Decoder configuration record in coded video

1. A method of processing visual media data, comprising:

performing a conversion between a visual media file and a bitstream of a visual media data according to a format rule,

wherein the format rule specifies a characteristic of a syntax element in the visual media file,

wherein the syntax element has a value that is indicative of a number of bytes used for indicating a constraint information associated with the bitstream,

wherein the format rule specifies that the syntax element specifies the number of bytes in a general constraint information syntax element in the visual media file and is coded in the visual media file using N bits, and wherein N is specified to be only equal to six,

wherein a track in the visual media file comprises a video bitstream comprising one or more output layer sets,

wherein the format rule specifies that a first bit with a particular bit index in the general constraint information syntax element corresponds to a second bit with the particular bit index in all general constraint information syntax structures in all profile tier level syntax structures to which the one or more output layer sets conform, and

wherein the format rule specifies that the first bit is set to one only if the second bit in all general constraint information syntax structures is set equal to one.

2. The method of claim 1 , wherein the format rule specifies that the syntax element is coded in the visual media file immediately after a profile tier level multilayer enabled flag syntax element in the visual media file.

3. The method of claim 1 ,

wherein the format rule specifies that the syntax element whose value is equal to one indicates that a general constraint information flag in the general constraint information syntax element is equal to zero and that the general constraint information syntax element is disallowed from being included in a profile tier level record in the visual media file.

4. The method of claim 1 , wherein the format rule specifies that a condition for including the general constraint information syntax element in the visual media file depends on whether the value indicated by the syntax element is greater than one.

5. The method of claim 1 , wherein the format rule specifies that five bits are used for another syntax element in the visual media file, and

wherein the another syntax element has another value that is indicative of a network abstraction layer unit type in a decoder configuration record in the visual media file.

6. The method of claim 1 ,

wherein the format rule specifies that another syntax element is indicated for the track, and

wherein the another syntax element indicates whether the track includes the video bitstream corresponding to a specific output layer set from the one or more output layer sets.

7. The method of claim 6 , wherein the another syntax element indicates that the track includes the video bitstream corresponding to multiple output layer sets.

8. The method of claim 6 , wherein the another syntax element indicates that the track includes the video bitstream not corresponding to the specific output layer set from the one or more output layer sets.

9. The method of claim 1 , wherein the conversion comprises generating the visual media file and storing the bitstream to the visual media file according to the format rule.

10. The method of claim 1 , wherein the conversion comprises generating the visual media file, and the method further comprises storing the visual media file in a non-transitory computer-readable recording medium.

11. The method of claim 1 , wherein the conversion comprises parsing the visual media file according to the format rule to reconstruct the bitstream.

12. The method of claim 1 , wherein the visual media file is processed by a versatile video coding (VVC).

13. An apparatus for processing visual media data comprising a processor and a non-transitory memory with instructions thereon, wherein the instructions upon execution by the processor, cause the processor to implement a method comprising:

performing a conversion between a visual media file and a bitstream of a visual media data according to a format rule,

wherein the format rule specifies a characteristic of a syntax element in the visual media file,

wherein the syntax element has a value that is indicative of a number of bytes used for indicating a constraint information associated with the bitstream,

wherein the format rule specifies that the syntax element specifies the number of bytes in a general constraint information syntax element in the visual media file and is coded in the visual media file using N bits, and wherein N is specified to be only equal to six,

wherein a track in the visual media file comprises a video bitstream comprising one or more output layer sets,

wherein the format rule specifies that a first bit with a particular bit index in the general constraint information syntax element corresponds to a second bit with the particular bit index in all general constraint information syntax structures in all profile tier level syntax structures to which the one or more output layer sets conform, and

wherein the format rule specifies that the first bit is set to one only if the second bit in all general constraint information syntax structures is set equal to one.

14. The apparatus of claim 13 , wherein the format rule specifies that five bits are used for another syntax element in the visual media file, and

wherein the another syntax element has another value that is indicative of a network abstraction layer unit type in a decoder configuration record in the visual media file.

15. The apparatus of claim 13 ,

wherein the format rule specifies that another syntax element is indicated for the track, and

wherein the another syntax element indicates whether the track includes a video bitstream corresponding to a specific output layer set from the one or more output layer sets.

16. The apparatus of claim 13 , wherein the format rule specifies that the syntax element is coded in the visual media file immediately after a profile tier level multilayer enabled flag syntax element in the visual media file.

17. The apparatus of claim 13 ,

wherein the format rule specifies that the syntax element whose value is equal to one indicates that a general constraint information flag in the general constraint information syntax element is equal to zero and that the general constraint information syntax element is disallowed from being included in a profile tier level record in the visual media file.

18. The apparatus of claim 13 , wherein the format rule specifies that a condition for including a general constraint information syntax element in the visual media file depends on whether the value indicated by the syntax element is greater than one.

19. A non-transitory computer-readable storage medium storing instructions that cause a processor to:

perform a conversion between a visual media file and a bitstream of a visual media data according to a format rule,

wherein the format rule specifies a characteristic of a syntax element in the visual media file,

wherein the syntax element has a value that is indicative of a number of bytes used for indicating a constraint information associated with the bitstream,

wherein the format rule specifies that the syntax element specifies the number of bytes in a general constraint information syntax element in the visual media file and is coded in the visual media file using N bits, and wherein N is specified to be only equal to six,

wherein a track in the visual media file comprises a video bitstream comprising one or more output layer sets,

wherein the format rule specifies that a first bit with a particular bit index in the general constraint information syntax element corresponds to a second bit with the particular bit index in all general constraint information syntax structures in all profile tier level syntax structures to which the one or more output layer sets conform, and

wherein the format rule specifies that the first bit is set to one only if the second bit in all general constraint information syntax structures is set equal to one.

20. A non-transitory computer-readable recording medium storing a bitstream of a visual media file which is generated by a method performed by a video processing apparatus, wherein the method comprises:

generating the visual media file based on a visual media data according to a format rule,

wherein the format rule specifies a characteristic of a syntax element in the visual media file,

wherein the syntax element has a value that is indicative of a number of bytes used for indicating a constraint information associated with the bitstream,

wherein the format rule specifies that the syntax element specifies the number of bytes in a general constraint information syntax element in the visual media file and is coded in the visual media file using N bits, and wherein N is specified to be only equal to six,

wherein a track in the visual media file comprises a video bitstream comprising one or more output layer sets,

wherein the format rule specifies that a first bit with a particular bit index in the general constraint information syntax element corresponds to a second bit with the particular bit index in all general constraint information syntax structures in all profile tier level syntax structures to which the one or more output layer sets conform, and

wherein the format rule specifies that the first bit is set to one only if the second bit in all general constraint information syntax structures is set equal to one.