A method of video processing includes performing a conversion between a video including a plurality of video layers and a bitstream of the video, wherein the bitstream includes a plurality of output layer sets (OLSs), each including one or more of the plurality of video layers, and the bitstream conforms to a format rule, wherein the format rule specifies that, for an OLS having a single layer, a profile-tier-level (PTL) syntax structure that indicates a profile, a tier and a level for the OLS is included in a video parameter set for the bitstream, and the PTL syntax structure for the OLS is also included in a sequence parameter set coded in the bitstream.

Disclosed herein are an image encoding and decoding method and apparatus. The image decoding method may include obtaining video coding layer (VCL) network abstraction layer (NAL) unit type information of a current picture from a bitstream, determining a NAL unit type of each of a plurality of slices included in the current picture, based on the obtained VCL NAL unit type information, and decoding the plurality of slices based on the determined NAL unit type. The current picture may include a first subpicture and a second subpicture having different NAL unit types based on that at least some of the plurality of slices have different NAL unit types, and a NAL unit type of the second subpicture may be determined based on a NAL unit type of the first subpicture.

Systems and processes are provided to generate a thumbnail image including a tuner configured for receiving and demodulating a video signal including a video packet having a packet header and a video frame, a processor configured for generating a modified packet header by modifying the packet header to set a number of reference frames to zero and to designate the video frame as unused for reference, decoding the video frame in response to the modified packet header to extract the video frame, and generating the thumbnail image in response to the video frame, a memory configured for storing the thumbnail image, and a video output configured for coupling the thumbnail image to a display in response to a user video search request.

The present invention includes an image information decoding method which comprises: a step of receiving a bitstream that includes a network abstraction layer (NAL) unit including information related to an encoded image; and a step of parsing an NAL unit header of the NAL unit. The NAL unit header includes layer information including reserved_one_5bits for identifying an extended layer in an extended bitstream and temporal_id for identifying a temporal layer of a bitstream. The reserved_one_5bits of the layer information is received prior to the temporal_id of the layer information. Thus, a method for describing scalability information in a hierarchical bitstream is provided.

A method of decoding a coded video bitstream implemented by a video decoder is provided. The method includes the video decoder receiving the coded video bitstream, the coded video bitstream containing a gradual decoding refresh (GDR) flag corresponding to a coded video sequence (CVS); determining, by the video decoder, whether a GDR picture is present in the CVS based on a value of the GDR flag; initiating, by the video decoder, decoding of the CVS at the GDR picture when the value of the GDR flag indicates that the GDR picture is present; and generating, by the video decoder, an image according to the CVS as decoded. A corresponding method of encoding implemented by a video encoder is also disclosed.

A video coding mechanism is disclosed. The mechanism includes receiving a bitstream comprising a plurality of sub-pictures partitioned from a picture such that a union of the sub-pictures covers a total area of the picture without overlap. The bitstream is parsed to obtain the one or more sub-pictures. The one or more sub-pictures are decoded to create a video sequence. The video sequence is forwarded for display.

According to the disclosure of the present document, by signaling NAL unit-related information for a first picture and a collocated reference picture-related information for a second picture following the first picture in a decoding order, a collocated reference picture with respect to the second picture can be limited, and thus the image coding efficiency can be enhanced.

Aspects of the disclosure provide a method, an apparatus, and non-transitory computer-readable storage medium for video decoding. The apparatus includes processing circuitry. The processing circuitry can decode, from a bitstream, pictures associated with views of respective layers in a coded video sequence (CVS). The processing circuitry is configured to determine, based on a first supplemental enhancement information (SEI) message and a second SEI message, positions of the views to be displayed in one dimension. The first SEI message includes scalability dimension information (SDI) and the second SEI message includes multiview view position (MVP) information. The processing circuitry is configured to display the decoded pictures based on the positions of the views in the one dimension.

A mechanism is provided that implements video coding and decoding such that only a specific partial image region on a screen can be independently decoded. A video decoding apparatus (31) according to an aspect of the present invention configures, in intra prediction, inter prediction, loop filter processing, or the like, a partial image region in a picture, handles a region outside the partial image region in a similar manner to a region outside the picture, and does not apply such restriction to a non-partial image region other than the partial image region in the picture.

The embodiments of the disclosure provide an image slice transforming method and an electronic device. The method includes: receiving an i-th image slice outputted by an image encoder, wherein the i-th image slice belongs to N image slices divided from an image frame, i is an index, and N is an integer; obtaining a slice header of the i-th image slice; transforming the i-th image slice into an i-th sub-frame by modifying the slice header of the i-th image slice.