Spatial scalable video coding

A method of forming a bitstream by an encoder device comprising:

• forming a group of resolution components by spatial subsampling video frames of a first video signal of a first resolution, wherein on the basis of video frames of the group of resolution components the first video signal is reconstructable;
• selecting one or more resolution components from the group of resolution components;
• and
• the encoder device forming the bitstream and decoder information on the basis of the one or more selected resolution components, wherein forming the bitstream and decoder information on the basis of the one or more selected resolution components comprises:
• if only a single resolution component is selected, then:
• the encoder device encoding a first resolution component of the group of resolution components, the first resolution component having a second resolution;
• and
• generating decoder information for a decoder to decode the single resolution component into a second video signal having the second resolution, the second resolution being lower than the first resolution;
• and
• if a first resolution component and one or more further resolution components are selected, then:
• the encoder device encoding the first resolution component and the one or more further resolution components of the group of resolution components into a first bitstream part and one or more further bitstreams parts respectively;
• combining the first bitstream part and the one or more further bitstreams parts;
• if the decoder information signals to the decoder device that the bitstream comprises all resolution components of the group, then:
• generating decoder information for the decoder to decode the first resolution component and the one or more further resolution components into video frames for reconstructing the first video signal, the encoder device inserting the decoder information into the bitstream;
• and
• if the decoder information signals to the decoder device that the bitstream does not comprise all resolution components of the group, the:
• generating decoder information for the decoder to decode the first resolution component and the one or more further resolution components into video frames for constructing a third video signal having a third resolution, the third resolution being higher than the second resolution and lower than the first resolution, the encoder device inserting the decoder information into the bitstream.

A decoding device comprising:

• one or more processors;
• and
• memory storing computer-readable instructions that, when executed by the one or more processors, cause the decoding device to carry out operations including:
• receiving a bitstream and decoder information, the bitstream comprising the decoder information, the decoder information signaling the decoder device the presence of one or more resolution components in the bitstream for forming a video signal, each resolution component representing a spatially subsampled version of a first video signal having a first resolution, the one or more resolution components being part of a resolution component group, the group comprising a plurality of resolution components on the basis of which the first video signal is reconstructable and wherein at least two or more resolution components have the same resolution;
• and
• parsing the bitstream and forming the video signal, wherein forming the video signal comprises:
• decoding at least one of the one or more resolution components into video frames on the basis of the decoder information,
• if the decoder information signals that the bitstream comprises only a first resolution component of the group, then:
• decoding parsed parts of the bitstream representing the first resolution component into video frames representing a second video signal of a second resolution, the second resolution being lower than the first resolution;
• if the decoder information signals that the bitstream comprises the first resolution component and one or more further resolution components of the group, then:
• decoding parsed parts of the bitstream representing the first resolution component and one or more further resolution components into video frames;
• if the decoder information signals that the bitstream comprises all resolution components of the group, then:
• reconstructing the first video signal into a reconstructed first video signal on the basis of the video frames;
• and
• if the decoder information signals that the bitstream does not all resolution components of the group, then:
• constructing a third video signal having a third resolution on the basis of the video frames, the third resolution being higher than the second resolution and lower than the first resolution.

An encoding device comprising:

• one or more processors;
• and
• memory storing computer-readable instructions that, when executed by the one or more processors, cause the encoding device to carry out operations including:
• forming a group of resolution components by spatial subsampling video frames of a first video signal having a first resolution, wherein on the basis of the video frames of the group of resolution components the first video signal is reconstructable and wherein at least two or more resolution components have the same resolution;
• selecting one or more resolution components from the group of resolution components;
• and
• forming a bitstream and decoder information on the basis of the one or more selected resolution components;
• wherein forming the bitstream and decoder information on the basis of the one or more selected resolution components comprises:
• if only a single resolution component is selected, then:
• encoding a first resolution component of the group of resolution components, the first resolution component having a second resolution;
• and
• generating information for a decoder to decode the single resolution component into a second video signal of the second resolution, the second resolution being lower than the first resolution;
• and
• if a first resolution component and one or more further resolution components are selected, then:
• encoding the first resolution component and the one or more further resolution components of the group of resolution components into a first bitstream part and one or more further bitstreams parts respectively;
• combining the first bitstream part and the one or more further bitstreams parts;
• if the decoder information signals to the decoder device that the bitstream comprises all resolution components of the group, then:
• generating information for the decoder to decode the first resolution component and the one or more further resolution components into video frames for reconstructing the first video signal, and inserting the decoder information into the bitstream;
• and
• if the decoder information signals to the decoder device that the bitstream does not comprise all resolution components of the group, then:
• generating information for the decoder to decode the first resolution component and the one or more further resolution components into video frames for constructing a third video signal having a third resolution, the third resolution being higher than the second resolution and lower than the first resolution, and inserting the decoder information into the bitstream.

A non-transitory computer-readable medium having instructions stored thereon that, when executed by one or more processors of a decoder device, cause the decoder device to carry out operations including:

• receiving a bitstream and decoder information, the bitstream comprising the decoder information, the decoder information signaling the decoder device the presence of one or more resolution components in the bitstream for forming the video signal, each resolution component comprising encoded media data and representing a spatially subsampled version of a first video signal having a first resolution, the one or more resolution components being part of a resolution component group, the group comprising a plurality of resolution components on the basis of which the first video signal is reconstructable;
• and
• parsing the bitstream and forming the video signal, wherein forming the video signal comprises:
• decoding the one or more resolution components into video frames on the basis of the decoder information;
• if the decoder information signals that the bitstream comprises only one first resolution component of the group, then:
• decoding parsed parts of the bitstream representing the first resolution component into video frames representing a second video signal of a second resolution, the second resolution being lower than the first resolution,
• if the decoder information signals that the bitstream comprises the first resolution component and one or more further resolution components of the group, then:
• decoding parsed parts of the bitstream representing the first resolution component and the one or more further resolution components into video frames;
• and,
• if the decoder information signals that the bitstream comprises all resolution components of the group, then:
• reconstructing the first video signal into a reconstructed first video signal on the basis of the video frames;
• and
• if the decoder information signals that the bitstream does not comprise all resolution components of the group, then:
• constructing on the basis of the video frames a third video signal having a third resolution, the third resolution being higher than the second resolution and lower than the first resolution.

A non-transitory computer-readable medium having instructions stored thereon that, when executed by one or more processors of an encoder device, cause the encoder device to carry out operations including:

• forming a group of resolution components by spatial subsampling video frames of a first video signal of a first resolution, wherein on the basis of video frames of the group of resolution components the first video signal is reconstructable;
• selecting one or more resolution components from the group of resolution components;
• and
• forming a bitstream and decoder information on the basis of the one or more selected resolution components, wherein forming the bitstream and decoder information on the basis of the one or more selected resolution components comprises:
• if only a single resolution component is selected, then:
• encoding a first resolution component of the group of resolution components, the first resolution component having a second resolution;
• and
• generating decoder information for a decoder to decode the single resolution component into a second video signal having the second resolution, the second resolution being lower than the first resolution;
• and
• if a first resolution component and one or more further resolution components are selected, then:
• encoding the first resolution component and the one or more further resolution components of the group of resolution components into a first bitstream part and one or more further bitstreams parts respectively;
• combining the first bitstream part and the one or more further bitstreams parts;
• if the decoder information signals to the decoder device that the bitstream comprises all resolution components of the group, then:
• generating decoder information for the decoder to decode the first resolution component and the one or more further resolution components into video frames for reconstructing the first video signal, the encoder device inserting the decoder information into the bitstream;
• and
• if the decoder information signals to the decoder device that the bitstream does not comprise all resolution components of the group, the:
• generating decoder information for the decoder to decode the first resolution component and the one or more further resolution components into video frames for constructing a third video signal having a third resolution, the third resolution being higher than the second resolution and lower than the first resolution, the encoder device inserting the decoder information into the bitstream.