Systems and methods for signaling temporal sub-layer information in video coding
This disclosure relates to video coding and more particularly to techniques for signaling temporal sub-layer information for coded video. According to an aspect of an invention, a range of a value of a third syntax element in a sequence parameter set is determined based on whether the sequence parameter set refers to a video parameter set, wherein the third syntax element specifies a maximum number of temporal sub-layers that is present in each coded video sequence referring to the sequence parameter set.
1. A method of decoding video data, the method comprising:
receiving a reference picture list structure;
for an entry in the reference picture list structure,
(i) parsing a first syntax element, wherein a value of the first syntax element equal to 1 specifies that the entry is an inter layer reference picture entry and the value of the first syntax element equal to 0 specifies that the entry is not an inter layer reference picture entry;
(ii) parsing a second syntax element, wherein a value of the second syntax element equal to 1 specifies that the entry is a short term reference picture entry and the value of the second syntax element equal to 0 specifies that the entry is a long term reference picture entry;
determining there is no reference picture, in a decoded picture buffer, with (i) a same layer identifier as a current picture and (ii) a picture order count value equal to a value for the entry in a picture order count list;
in response to determining there is no reference picture, generating a picture; and
marking the picture as follows:
in a case that the first syntax element is equal to 0 and the second syntax element is equal to 1, the picture is marked as used for short-term reference; and
in a case that the first syntax element equal to 0 and the second syntax element equal to 0, the picture is marked as used for long-term reference.
2. A device comprising:
a processor, and
a memory associated with the processor; wherein the processor is configured to perform the following steps:
receiving a reference picture list structure;
for an entry in the reference picture list structure,
(i) parsing a first syntax element, wherein a value of the first syntax element equal to 1 specifies that the entry is an inter layer reference picture entry and the value of the first syntax element equal to 0 specifies that the entry is not an inter layer reference picture entry;
(ii) parsing a second syntax element, wherein a value of the second syntax element equal to 1 specifies that the entry is a short term reference picture entry and the value of the second syntax element equal to 0 specifies that the entry is a long term reference picture entry;
determining there is no reference picture, in a decoded picture buffer, with (i) a same layer identifier as a current picture and (ii) a picture order count value equal to a value for the entry in a picture order count list;
in response to determining there is no reference picture, generating a picture; and
marking the picture as follows:
in a case that the first syntax element is equal to 0 and the second syntax element is equal to 1, the picture is marked as used for short-term reference, and
in a case that the first syntax element equal to 0 and a second syntax element equal to 0, the picture is marked as used for long-term reference.