Granted Patent B2

US 12,401,825 · App. 17/977,184 · Granted Aug 26, 2025

Inventors: Virginie Drugeon (Darmstadt, DE); Tadamasa Toma (Osaka, JP); Takahiro Nishi (Nara, JP); Kiyofumi Abe (Osaka, JP)

Assignee: PANASONIC INTELLECTUAL PROPERTY CORPORATION OF AMERICA

H04N19/70H04N19/31

Abstract

Claims (64)

1. An encoder comprising:

circuitry; and

memory coupled to the circuitry, wherein

in operation, the circuitry:

writes a first parameter into a video parameter set, the first parameter indicating a maximum number of one or more temporal sublayers in a layer set unit, the layer set unit being a unit which corresponds to a stream and includes one or more layers; and

writes a second parameter into a sequence parameter set, the second parameter indicating a maximum number of one or more temporal sublayers in a sequence unit, the sequence unit being a unit which corresponds to at least a portion of the stream and for which the sequence parameter set is referred to,

in a case where a reference is made to the video parameter set, the second parameter is limited to less than or equal to the first parameter, and

in a case where no reference is made to the video parameter set, the second parameter is limited to less than or equal to a fixed value.

2. The encoder according to claim 1 , wherein

the fixed value is an upper limit of the first parameter.

3. The encoder according to claim 1 , wherein

the first parameter has a value obtained by subtracting 1 from the maximum number of one or more temporal sublayers in the layer set unit,

the second parameter has a value obtained by subtracting 1 from the maximum number of one or more temporal sublayers in the sequence unit,

the fixed value is 6,

in the case where the reference is made to the video parameter set, the second parameter is limited to a range from 0 to the first parameter, and

in the case where no reference is made to the video parameter set, the second parameter is limited to a range from 0 to 6.

4. The encoder according to claim 1 , wherein

the circuitry writes a third parameter into the sequence parameter set, the third parameter (i) indicating that the reference is made to the video parameter set and indicating an identifier of the video parameter set, when the third parameter is greater than 0, and (ii) indicating that no reference is made to the video parameter set, when the third parameter is 0,

when the third parameter is greater than 0, the second parameter is limited to less than or equal to the first parameter, and

when the third parameter is 0, the second parameter is limited to less than or equal to the fixed value.

5. A decoder comprising:

circuitry; and

memory coupled to the circuitry, wherein

in operation, the circuitry:

reads a first parameter from a video parameter set, the first parameter indicating a maximum number of one or more temporal sublayers in a layer set unit, the layer set unit being a unit which corresponds to a stream and includes one or more layers, and

reads a second parameter from a sequence parameter set, the second parameter indicating a maximum number of one or more temporal sublayers in a sequence unit, the sequence unit being a unit which corresponds to at least a portion of the stream and for which the sequence parameter set is referred to,

in a case where a reference is made to the video parameter set, the second parameter is limited to less than or equal to the first parameter, and

in a case where no reference is made to the video parameter set, the second parameter is limited to less than or equal to a fixed value.

6. The decoder according to claim 5 , wherein

the fixed value is an upper limit of the first parameter.

7. The decoder according to claim 5 , wherein

the first parameter has a value obtained by subtracting 1 from the maximum number of one or more temporal sublayers in the layer set unit,

the second parameter has a value obtained by subtracting 1 from the maximum number of one or more temporal sublayers in the sequence unit,

the fixed value is 6,

in the case where the reference is made to the video parameter set, the second parameter is limited to a range from 0 to the first parameter, and

in the case where no reference is made to the video parameter set, the second parameter is limited to a range from 0 to 6.

8. The decoder according to claim 5 , wherein

the circuitry reads a third parameter from the sequence parameter set, the third parameter (i) indicating that the reference is made to the video parameter set and indicating an identifier of the video parameter set, when the third parameter is greater than 0, and (ii) indicating that no reference is made to the video parameter set, when the third parameter is 0,

when the third parameter is greater than 0, the second parameter is limited to less than or equal to the first parameter, and

when the third parameter is 0, the second parameter is limited to less than or equal to the fixed value.

9. A decoder comprising:

circuitry; and

memory coupled to the circuitry, wherein

in operation, the circuitry:

reads a first parameter from a first parameter set, the first parameter indicating a maximum number of one or more temporal sublayers in a layer set unit, the layer set unit being a unit which corresponds to a stream and includes one or more layers, the first parameter set being a parameter set for the layer set unit; and

reads a second parameter from a second parameter set, the second parameter indicating a maximum number of one or more temporal sublayers in a random access unit, the random access unit being a unit which corresponds to at least a portion of the stream, the second parameter set being a parameter set for the random access unit,

in a case where a reference is made to the first parameter set, the second parameter is limited to less than or equal to the first parameter, and

in a case where no reference is made to the first parameter set, the second parameter is limited to less than or equal to a fixed value.

10. An encoding method comprising:

writing a first parameter into a video parameter set, the first parameter indicating a maximum number of one or more temporal sublayers in a layer set unit, the layer set unit being a unit which corresponds to a stream and includes one or more layers; and

writing a second parameter into a sequence parameter set, the second parameter indicating a maximum number of one or more temporal sublayers in a sequence unit, the sequence unit being a unit which corresponds to at least a portion of the stream and for which the sequence parameter set is referred to, wherein

in a case where a reference is made to the video parameter set, the second parameter is limited to less than or equal to the first parameter, and

in a case where no reference is made to the video parameter set, the second parameter is limited to less than or equal to a fixed value.

11. A decoding method comprising:

reading a first parameter from a video parameter set, the first parameter indicating a maximum number of one or more temporal sublayers in a layer set unit, the layer set unit being a unit which corresponds to a stream and includes one or more layers; and

reading a second parameter from a sequence parameter set, the second parameter indicating a maximum number of one or more temporal sublayers in a sequence unit, the sequence unit being a unit which corresponds to at least a portion of the stream and for which the sequence parameter set is referred to, wherein

in a case where a reference is made to the video parameter set, the second parameter is limited to less than or equal to the first parameter, and

in a case where no reference is made to the video parameter set, the second parameter is limited to less than or equal to a fixed value.

12. A non-transitory medium storing a bitstream,

the bitstream including a video parameter set and a sequence parameter set for causing a decoder that reads out the bitstream to perform a decoding process, wherein

the video parameter set includes a first parameter indicating a maximum number of one or more temporal sublayers in a layer set unit, the layer set unit being a unit which corresponds to the bitstream and includes one or more layers,

the sequence parameter set includes a second parameter indicating a maximum number of one or more temporal sublayers in a sequence unit, the sequence unit being a unit for which the sequence parameter set is referred to in the bitstream,

in a case where a reference is made to the video parameter set, the second parameter is limited to less than or equal to the first parameter, and

in a case where no reference is made to the video parameter set, the second parameter is limited to less than or equal to a fixed value.

Assignments (1)

Continuity (3)

References Cited (13)