ISO 23000-19:2018 pdf free

ISO 23000-19:2018 pdf free.Information technology – Multimedia application format (MPEG-A)
As illustrated in Figure 3, video media components are often preprocessed (e.g. subsampled) and encoded in multiple media streams, typically different in bit rate and encoded resolution. Media streams can be encrypted and encapsulated into CMAF fragments, which can then be packaged as CMAF addressable media objects appropriate for one or more delivery methods. CMAF addressable media objects can be made available as resources and identified as defined by other media application specifications.
CMAF addressable media objects are derived from CMAF fragments and CMAF chunks as specified in Clause 7, and inherit CMAF fragment constraints such as alignment of media sample sequences within a CMAF fragment, CMAF fragment time alignment within a CMAF switching set, CMAF track and CMAF media profile constraints, etc. This makes CMAF fragment encoding and decoding independent of the CMAF addressable media objects used to store and transport the CMAF fragments. But CMAF addressable media objects need not be constructed by packaging complete CMAF fragments as long as the resulting CMAF addressable media objects conform to CMAF fragment and CMAF track constraints.
For live streaming, a CMAF fragment in each CMAF track can be encoded simultaneously from each media content source component, and each CMAF fragment packaged and made available as soon as possible as a CMAF addressable media object, such as a CMAF segment or a CMAF chunk.
The feature of synchronizing separately stored CMAF tracks during playback is referred to as late binding. The late binding timing model and accurate recording of CMAF fragment presentation times during encoding are necessary to synchronize late bound CMAF tracks during delivery and presentation.
In the CMAF hypothetical application model, all CMAF tracks in a CMAF presentation share the same CMAF presentation timeline, which has a value of zero at the earliest media sample intended for presentation. All CMAF tracks in a CMAF presentation also share a common track decode timeline origin. A media sample of a CMAF track T1 that has a CMAF track presentation time of X is presented at the same time as the media sample of any other CMAF track T2 that also has the CMAF track presentation time X (the duration X having been divided by each track’s timescale).ISO 23000-19 pdf download.