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 coded video sequence start (CVSS) access unit (AU), wherein the CVSS AU contains a picture unit (PU) for each layer, and wherein a coded picture in each PU is a coded layer video sequence start (CLVSS) picture; identifying the coded picture from one of the layers based on a picture order count (POC) value; and decoding the coded picture to obtain a decoded picture.
1 . An encoding apparatus, comprising:
a memory storing instructions;
one or more processors coupled to the memory, the one or more processors configured to execute the instructions stored in the memory to cause the encoding apparatus to:
insert a picture unit (PU) containing a coded picture in each layer of a coded video sequence start (CVSS) access unit (AU), wherein the coded picture in each layer is a coded layer video sequence start (CLVSS) picture, wherein the CLVSS picture is associated with a no output before recovery flag, and wherein the no output before recovery flag is equal to 1; and
encode a coded layer video sequence (CLVS) including the CVSS AU into a bitstream.
2 . The encoding apparatus of claim 1 , wherein the one or more processors configured to store the bitstream for communication toward a video decoder.
3 . The encoding apparatus of claim 1 , wherein the CLVSS picture is an intra random access point (IRAP) picture.
4 . The encoding apparatus of claim 1 , wherein the CLVSS picture is a gradual decoding refresh (GDR) picture.
5 . The encoding apparatus of claim 1 , wherein each layer of the CVSS AU is specified by a video parameter set (VPS), and wherein the CVSS AU is an initial AU of a coded video sequence (CVS).
6 . The encoding apparatus of claim 1 , wherein the one or more processors configured to:
insert a picture unit (PU) containing a coded picture in each layer of a second coded video sequence start (CVSS) access unit (AU) into a second video bitstream, wherein the coded picture in each PU is not a CLVSS picture; and
ensure that a conforming bitstream corresponding to the second video bitstream is encoded.
7 . The encoding apparatus of claim 1 , wherein the encoding apparatus is constrained such that the coded picture in each layer is the CLVSS picture.
8 . A non-transitory computer-readable medium storing a bitstream that, when decoded by a decoding device, is used by the decoding device to generate a video, the bitstream comprising:
a picture unit (PU) containing a coded picture in each layer of a coded video sequence start (CVSS) access unit (AU), wherein the coded picture in each layer is a coded layer video sequence start (CLVSS) picture; and
a coded layer video sequence (CLVS) including the CVSS AU,
wherein the generating the video comprises:
associating the CLVSS picture with a no output before recovery flag, and the no output before recovery flag is equal to 1; and
decoding the coded picture to obtain a decoded picture.
9 . The non-transitory computer-readable medium of claim 8 , wherein the CLVSS picture is an intra random access point (IRAP) picture.
10 . The non-transitory computer-readable medium of claim 8 , wherein the CLVSS picture is a gradual decoding refresh (GDR) picture.
11 . The non-transitory computer-readable medium of claim 8 , wherein each layer of the CVSS AU is specified by a video parameter set (VPS).
12 . The non-transitory computer-readable medium of claim 8 , wherein the CVSS AU is an initial AU of a coded video sequence (CVS).
13 . A non-transitory computer-readable medium storing instructions that, when executed by one or more processors, cause a video processing apparatus to:
receive a bitstream including a coded video sequence start (CVSS) access unit (AU), wherein the CVSS AU contains a picture unit (PU) for each layer, and wherein a coded picture in each PU is a coded layer video sequence start (CLVSS) picture;
identify the coded picture from one of the layers based on a picture order count (POC) value; and
decode the coded picture to obtain a decoded picture.
14 . The non-transitory computer-readable medium of claim 13 , wherein the CLVSS picture is an intra random access point (IRAP) picture.
15 . The non-transitory computer-readable medium of claim 13 , wherein the CLVSS picture is a gradual decoding refresh (GDR) picture.
16 . The non-transitory computer-readable medium of claim 13 , wherein the CLVSS picture is associated with a no output before recovery flag, and wherein the no output before recovery flag is equal to 1.
17 . The non-transitory computer-readable medium of claim 13 , wherein each layer of the CVSS AU is specified by a video parameter set (VPS).
18 . The non-transitory computer-readable medium of claim 13 , wherein the CVSS AU is an initial AU of a coded video sequence (CVS).
19 . The non-transitory computer-readable medium of claim 13 , wherein the one or more processors further cause the video processing apparatus to display the coded picture as decoded on a display of an electronic device.
20 . The non-transitory computer-readable medium of claim 13 , wherein the one or more processors further cause the video processing apparatus to:
receive a second video bitstream including a second CVSS AU, wherein the second CVSS AU contains a picture unit (PU) for each layer, and wherein a coded picture in each PU is not a CLVSS picture; and
in response to the second video bitstream being received, take some other corrective measures to ensure that a conforming bitstream corresponding to the second video bitstream is received prior to decoding the coded picture.