User guide

2-3
Getting Started
Digital Cinema Distribution Master (DCDM)
The Digital Cinema Distribution Master (DCDM) as the next phase for
a DCP is deemed the exchange format by DCI for environments in-
volved in the task to create D-Cinema content. It can be used as a com-
plete and standardized format to communicate movies, for instance,
between studio and post production.
To serve as a master and exchange format the DCDM should be saved
in very high quality (i.e. in 16-bit X’Y’Z’ in the TIFF file format) with the
resolution, frame rate and audio channel distribution of the later DCP
(see also section “Possible Formats for a DCI Mastering” on page 2-4).
It is one of CLIPSTER’s advantages that an explicit creation of a DCDM
is not mandatory. With CLIPSTER a DCP can be made from a DSM di-
rectly and you do not have to make a DCDM first in order to get a DCP.
Nevertheless, in case a DCDM is required, it can be generated with
CLIPSTER easily.
JPEG2000
For the sake of storage space and bandwidth the size of a DCP must be
reduced so that it can be transported, saved and displayed without
great efforts. For this the image files of the DCP will be converted to
12 bit (X’Y’Z’) and then encoded with JPEG2000 (lossy compression).
For maximum efficiency CLIPSTER encodes the image data with a vari-
able bit rate (VBR). The audio data will not be compressed.
Same as with the DCDM, with CLIPSTER you do not have to create the
JPEG2000 material explicitly to get a DCP. A DCP can be created from
a DSM directly which will include the JPEG2000 compression automat-
ically. However, if only the JPEG2000 encoded data is required, it can
be created with CLIPSTER without difficulty.
The DCI specification limits the data rate for a successful presentation
in a digital cinema theater to a file size of 1.302083 MB per 2K image
at 24 frames per second, equivalent to a sustained data rate of
250 Mbit/s. For a frame rate of 48 fps, a 2K distribution should be set
to a maximum of 651,041 bytes per frame (also 250 Mbit/s).
DCI suggested to store the DCDM in 12 bit padded to 16 bit
that the SMPTE in their standards reduced to 12 bit altogether.
For best results CLIPSTER will store the data in true 16 bit when
creating a DCDM, meaning when the DSM is in 16 bit already,
it will be stored in the DCDM in 16 bit as well and not rounded
down to 12 bit.
In CLIPSTER the settings of a JPEG2000 encoding are config-
ured by default to this maximum data rate specified by DCI, i.e.
to the highest quality allowed for a DCP.