Prepared and drafted by the International Telecommunications Union’s Telecommunication Standardization Sector (ITU-T) and adopted by the Joint Technical Committee ISO/IEC JTC 1, ISO/IEC 13818-1:2018 – Information technology – Generic coding of moving pictures and associated audio information – Part 1: Systems has been revised.
The ISO/IEC 13818 series is focused on the generic coding of moving pictures and associated audio information, and the coding standard its documents specify is known as MPEG-2 (MPEG deriving from The Moving Picture Experts Group). This format, while not as efficient as High Efficiency Video Coding (HEVC), for example, is still commonly used due to its backwards compatibility with existing hardware and software. MPEG-2 is used in DVDs, and it is the most widely used codec for cable television broadcast.
ISO/IEC 13818-1:2018 addresses the systems layer of this coding, through either a transport stream or program stream—both are constructed from packetized elementary stream (PES) packets and packets containing other necessary information. The recommendation addresses combining one or more elementary streams of audio and video into single or multiple streams suitable for storage or transmission. Systems coding follows the syntactical and semantic rules imposed by ISO/IEC 13818-1:2018.
The system layer of the coding supports six basic functions, according to ISO/IEC 13818-1:2018:
- the synchronization of multiple compressed streams on decoding
- the interleaving of multiple compressed streams into a single stream
- the initialization of buffering for decoding start up
- continuous buffer management
- time identification
- multiplexing and signaling of various components in a system stream
ISO/IEC 13818-1:2018 revises the 2015 edition of the same international standard, and it differs substantially from the previous version of the document. As we noted in a past post, numerous corrigenda and amendments were released for the ISO/IEC 1318-1:2015 standard, each making updates to the original recommendations. All eight of these revising documents are incorporated in the new standard.
This means that, from previous corrigenda, ISO/IEC 13818-1:2018 features alterations to the system target decoder buffer sizes for high efficiency video coding (HEVC), and it removes the semantic elements from the section on Semantic definition of fields in metadata descriptor.
By incorporating the six amendments to ISO/IEC 13818-1:2015, ISO/IEC 13818-1:2018 comprises changes to the following:
- Delivery of timeline for external data (from Amendment 1)
- Carriage of layered HEVC (from Amendment 2)
- Carriage of green metadata in MPEG2 systems (from Amendment 3)
- New profiles and levels for MPEG4 audio descriptor (from Amendment 4)
- Carriage of MPEGH 3D audio over MPEG2 systems (from Amendment 5)
- Carriage of Quality Metadata in MPEG-2 Systems (from Amendment 6)
ISO/IEC 13818-1:2018 is just one standard in a series of international recommendations on the generic coding of moving pictures and associated audio information. Parts one through three are available as the ISO/IEC 13818 Information technology – Generic Coding of Moving Pictures and Audio Information Package.
ISO/IEC 13818-1:2018 – Information technology – Generic coding of moving pictures and associated audio information – Part 1: Systems is available on the ANSI Webstore.