynchronous to said recovered system time reference value.
10. The method of claim 9 , wherein said system time reference value is generated using an NCO device.
11. The method of claim 9 , further comprising generating one or more offset values.
12. The method of claim 11 , wherein an NCO device uses said offset values to generate said system time reference values.
13. The method of claim 9 , comprising repeating at least steps (a) through (e).
14. The method of claim 9 , comprising controlling a rate of outputting said recovered system time reference value using at least one recovered system time reference value.
15. A method of processing data in a data stream using an A/V decoder comprising:
(a) receiving at least one input time reference value from the data in the data stream;
(b) generating at least one system time reference value using an NCO device;
(c) comparing said system time reference value to said input time reference value;
(d) locking said system time reference value to said input time reference value, forming at least one recovered system time reference value;
(e) outputting said recovered system time reference value;
(f) controlling a rate of outputting said recovered system time reference value using at least one system time reference value; and
(g) processing the data using at least one clock asynchronous to said recovered system time reference value.
16. The method of claim 15 , comprising repeating at least steps (a) through (e).
17. The method of claim 15 , further comprising generating one or more offset values.
18. The method of claim 17 , wherein said NCO device uses said offset values to generate said system time reference values.