Method for mixed NAL unit type support in a coded picture
Methods and systems are provided for decoding at least one video stream. A method includes receiving a first network abstraction layer (NAL) unit of a first slice of a coded picture and a second VCL NAL unit of a second slice of the coded picture, the first VCL NAL unit having a first VCL NAL unit type and the second VCL NAL unit having a second VCL NAL unit type that is different from the first VCL NAL unit type, and decoding the coded picture, the decoding including determining a picture type of the coded picture based on the first VCL NAL unit type of the first VCL NAL unit and the second VCL NAL unit type of the second VCL NAL unit, or based on an indicator, received by the at least one processor, indicating that the coded picture includes mixed VCL NAL unit types.
1. A method of video decoding performed by at least one processor, the method comprising:
receiving video data comprising a first video coding layer (VCL) network abstraction layer (NAL) unit of a first slice of a coded picture of the video data and a second VCL NAL unit of a second slice of the coded picture, the video data further comprising a mixed_nalu_types_in_pic_flag;
determining a value of the mixed_nalu_types_in_pic_flag and whether the coded picture is a step-wise temporal sub-layer access (STSA) picture based on a first VCL NAL unit type indicating the first VCL NAL unit contains an STSA picture coded slice, and a second VCL NAL unit type indicating the second VCL NAL unit does not contain an instantaneous decoding reference (IDR) picture coded slice; and
decoding the coded picture, the decoding comprising determining a nal_unit_type of the coded picture based on the value of the mixed_nalu_types_in_pic_flag,
wherein the value of the mixed_nalu_types_in_pic_flag being 0 indicates that a value of the nal_unit_type shall be the same for all coded slice NAL units of the coded picture.
2. The method of claim 1 ,
further comprising determining whether the coded picture is a trailing picture.
3. The method of claim 1 ,
further comprising determining whether the coded picture is a random access decodable leading (RADL) picture.
4. The method of claim 1 , wherein
the first VCL NAL unit indicates a gradual decoding refresh (GDR) picture coded slice.
5. The method of claim 1 , wherein
the second VCL NAL unit indicates an instantaneous decoding reference (IDR) picture coded slice.
6. The method of claim 1 , wherein
the second VCL NAL unit indicates a clean random access (CRA) picture coded slice.
7. The method of claim 1 , wherein,
the video data comprises the mixed_nalu_types_in_pic_flag in a picture header or a slice header,
the first VCL NAL unit indicates the STSA picture coded slice, and
the second VCL NAL unit indicates a clean random access (CRA) picture coded slice.
8. A method of video encoding performed by at least one processor, the method comprising:
obtaining video data comprising a picture to be encoded; and
determining a first video coding layer (VCL) network abstraction layer (NAL) unit of a first slice of the picture of the video data and a second VCL NAL unit of a second slice of the picture;
determining a value of mixed_nalu_types_in_pic_flag and whether the video data is a step-wise temporal sub-layer access (STSA) picture based on a first VCL NAL unit type indicating the first VCL NAL unit contains an STSA picture coded slice, and a second VCL NAL unit type indicating the second VCL NAL unit does not contain an instantaneous decoding reference (IDR) picture coded slice, wherein the value of the mixed_nalu_types_in_pic_flag being 0 indicates that a value of the nal_unit_type shall be the same for all coded slice NAL units of the coded picture; and
encoding the video data comprising the picture based at least on the determined value of mixed_nalu_types_in_pic_flag and whether the video data is the STSA picture.
9. The method of claim 8 , further comprising determining whether the picture is a trailing picture.
10. The method of claim 8 , further comprising determining whether the picture is a random access decodable leading (RADL) picture.
11. The method of claim 8 , wherein
the first VCL NAL unit indicates a gradual decoding refresh (GDR) picture coded slice.
12. The method of claim 8 , wherein
the second VCL NAL unit indicates an instantaneous decoding reference (IDR) picture coded slice.
13. The method of claim 8 , wherein
the second VCL NAL unit indicates a clean random access (CRA) picture coded slice.
14. The method of claim 8 , wherein,
the video data comprises the mixed_nalu_types_in_pic_flag in a picture header or a slice header,
the first VCL NAL unit indicates the STSA picture coded slice, and
the second VCL NAL unit indicates a clean random access (CRA) picture coded slice.
15. A method of processing visual media data, the method comprising:
performing a conversion between a visual media file and a bitstream of a visual media data according to a format rule, the bitstream of the visual media data comprising a first video coding layer (VCL) network abstraction layer (NAL) unit of a first slice of a coded picture of the visual media data and a second VCL NAL unit of a second slice of the coded picture, bitstream of the visual media data further comprising a mixed_nalu_types_in_pic_flag, and the format rule indicating that coding of the bitstream of the visual media data is based on whether the coded the picture is a step-wise temporal sub-layer access (STSA) picture based on (i) a first VCL NAL unit type indicating the first VCL NAL unit contains an STSA picture coded slice, and (ii) a second VCL NAL unit type indicating the second VCL NAL unit does not contain an instantaneous decoding reference (IDR) picture coded slice,
wherein the value of the mixed_nalu_types_in_pic_flag being 0 indicates that a value of the nal_unit_type shall be the same for all coded slice NAL units of the coded picture.
16. The method of claim 15 , wherein the format rule further indicates to determine whether the coded picture is a trailing picture.
17. The method of claim 15 , wherein the format rule further indicates to determine whether the coded picture is a random access decodable leading (RADL) picture.
18. The method of claim 15 , wherein the first VCL NAL unit indicates a gradual decoding refresh (GDR) picture coded slice.
19. The method of claim 15 , wherein the second VCL NAL unit indicates an instantaneous decoding reference (IDR) picture coded slice.
20. The method of claim 15 , wherein the second VCL NAL unit indicates a clean random access (CRA) picture coded slice.
21. The method of claim 15 , wherein the video data comprises the mixed_nalu_types_in_pic_flag in a picture header or a slice header,
the first VCL NAL unit indicates the STSA picture coded slice, and
the second VCL NAL unit indicates a clean random access (CRA) picture coded slice.