Video coding system with intra prediction mechanism and method of operation thereof

1. A method of operation of a video coding system, comprising:

generating an intra block motion vector from a first neighboring coding unit, based on a constrained intra prediction flag that is enabled in a first frame,

wherein the first neighboring coding unit is different from a sample coding unit in the first frame,

wherein the sample coding unit is derived with an intra motion vector using an intra-picture prediction mode, and

wherein the intra motion vector corresponds to a displacement between a first location of the first neighboring coding unit and a second location of the sample coding unit;

generating a current coding unit based on the generated intra block motion vector,

wherein the current coding unit is adjacent to the first neighboring coding unit; and

generating a video bitstream based on the generated current coding unit.

2. The method as claimed in claim 1 ,

wherein the first neighboring coding unit is further different from a second neighboring coding unit in the first frame,

wherein the second neighboring coding unit is derived from a previous coding unit that corresponds to a second frame, and

wherein the second frame is generated before the first frame.

3. The method as claimed in claim 1 ,

wherein the first neighboring coding unit is further different from a sample coding unit in the first frame,

wherein the sample coding unit is derived from a second neighboring coding unit in the first frame.

4. The method as claimed in claim 1 , further comprising generating a second neighboring coding unit in the first frame,

wherein the second neighboring coding unit is unavailable for pointing the current coding unit based on determination that the second neighboring coding unit is derived from a previous coding unit in a previous frame, and

wherein the previous frame is generated before the first frame.

5. A method of operation of a video coding system, comprising:

generating an intra block motion vector from a first neighboring coding unit, based on a constrained intra prediction flag that is enabled in a first frame,

wherein the generated intra block motion vector points to the first neighboring coding unit that is different from a sample coding unit in the first frame that includes a propagation error,

wherein the sample coding unit is derived with an intra motion vector using an intra-picture prediction mode, and

wherein the intra motion vector corresponds to a displacement between a first location of the first neighboring coding unit and a second location of the sample coding unit;

generating a current coding unit based on the generated intra block motion vector,

wherein the current coding unit is adjacent to the first neighboring coding unit; and

generating a video bitstream based on the generated current coding unit.

6. The method as claimed in claim 5 ,

wherein the first neighboring coding unit is further different from a second neighboring coding unit in the first frame, and

wherein the second neighboring coding unit is derived from a previous coding unit in a previous frame generated before the first frame.

7. The method as claimed in claim 5 ,

wherein the sample coding unit is derived from a second neighboring coding unit in the first frame with the intra motion vector using the intra-picture prediction mode,

wherein the second neighboring coding unit is derived from a previous coding unit in a previous frame generated before the first frame, based on an inter-picture prediction mode, and

wherein the second neighboring coding unit is with an inter motion vector.

8. The method as claimed in claim 5 , further comprising generating a second neighboring coding unit in the first frame,

wherein the second neighboring coding unit is unavailable for pointing the current coding unit, based on determination that the second neighboring coding unit is derived from a previous coding unit in a previous frame, and

wherein the previous frame is generated before the first frame with an inter motion vector using an inter-picture prediction mode.

9. A video coding system, comprising:

circuitry configured to:

generate an intra block motion vector from a first neighboring coding unit, based on a constrained intra prediction flag that is enabled in a first frame,

wherein the first neighboring coding unit is different from a sample coding unit in the first frame,

wherein the sample coding unit is derived with an intra motion vector using an intra-picture prediction mode, and

wherein the intra motion vector corresponds to a displacement between a first location of the first neighboring coding unit and a second location of the sample coding unit;

generate a current coding unit based on the generated intra block motion vector,

wherein the current coding unit is adjacent to the first neighboring coding unit; and

generate a video bitstream based on the generated current coding unit for a video decoder,

wherein the video decoder is configured to receive the video bitstream and decode the video bitstream to display on a device.

10. The system as claimed in claim 9 ,

wherein the circuitry is further configured to generate the intra block motion vector that points to the first neighboring coding unit that is further different from a second neighboring coding unit in the first frame, and

wherein the second neighboring coding unit is derived from a previous coding unit that corresponds to a second frame; and

wherein the second frame is generated before the first frame.

11. The system as claimed in claim 9 ,

wherein the sample coding unit is derived from a second neighboring coding unit in the first frame.

12. The system as claimed in claim 9 ,

wherein the circuitry is further configured to generate a second neighboring coding unit in the first frame,

wherein the second neighboring coding unit is unavailable to point the current coding unit based on determination that the second neighboring coding unit is derived from a previous coding unit in a previous frame, and

wherein the previous frame is generated before the first frame.

13. The system as claimed in claim 9 ,

wherein the sample coding unit includes a propagation error.

14. The system as claimed in claim 13 ,

wherein the circuitry is further configured to generate the intra block motion vector that points to the first neighboring coding unit that is further different from a second neighboring coding unit in the first frame, and

wherein the second neighboring coding unit is derived from a previous coding unit in a previous frame generated before the first frame.

15. The system as claimed in claim 13 ,

wherein the sample coding unit is derived from a second neighboring coding unit in the first frame with the intra motion vector using the intra-picture prediction mode.

16. The system as claimed in claim 15 ,

wherein the sample coding unit is derived from a second neighboring coding unit in the first frame with the intra motion vector based on the intra-picture prediction mode,

wherein the second neighboring coding unit is derived from a previous coding unit in a previous frame generated before the first frame, based on an inter-picture prediction mode, and

wherein the second neighboring coding unit is with an inter motion vector.

17. The system as claimed in claim 13 ,

wherein the circuitry is further configured to generate a second neighboring coding unit in the first frame,

wherein the second neighboring coding unit is unavailable for pointing the current coding unit based on determination that the second neighboring coding unit is derived from a previous coding unit in a previous frame, and

wherein the previous frame is generated before the first frame with an inter motion vector using an inter-picture prediction mode.