Method, device, and computer program for encapsulating and parsing timed media data

An apparatus for encapsulating a video bitstream organized into slice segments, the slice segments comprising a plurality of coding units, the apparatus comprising:

• a hardware processor;
• and
• a memory storing one or more programs configured to be executed by the hardware processor, the one or more programs including instructions for:
• obtaining a region of interest comprising one or more tiles, each tile comprising a set of one or more coding units;
• determining whether the region of interest forms part of a slice segment;
• if it is determined that the region of interest forms part of a slice segment, defining a new slice segment comprising the coding units of only the region of interest;
• and
• encapsulating the bitstream comprising the coding units of the region of interest using the new slice segment if it is determined that the region of interest forms part of a slice segment, and using the slice segment otherwise.