System and method for video coding using adaptive segmentation

• US 9,924,161 B2
• Filed: 11/19/2012
• Issued: 03/20/2018
• Est. Priority Date: 09/11/2008
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google LLC (Alphabet Inc.)
• Inventors: Wilkins, Paul, Bankoski, James, Xu, Yaowu
• Primary Examiner(s): Prince, Jessica M
• Application Number:
  US13/680,636
• Publication Number:
  US 20130101019A1
• Time in Patent Office: 1,947 Days
• Field of Search: 37524002
• 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 reading, from the video information, a segment map associating at least some of the plurality of blocks in a first frame of the plurality of frames with at least one segment identifier, reading, from the video information, a current block to be decoded by a decoder, reading, from the segment map, a segment identifier that is associated with the current block, reading, from the video information, at least one segment parameter associated with the segment identifier that is associated with the current block and decoding the current block using the at least one segment parameter associated with the segment identifier that is associated with the current block.

Claims

1. A method for decoding compressed video information, comprising:

receiving a compressed video stream, the compressed video stream including compressed video information, the compressed video information including a plurality of frames, each frame from the plurality of frames including a plurality of blocks;

reading, from the compressed video information, a segment map associating at least some of the plurality of blocks in a first frame of the plurality of frames with at least one segment identifier;

reading, from the compressed video information, a current block to be decoded by a decoder;

reading, from the segment map, a segment identifier that is associated with the current block;

reading, from the compressed video information, at least one segment parameter associated with the segment identifier that is associated with the current block;

decoding, by a processor in response to instructions stored on a non-transitory computer readable medium, the current block using the at least one segment parameter associated with the segment identifier that is associated with the current block; and

outputting the decoded current block for presentation.

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

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

and where the method further comprises;

updating the alternate 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 subsequent to the first frame specifies an updated segment parameter for a specific one of the segments; and

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

5. The method of claim 4, 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 compressed video information, a record indicative of a segmentation condition of a frame subsequent to the first frame; and

setting the at least one segment parameter to a respective default parameter and suppressing the reading of the segment map, the reading of the segment identifier and the reading of the at least one segment parameter for all blocks of the frame subsequent to the first frame when the segmentation condition indicates to not apply segmentation.

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

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

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

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

9. The method of claim 1, further comprising:

determining whether a frame subsequent to the first frame is a key frame; and

setting the at least one segment parameter to a default value when the frame subsequent to the first 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;

selecting a current block of the first frame for encoding by an encoder;

encoding a segment identifier associated with the current block based on the segment map;

encoding, by a processor in response to instructions stored on a non-transitory computer readable medium, the current block using the at least one segment parameter associated with the segment identifier that is associated with the current block;

including the encoded segment identifier and the encoded current block in an output bitstream; and

transmitting or storing the output bitstream.

11. The method of claim 10, further comprising:

for 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 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 second frame.

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

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

and where the method further comprises;

updating the alternate reference frame using the at least one segment parameter.

16. The method of claim 10, further comprising:

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

18. A method for decoding a stream of encoded video information, the method comprising:

receiving an encoded video stream, the encoded video stream including encoded video information, the encoded video information including a plurality of frames, each frame from the plurality of frames including a plurality of blocks;

for at least a first frame, reading from the encoded video information a segment map associating at least some of the plurality of blocks in the first frame with at least one segment identifier;

reading, from the encoded video information, a current block of the first frame to be decoded by a decoder;

reading, from the segment map, a segment identifier associated with the current block;

reading, from the encoded video information, at least one segment parameter associated with the segment identifier that is associated with the current block;

decoding the current block using the at least one segment parameter associated with the segment identifier that is associated with the current block;

for a second frame, decoding, by a processor in response to instructions stored on a non-transitory computer readable medium, a block from the second frame corresponding to the current block in the first frame using the segment identifier that is associated with the current block; and

outputting the decoded block from the second frame for presentation.

19. The method of claim 18, wherein the at least one segment parameter includes at least one of a quantization parameter, a loop filter type, a loop filter strength value or a subpixel interpolation filter.

20. The method of claim 18, wherein the second frame includes frame level header information including a bit indicating whether segmentation is enabled or disabled for the second frame, a bit indicating whether or not to update the segment map, a bit indicating whether to update the at least one segmentation parameter for the second frame, a value for each of the at least one segmentation parameter, and a bit indicating whether the value is a delta value or an absolute value.