ADVANCED INTERPOLATION TECHNIQUES FOR MOTION COMPENSATION IN VIDEO CODING

• US 20090257503A1
• Filed: 04/08/2009
• Published: 10/15/2009
• Est. Priority Date: 04/10/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Karczewicz, Marta, Ye, Yan, Chen, Peisong
• Granted Patent: US 8,971,412 B2
• Time in Patent Office: Days
• US Class Current: 375/240.170
• CPC Class Codes: H04N 19/117 Filters, e.g. for pre-processing or post-processing sub-band filter banks H04N19/635
• CPC Class Codes: H04N 19/136 Incoming video signal characteristics or properties
• CPC Class Codes: H04N 19/147 according to rate distortion criteria rate-distortion as a criterion for motion estimation H04N19/567
• CPC Class Codes: H04N 19/182 the unit being a pixel
• CPC Class Codes: H04N 19/192 the adaptation method, adaptation tool or adaptation type being iterative or recursive
• CPC Class Codes: H04N 19/523 with sub-pixel accuracy
• CPC Class Codes: H04N 19/82 involving filtering within a prediction loop

Abstract

This disclosure describes various interpolation techniques performed by an encoder and a decoder during the motion compensation process of video coding. In one example, an encoder interpolates pixel values of reference video data based on a plurality of different pre-defined interpolation filters. In this example, the decoder receives a syntax element that identifies an interpolation filter, and interpolates pixel values of reference video data based on the interpolation filter identified by the syntax element. In another example, a method of interpolating predictive video data includes generating half-pixel values based on integer pixel values, rounding the half-pixel values to generate half-pixel interpolated values, storing the half-pixel values as non-rounded versions of the half-pixel values, and generating quarter-pixel values based on the non-rounded versions of the half-pixel values and the integer pixel values.

Claims

1. A method of interpolating predictive video data for video coding, the method comprising:

generating half-pixel values based on integer pixel values;

rounding the half-pixel values to generate half-pixel interpolated values;

storing the half-pixel values as non-rounded versions of the half-pixel values; and

generating quarter-pixel values based on the non-rounded versions of the half-pixel values and the integer pixel values.

2. The method of claim 1 further comprising:

generating another half-pixel value based on a plurality of the non-rounded versions of the half-pixel values; and

generating additional quarter-pixel values based on the another half-pixel value and the non-rounded versions of the half-pixel values.

3. The method of claim 1, wherein every one of the values can be stored within a sixteen-bit data structure, the method further comprising:

generating another half-pixel value based on a plurality of the non-rounded versions of the half-pixel values;

rounding the another half-pixel value so that the another half-pixel value can be stored within the sixteen-bit data structure; and

generating additional quarter-pixel values based on the another half-pixel value and the non-rounded versions of the half-pixel values.

4. The method of claim 1, further comprising:

encoding one or more video blocks based on the integer pixel values, the half-pixel values and/or the quarter-pixel values.

5. The method of claim 1, further comprising:

decoding one or more video blocks based on the integer pixel values, the half-pixel values and/or the quarter-pixel values.

6. An apparatus that interpolates predictive video data for video coding, wherein the apparatus includes a motion compensation unit that:

generates half-pixel values based on integer pixel values;

rounds the half-pixel values to generate half-pixel interpolated values;

stores the half-pixel values as non-rounded versions of the half-pixel values; and

generates quarter-pixel values based on the non-rounded versions of the half-pixel values and the integer pixel values.

7. The apparatus of claim 6, wherein the motion compensation unit:

generates another half-pixel value based on a plurality of the non-rounded versions of the half-pixel values; and

generates additional quarter-pixel values based on the another half-pixel value and the non-rounded versions of the half-pixel values.

8. The apparatus of claim 6, wherein every one of the values can be stored within a sixteen-bit data structure, wherein the motion compensation unit:

generates another half-pixel value based on a plurality of the non-rounded versions of the half-pixel values;

rounds the another half-pixel value so that the another half-pixel value can be stored within the sixteen-bit data structure; and

generates additional quarter-pixel values based on the another half-pixel value and the non-rounded versions of the half-pixel values.

9. The apparatus of claim 6, wherein the apparatus comprises a video encoder that includes the motion compensation unit, wherein the video encoder:

predictively encodes one or more video blocks based on the integer pixel values, the half-pixel values and/or the quarter-pixel values.

10. The apparatus of claim 6, wherein the apparatus comprises a video decoder that includes the motion compensation unit, wherein the video decoder:

predictively decodes one or more video blocks based on the integer pixel values, the half-pixel values and/or the quarter-pixel values.

11. The apparatus of claim 6, wherein the apparatus comprises an integrated circuit.

12. The apparatus of claim 6, wherein the apparatus comprises a microprocessor.

13. A computer-readable storage medium comprising instructions that upon execution cause a device to interpolate predictive video data for video coding, wherein the instructions cause the device to:

generate half-pixel values based on integer pixel values;

round the half-pixel values to generate half-pixel interpolated values;

store the half-pixel values as non-rounded versions of the half-pixel values; and

generate quarter-pixel values based on the non-rounded versions of the half-pixel values and the integer pixel values.

14. The computer-readable storage medium of claim 13, further comprising instructions that upon execution cause a device to:

generate another half-pixel value based on a plurality of the non-rounded versions of the half-pixel values; and

generate additional quarter-pixel values based on the another half-pixel value and the non-rounded versions of the half-pixel values.

15. The computer-readable storage medium of claim 13, wherein every one of the values can be stored within a sixteen-bit data structure, the computer-readable medium further comprising instructions that upon execution cause a device to:

generate another half-pixel value based on a plurality of the non-rounded versions of the half-pixel values;

round the another half-pixel value so that the another half-pixel value can be stored within the sixteen-bit data structure; and

generate additional quarter-pixel values based on the another half-pixel value and the non-rounded versions of the half-pixel values.

16. The computer-readable storage medium of claim 13, further comprising instructions that upon execution cause a device to:

encode one or more video blocks based on the integer pixel values, the half-pixel values and/or the quarter-pixel values.

17. The computer-readable storage medium of claim 13, further comprising instructions that upon execution cause a device to:

decode one or more video blocks based on the integer pixel values, the half-pixel values and/or the quarter-pixel values.

18. A device that interpolates predictive video data for video coding, the device comprising:

means for generating half-pixel values based on integer pixel values;

means for rounding the half-pixel values to generate half-pixel interpolated values;

means for storing the half-pixel values as non-rounded versions of the half-pixel values; and

means for generating quarter-pixel values based on the non-rounded versions of the half-pixel values and the integer pixel values.

19. The device of claim 18, further comprising:

means for generating another half-pixel value based on a plurality of the non-rounded versions of the half-pixel values; and

means for generating additional quarter-pixel values based on the another half-pixel value and the non-rounded versions of the half-pixel values.

20. The device of claim 18, wherein every one of the values can be stored within a sixteen-bit data structure, the device further comprising:

means for generating another half-pixel value based on a plurality of the non-rounded versions of the half-pixel values;

means for rounding the another half-pixel value so that the another half-pixel value can be stored within the sixteen-bit data structure; and

means for generating additional quarter-pixel values based on the another half-pixel value and the non-rounded versions of the half-pixel values.

21. The device of claim 18, further comprising:

means for encoding one or more video blocks based on the integer pixel values, the half-pixel values and/or the quarter-pixel values.

22. The device of claim 18, further comprising:

means for decoding one or more video blocks based on the integer pixel values, the half-pixel values and/or the quarter-pixel values.

23. A device that encodes video data, the device comprising:

a video encoder including a motion compensation unit that generates half-pixel values based on integer pixel values, rounds the half-pixel values to generate half-pixel interpolated values, stores the half-pixel values as non-rounded versions of the half-pixel values, and generates quarter-pixel values based on the non-rounded versions of the half-pixel values and the integer pixel values; and

a wireless transmitter that transmits the video data encoded by the motion compensation unit to another device.

24. The device of claim 23, wherein the device comprises a wireless communication handset.

25. A device that decodes video data, the device comprising:

a wireless receiver that receives the video data; and

a video decoder including a motion compensation unit that decodes the video data, wherein in decoding the video data, the motion compensation unit;

generates half-pixel values based on integer pixel values;

rounds the half-pixel values to generate half-pixel interpolated values;

stores the half-pixel values as non-rounded versions of the half-pixel values; and

generates quarter-pixel values based on the non-rounded versions of the half-pixel values and the integer pixel values.

26. The device of claim 25, wherein the device comprises a wireless communication handset.