Adaptive upsampling filters

1. A video coder for coding video data, the video coder comprising:

a processor configured to:

determine a phase shift between first layer video data and second layer video data from one or more syntax elements or one or more headers of the first layer video data or the second layer video data,

select a filter from a filter set for upsampling the first layer video data based on (1) the determined phase shift and (2) a phase calculated based on a spatial aspect ratio between the first layer video data and the second layer video data,

upsample the first layer video data using the selected filter, the upsampled first layer video data having the same spatial resolution as the second layer video data, and

code the second layer video data based at least on the upsampled first layer video data; and

a memory in communication with the processor, the memory configured to store the upsampled first layer video data.

2. The video coder of claim 1 , wherein the processor is configured to select the filter based on a sum of the determined phase shift and the phase.

3. The video coder of claim 1 , wherein the processor is configured to determine the phase shift for luma color component data.

4. The video coder of claim 1 , wherein the processor is configured to determine the phase shift for chroma color component data.

5. The video coder of claim 1 , wherein the processor is configured to determine the phase shift for luma color component data and chroma color component data.

6. The video coder of claim 1 , wherein the processor is configured to determine if the phase shift comprises − 1/16 or 1/16.

7. The video coder of claim 1 , wherein the processor is configured to determine the phase shift from a picture header.

8. The video coder of claim 1 , wherein the first layer video data comprises a first layer block, slice, or picture.

9. The video coder of claim 1 , wherein the processor comprises a decoder.

10. The video coder of claim 1 , wherein the processor comprises an encoder.

11. The video coder of claim 1 , wherein the video coder is part of a device, the device selected from the group consisting of a desktop computer, a notebook computer, a tablet computer, a set-top box, a telephone handset, a television, a camera, a display device, a digital media player, a video gaming console, and a video streaming device.

12. A method of coding video data, the method comprising:

under the control of an electronic processor in communication with a memory unit:

determining a phase shift between first layer video data and second layer video data from one or more syntax elements or one or more headers of the first layer video data or the second layer video data;

selecting a filter from a filter set for upsampling the first layer video data based on (1) the determined phase shift and (2) a phase calculated based on a spatial aspect ratio between the first layer video data and the second layer video data;

upsampling the first layer video data using the selected filter, the upsampled first layer video data having the same spatial resolution as the second layer video data;

coding the second layer video data based at least on the upsampled first layer video data; and

storing the up sampled first layer video data in the memory unit.

13. The method of claim 12 , further comprising selecting the filter based on a sum of the determined phase shift and the phase.

14. The method of claim 12 , wherein the determining the phase shift comprises determining the phase shift for luma color component data.

15. The method of claim 12 , wherein the determining the phase shift comprises determining the phase shift for chroma color component data.

16. The method of claim 12 , wherein the determining the phase shift comprises determining the phase shift for luma color component data and chroma color component data.

17. The method of claim 12 , wherein the determining the phase shift comprises determining if the phase shift comprises − 1/16 or 1/16.

18. The method of claim 12 , wherein the determining the phase shift comprises determining the phase shift from a picture header.

19. The method of claim 12 , wherein the first layer video data comprises a first layer block, slice, or picture.

20. The method of claim 12 , further comprising receiving a syntax element extracted from an encoded video bit stream, the syntax element comprising an indication of the phase shift.

21. The method of claim 12 , further comprising generating a syntax element for an encoded video bit stream based at least on the phase shift.

22. A video coder for coding video data, the video coder comprising:

means for determining a phase shift between first layer video data and second layer video data from one or more syntax elements or one or more headers of the first layer video data or the second layer video data;

means for selecting a filter from a filter set for upsampling the first layer video data based on (1) the determined phase shift and (2) a phase calculated based on a spatial aspect ratio between the first layer video data and the second layer video data;

means for upsampling the first layer video data using the selected filter, the upsampled first layer video data having the same spatial resolution as the second layer video data;

means for storing the upsampled first layer video data; and

means for coding the second layer video data based at least on the upsampled first layer video data.

23. The video coder of claim 22 , wherein the means for selecting is configured to select the filter based on a sum of the determined phase shift and the phase.

24. The video coder of claim 22 , wherein the means for determining is configured to determine the phase shift for luma color component data.

25. The video coder of claim 22 , wherein the means for determining is configured to determine the phase shift for chroma color component data.

26. The video coder of claim 22 , wherein the means for determining is configured to determine the phase shift from a picture header.

27. The video coder of claim 22 , wherein the first layer video data comprises a first layer block, slice, or picture.

28. A non-transitory computer storage that stores executable program instructions that direct a video coder for coding video data to perform a process that comprises:

determining a phase shift between first layer video data and second layer video data from one or more syntax elements or one or more headers of the first layer video data or the second layer video data;

selecting a filter from a filter set for upsampling the first layer video data based on (1) the determined phase shift and (2) a phase calculated based on a spatial aspect ratio between the first layer video data and the second layer video data;

upsampling the first layer video data using the selected filter, the upsampled first layer video data having the same spatial resolution as the second layer video data; and

coding the second layer video data based at least on the upsampled first layer video data.

29. The non-transitory computer storage of claim 28 , wherein the process further comprises selecting the filter based on a sum of the determined phase shift and the phase.

30. The non-transitory computer storage of claim 28 , wherein the determining the phase shift comprises determining the phase shift for luma color component data.

31. The non-transitory computer storage of claim 28 , wherein the determining the phase shift comprises determining the phase shift for chroma color component data.

32. The non-transitory computer storage of claim 28 , wherein the determining the phase shift comprises determining the phase shift from a picture header.

33. The non-transitory computer storage of claim 28 , wherein the first layer video data comprises a first layer block, slice, or picture.