Flexible cadence follower for film in video
View Patent ↗A system for cadence break detection is provided. The system includes a field system receiving a plurality of fields of image data. A threshold system generates a cadence break signal if a difference in two fields exceeds a predetermined threshold. A sequence system generates the cadence break signal if a sequence of differences between the plurality of fields does not match a predetermined sequence.
1. A system for cadence break detection comprising:
a field system configured receiving a plurality of fields of image data, each field of image data including sequence data for indicating a film to video conversion sequence cadence, and for generating a film to video conversion sequence cadence data; and
a cadence following circuit configured to receive the film to video conversion sequence data and to generate a cadence break signal comprising:
a threshold system configured to generate the cadence break signal if a difference in two fields exceeds a predetermined threshold;
a sequence system configured to generate the cadence break signal if a sequence of difference between the plurality of fields does not match a predetermined sequence; and
a free run counter configured to receive a field end signal and sequence number data and to generate a plurality of bitmap select fields.
2. The system of claim 1 wherein the threshold system comprises a field maximum threshold system generating a cadence break signal if a difference in two fields exceeds a predetermined maximum threshold.
3. The system of claim 1 wherein the threshold system comprises a field minimum threshold system generating a cadence break signal if a difference in two fields exceeds a predetermined minimum threshold.
4. The system of claim 1 further comprising a weave direction bitmap identifying whether a first field should be combined with a previous field or a subsequent field.
5. The system of claim 1 further comprising a frame motion bitmap identifying whether a field difference can exceed a threshold.
6. The system of claim 1 further comprising a field motion change bitmap identifying whether a difference between two field comparison values should be positive or negative.
7. The system of claim 1 further comprising a low confidence system generating low confidence data based on the plurality of fields of image data and providing the low confidence data to a de-interlacer.
8. The system of claim 1 further comprising a FUTURE_PAST_BITMAP configured to receive one of the plurality bitmap select fields and to generate control data to cause one of a future fields or a past field to be woven into a current field in a de-interlacer.
9. The system of claim 8 further comprising:
a MOTION_CNT_BITMAP configured to receive one of the plurality bitmap select field and to generate an indictor representing whether a frame motion value is expected to be high on a predetermined field; and
a FCOMP BITMAP configured to receive one of the plurality bitmap select fields and to generate an indicator representing whether a change in field motion in the predetermined field is expected to be negative or positive.
10. A method for cadence break detection comprising:
receiving a plurality of fields of image data, each field of image data including sequence data for indicating a film to video conversion sequence cadence;
receiving a field end signal and sequence number data and to generate a plurality of bitmap select fields generating a film to video conversion sequence cadence data;
determining a difference between two of the fields of image data;
generating cadence break data if the difference between the two fields of image data exceeds a predetermined threshold as a function of the film to video conversion sequence cadence data; and
generating the cadence break data if a difference between a first difference between two of the fields of image data and a second difference between two of the fields of image data does not match predetermined sequence data.
11. The method of claim 10 further comprising generating low confidence data based on the image data.
12. The method of claim 10 wherein generating the cadence break data if the difference between the two fields of image data exceeds the predetermined threshold comprises generating the cadence break data if the difference between the two fields of image data exceeds a scene change threshold.
13. The method of claim 10 wherein generating the cadence break data if the difference between the two fields of image data exceeds the predetermined threshold comprises generating the cadence break data if the difference between the two fields of image data exceeds a minimum motion threshold.
14. The method of claim 10 wherein determining the difference between two of the fields of image data comprises summing the number of pixels in one of the two fields of image data that are different from corresponding pixels in the other of the two fields of image data.
15. The method of claim 10 wherein the first difference between two of the fields of image data is determined by averaging corresponding pixels in two adjacent lines of one of the two fields of image data and subtracting the average from a corresponding pixel in the other of the two fields of image data.
16. A system for cadence break detection comprising:
a field system receiving a plurality of fields of image data;
a processor configured to generate a cadence break signal if a difference in two fields exceeds a predetermined threshold;
the processor further configured to generate the cadence break signal if a sequence of differences between the plurality of fields does not match a predetermined sequence; and
a free run counter configured to receive a field end signal and sequence number data and to generate a plurality of bitmap select fields.
17. The system of claim 16 further comprising means for generating a cadence break signal if a difference in two fields exceeds a predetermined maximum threshold.
18. The system of claim 16 further comprising means for generating a cadence break signal if a difference in two fields exceeds a predetermined minimum threshold.