Dynamic coefficient reordering

Patent metadata

Field	Value
Publication number	US-8942290-B2
Application number	US-201213599315-A
Country	US
Kind code	B2
Filing date	Aug 30, 2012
Priority date	May 12, 2003
Publication date	Jan 27, 2015
Grant date	Jan 27, 2015

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.

First claim

What is claimed is:

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.

Assignees

• Ameres Eric
• Bankoski James
• Lavarnway Scott
• Xu Yaowu
• Miller Dan
• Grange Adrian
• Wilkins Paul
• Google Inc

Inventors

• Ameres Eric
• Bankoski James
• Lavarnway Scott
• Xu Yaowu
• Miller Dan
• Grange Adrian
• Wilkins Paul

Classifications

• H04N19/139

  Analysis of motion vectors, e.g. their magnitude, direction, variance or reliability · CPC title

• H04N19/523

  with sub-pixel accuracy · CPC title

• H04N19/114

  Adapting the group of pictures [GOP] structure, e.g. number of B-frames between two anchor frames (H04N19/107 takes precedence) · CPC title

• H04N19/14

  Coding unit complexity, e.g. amount of activity or edge presence estimation (H04N19/146 takes precedence) · CPC title

• H04N19/129

  Scanning of coding units, e.g. zig-zag scan of transform coefficients or flexible macroblock ordering [FMO] · CPC title