FRAME-LEVEL DEPENDENT BIT ALLOCATION IN HYBRID VIDEO ENCODING

• US 20140029664A1
• Filed: 01/30/2013
• Published: 01/30/2014
• Est. Priority Date: 07/27/2012
• Status: Abandoned Application

• Current Assignee: Dynamic Invention LLC
• Original Assignee: Hong Kong University of Science and Technology
• Inventors: AU, Oscar Chi Lim, PANG, Chao, DAI, Jingjing, ZOU, Feng
• Application Number:
  US13/754,835
• Publication Number:
  US 20140029664A1
• Time in Patent Office: Days
• US Class Current: 375/240.03
• CPC Class Codes: H04N 19/115 Selection of the code volume for a coding unit prior to coding
• 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 19/149 by estimating the code amount by means of a model, e.g. mathematical model or statistical model
• CPC Class Codes: H04N 19/172 the region being a picture, frame or field
• CPC Class Codes: H04N 19/19 using optimisation based on Lagrange multipliers

Abstract

Frame-level dependent bit allocation for hybrid video coding is presented to address issues relating to computational complexity of multi-pass coding of video data. An interframe dependency (IFDM) approach is presented which enables a quantitative measure of the coding dependency between the current frame and its reference frame. Based on the IFDM, buffer-constrained frame-level dependent bit allocation is determined (IFDM-DBA). Successive convex approximation techniques are utilized to convert an original optimization into a series of convex optimization problems.

Claims

1. A method, comprising:

determining total available bits for a group of pictures;

estimating a difference in motion between a current frame and a preceding frame before the current frame in the group of pictures;

determining a difference in residue between the current frame and the preceding frame;

approximating, based on at least one of the difference in motion or the difference in residue, by successive convex approximation, distortion of the current frame relative to the preceding frame; and

determining a bit allocation for the current frame based on the approximating the at least one of the difference in motion or the difference in residue.

2. The method of claim 1, wherein the total available bits is a function of a number of bits remaining from a previous group of pictures.

3. The method of claim 1, wherein the estimating the difference in motion comprises checking position of a pixel based on integer-pixel format.

4. The method of claim 1, wherein the determining the difference in residue comprises quantizing the difference in residue.

5. The method of claim 1, wherein the successive convex approximation comprises converging the difference in motion or the difference in residue to a single point facilitating solution of a convex approximation.

6. The method of claim 5, wherein the single point satisfies a Karush-Kuhn-Tucker condition enabling solution of a convex optimization problem in the successive convex approximation.

7. The method of claim 1, determining another bit allocation for a subsequent frame after the current frame and the current frame, wherein the determining is based in part on at least one of the estimated difference in motion between the current frame and the preceding frame or the difference in residue between the current frame and the preceding frame.

8. The method of claim 1, wherein the determining of the bit allocation is based on a memory buffer constraint.

9. The method of claim 7, wherein the memory buffer constraint limits a total bit allocation for all frames of the group of pictures to a processing capacity of a memory component associated with the memory buffer constraint.

10. A computer-readable storage medium comprising computer executable instructions that, in response to execution, cause a computing system comprising a processor to perform operations, comprising:

determining total available bits for a group of pictures;

estimating a difference in motion between a current frame and a previous frame preceding the current frame in the group of pictures;

determining a residual difference between the current frame and the previous frame;

approximating, based on at least one of the difference in motion or the residual difference, by successive convex approximation, distortion of the current frame versus the previous frame; and

determining a bit allocation for the current frame based on the approximating.

11. The computer-readable storage medium of claim 10, wherein the total available bits is a function of a number of bits remaining from a previous group of pictures.

12. The computer-readable storage medium of claim 10, wherein the estimating the difference in motion comprises checking an integer-pixel position of a first pixel with reference to an integer-pixel position of a second pixel.

13. The computer-readable storage medium of claim 10, wherein the determining the residual difference comprises applying a quantization to the residual difference.

14. The computer-readable storage medium of claim 10, wherein the operations further comprise determining another bit allocation for a subsequent frame and the current frame, wherein the determining is based at least in part on at least one of the difference in motion between the current frame and the previous frame or the residual difference between the current frame and the previous frame.

15. The computer-readable storage medium of claim 10, wherein the determining of the bit allocation is based at least in part on a memory buffer constraint.

16. The computer-readable storage medium of claim 15, wherein the memory buffer constraint comprises a limit on a total bit allocation for all frames of the group of pictures to a processing capacity of a memory component associated with the memory buffer constraint.

17. A system, comprising:

a memory to store computer-executable instructions; and

a processor, communicatively coupled to the memory, that facilitates execution of the computer-executable instructions to perform operations relating to allocation bits for a plurality of frames comprising a group of pictures, the operations comprising;

determining interframe dependency between a current frame and a previous frame in the plurality of frames;

determining a buffer-constrained frame-level dependent bit allocation; and

applying at least one successive convex approximation to the buffer-constrained frame-level dependent bit allocation facilitating deriving the bit allocation for the current frame.

18. The system of claim 17, wherein the buffer-constrained frame-level dependent bit allocation is constrained by a capacity of a memory buffer component associated with the processor.

19. The system of claim 17, wherein the determining the interframe dependency further comprises determining at least one of variance between discrete cosine transforms or a quantization step size.

20. The system of claim 19, wherein the operations further comprise determining another bit allocation for a subsequent frame, wherein the determining comprises applying, to the subsequent frame, at least one of the variance between discrete cosine transforms for the current frame or the quantization step size for the current frame.