System and method for generating linear time code data
View Patent ↗The present invention relates to a linear time code (LTC) generator that is adapted to generate LTC data. The LTC generator comprises a rising edge detector that is adapted to detect a frame sync input corresponding to a beginning of a frame time of video data and to generate a first synchronization signal corresponding to the frame sync input and a frame length measurement block that is adapted to count a number of clock cycles in the frame time. The LTC generator further comprises a bit rate calculator that is adapted to determine a bit rate of the frame time based on the number of clock cycles in the frame time and a bit rate counter block that is adapted to generate a second synchronization signal corresponding to the bit rate. Finally, the LTC generator comprises an output device that is adapted to insert a first data bit of the LTC data into a digital bit stream according to the first synchronization signal and to insert subsequent data bits of the LTC data into the digital bit stream according to the second synchronization signal.
1. A linear time code (LTC) generator that is adapted to generate LTC data, the LTC generator comprising:
a detector that is adapted to detect a frame sync input corresponding to a beginning of a frame time of video data and to generate a first synchronization signal corresponding to the frame sync input;
a frame length determination block that is adapted to determine a frame length of the video data in clock cycles by counting a number of clock cycles in the frame time;
a bit rate counter block that is adapted to generate a second synchronization signal corresponding to a bit rate that is determined from the frame length in clock cycles; and
an output device that is adapted to insert a first data bit of the LTC data into a digital bit stream according to the first synchronization signal and to insert subsequent data bits of the LTC data into the digital bit stream according to the second synchronization signal, so that the application of the LTC data is not dependent on the frame length, wherein said bit rate being determined according to the formula
2
*
BitRate
=
2
n
*
x
Frame_time
_in
_clock
_cycles
where x is twice a length of a time code information word of the linear time code data and n is a number of time code information bits.
2. The linear time code generator according to claim 1 , said output device being adapted to insert the LTC data across a single frame time if the frame of video data has a frame rate below a predetermined threshold.
3. The linear time code generator according to claim 1 , said output device being adapted to insert the LTC data across two frame times if the frame of video data has a frame rate above a predetermined threshold.
4. The linear time code generator according to claim 1 , said output device being adapted to store the LTC data in association with a corresponding frame of video data.
5. A method for applying linear time code (LTC) data to a digital bit stream, the method comprising the steps of:
counting a number of clock cycles in a frame time of video data;
determining a flame length of the video data in clock cycles by counting a number of clock cycles in the flame time;
inserting a first data bit of the linear time code data into the digital bit stream according to a first synchronization signal that corresponds to a start of the flame time; and
inserting subsequent data bits of the linear time code data into the digital bit stream according to a second synchronization signal that corresponds to a bit rate that is determined from the flame length in clock cycles, so that the application of the LTC data is not dependent on the flame length, wherein said bit rate being determined according to the formula
2
*
BitRate
=
2
n
*
x
Frame_time
_in
_clock
_cycles
where x is twice a length of a time code information word of the linear time code data and n is a number of time code information bits.
6. The method for applying linear time code data to a digital bit stream according to claim 5 , comprising the step of:
inserting the LTC data across a single frame time if the frame of video data has a frame rate below a predetermined threshold.
7. The method for applying linear time code data to a digital bit stream according to claim 5 , comprising the step of:
inserting the LTC data across two frame times if the frame of video data has a frame rate above a predetermined threshold.
8. The method for applying linear time code data to a digital bit stream according to claim 5 , further comprising the step of:
storing the LTC data in association with a corresponding frame of video data.