Methods, encoders and decoders for coding of video sequencing

A method, performed by an encoder, for encoding frames of a video sequence into an encoded representation of the video sequence, wherein the encoded representation comprises one or more encoded units representing the frames, wherein the encoded representation is encoded using a color format including two or more color components, the method comprising:

• for a first set of frames, encoding the first set of frames into a first set of encoded units, while specifying at least one residual parameter in one or more of the first set of encoded units, wherein the at least one residual parameter instructs the decoder of how to generate residuals;
• and
• for a second set of frames, encoding the second set of frames into a second set of encoded units, while refraining from specifying the at least one residual parameter, wherein the refraining from specifying the at least one residual parameter is performed only for inter-coded blocks of the second set of frames and only for a subset of the color components.

A method, performed by an encoder, for encoding frames of a video sequence into an encoded representation of the video sequence, wherein the encoded representation comprises one or more encoded units representing the frames, wherein the method comprises:

• for a first set of frames, encoding the first set of frames into a first set of encoded units, wherein each frame of the first set has a first level of fidelity;
• for a second set of frames, encoding the second set of frame into a second set of encoded units, wherein each frame of the second set has a second level of fidelity, wherein the second level of fidelity is less than the first level of fidelity.

A method, performed by a decoder, for decoding an encoded representation of frames of a video sequence into frames of the video sequence, wherein the encoded representation comprises one or more encoded units representing the frames of the video sequence, wherein the encoded representation is encoded using a color format including two or more color components, wherein the method comprises:

• decoding a first set of encoded units into a first set of frames, while obtaining a first level of fidelity for each frame of the first set, wherein the first level of fidelity relates to availability of at least one color component;
• decoding a second set of encoded units into a second set of frames, while obtaining a second level of fidelity of each frame of the second set, wherein the second level of fidelity relates to availability of at least one color component,
• when the second level of fidelity is less than the first level of fidelity, enhancing the second set of frames towards obtaining the first level of fidelity for each frame of the second set, wherein the enhancing comprises deriving at least one further color component for each frame of the second set based on said at least one color component that is available from frames preceding and following said each frame.