FIELD

The disclosed subject matter relates to video coding and decoding, and more specifically, to a signaling mechanism of output layer set for scalable video stream.

BACKGROUND

ITU-T VCEG (Q6/16) and ISO/IEC MPEG (JTC 1/SC 29/WG 11) published the H.265/HEVC (High Efficiency Video Coding) standard in 2013 (version 1) 2014 (version 2) 2015 (version 3) and 2016 (version 4). In 2015, these two standard organizations jointly formed the JVET (Joint Video Exploration Team) to explore the potential of developing the next video coding standard beyond HEVC. In October 2017, they issued the Joint Call for Proposals on Video Compression with Capability beyond HEVC (CfP). By Feb. 15, 2018, total 22 CfP responses on standard dynamic range (SDR), 12 CfP responses on high dynamic range (HDR), and 12 CfP responses on 360 video categories were submitted, respectively. In April 2018, all received CfP responses were evaluated in the 122 MPEG/10th JVET meeting. As a result of this meeting, JVET formally launched the standardization process of next-generation video coding beyond HEVC. The new standard was named Versatile Video Coding (VVC), and JVET was renamed as Joint Video Expert Team.

SUMMARY

In an embodiment, there is provided a method of decoding an encoded video bitstream using at least one processor including obtaining a coded video sequence including a plurality of output layer sets from the encoded video bitstream; obtaining a first flag indicating whether each output layer set of the plurality of output layer sets includes more than one layer; based on the first flag indicating that the each output layer set includes more than the one layer, obtaining a first syntax element indicating an output layer set mode; selecting at least one layer from among layers included in the plurality of output layer sets as at least one output layer based on at least one of the first flag and the first syntax element; and outputting the at least one output layer.

In an embodiment, there is provided a device for decoding an encoded video bitstream, including at least one memory configured to store program code; and at least one processor configured to read the program code and operate as instructed by the program code, the program code including: first obtaining code configured to cause the at least one processor to obtain a coded video sequence including a plurality of output layer sets from the encoded video bitstream; second obtaining code configured to cause the at least one processor to obtain a first flag indicating whether each output layer set of the plurality of output layer sets includes more than one layer; third obtaining code configured to cause the at least one processor to, based on the first flag indicating that the each output layer set includes more than the one layer, obtain a first syntax element indicating an output layer set mode; selecting code configured to cause the at least one processor to select at least one layer from among layers included in the plurality of output layer sets as at least one output layer based on at least one of the first flag and the first syntax element; and outputting code configured to cause the at least one processor to output the at least one output layer.

In an embodiment, there is provided a non-transitory computer-readable medium storing instructions, the instructions including one or more instructions that, when executed by one or more processors of a device for decoding an encoded video bitstream, cause the one or more processors to: obtain a coded video sequence including a plurality of output layer sets from the encoded video bitstream; obtain a first flag indicating whether each output layer set of the plurality of output layer sets includes more than one layer; based on the first flag indicating that the each output layer set includes more than the one layer, obtain a first syntax element indicating an output layer set mode; select at least one layer from among layers included in the plurality of output layer sets as at least one output layer based on at least one of the first flag and the first syntax element; output the at least one output layer.

