Method and device for coding a scalable video stream, a data stream, and an associated decoding method and device

A method of decoding a video sequence received in the form of a base level and a refinement level, a group of pictures of the base level comprising intra coded or mono-predicted end images and bi-predicted images, the refinement level comprising at least one image with no temporal correspondent in the base level, said method comprising:

• predictive decoding of said image with no temporal correspondent by making reference to a plurality of images, each image of said plurality being an image of the refinement level with no temporal correspondent in the base level or an image of the refinement level corresponding temporally to an end image,
• wherein the decoding of the images of the refinement level, with no temporal correspondent in the base level and situated temporally between an anchoring image and the end image, is performed on the basis of the anchoring image and the image of the refinement level temporally corresponding to that end image, the anchoring image being an image of the refinement level with no temporal correspondent in the base level and temporally neighboring an image of the base level that is bi-predicted with reference to the end images.

A device for coding a video sequence in the form of a base level and an refinement level, a group of pictures of the base level comprising intra coded or mono-predicted end images and bi-predicted images, the refinement level comprising at least one image with no temporal correspondent in the base level, said device comprising:

• means for predictive coding of said image with no temporal correspondent by making reference to a plurality of images configured such that each image of said plurality is an image of the refinement level with no temporal correspondent in the base level or an image of the refinement level corresponding temporally to an end image;
• and
• means for determining as an anchoring image an image of the refinement level with no temporal correspondent in the base level and temporally neighboring an image of the base level that is bi-predicted with reference to the end images.

A device for decoding a video sequence received in the form of a base level and an refinement level, a group of pictures of the base level comprising intra coded or mono-predicted end images and bi-predicted images, the refinement level comprising at least one image with no temporal correspondent in the base level, said device comprising:

• means for predictive decoding of said image with no temporal correspondent by making reference to a plurality of images configured such that each image of said plurality is an image of the refinement level with no temporal correspondent in the base level or an image of the refinement level corresponding temporally to an end image,
• wherein the decoding of the images of the refinement level, with no temporal correspondent in the base level and situated temporally between an anchoring image and the end image, is performed on the basis of the anchoring image and the image of the refinement level temporally corresponding to that end image, the anchoring image being an image of the refinement level with no temporal correspondent in the base level and temporally neighboring an image of the base level that is bi-predicted with reference to the end images.

A non-transitory computer-readable medium storing a data stream representing a video sequence in the form of a base level and an refinement level, a group of pictures of the base level comprising intra coded or mono-predicted end images and bi-predicted images, the refinement level comprising at least one image with no temporal correspondent in the base level,

• wherein said image with no temporal correspondent is predictively coded by making reference to a plurality of images, each image of said plurality being an image of the refinement level, with no temporal correspondent in the base level and temporally neighboring an image of the base level that is bi-predicted with reference to the end image, is determined as an anchoring image.

A method of coding a video sequence in the form of a base level and a refinement level, a group of pictures of the base level comprising intra coded or mono-predicted end images and bi-predicted images, the refinement level comprising at least one B-hierarchical image with no temporal correspondent in the base level, said method comprising:

• predictive coding of said B-hierarchical image with no temporal correspondent by making reference to at least one image of the refinement level with no temporal correspondent in the base level;
• and
• determining as an anchoring image an image of the refinement level with no temporal correspondent in the base level and temporally neighboring an image of the base level that is bi-predicted with reference to the end images.

A method of decoding a video sequence received in the form of a base level and an refinement level, a group of pictures of the base level comprising intra coded or mono-predicted end images and bi-predicted images, the refinement level comprising at least one B-hierarchical image with no temporal correspondent in the base level, said method comprising:

• predictive decoding of said B-hierarchical image with no temporal correspondent by making reference to at least one image of the refinement level with no temporal correspondent in the base level,
• wherein the decoding of the images of the refinement level, with no temporal correspondent in the base level and situated temporally between an anchoring image and the end image, is performed on the basis of the anchoring image and the image of the refinement level temporally corresponding to that end image, the anchoring image being an image of the refinement level with no temporal correspondent in the base level and temporally neighboring an image of the base level that is bi-predicted with reference to the end images.

A device for coding a video sequence in the form of a base level and an refinement level, a group of pictures of the base level comprising intra coded or mono-predicted end images and bi-predicted images, the refinement level comprising at least one B-hierarchical image with no temporal correspondent in the base level, said device comprising:

• means for predictive coding of said B-hierarchical image with no temporal correspondent by making reference to at least one an image of the refinement level with no temporal correspondent in the base level;
• and
• means for determining as an anchoring image an image of the refinement level with no temporal correspondent in the base level and temporally neighboring an image of the base level that is bi-predicted with reference to the end images.

A device for decoding a video sequence received in the form of a base level and an refinement level, a group of pictures of the base level comprising intra coded or mono-predicted end images and bi-predicted images, the refinement level comprising at least one B-hierarchical image with no temporal correspondent in the base level, said device comprising:

• means for predictive decoding of said B-hierarchical image with no temporal correspondent by making reference to at least one image of the refinement level with no temporal correspondent in the base level,
• wherein the decoding of the images of the refinement level, with no temporal correspondent in the base level and situated temporally between an anchoring image and the end image, is performed on the basis of the anchoring image and the image of the refinement level temporally corresponding to that end image, the anchoring image being an image of the refinement level with no temporal correspondent in the base level and temporally neighboring an image of the base level that is bi-predicted with reference to the end images.

A non-transitory computer-readable medium storing a data stream representing a video sequence in the form of a base level and an refinement level, a group of pictures of the base level comprising intra coded or mono-predicted end images and bi-predicted images, the refinement level comprising at least one B-hierarchical image with no temporal correspondent in the base level,

• wherein said B-hierarchical image with no temporal correspondent is predictively coded by making reference to at least one image of the refinement level, with no temporal correspondent in the base level and temporally neighboring an image of the base level that is bi-predicted with reference to the end image, is determined as an anchoring image.