Dynamic coefficient reordering

• US 8,942,290 B2
• Filed: 08/30/2012
• Issued: 01/27/2015
• Est. Priority Date: 05/12/2003
• Status: Expired due to Term

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Ameres, Eric, Bankoski, James, Lavarnway, Scott, Xu, Yaowu, Miller, Dan, Grange, Adrian, Wilkins, Paul
• Primary Examiner(s): Dastouri, Mehrdad
• Assistant Examiner(s): ANDERSON II, JAMES M
• Application Number:
  US13/599,315
• Publication Number:
  US 20120320989A1
• Time in Patent Office: 880 Days
• Field of Search: None
• US Class Current: 375/240.18
• CPC Class Codes: H04N 19/114 Adapting the group of pictures [GOP] structure, e.g. number of B-frames between two anchor frames H04N19/107 takes precedence
• 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 19/129 Scanning of coding units, e.g. zig-zag scan of transform coefficients or flexible macroblock ordering [FMO]
• CPC Class Codes: H04N 19/13 Adaptive entropy coding, e.g. adaptive variable length coding [AVLC] or context adaptive binary arithmetic coding [CABAC]
• CPC Class Codes: H04N 19/139 Analysis of motion vectors, e.g. their magnitude, direction, variance or reliability
• CPC Class Codes: H04N 19/14 Coding unit complexity, e.g. amount of activity or edge presence estimation H04N19/146 takes precedence
• CPC Class Codes: H04N 19/152 by measuring the fullness of the transmission buffer
• CPC Class Codes: H04N 19/154 Measured or subjectively estimated visual quality after decoding, e.g. measurement of distortion use of rate-distortion criteria H04N19/147
• CPC Class Codes: H04N 19/156 Availability of hardware or computational resources, e.g. encoding based on power-saving criteria
• CPC Class Codes: H04N 19/172 the region being a picture, frame or field
• CPC Class Codes: H04N 19/177 the unit being a group of pictures [GOP]
• CPC Class Codes: H04N 19/52 by predictive encoding
• CPC Class Codes: H04N 19/523 with sub-pixel accuracy

Abstract

A system, apparatus, and method of compressing video data having at least one frame having at least one block having an array of pixels. The method includes transforming the pixels of the at least one block into coefficients, creating a default transmission order of the coefficients, creating an optimal transmission order of the coefficients, comparing a coefficient position of at least one of the coefficients in the optimal transmission order with a coefficient position of the at least one of the coefficients in the default transmission order; determining an update value based on the comparison, and selectively encoding position information of the at least one of the coefficients in the optimal transmission order based on the update value.

Claims

1. A method of compressing video data, the method comprising:

transforming an array of pixels of a block of a frame of the video data into coefficients;

creating a default transmission order of the coefficients of the block;

creating an optimal transmission order of the coefficients of the block;

comparing a coefficient position of a coefficient from the coefficients in the optimal transmission order with a coefficient position of the coefficient in the default transmission order;

determining an update value based on the comparison, the update value indicative of whether the coefficient position of the coefficient in the optimal transmission order is the same as the coefficient position of the coefficient in the default transmission order; and

selectively encoding position information of the coefficient in the optimal transmission order based on the update value,

wherein the position information is at least one of the coefficient position or band information, the band information indicating a position of a group of coefficients.

2. The method of claim 1, further comprising:

transmitting, the coefficients and the optimal transmission order of the coefficients.

3. The method of claim 2, further comprising:

limiting the transmission of the optimal transmission order to changes in coefficient order from a current frame to a next frame.

4. The method of claim 1, further comprising:

consolidating the optimal transmission order of the coefficients into bands of coefficients, each band having a plurality of coefficients organized according to the default transmission order; and

selectively encoding only the band information and the coefficients.

5. The method of claim 4, wherein selectively encoding only the band information and the coefficients comprises only transmitting the band information when a coefficient changes bands from a current frame to a next frame.

6. The method of claim 4, wherein selectively encoding only the band information and the coefficients comprises always transmitting all the band information.

7. The method of claim 1, further comprising:

determining if a given frame is a key frame;

if it is determined that the given frame is a key frame, transmitting the entire optimal transmission order of the coefficients for the given frame; and

if it is determined that the given frame is not a key frame, transmitting only changes in coefficient order of the coefficients from a previous frame to the given frame.

8. The method of claim 1, wherein the optimal transmission order of the coefficients is created for each frame of the video data.

9. The method of claim 1, wherein transforming the pixels of the block into coefficients comprises:

transforming the pixels of the block into discrete cosine transform coefficients.

10. The method of claim 1, wherein the frame includes a plurality of blocks that includes the block and wherein each block from the plurality of blocks has the same number of coefficients and coefficient positions.

11. The method of claim 1, wherein each corresponding respective coefficient position conveys the same information from block to block.

12. An apparatus for compressing video data, the apparatus, comprising:

a memory; and

a processor configured to execute instructions stored in the memory to;

transform an array of pixels of a block of a frame of the video data into coefficients;

create a default transmission order of the coefficients of the block;

create an optimal transmission order of the coefficients of the block;

compare a coefficient position of a coefficient from the coefficients in the optimal transmission order with a coefficient position of the coefficient in the default transmission order;

determine an update value based on the comparison, the update value indicative of whether the coefficient position of the coefficient in the optimal transmission order is the same as the coefficient position of the coefficient in the default transmission order; and

selectively encode position information of the coefficient in the optimal transmission order based on the update value,

wherein the position information is at least one of the coefficient position or band information, the band information indicating a position of a group of coefficients.

13. The apparatus of claim 12, wherein the instructions further comprises instructions to:

consolidate the optimal transmission order of the coefficients into bands of coefficients, each band having a plurality of coefficients organized according to the default transmission order.

14. The apparatus of claim 13, wherein the instructions further comprise instructions to:

selectively encode only the band information and the coefficients.

15. The apparatus of claim 14, wherein the instructions to selectively encode only the band information and the coefficients comprise instructions to:

only transmit the band information when a coefficient changes bands from a current frame to a next frame.

16. The apparatus of claim 12, wherein the instructions further comprise instructions to:

determine if a given frame is a key frame;

if it is determined that the given frame is a key frame, transmit the entire optimal transmission order of the coefficients for the given frame; and

if it is determined that the given frame is not a key frame, transmit only changes in coefficient order of the coefficients from a previous frame to the given frame.