A Media Block or Integrated Media Block is a component in a digital cinema projection system. Its purpose is to transfer the image data from a DCP server to the projector's imaging device in compliance with DCI anti-piracy encryption requirements.
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Terminology
The term "Media Block" refers to a device attached directly to the motherboard of a DCP server. The media block is usually connected to the projector by dual-link SDI cables. A media block is limited to processing 2K output, downscaling 4K DCPs if necessary.
The term "Integrated Media Block" (IMB) refers to a device attached to the projector, which receives image data from the server, usually via a cat6 Ethernet connection. They can process 2K and 4K output.
Security Features
Upon ingestion into a DCP server, KDMs are stored on flash memory in the media block or IMB. A KDM is written to enable the playback of a specific DCP on a specific media block or IMB, identified by its serial number during the authoring process. Media blocks and IMBs also contain a secure clock that is set in the factory cannot be altered by the end user, which the DCP servers to which they are attached use to determine showtimes. The secure clock prevents theaters from showing encrypted movies outside the times authorized by the KDM (e.g. after it has expired) by simply changing the date and time in the server's BIOS. Media blocks and IMBs also typically include anti-tamper devices, designed to self-destruct the unit if unauthorized modification of its hardware, software or secure clock is attempted.