Instruction manual

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KONA 3 Installation and Operation Manual — Transporting 2K Data: HSDL
Now we are seeing the first generation of what can truly be referred to as “digital cinema”
cameras as they lack video recording devices, specifically tape recording capability, in their
design and instead concentrate on producing electronic data that aims to emulate the
image quality of traditional photochemical film processes. This era is still early in its
development but the pace of development promises that it will soon draw close to the
quality, and in some users opinions, the ease of use of capturing images to motion picture
film.
Transporting 2K Data: HSDL Defined
Moving 2K data is no small task; remember that at 12.2MB/frame, data moves at nearly
300MB/sec. Storage devices, such as RAIDs or SANs must have very high bandwidth
capabilities to handle recording or playing back data at full speed. The storage devices
must also have adequate space to hold this data as an hour of 2K just exceeds 1 Terabyte.
But storage devices are for storing the data; transporting the data is something different.
HSDL (High Speed Data Link) is easiest for video professionals to understand in this
way: HSDL is like Dual Link HD for the transmission of 2K data. Where Dual Link HD
moves across two SDI cables as video, HSDL moves 2K data over the SDI cables. Because
of the amount of data previously mentioned, full size 2048x1556 images cannot be
transmitted over the dual SDI lines at full frame rate. Instead of moving the data at 23.98
(24) frames per second, the HSDL transport stream often adheres to 14.98 frames per
second. Because this is transmitted data, not video, the data can be recorded at the 14.98
frames per second rate to a high speed storage device and then played back from this high
speed storage device at full speed, typically 23.98 frames per second. In contrast to
2048x1556 images, 2048x1080 digital cinema 2K can move across HSDL at the full
frame rate of 23.98 frames per second.
Facilities with two lines of HD-SDI rated cable, in a limited sense, are already prepared
for the transmission of 2K data when attached to HSDL devices. If a facility already has
storage that can exceed 300MB per second, that facility might also be ready to record and
play back 2K data at full frame rate. Again, this transition to a “digital film” environment
is far less cumbersome than a 4K digital environment where such numbers double those
of 2K.
So a third advantage, beyond image size and color reproduction, is the ability of 2K data
to use pre-existing elements of HD infrastructure when adopting 2K. For many facilities,
be they large full-service or boutique, this makes the financial transition from HD to 2K
less of a burden. While a transition to 4K would produce higher quality for most facilities,
it would not be nearly as easy to achieve financially.
The AJA KONA 3: An Ideal 2K Input/Output Device
Opening the door to data-centric workflow and universal mastering, the AJA KONA 3
card represents a perfect input/output device (capture card) for facilities considering
entering the “film as digital” landscape. The card is ideal because it’s capable of working
with SD, HD, Dual Link HD and 2K. The KONA 3 card can receive and send 2K data
via HSDL—making it compatible with a number of devices such as telecines and digital
disk recorders (DDRs) already on the market and working with 2K data.