DCI Specs - Digital Cinema Initiatives

D. Audio – This interface is required to stream multiple digital audiochannels to the Cinema Audio Processor. This is required to be in anAES3 format. For worst-case audio bandwidth, 37 Mbits/sec is required(16 channels * 24 bit sample * 96 kHz = 37 Mbits/sec).• Security Messaging – The Media Block is required to communicatestandardized security messages (see Section 9.4.5. Intra-TheaterCommunications) via a standard 100Base-T Ethernet [IEEE 802.3] interface tothe projector and remote Secure Processing Blocks. This communications facilityis referred to as the intra-auditorium security network and it may physically bepart of other/existing auditorium networks, which carry other types of traffic (e.g.,command, control and status). However, it is distinguished in that securitymessaging is required to utilize Transport Layer Security (TLS) at all times. SeeSection 9.4.5 Intra-Theater Communications for security messagingrequirements.7.5.5. Projection System7.5.5.1. IntroductionThe Projection System is required to change digital image data into the light thatappears on the screen. The projection system is required to support many interfaces anddifferent Digital Cinema system architectures. One of these architectures includes theMedia Block (described above) installed in the projector. In this type of architecture, all ofthe content is ported through a single data interface. When the Media Block is externalto the Projector, Link Encryption is required. The corresponding Link Decryption Block isrequired at the projector interface.Alternative content can come from an external interface, even when the Media Block ispresent inside the projector.7.5.5.2. Projection System InterfacesThe Projection System not only provides the main image on the screen, it can providesubtitles, open captioning, and still pictures. This requires extra interfaces from theMedia Block, if the Media Block is not installed in the projector. These interfaces arenoted below. (For the complete interface specification refer to Section 8 PROJECTION.)• Subpicture – The subpicture (bit mapped image data with alpha channel)information will need either a separate interface into the projector, or the MediaBlock is required to overlay the subpicture with the main image and send itthrough the main image interface. A subpicture interface is required to be a100Base-T Ethernet [IEEE 802.3] interface with enough sustained bandwidth tosupport subpictures at up to 24 FPS for 4K content and 24 FPS or 48 FPS for 2Kcontent.• Timed Text – Information can also enter into the projector through a data port orbe rendered and overlaid in the Media Block. The interface is required to be a100Base-T Ethernet [IEEE 802.3] interface.• Control and Status – The projection system is required to also provide a100Base-T Ethernet [IEEE 802.3] data interface that can receive controlinformation and send status to the Media Block and SMS.DCI Digital Cinema System Specification v.1.2 Page 73