METHODS AND SYSTEMS FOR PERFORMING GRADUAL DECODING REFRESH PROCESSING ON PICTURES

1 . A method for encoding a video sequence, comprising:

receiving a video sequence;

encoding a first flag indicating whether gradual decoding refresh (GDR) pictures are enabled in the video sequence, wherein the first flag has a first value indicating the GDR pictures are enabled in the video sequence or a second value indicating the GDR pictures are disabled in the video sequence;

encoding a second flag indicating whether a picture is a GDR picture, wherein the second flag has a first value indicating the picture is a GDR picture or a second value indicating the picture is not a GDR picture; and

when the second flag has the first value indicating the picture is a GDR picture, encoding a parameter indicating a recovery point picture of decoded pictures in an output order.

2 . The method according to claim 1 , wherein when the first flag has the second value, the second flag has the second value.

3 . The method according to claim 1 , wherein the first flag is signaled in a sequence parameter set (SPS) associated with the video sequence and the second flag is signaled in a picture header (PH) associated with the picture in the video sequence.

4 . The method according to claim 1 , wherein the first value of the first flag is equal to 1, and the second value of the first flag is equal to 0.

5 . The method according to claim 1 , wherein the first value of the second flag is equal to 1, and the second value of the second flag is equal to 0.

6 . The method according to claim 1 , wherein the recovery point picture is a last picture in a GDR period.

7 . The method according to claim 6 , wherein the recovery point picture includes a clean region and an intra-coded region.

8 . A method of decoding a bitstream to output one or more pictures for a video stream, the method comprising:

receiving a bitstream; and

decoding, using coded information of the bitstream, one or more pictures,

wherein the decoding comprises:

decoding a first flag indicating whether gradual decoding refresh (GDR) pictures are enabled in a video sequence, wherein the first flag has a first value indicating the GDR pictures are enabled in the video sequence or a second value indicating the GDR pictures are disabled in the video sequence;

decoding a second flag indicating whether a picture is a GDR picture, wherein the second flag has a first value indicating the picture is a GDR picture or a second value indicating the picture is not a GDR picture; and

when the second flag has the first value indicating the picture is a GDR picture, decoding a parameter indicating a recovery point picture of decoded pictures in an output order.

9 . The method according to claim 8 , wherein when the first flag has the second value, the second flag has the second value.

10 . The method according to claim 8 , wherein the first flag is decoded from a sequence parameter set (SPS) associated with the video sequence and the second flag is decoded from a picture header (PH) associated with the picture in the video sequence.

11 . The method according to claim 8 , wherein the first value of the first flag is equal to 1, and the second value of the first flag is equal to 0.

12 . The method according to claim 8 , wherein the first value of the second flag is equal to 1, and the second value of the second flag is equal to 0.

13 . The method according to claim 8 , wherein the recovery point picture is a last picture in a GDR period.

14 . The method according to claim 13 , wherein the recovery point picture includes a clean region and an intra-coded region.

15 . A non-transitory computer readable storage medium storing a set of instructions to cause one or more processors of a device to perform operations for decoding an encoded bitstream to output one or more pictures for a video stream, the operations comprising:

acquiring the encoded bitstream comprising a first flag and a second flag;

decoding the first flag indicating whether gradual decoding refresh (GDR) pictures are enabled in a video sequence, wherein the first flag has a first value indicating the GDR pictures are enabled in a video sequence or a second value indicating the GDR pictures are disabled in the video sequence;

decoding the second flag indicating whether a picture is a GDR picture, wherein the second flag has a first value indicating the picture is a GDR picture or a second value indicating the picture is not a GDR picture; and

when the second flag has the first value indicating the picture is a GDR picture, decoding a parameter indicating a recovery point picture of decoded pictures in an output order.

16 . The non-transitory computer readable storage medium according to claim 15 , wherein when the first flag has the second value, the second flag has the second value.

17 . The non-transitory computer readable storage medium according to claim 15 , wherein the first flag is decoded from a sequence parameter set (SPS) associated with the video sequence and the second flag is decoded from a picture header (PH) associated with the picture in the video sequence.

18 . The non-transitory computer readable storage medium according to claim 15 , wherein the first value of the first flag is equal to 1, and the second value of the first flag is equal to 0; the first value of the second flag is equal to 1, and the second value of the second flag is equal to 0.

19 . The non-transitory computer readable storage medium according to claim 15 , wherein the recovery point picture is a last picture in a GDR period.

20 . The non-transitory computer readable storage medium according to claim 19 , wherein the recovery point picture includes a clean region and an intra-coded region.