SYSTEM AND METHOD FOR VIDEO ENCODING USING ADAPTIVE SEGMENTATION

• US 20100061444A1
• Filed: 12/05/2008
• Published: 03/11/2010
• Est. Priority Date: 09/11/2008
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: ON2 Technologies Incorporated (Alphabet Inc.)
• Inventors: Bankoski, James, Wilkins, Paul, Xu, Yaowu
• Granted Patent: US 8,325,796 B2
• Time in Patent Office: Days
• US Class Current: 375/240.20
• CPC Class Codes: H04N 19/10 using adaptive coding
• 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 19/124 Quantisation
• CPC Class Codes: H04N 19/17 the unit being an image region, e.g. an object
• CPC Class Codes: H04N 19/176 the region being a block, e.g. a macroblock
• CPC Class Codes: H04N 19/196 being specially adapted for the computation of encoding parameters, e.g. by averaging previously computed encoding parameters processing of motion vectors H04N19/513
• CPC Class Codes: H04N 19/21 with binary alpha-plane coding for video objects, e.g. context-based arithmetic encoding [CAE]
• CPC Class Codes: H04N 19/463 by compressing encoding parameters before transmission
• CPC Class Codes: H04N 19/523 with sub-pixel accuracy
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 19/82 involving filtering within a prediction loop

Abstract

A method for decoding compressed video information is disclosed. The video information can include a plurality of frames each having a plurality of blocks. The method includes reading from the video information a segment map that associates blocks in the frame with four segment identifiers. Each segment identifier is associated with one or more segment parameters, such as quantization parameters, loop filter type, loop filter strength and sub-pixel interpolation filter. The blocks in each segment are then decoded using the associated segment parameters. Segment parameters can persist to following frames unless overwritten by a subsequent frame. A frame can also include a bit suppressing segmentation, in which case default parameters are sued for all blocks in the frame.

Claims

1. A method for decoding compressed video information including a plurality of frames each having a plurality of blocks, comprising:

reading from the video information a segment map associating at least one block in at least one frame with at least one segment identifier, the segment identifier being decoded using a binary arithmetic decoder;

reading from the video information at least one segment parameter associated with the at least one segment identifier; and

decoding the at least one block using at least one segment parameter.

2. The method of claim 1, wherein the segment parameter includes at least one of a quantization parameter, a loop filter type, a loop filter strength value and a sub-pixel interpolation filter.

3. The method of claim 2, wherein a plurality of segment parameters are associated with the at least one segment identifier and a first one of the plurality of segment parameters includes a value indicative of an alternative reference frame;

and where the method further comprises;

updating the specified alternative reference frame using at least a second one of the plurality of segment parameters associated with the at least one segment identifier.

4. The method of claim 1, further comprising:

determining whether a frame being decoded specifies an updated segment parameter for a specific one of the segments; and

associating that specified updated segment parameter to the specific one of the segments.

5. The method of claim 2, wherein the updated segment parameter is an incremental value to be added to the at least one segment parameter.

6. The method of claim 1, further comprising:

reading from the video information associated with a particular frame a record indicative of a segmentation condition; and

when the segmentation condition is false, setting the segment parameter to a default parameter and suppressing the reading of the segment map and the reading of the at least one segment parameter.

7. The method of claim 1, wherein reading the segment map further comprises:

reading the at least one segment identifier in portions of the video information that are interleaved with data specific to the at least one block.

8. The method of claim 1, wherein reading the segment map further comprises:

reading the at least one segment identifier in a header file associated with at the least one frame.

9. The method of claim 1, further comprising:

determining whether the at least one frame is a key frame; and

setting the at least one segment parameter to a default value when the at least one frame is a key frame.

10. A method for creating a stream of encoded video information including a plurality of frames each having a plurality of blocks, comprising:

for at least a first frame, creating a segment map associating at least one block in the first frame with at least one segment identifier, and associating the at least one segment identifier with at least one segment parameter;

encoding the segment identifier using a binary arithmetic encoder; and

encoding the at least one block using the at least one segment parameter.

11. The method of claim 10, further comprising;

for at least a second frame, detecting a segmentation modification condition;

when the segmentation modification condition is detected, updating the at least one segment parameter and storing the updated segment parameter with video information associated with the second frame.

12. The method of claim 11, wherein the updated segment parameter is an incremental value.

13. The method of claim 10, further comprising;

for at least a second frame, detecting a segmentation condition; and

when the segmentation condition is detected, storing a segmentation flag with encoded video information associated with the at least a second frame.

14. The method of claim 10, wherein the at least one segment parameter includes at least one of quantization parameters, loop filter type, loop filter strength and sub-pixel interpolation filter.

15. The method of claim 14, wherein the at least one segment parameter includes a value indicative of an alternative reference frame;

and where the method further comprises;

updating the specified alternative reference frame using the at least one segment parameter.

16. The method of claim 10, further comprising:

storing the segment identifier in portions of the video information that are interleaved with data specific to the at least one block.

17. The method of claim 10, further comprising:

storing the segment identifier in a header portion of the first frame.

18. A method for decoding a stream of encoded video information including a plurality of frames each having a plurality of blocks, comprising:

for at least a first frame, reading from the video information a segment map associating at least one block in the first frame with at least one segment identifier, the segment identifier being decoded using a binary arithmetic decoder;

reading from the encoded video information at least one segment parameter associated with the at least one segment identifier;

decoding the at least one block using the at least one segment parameter; and

for at least a second frame, decoding a block in the second frame corresponding to the at least one block in the first frame using the at least one segment identifier.

19. The method of claim 18, wherein decoding a block in the second frame further comprises:

reading from the encoded video information a record associated with the at least a second frame, the record indicative of a segmentation condition for the second frame;

when the segmentation condition exists for the second frame, decoding a block in the second frame corresponding to the at least one block in the first frame using the at least one segment identifier.

20. The method of claim 18, wherein the segment parameters include at least one of a quantization parameter, a loop filter type, a loop filter strength value and a sub-pixel interpolation filter.