Method and system of NAL unit header structure for signaling new elements
A method and apparatus of video coding are disclosed. In the encoding side, video data are received, where a GDR (Gradual Decoding Refresh) picture type is supported by the encoding device. A syntax structure including a first syntax in NAL (Network Access Layer) unit header is generated, where an NAL unit type indicated by the first syntax comprises the GDR picture type. Encoded video data including the syntax structure from the video data are generated. A corresponding method and apparatus for the decoding side are also disclosed.
1. A method of video encoding, the method comprising:
receiving video data at an encoding device, wherein a GDR (Gradual Decoding Refresh) picture type is supported by the encoding device;
generating a syntax structure including
a first syntax in an NAL (Network Access Layer) unit header of an NAL unit, the first syntax indicating an NAL unit type selected from a group of types including the GDR picture type,
a second syntax in the NAL unit header, the second syntax indicating whether a set of NAL unit header field data is included in the NAL unit header, and
in a case that the first syntax indicates the GDR picture type and the second syntax indicates that the set of NAL unit header field data is included in the NAL unit header, a refreshed region flag included in the set of NAL unit header field data, the refreshed region flag indicating whether a corresponding coded image area contained in the NAL unit belongs to a refreshed region in a current picture; and
generating encoded video data arranged in the NAL unit according to the syntax structure and the video data.
2. The method of claim 1 , wherein, in the case that the first syntax indicates the GDR picture type and the second syntax indicates that the set of NAL unit header field data is included in the NAL unit header, the syntax structure further includes GDR related data included in the set of NAL unit header field data the GDR related data including the refreshed region flag.
3. The method of claim 2 , wherein the coded image area corresponds to a coded tile group.
4. The method of claim 2 , wherein the coded image area corresponds to a coded slice.
5. The method of claim 2 , wherein the GDR related data comprise a GDR picture count syntax to indicate a number of current and subsequent coded GDR pictures preceding a recovery point in an output order.
6. The method of claim 2 , wherein the GDR related data comprise a recovery picture count to specify a recovery point of decoded pictures in an output order.
7. The method of claim 1 , wherein the group of types comprises a DRAP (Dependent Random Access Point) picture type.
8. The method of claim 1 , wherein the group of types type comprises an IRAP (Intra Random Access Point) picture type.
9. An apparatus for video encoding, the apparatus comprises one or more electronic circuits or processors configured to:
receive video data at an encoding device, wherein a GDR (Gradual Decoding Refresh) picture type is supported by the apparatus;
generate a syntax structure including
a first syntax in an NAL (Network Access Layer) unit header of an NAL unit, the first syntax indicating an NAL unit type selected from a group of types including the GDR picture type,
a second syntax in the NAL unit header, the second syntax indicating whether a set of NAL unit header field data is included in the NAL unit header, and
in a case that the first syntax indicates the GDR picture type and the second syntax indicates that the set of NAL unit header field data is included in the NAL unit header, a refreshed region flag included in the set of NAL unit header field data, the refreshed region flag indicating whether a corresponding coded image area contained in the NAL unit belongs to a refreshed region in a current picture; and
generate encoded video data arranged in the NAL unit according to the syntax structure and the video data.
10. The apparatus of claim 9 , wherein the set of NAL unit header field data includes a GDR picture count syntax indicating a number of current and subsequent coded GDR pictures preceding a recovery point in an output order.
11. A method of video decoding, the method comprising:
receiving, by a decoding device, encoded video data arranged in an NAL (Network Access Layer) unit according to a syntax structure, wherein a GDR (Gradual Decoding Refresh) picture type is supported by the decoding device;
parsing the syntax structure to obtain
a first syntax in an NAL unit header of the NAL unit, the first syntax indicating an NAL unit type selected from a group of types including the GDR picture type,
a second syntax in the NAL unit header, the second syntax indicating whether a set of NAL unit header field data is included in the NAL unit header, and
in a case that the first syntax indicates the GDR picture type and the second syntax indicates that the set of NAL unit header field data is included in the NAL unit header, a refreshed region flag included in the set of NAL unit header field data, the refreshed region flag indicating whether a corresponding coded image area contained in the NAL unit belongs to a refreshed region in a current picture; and
generating decoded video data from the encoded video data according to one or more of the first syntax, the second first syntax, and the refreshed region flag.
12. The method of claim 11 , wherein, in the case that the first syntax indicates the GDR picture type and the second syntax indicates that the set of NAL unit header field data is included in the NAL unit header, the syntax structure further includes GDR related data included in the set of NAL unit header field data, the GDR related data including the refreshed region flag.
13. The method of claim 12 , wherein the coded image area corresponds to a coded tile group.
14. The method of claim 12 , wherein the coded image area corresponds to a coded slice.
15. The method of claim 12 , wherein the GDR related data comprise a GDR picture count syntax to indicate a number of current and subsequent coded GDR pictures preceding a recovery point in an output order.
16. The method of claim 12 , wherein the GDR related data comprise a recovery picture count to specify a recovery point of decoded pictures in an output order.
17. The method of claim 11 , wherein the group of types comprises a DRAP (Dependent Random Access Point) picture type.
18. The method of claim 11 , wherein the group of types comprises an IRAP (Intra Random Access Point) picture type.
19. An apparatus for video decoding, the apparatus comprises one or more electronic circuits or processors configured to:
receive encoded video data arranged in an NAL (Network Access Layer) unit according to a syntax structure, wherein a GDR (Gradual Decoding Refresh) picture type is supported by the apparatus;
parse the syntax structure to obtain
a first syntax in an NAL unit header of the NAL unit, the first syntax indicating an NAL unit type selected from a group of types including the GDR picture type,
a second syntax in the NAL unit header, the second syntax indicating whether a set of NAL unit header field data is included in the NAL unit header, and
in a case that the first syntax indicates the GDR picture type and the second syntax indicates that the set of NAL unit header field data is included in the NAL unit header, a refreshed region flag included in the set of NAL unit header field data, the refreshed region flag indicating whether a corresponding coded image area contained in the NAL unit belongs to a refreshed region in a current picture; and
generate decoded video data from the encoded video data according to one or more of the first syntax, the second first syntax, and the refreshed region flag.
20. The apparatus of claim 19 , wherein the set of NAL unit header field data includes a GDR picture count syntax to indicating a number of current and subsequent coded GDR pictures preceding a recovery point in an output order.
21. A non-transitory computer-readable medium storing program codes which when executed by one or more processors cause the one or more processors to perform a decoding process, and the decoding process comprising:
receiving encoded video data arranged in an NAL (Network Access Laver) unit according to a syntax structure, wherein a GDR (Gradual Decoding Refresh) picture type is supported by the decoding process;
parsing the syntax structure to obtain
a first syntax in an NAL unit header of the NAL unit, the first syntax indicating an NAL unit type selected from a group of types including the GDR picture type,
a second syntax in the NAL unit header, the second syntax indicating whether a set of NAL unit header field data is included in the NAL unit header, and
in a case that the first syntax indicates the GDR picture type and the second syntax indicates that the set of NAL unit header field data is included in the NAL unit header, a refreshed region flag included in the set of NAL unit header field data, the refreshed region flag indicating whether a corresponding coded image area contained in the NAL unit belongs to a refreshed region in a current picture; and
generating decoded video data from the encoded video data according to one or more of the first syntax, the second first syntax, and the refreshed region flag.