Coding and decoding methods of a picture block, corresponding devices and data stream

Patent metadata

Field	Value
Publication number	US-11750830-B2
Application number	US-202218086554-A
Country	US
Kind code	B2
Filing date	Dec 21, 2022
Priority date	Feb 22, 2013
Publication date	Sep 5, 2023
Grant date	Sep 5, 2023

Abstract

A method for decoding a picture block is disclosed. The decoding method comprises: —decoding ( 10 ) at least one stream S_diff into decoded data and into one information for identifying a reconstructed reference picture in a decoder picture buffer; —reconstructing ( 12 ) a special reference picture from at least the identified reconstructed reference picture and from the decoded data; —reconstructing ( 16 ) the picture block from at least the special reference picture, wherein the at least the special reference picture is not displayed.

First claim

The invention claimed is:

1. A decoding method comprising:
while inter-layer prediction is enabled, reconstructing a second layer reference picture from a first layer reference picture of a decoder picture buffer of a scalable multi-layered stream and from data decoded from a second layer of the scalable multi-layered stream and storing the reconstructed second layer reference picture in the decoder picture buffer;
decoding a flag indicating whether to display the reconstructed second layer reference picture; and
reconstructing a picture block of a subsequently decoded picture at least from the reconstructed second layer reference picture.

2. The decoding method according to claim 1 , wherein the data decoded from the second layer are representative of a pixel-by-pixel difference between the second layer reference picture and the first layer reference picture.

3. The decoding method according to claim 1 , wherein the first layer is a base layer.

4. The decoding method of claim 1 , further comprising decoding from the second layer information for identifying the first layer reference picture.

5. The decoding method of claim 1 , wherein the second layer reference picture and the first layer reference picture are temporally aligned.

6. The decoding method according to claim 1 , wherein a part of the second layer is configured to be decoded using information from the first layer.

7. The decoding method according to claim 1 , further comprising decoding a flag indicating that a subsequently decoded picture of the second layer is not using any inter-layer prediction, wherein inter-layer prediction is disabled after decoding the flag.

8. An encoding method comprising:
while inter-layer prediction is enabled, encoding in a second layer of a multi-layered stream a second layer reference picture of a decoder picture buffer from a first layer reference picture of the decoder picture buffer of the scalable multi-layered stream;
encoding a flag indicating whether to display the reconstructed second layer reference picture; and
encoding a picture block of a subsequently encoded picture at least from the second layer reference picture.

9. The encoding method according to claim 8 , wherein encoding in the second layer the second layer reference picture comprises determining the pixel-by-pixel difference between the second layer reference picture and the first layer reference picture and encoding the pixel-by-pixel difference.

10. The encoding method according to claim 8 , wherein the first layer is a base layer.

11. The encoding method of claim 8 , further comprising encoding in the second layer information for identifying the first layer reference picture.

12. The encoding method of claim 8 , wherein the second layer reference picture and the first layer reference picture are temporally aligned.

13. The encoding method according to claim 8 , further comprising encoding a flag indicating whether to display the reconstructed second layer reference picture that a subsequently encoded picture of the second layer is not using any inter-layer prediction, wherein inter-layer prediction is disabled after decoding the flag.

14. A decoder comprising at least a processor configured to:
while inter-layer prediction is enabled, reconstruct a second layer reference picture from a first layer reference picture of a decoder picture buffer of a scalable multi-layered stream and from data decoded from a second layer of the scalable multi-layered stream and store the reconstructed second layer reference picture in the decoder picture buffer;
decode a flag indicating whether to display the reconstructed second layer reference picture; and
reconstruct a picture block of a subsequently decoded picture at least from the reconstructed second layer reference picture.

15. The decoder according to claim 14 , wherein the data decoded from the second layer are representative of a pixel-by-pixel difference between the second layer reference picture and the first layer reference picture.

16. The decoder according to claim 14 , wherein the first layer is a base layer.

17. The decoder according to claim 14 , wherein the second layer reference picture and the first layer reference picture are temporally aligned.

18. The decoder according to claim 14 , wherein the at least one processor is further configured to decode from the second layer information for identifying the first layer reference picture.

19. The decoder according to claim 14 , wherein the at least one processor is further configured to decode a flag indicating that a subsequently decoded picture of the second layer is not using any inter-layer prediction, wherein inter-layer prediction is disabled after decoding the flag.

20. An encoder comprising at least a processor configured to:
while inter-layer prediction is enabled, encode in a second layer of a scalable multi-layered stream a second layer reference picture of a decoder picture buffer from a first layer reference picture of the decoder picture buffer of the scalable multi-layered stream;
encode a flag indicating whether to display the reconstructed second layer reference picture;
encode a picture block of a subsequently encoded picture at least from the second layer reference picture.

21. The encoder according to claim 20 , wherein to encode in the second layer the second layer reference picture comprises determining the pixel-by-pixel difference between the second layer reference picture and the first layer reference picture and encoding the pixel-by-pixel difference.

22. The encoder according to claim 20 , wherein the first layer is a base layer.

23. The encoder according to claim 20 , wherein the second layer reference picture and the first layer reference picture are temporally aligned.

24. The encoder according to claim 20 , wherein the at least one processor is further configured to encode in the second layer information for identifying the first layer reference picture.

25. The encoder according to claim 20 , wherein the at least one processor is further configured to encode a flag indicating that a subsequently encoded picture of the second layer is not using any inter-layer prediction, wherein inter-layer prediction is disabled after decoding the flag.

Assignees

• Interdigital Vc Holdings Inc

Inventors

• Bordes Philippe
• Hiron Franck
• Andrivon Pierre
• Lopez Patrick
• Salmon Philippe

Classifications

• H04N19/44 Primary

  Decoders specially adapted therefor, e.g. video decoders which are asymmetric with respect to the encoder · CPC title

• H04N19/176

  the region being a block, e.g. a macroblock · CPC title

• H04N19/30 Primary

  using hierarchical techniques, e.g. scalability (H04N19/63 takes precedence) · CPC title

• H04N19/50

  using predictive coding (H04N19/61 takes precedence) · CPC title

• H04N19/573

  Motion compensation with multiple frame prediction using two or more reference frames in a given prediction direction · CPC title