Bandwidth and Data Storage
Origin's resolution and bit depth require tremendous storage capacity and throughput. Origin outputs 16-bit uncompressed linear values in its primary 4K data mode offering the highest fidelity. Combined with the 4K x 2K resolution, each uncompressed raw frame of 16-bit data is at least 16MB. At 24fps, that represents more than 400MBytes per second (1.44TBytes/hr). This makes Origin's "digital negative" Bayer-pattern output more attractive, since it preserves full image quality but only requires one third the bandwidth of RGB. Read more about Bayer data below.
| Film footage vs. 4K data storage | |||
| Small project | Larger project | Intensive, multi-camera |
|
| Footage per day | 6,000 | 10,000 | 25,000 |
| Frames per day | 96,000 | 160,000 | 400,000 |
| Storage per day (16 bit uncompressed raw Bayer) |
1.59TB | 2.65TB | 6.63TB |
| Shooting days | 17 | 50 | 60 |
| Total Footage | 100,000 | 500,000 | 1,500,000 |
| Total Storage | 27TB | 133.5TB | 398TB |
In order to support the I/O bandwidth required for 4K data streams, Origin implements a 4xInfiniband protocol over a single highly reliable fiber optic connection. InfiniBand is a well established networking technology that is well positioned to take full advantage of the emerging PCI-Express architecture that will re-define the IT word in the years to come. The most attractive features of InfiniBand are high QoS (quality of service), low latency and switched fabric architecture. Sustained data rates in excess of 850MBytes/sec have been widely demonstrated and ensure low-latency image data delivery.
At 400MBytes/sec., 60 minutes of footage would occupy 1.44 Terabytes. Origin's recorder must offer both tremendous capacity and tremendous I/O performance. Disk capacity has tended to double every 9 to 12 months, but the real limiter is disk I/O speed, something that has improved only slightly every year.
Bandwidth requirements dictate a parallel disk recording configuration. DALSA offers a number of capture solutions for recording data from the Origin. In a studio setting, camera output could be streamed directly into a storage network, but when "on location" the camera needs a field recorder which must be offloaded when full (much like film magazines).
Bayer data: the digital version of film negative
As mentioned above, one convenient way to reduce the bandwidth and recorder storage requirements is to record Bayer data from the camera instead of full RGB. Color set monitors can be driven from Origin's 1K DVI-D output, but the main 4K data stream can be output to the recorder either as raw Bayer data instead of reconstructed RGB. The Bayer output can be considered as a form of lossless data compaction—it requires only one third of the bandwidth and storage capacity without compromising image quality. Bayer data acts as "digital negative" and makes an ideal original archive format. Full reconstruction isn't necessary until each sequence goes through an editing, compositing, or color grading process in postproduction; if you choose to generate lower-resolution proxies for on-set feedback, the color information is reconstructed on the fly.
