Method for picture output with output layer set
Systems and methods for coding and decoding are provided. A method includes encoding a video stream including video data partitioned into a plurality of layers, wherein the encoding includes determining whether a first picture of the video stream is to be output based on a syntax element that indicates a mode of output layer set signaling.
1 . A method of video decoding, the method comprising:
obtaining a value for a variable indicating a mode of output layer set signaling,
the variable having a first value the indicates that a total number of output layer sets specified by a parameter set is equal to a maximum allowed number of layers in a video sequence of a video bitstream referring to the parameter set, an i-th output layer set from among the output layer sets includes layers with layer indices from 0 to i, inclusive, and for each output layer set among the output layer sets, only a highest layer in the output layer set is to be output, and
the variable having a second value that indicates that the total number of output layer sets specified by the parameter set is equal to the maximum allowed number of layers in the video sequence of the video bitstream referring to the parameter set, the i-th output layer set from among the output layer sets includes layers with layer indices from 0 to i, inclusive, and for each output layer set among the output layer sets, all layers in the output layer set are to be output; and
decoding the video seuence of the video bitstream based on the variable indicating the mode of output layer set signaling.
2 . The method of claim 1 , wherein the parameter set is a video parameter set.
3 . The method of claim 1 , further comprising:
obtaining a respective subpicture layer identifier for each layer of each output layer set among the output layer sets; and
decoding the respective subpicture layer identifier for each layer of each output layer set.
4 . The method of claim 1 , wherein the first value is equal to 0, and wherein the second value is equal to 1.
5 . The method of claim 1 , wherein, the mode of output layer set signaling having a third value indicates that the total number of output layer sets specified by the parameter set is explicitly signaled in the video bitstream, the third value being equal to 2.
6 . A method of video encoding, the method comprising:
obtaining a value for a variable indicating a mode of output layer set signaling,
the variable having a first value indicates that a total number of output layer sets specified by a parameter set is equal to a maximum allowed number of layers in a video sequence of a video bitstream referring to the parameter set, an i-th output layer set from among the output layer sets includes layers with layer indices from 0 to i, inclusive, and for each output layer set among the output layer sets, only a highest layer in each output layer set is to be output, and
the variable having a second value indicates that the total number of output layer sets specified by the parameter set is equal to the maximum allowed number of layers in a video sequence of the video bitstream referring to the parameter, the i-th output layer set from among the output layer sets includes layers with layer indices from 0 to i, inclusive, and for each output layer set among the output layer sets, all layers in the output layer set are to be output; and
encoding the video sequence of the video bitstream based on the variable indicating the mode of output layer set signaling.
7 . The method of claim 6 , wherein the parameter set is a video parameter set.
8 . The method of claim 6 , method the first value is equal to 0, and wherein the second value is equal to 1.
9 . The method of claim 6 , wherein the mode of output laver set signaling having a third value indicates that the total number of output layer sets specified by the parameter set is explicitly signaled in a video bitstream having the coded video sequence, the third value being equal to 2.
10 . A non-transitory computer-readable medium storing computer instructions configured to store a video bitstream that is generated by a video encoding method, the video encoding method comprising:
setting a value for a variable indicating a mode of output layer set signaling,
the first picture is to be output is based on the variable, and
the variable having a first value indicates that a total number of output layer sets specified by a parameter set is equal to a maximum allowed number of layers in a video sequence of the video bitstream referring to the parameter set, an i-th output later set from among the output layer sets includes layers with layer indices from 0 to i, inclusive, and for each output layer set among the output layer sets, only a highest layer in each output layer set is to be output, and
the variable having a second value indicates that the total number of output laver sets specified by the parameter set is equal to the maximum allowed number of layer is in the video sequence of the video bitstream referring to the parameter set, the i-th output layer set from among the output layer sets includes lavers with layer indices from 0 to i, inclusive, and for each output layer set among the output layer sets, all layers in the output layer set are to be output; and
encoding video sequence of the video bitstream based on the variable indicating the mode of output layer set signaling.
11 . The non-transitory computer-readable medium of claim 10 , wherein the parameter set is a video parameter set.
12 . The non-transitory computer-readable medium of claim 11 , wherein the first value is equal to 0, and wherein the second value is equal to 1.
13 . The non-transitory computer-readable medium of claim 11 , wherein the mode of output layer set signaling having a third value indicates that the total number of output layer sets specified by the parameter set is explicitly signaled, the third value being equal to 2.