Brand for a media file

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

• perform a conversion between a visual media file and a bitstream, wherein the visual media file comprises image items each comprising a sequence of one or more pictures according to a media file format, wherein the bitstream comprises access units each comprising one or more pictures each belonging to a layer according to a video coding format,
• wherein the media file format specifies one or more file brands or one or more image item types associated with the video coding format, and
• wherein the media file format specifies that the bitstream conforms to one of the one or more file brands or one of the one or more image item types includes a single access unit, and wherein the single access unit includes a single picture that is at least partially intra-coded.

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, wherein the visual media file comprises image items each comprising a sequence of one or more pictures according to a media file format, wherein the bitstream comprises access units each comprising one or more pictures each belonging to a layer according to a video coding format,
• wherein the media file format specifies one or more file brands or one or more image item types associated with the video coding format, and
• wherein the media file format specifies that the bitstream conforms to one of the one or more file brands or one of the one or more image item types includes a single access unit, and wherein the single access unit includes a single picture that is at least partially intra-coded.