Support of mixed IRAP and non-IRAP pictures within an access unit in multi-layer video bitstreams
A method of decoding implemented by a video decoder is provided. The method includes receiving a bitstream including a sequence parameter set (SPS) containing a first flag and an indicator of a length of a picture order count (POC) most significant bits (MSB) value when present in a header referring to the SPS, where a value of the first flag specifies that a second flag is present in the header referring to the SPS, and where a value of the second flag specifies that the POC MSB value is present in the header; determining a POC value based on the POC MSB value; identifying a picture from the bitstream based on the POC value; and decoding the picture to obtain a decoded picture.
1 . An encoding device, comprising:
a memory storing instructions; and
one or more processors coupled to the memory, the one or more processors configured to execute the instructions to cause the encoding device to:
set a first flag in a sequence parameter set (SPS) to a value to specify that a second flag is present in a header;
provide in the SPS an indicator of a length of a picture order count (POC) most significant bits (MSB) value in the header;
set the second flag in the header to a value to specify that the POC MSB value is present in the header; and
encode the SPS and the header into a bitstream.
2 . The encoding device of claim 1 , wherein the first flag comprises a POC MSB flag designated as sps_poc_msb_cycle_flag.
3 . The encoding device of claim 1 , wherein the value of the first flag is one.
4 . The encoding device of claim 1 , wherein the second flag comprises another POC MSB flag and is designated as ph_poc_msb_cycle_present_flag.
5 . The encoding device of claim 1 , wherein the value of the second flag is one.
6 . The encoding device of claim 1 , wherein a POC value is determined by adding the POC MSB value to a POC least significant bits (LSB) value.
7 . The encoding device of claim 1 , wherein the second flag is a picture-level flag.
8 . A non-transitory computer-readable storage medium storing instructions that, wherein executed by one or more processors, cause a video processing apparatus to:
receive a bitstream including a sequence parameter set (SPS) comprising a first flag and an indicator of a length of a picture order count (POC) most significant bits (MSB) value when the POC MSB value is present in a header;
determine whether a second flag is present in the header based on a value of the first flag;
determine whether the POC MSB value is present in the header based on a value of the second flag when the second flag is present;
determine a POC value, based on the POC MSB value when the POC MSB value is present;
identify a picture from the bitstream based on the POC value; and
decode the picture to obtain a decoded picture.
9 . The non-transitory computer-readable storage medium of claim 8 , wherein the first flag comprises a POC MSB flag designated as sps_poc_msb_cycle_flag.
10 . The non-transitory computer-readable storage medium of claim 8 , wherein the second flag comprises another POC MSB flag and is designated as ph_poc_msb_cycle_present_flag.
11 . The non-transitory computer-readable storage medium of claim 8 , wherein the second flag is a picture-level flag.
12 . A method of storing a bitstream, comprising:
obtaining the bitstream, wherein the bitstream comprises:
a sequence parameter set (SPS) and a header, wherein the SPS comprises a first flag and an indicator of a length of a picture order count (POC) most significant bits (MSB) value, wherein the header comprises a second flag and the POC MSB value, wherein a value of the first flag specifies that the second flag is present in the header, and wherein a value of the second flag specifies that the POC MSB value is present in the header;
a POC value based on the POC MSB value, and
a picture based on the POC value; and
storing the bitstream in a non-transitory computer-readable storage medium.
13 . The method of claim 12 , wherein the first flag comprises a POC MSB flag designated as sps_poc_msb_cycle_flag.
14 . The method of claim 12 , wherein the value of the first flag is one.
15 . The method of claim 12 , wherein the second flag comprises another POC MSB flag and is designated as ph_poc_msb_cycle_present_flag.
16 . The method of claim 12 , wherein the value of the second flag is one.
17 . The method of claim 12 , wherein the POC value comprises a concatenation of the POC MSB value to a POC least significant bits (LSB) value.
18 . The method of claim 12 , wherein the second flag is a picture-level flag.
19 . The method of claim 12 , wherein the indicator of the length plus 1 specifies the length, in bits, of the POC MSB.
20 . The method of claim 12 , wherein the POC value comprises the POC MSB value added to a POC least significant bits (LSB) value.